1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * USB hub driver.
   4 *
   5 * (C) Copyright 1999 Linus Torvalds
   6 * (C) Copyright 1999 Johannes Erdfelt
   7 * (C) Copyright 1999 Gregory P. Smith
   8 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
   9 *
  10 * Released under the GPLv2 only.
  11 */
  12
  13#include <linux/kernel.h>
  14#include <linux/errno.h>
  15#include <linux/module.h>
  16#include <linux/moduleparam.h>
  17#include <linux/completion.h>
  18#include <linux/sched/mm.h>
  19#include <linux/list.h>
  20#include <linux/slab.h>
  21#include <linux/kcov.h>
  22#include <linux/ioctl.h>
  23#include <linux/usb.h>
  24#include <linux/usbdevice_fs.h>
  25#include <linux/usb/hcd.h>
  26#include <linux/usb/onboard_hub.h>
  27#include <linux/usb/otg.h>
  28#include <linux/usb/quirks.h>
  29#include <linux/workqueue.h>
  30#include <linux/mutex.h>
  31#include <linux/random.h>
  32#include <linux/pm_qos.h>
  33#include <linux/kobject.h>
  34
  35#include <linux/bitfield.h>
  36#include <linux/uaccess.h>
  37#include <asm/byteorder.h>
  38
  39#include "hub.h"
  40#include "otg_productlist.h"
  41
  42#define USB_VENDOR_GENESYS_LOGIC		0x05e3
  43#define USB_VENDOR_SMSC				0x0424
  44#define USB_PRODUCT_USB5534B			0x5534
  45#define USB_VENDOR_CYPRESS			0x04b4
  46#define USB_PRODUCT_CY7C65632			0x6570
  47#define USB_VENDOR_TEXAS_INSTRUMENTS		0x0451
  48#define USB_PRODUCT_TUSB8041_USB3		0x8140
  49#define USB_PRODUCT_TUSB8041_USB2		0x8142
  50#define USB_VENDOR_MICROCHIP			0x0424
  51#define USB_PRODUCT_USB4913			0x4913
  52#define USB_PRODUCT_USB4914			0x4914
  53#define USB_PRODUCT_USB4915			0x4915
  54#define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	BIT(0)
  55#define HUB_QUIRK_DISABLE_AUTOSUSPEND		BIT(1)
  56#define HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL	BIT(2)
  57
  58#define USB_TP_TRANSMISSION_DELAY	40	/* ns */
  59#define USB_TP_TRANSMISSION_DELAY_MAX	65535	/* ns */
  60#define USB_PING_RESPONSE_TIME		400	/* ns */
  61#define USB_REDUCE_FRAME_INTR_BINTERVAL	9
  62
  63/*
  64 * The SET_ADDRESS request timeout will be 500 ms when
  65 * USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT quirk flag is set.
  66 */
  67#define USB_SHORT_SET_ADDRESS_REQ_TIMEOUT	500  /* ms */
  68
  69/* Protect struct usb_device->state and ->children members
  70 * Note: Both are also protected by ->dev.sem, except that ->state can
  71 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
  72static DEFINE_SPINLOCK(device_state_lock);
  73
  74/* workqueue to process hub events */
  75static struct workqueue_struct *hub_wq;
  76static void hub_event(struct work_struct *work);
  77
  78/* synchronize hub-port add/remove and peering operations */
  79DEFINE_MUTEX(usb_port_peer_mutex);
  80
  81/* cycle leds on hubs that aren't blinking for attention */
  82static bool blinkenlights;
  83module_param(blinkenlights, bool, S_IRUGO);
  84MODULE_PARM_DESC(blinkenlights, "true to cycle leds on hubs");
  85
  86/*
  87 * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
  88 * 10 seconds to send reply for the initial 64-byte descriptor request.
  89 */
  90/* define initial 64-byte descriptor request timeout in milliseconds */
  91static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
  92module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
  93MODULE_PARM_DESC(initial_descriptor_timeout,
  94		"initial 64-byte descriptor request timeout in milliseconds "
  95		"(default 5000 - 5.0 seconds)");
  96
  97/*
  98 * As of 2.6.10 we introduce a new USB device initialization scheme which
  99 * closely resembles the way Windows works.  Hopefully it will be compatible
 100 * with a wider range of devices than the old scheme.  However some previously
 101 * working devices may start giving rise to "device not accepting address"
 102 * errors; if that happens the user can try the old scheme by adjusting the
 103 * following module parameters.
 104 *
 105 * For maximum flexibility there are two boolean parameters to control the
 106 * hub driver's behavior.  On the first initialization attempt, if the
 107 * "old_scheme_first" parameter is set then the old scheme will be used,
 108 * otherwise the new scheme is used.  If that fails and "use_both_schemes"
 109 * is set, then the driver will make another attempt, using the other scheme.
 110 */
 111static bool old_scheme_first;
 112module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
 113MODULE_PARM_DESC(old_scheme_first,
 114		 "start with the old device initialization scheme");
 115
 116static bool use_both_schemes = true;
 117module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
 118MODULE_PARM_DESC(use_both_schemes,
 119		"try the other device initialization scheme if the "
 120		"first one fails");
 121
 122/* Mutual exclusion for EHCI CF initialization.  This interferes with
 123 * port reset on some companion controllers.
 124 */
 125DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
 126EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
 127
 128#define HUB_DEBOUNCE_TIMEOUT	2000
 129#define HUB_DEBOUNCE_STEP	  25
 130#define HUB_DEBOUNCE_STABLE	 100
 131
 132static void hub_release(struct kref *kref);
 133static int usb_reset_and_verify_device(struct usb_device *udev);
 134static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
 135static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
 136		u16 portstatus);
 137
 138static inline char *portspeed(struct usb_hub *hub, int portstatus)
 139{
 140	if (hub_is_superspeedplus(hub->hdev))
 141		return "10.0 Gb/s";
 142	if (hub_is_superspeed(hub->hdev))
 143		return "5.0 Gb/s";
 144	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
 145		return "480 Mb/s";
 146	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
 147		return "1.5 Mb/s";
 148	else
 149		return "12 Mb/s";
 150}
 151
 152/* Note that hdev or one of its children must be locked! */
 153struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
 154{
 155	if (!hdev || !hdev->actconfig || !hdev->maxchild)
 156		return NULL;
 157	return usb_get_intfdata(hdev->actconfig->interface[0]);
 158}
 159
 160int usb_device_supports_lpm(struct usb_device *udev)
 161{
 162	/* Some devices have trouble with LPM */
 163	if (udev->quirks & USB_QUIRK_NO_LPM)
 164		return 0;
 165
 166	/* Skip if the device BOS descriptor couldn't be read */
 167	if (!udev->bos)
 168		return 0;
 169
 170	/* USB 2.1 (and greater) devices indicate LPM support through
 171	 * their USB 2.0 Extended Capabilities BOS descriptor.
 172	 */
 173	if (udev->speed == USB_SPEED_HIGH || udev->speed == USB_SPEED_FULL) {
 174		if (udev->bos->ext_cap &&
 175			(USB_LPM_SUPPORT &
 176			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
 177			return 1;
 178		return 0;
 179	}
 180
 181	/*
 182	 * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
 183	 * However, there are some that don't, and they set the U1/U2 exit
 184	 * latencies to zero.
 185	 */
 186	if (!udev->bos->ss_cap) {
 187		dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
 188		return 0;
 189	}
 190
 191	if (udev->bos->ss_cap->bU1devExitLat == 0 &&
 192			udev->bos->ss_cap->bU2DevExitLat == 0) {
 193		if (udev->parent)
 194			dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
 195		else
 196			dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
 197		return 0;
 198	}
 199
 200	if (!udev->parent || udev->parent->lpm_capable)
 201		return 1;
 202	return 0;
 203}
 204
 205/*
 206 * Set the Maximum Exit Latency (MEL) for the host to wakup up the path from
 207 * U1/U2, send a PING to the device and receive a PING_RESPONSE.
 208 * See USB 3.1 section C.1.5.2
 209 */
 210static void usb_set_lpm_mel(struct usb_device *udev,
 211		struct usb3_lpm_parameters *udev_lpm_params,
 212		unsigned int udev_exit_latency,
 213		struct usb_hub *hub,
 214		struct usb3_lpm_parameters *hub_lpm_params,
 215		unsigned int hub_exit_latency)
 216{
 217	unsigned int total_mel;
 218
 219	/*
 220	 * tMEL1. time to transition path from host to device into U0.
 221	 * MEL for parent already contains the delay up to parent, so only add
 222	 * the exit latency for the last link (pick the slower exit latency),
 223	 * and the hub header decode latency. See USB 3.1 section C 2.2.1
 224	 * Store MEL in nanoseconds
 225	 */
 226	total_mel = hub_lpm_params->mel +
 227		max(udev_exit_latency, hub_exit_latency) * 1000 +
 228		hub->descriptor->u.ss.bHubHdrDecLat * 100;
 229
 230	/*
 231	 * tMEL2. Time to submit PING packet. Sum of tTPTransmissionDelay for
 232	 * each link + wHubDelay for each hub. Add only for last link.
 233	 * tMEL4, the time for PING_RESPONSE to traverse upstream is similar.
 234	 * Multiply by 2 to include it as well.
 235	 */
 236	total_mel += (__le16_to_cpu(hub->descriptor->u.ss.wHubDelay) +
 237		      USB_TP_TRANSMISSION_DELAY) * 2;
 238
 239	/*
 240	 * tMEL3, tPingResponse. Time taken by device to generate PING_RESPONSE
 241	 * after receiving PING. Also add 2100ns as stated in USB 3.1 C 1.5.2.4
 242	 * to cover the delay if the PING_RESPONSE is queued behind a Max Packet
 243	 * Size DP.
 244	 * Note these delays should be added only once for the entire path, so
 245	 * add them to the MEL of the device connected to the roothub.
 246	 */
 247	if (!hub->hdev->parent)
 248		total_mel += USB_PING_RESPONSE_TIME + 2100;
 249
 250	udev_lpm_params->mel = total_mel;
 251}
 252
 253/*
 254 * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
 255 * a transition from either U1 or U2.
 256 */
 257static void usb_set_lpm_pel(struct usb_device *udev,
 258		struct usb3_lpm_parameters *udev_lpm_params,
 259		unsigned int udev_exit_latency,
 260		struct usb_hub *hub,
 261		struct usb3_lpm_parameters *hub_lpm_params,
 262		unsigned int hub_exit_latency,
 263		unsigned int port_to_port_exit_latency)
 264{
 265	unsigned int first_link_pel;
 266	unsigned int hub_pel;
 267
 268	/*
 269	 * First, the device sends an LFPS to transition the link between the
 270	 * device and the parent hub into U0.  The exit latency is the bigger of
 271	 * the device exit latency or the hub exit latency.
 272	 */
 273	if (udev_exit_latency > hub_exit_latency)
 274		first_link_pel = udev_exit_latency * 1000;
 275	else
 276		first_link_pel = hub_exit_latency * 1000;
 277
 278	/*
 279	 * When the hub starts to receive the LFPS, there is a slight delay for
 280	 * it to figure out that one of the ports is sending an LFPS.  Then it
 281	 * will forward the LFPS to its upstream link.  The exit latency is the
 282	 * delay, plus the PEL that we calculated for this hub.
 283	 */
 284	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
 285
 286	/*
 287	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
 288	 * is the greater of the two exit latencies.
 289	 */
 290	if (first_link_pel > hub_pel)
 291		udev_lpm_params->pel = first_link_pel;
 292	else
 293		udev_lpm_params->pel = hub_pel;
 294}
 295
 296/*
 297 * Set the System Exit Latency (SEL) to indicate the total worst-case time from
 298 * when a device initiates a transition to U0, until when it will receive the
 299 * first packet from the host controller.
 300 *
 301 * Section C.1.5.1 describes the four components to this:
 302 *  - t1: device PEL
 303 *  - t2: time for the ERDY to make it from the device to the host.
 304 *  - t3: a host-specific delay to process the ERDY.
 305 *  - t4: time for the packet to make it from the host to the device.
 306 *
 307 * t3 is specific to both the xHCI host and the platform the host is integrated
 308 * into.  The Intel HW folks have said it's negligible, FIXME if a different
 309 * vendor says otherwise.
 310 */
 311static void usb_set_lpm_sel(struct usb_device *udev,
 312		struct usb3_lpm_parameters *udev_lpm_params)
 313{
 314	struct usb_device *parent;
 315	unsigned int num_hubs;
 316	unsigned int total_sel;
 317
 318	/* t1 = device PEL */
 319	total_sel = udev_lpm_params->pel;
 320	/* How many external hubs are in between the device & the root port. */
 321	for (parent = udev->parent, num_hubs = 0; parent->parent;
 322			parent = parent->parent)
 323		num_hubs++;
 324	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
 325	if (num_hubs > 0)
 326		total_sel += 2100 + 250 * (num_hubs - 1);
 327
 328	/* t4 = 250ns * num_hubs */
 329	total_sel += 250 * num_hubs;
 330
 331	udev_lpm_params->sel = total_sel;
 332}
 333
 334static void usb_set_lpm_parameters(struct usb_device *udev)
 335{
 336	struct usb_hub *hub;
 337	unsigned int port_to_port_delay;
 338	unsigned int udev_u1_del;
 339	unsigned int udev_u2_del;
 340	unsigned int hub_u1_del;
 341	unsigned int hub_u2_del;
 342
 343	if (!udev->lpm_capable || udev->speed < USB_SPEED_SUPER)
 344		return;
 345
 346	/* Skip if the device BOS descriptor couldn't be read */
 347	if (!udev->bos)
 348		return;
 349
 350	hub = usb_hub_to_struct_hub(udev->parent);
 351	/* It doesn't take time to transition the roothub into U0, since it
 352	 * doesn't have an upstream link.
 353	 */
 354	if (!hub)
 355		return;
 356
 357	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
 358	udev_u2_del = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat);
 359	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
 360	hub_u2_del = le16_to_cpu(udev->parent->bos->ss_cap->bU2DevExitLat);
 361
 362	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
 363			hub, &udev->parent->u1_params, hub_u1_del);
 364
 365	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
 366			hub, &udev->parent->u2_params, hub_u2_del);
 367
 368	/*
 369	 * Appendix C, section C.2.2.2, says that there is a slight delay from
 370	 * when the parent hub notices the downstream port is trying to
 371	 * transition to U0 to when the hub initiates a U0 transition on its
 372	 * upstream port.  The section says the delays are tPort2PortU1EL and
 373	 * tPort2PortU2EL, but it doesn't define what they are.
 374	 *
 375	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
 376	 * about the same delays.  Use the maximum delay calculations from those
 377	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
 378	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
 379	 * assume the device exit latencies they are talking about are the hub
 380	 * exit latencies.
 381	 *
 382	 * What do we do if the U2 exit latency is less than the U1 exit
 383	 * latency?  It's possible, although not likely...
 384	 */
 385	port_to_port_delay = 1;
 386
 387	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
 388			hub, &udev->parent->u1_params, hub_u1_del,
 389			port_to_port_delay);
 390
 391	if (hub_u2_del > hub_u1_del)
 392		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
 393	else
 394		port_to_port_delay = 1 + hub_u1_del;
 395
 396	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
 397			hub, &udev->parent->u2_params, hub_u2_del,
 398			port_to_port_delay);
 399
 400	/* Now that we've got PEL, calculate SEL. */
 401	usb_set_lpm_sel(udev, &udev->u1_params);
 402	usb_set_lpm_sel(udev, &udev->u2_params);
 403}
 404
 405/* USB 2.0 spec Section 11.24.4.5 */
 406static int get_hub_descriptor(struct usb_device *hdev,
 407		struct usb_hub_descriptor *desc)
 408{
 409	int i, ret, size;
 410	unsigned dtype;
 411
 412	if (hub_is_superspeed(hdev)) {
 413		dtype = USB_DT_SS_HUB;
 414		size = USB_DT_SS_HUB_SIZE;
 415	} else {
 416		dtype = USB_DT_HUB;
 417		size = sizeof(struct usb_hub_descriptor);
 418	}
 419
 420	for (i = 0; i < 3; i++) {
 421		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 422			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
 423			dtype << 8, 0, desc, size,
 424			USB_CTRL_GET_TIMEOUT);
 425		if (hub_is_superspeed(hdev)) {
 426			if (ret == size)
 427				return ret;
 428		} else if (ret >= USB_DT_HUB_NONVAR_SIZE + 2) {
 429			/* Make sure we have the DeviceRemovable field. */
 430			size = USB_DT_HUB_NONVAR_SIZE + desc->bNbrPorts / 8 + 1;
 431			if (ret < size)
 432				return -EMSGSIZE;
 433			return ret;
 434		}
 435	}
 436	return -EINVAL;
 437}
 438
 439/*
 440 * USB 2.0 spec Section 11.24.2.1
 441 */
 442static int clear_hub_feature(struct usb_device *hdev, int feature)
 443{
 444	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 445		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
 446}
 447
 448/*
 449 * USB 2.0 spec Section 11.24.2.2
 450 */
 451int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
 452{
 453	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 454		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
 455		NULL, 0, 1000);
 456}
 457
 458/*
 459 * USB 2.0 spec Section 11.24.2.13
 460 */
 461static int set_port_feature(struct usb_device *hdev, int port1, int feature)
 462{
 463	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 464		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
 465		NULL, 0, 1000);
 466}
 467
 468static char *to_led_name(int selector)
 469{
 470	switch (selector) {
 471	case HUB_LED_AMBER:
 472		return "amber";
 473	case HUB_LED_GREEN:
 474		return "green";
 475	case HUB_LED_OFF:
 476		return "off";
 477	case HUB_LED_AUTO:
 478		return "auto";
 479	default:
 480		return "??";
 481	}
 482}
 483
 484/*
 485 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
 486 * for info about using port indicators
 487 */
 488static void set_port_led(struct usb_hub *hub, int port1, int selector)
 489{
 490	struct usb_port *port_dev = hub->ports[port1 - 1];
 491	int status;
 492
 493	status = set_port_feature(hub->hdev, (selector << 8) | port1,
 494			USB_PORT_FEAT_INDICATOR);
 495	dev_dbg(&port_dev->dev, "indicator %s status %d\n",
 496		to_led_name(selector), status);
 497}
 498
 499#define	LED_CYCLE_PERIOD	((2*HZ)/3)
 500
 501static void led_work(struct work_struct *work)
 502{
 503	struct usb_hub		*hub =
 504		container_of(work, struct usb_hub, leds.work);
 505	struct usb_device	*hdev = hub->hdev;
 506	unsigned		i;
 507	unsigned		changed = 0;
 508	int			cursor = -1;
 509
 510	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
 511		return;
 512
 513	for (i = 0; i < hdev->maxchild; i++) {
 514		unsigned	selector, mode;
 515
 516		/* 30%-50% duty cycle */
 517
 518		switch (hub->indicator[i]) {
 519		/* cycle marker */
 520		case INDICATOR_CYCLE:
 521			cursor = i;
 522			selector = HUB_LED_AUTO;
 523			mode = INDICATOR_AUTO;
 524			break;
 525		/* blinking green = sw attention */
 526		case INDICATOR_GREEN_BLINK:
 527			selector = HUB_LED_GREEN;
 528			mode = INDICATOR_GREEN_BLINK_OFF;
 529			break;
 530		case INDICATOR_GREEN_BLINK_OFF:
 531			selector = HUB_LED_OFF;
 532			mode = INDICATOR_GREEN_BLINK;
 533			break;
 534		/* blinking amber = hw attention */
 535		case INDICATOR_AMBER_BLINK:
 536			selector = HUB_LED_AMBER;
 537			mode = INDICATOR_AMBER_BLINK_OFF;
 538			break;
 539		case INDICATOR_AMBER_BLINK_OFF:
 540			selector = HUB_LED_OFF;
 541			mode = INDICATOR_AMBER_BLINK;
 542			break;
 543		/* blink green/amber = reserved */
 544		case INDICATOR_ALT_BLINK:
 545			selector = HUB_LED_GREEN;
 546			mode = INDICATOR_ALT_BLINK_OFF;
 547			break;
 548		case INDICATOR_ALT_BLINK_OFF:
 549			selector = HUB_LED_AMBER;
 550			mode = INDICATOR_ALT_BLINK;
 551			break;
 552		default:
 553			continue;
 554		}
 555		if (selector != HUB_LED_AUTO)
 556			changed = 1;
 557		set_port_led(hub, i + 1, selector);
 558		hub->indicator[i] = mode;
 559	}
 560	if (!changed && blinkenlights) {
 561		cursor++;
 562		cursor %= hdev->maxchild;
 563		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
 564		hub->indicator[cursor] = INDICATOR_CYCLE;
 565		changed++;
 566	}
 567	if (changed)
 568		queue_delayed_work(system_power_efficient_wq,
 569				&hub->leds, LED_CYCLE_PERIOD);
 570}
 571
 572/* use a short timeout for hub/port status fetches */
 573#define	USB_STS_TIMEOUT		1000
 574#define	USB_STS_RETRIES		5
 575
 576/*
 577 * USB 2.0 spec Section 11.24.2.6
 578 */
 579static int get_hub_status(struct usb_device *hdev,
 580		struct usb_hub_status *data)
 581{
 582	int i, status = -ETIMEDOUT;
 583
 584	for (i = 0; i < USB_STS_RETRIES &&
 585			(status == -ETIMEDOUT || status == -EPIPE); i++) {
 586		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 587			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
 588			data, sizeof(*data), USB_STS_TIMEOUT);
 589	}
 590	return status;
 591}
 592
 593/*
 594 * USB 2.0 spec Section 11.24.2.7
 595 * USB 3.1 takes into use the wValue and wLength fields, spec Section 10.16.2.6
 596 */
 597static int get_port_status(struct usb_device *hdev, int port1,
 598			   void *data, u16 value, u16 length)
 599{
 600	int i, status = -ETIMEDOUT;
 601
 602	for (i = 0; i < USB_STS_RETRIES &&
 603			(status == -ETIMEDOUT || status == -EPIPE); i++) {
 604		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 605			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, value,
 606			port1, data, length, USB_STS_TIMEOUT);
 607	}
 608	return status;
 609}
 610
 611static int hub_ext_port_status(struct usb_hub *hub, int port1, int type,
 612			       u16 *status, u16 *change, u32 *ext_status)
 613{
 614	int ret;
 615	int len = 4;
 616
 617	if (type != HUB_PORT_STATUS)
 618		len = 8;
 619
 620	mutex_lock(&hub->status_mutex);
 621	ret = get_port_status(hub->hdev, port1, &hub->status->port, type, len);
 622	if (ret < len) {
 623		if (ret != -ENODEV)
 624			dev_err(hub->intfdev,
 625				"%s failed (err = %d)\n", __func__, ret);
 626		if (ret >= 0)
 627			ret = -EIO;
 628	} else {
 629		*status = le16_to_cpu(hub->status->port.wPortStatus);
 630		*change = le16_to_cpu(hub->status->port.wPortChange);
 631		if (type != HUB_PORT_STATUS && ext_status)
 632			*ext_status = le32_to_cpu(
 633				hub->status->port.dwExtPortStatus);
 634		ret = 0;
 635	}
 636	mutex_unlock(&hub->status_mutex);
 637	return ret;
 638}
 639
 640int usb_hub_port_status(struct usb_hub *hub, int port1,
 641		u16 *status, u16 *change)
 642{
 643	return hub_ext_port_status(hub, port1, HUB_PORT_STATUS,
 644				   status, change, NULL);
 645}
 646
 647static void hub_resubmit_irq_urb(struct usb_hub *hub)
 648{
 649	unsigned long flags;
 650	int status;
 651
 652	spin_lock_irqsave(&hub->irq_urb_lock, flags);
 653
 654	if (hub->quiescing) {
 655		spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
 656		return;
 657	}
 658
 659	status = usb_submit_urb(hub->urb, GFP_ATOMIC);
 660	if (status && status != -ENODEV && status != -EPERM &&
 661	    status != -ESHUTDOWN) {
 662		dev_err(hub->intfdev, "resubmit --> %d\n", status);
 663		mod_timer(&hub->irq_urb_retry, jiffies + HZ);
 664	}
 665
 666	spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
 667}
 668
 669static void hub_retry_irq_urb(struct timer_list *t)
 670{
 671	struct usb_hub *hub = from_timer(hub, t, irq_urb_retry);
 672
 673	hub_resubmit_irq_urb(hub);
 674}
 675
 676
 677static void kick_hub_wq(struct usb_hub *hub)
 678{
 679	struct usb_interface *intf;
 680
 681	if (hub->disconnected || work_pending(&hub->events))
 682		return;
 683
 684	/*
 685	 * Suppress autosuspend until the event is proceed.
 686	 *
 687	 * Be careful and make sure that the symmetric operation is
 688	 * always called. We are here only when there is no pending
 689	 * work for this hub. Therefore put the interface either when
 690	 * the new work is called or when it is canceled.
 691	 */
 692	intf = to_usb_interface(hub->intfdev);
 693	usb_autopm_get_interface_no_resume(intf);
 694	kref_get(&hub->kref);
 695
 696	if (queue_work(hub_wq, &hub->events))
 697		return;
 698
 699	/* the work has already been scheduled */
 700	usb_autopm_put_interface_async(intf);
 701	kref_put(&hub->kref, hub_release);
 702}
 703
 704void usb_kick_hub_wq(struct usb_device *hdev)
 705{
 706	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 707
 708	if (hub)
 709		kick_hub_wq(hub);
 710}
 711
 712/*
 713 * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
 714 * Notification, which indicates it had initiated remote wakeup.
 715 *
 716 * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
 717 * device initiates resume, so the USB core will not receive notice of the
 718 * resume through the normal hub interrupt URB.
 719 */
 720void usb_wakeup_notification(struct usb_device *hdev,
 721		unsigned int portnum)
 722{
 723	struct usb_hub *hub;
 724	struct usb_port *port_dev;
 725
 726	if (!hdev)
 727		return;
 728
 729	hub = usb_hub_to_struct_hub(hdev);
 730	if (hub) {
 731		port_dev = hub->ports[portnum - 1];
 732		if (port_dev && port_dev->child)
 733			pm_wakeup_event(&port_dev->child->dev, 0);
 734
 735		set_bit(portnum, hub->wakeup_bits);
 736		kick_hub_wq(hub);
 737	}
 738}
 739EXPORT_SYMBOL_GPL(usb_wakeup_notification);
 740
 741/* completion function, fires on port status changes and various faults */
 742static void hub_irq(struct urb *urb)
 743{
 744	struct usb_hub *hub = urb->context;
 745	int status = urb->status;
 746	unsigned i;
 747	unsigned long bits;
 748
 749	switch (status) {
 750	case -ENOENT:		/* synchronous unlink */
 751	case -ECONNRESET:	/* async unlink */
 752	case -ESHUTDOWN:	/* hardware going away */
 753		return;
 754
 755	default:		/* presumably an error */
 756		/* Cause a hub reset after 10 consecutive errors */
 757		dev_dbg(hub->intfdev, "transfer --> %d\n", status);
 758		if ((++hub->nerrors < 10) || hub->error)
 759			goto resubmit;
 760		hub->error = status;
 761		fallthrough;
 762
 763	/* let hub_wq handle things */
 764	case 0:			/* we got data:  port status changed */
 765		bits = 0;
 766		for (i = 0; i < urb->actual_length; ++i)
 767			bits |= ((unsigned long) ((*hub->buffer)[i]))
 768					<< (i*8);
 769		hub->event_bits[0] = bits;
 770		break;
 771	}
 772
 773	hub->nerrors = 0;
 774
 775	/* Something happened, let hub_wq figure it out */
 776	kick_hub_wq(hub);
 777
 778resubmit:
 779	hub_resubmit_irq_urb(hub);
 780}
 781
 782/* USB 2.0 spec Section 11.24.2.3 */
 783static inline int
 784hub_clear_tt_buffer(struct usb_device *hdev, u16 devinfo, u16 tt)
 785{
 786	/* Need to clear both directions for control ep */
 787	if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
 788			USB_ENDPOINT_XFER_CONTROL) {
 789		int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 790				HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
 791				devinfo ^ 0x8000, tt, NULL, 0, 1000);
 792		if (status)
 793			return status;
 794	}
 795	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 796			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
 797			       tt, NULL, 0, 1000);
 798}
 799
 800/*
 801 * enumeration blocks hub_wq for a long time. we use keventd instead, since
 802 * long blocking there is the exception, not the rule.  accordingly, HCDs
 803 * talking to TTs must queue control transfers (not just bulk and iso), so
 804 * both can talk to the same hub concurrently.
 805 */
 806static void hub_tt_work(struct work_struct *work)
 807{
 808	struct usb_hub		*hub =
 809		container_of(work, struct usb_hub, tt.clear_work);
 810	unsigned long		flags;
 811
 812	spin_lock_irqsave(&hub->tt.lock, flags);
 813	while (!list_empty(&hub->tt.clear_list)) {
 814		struct list_head	*next;
 815		struct usb_tt_clear	*clear;
 816		struct usb_device	*hdev = hub->hdev;
 817		const struct hc_driver	*drv;
 818		int			status;
 819
 820		next = hub->tt.clear_list.next;
 821		clear = list_entry(next, struct usb_tt_clear, clear_list);
 822		list_del(&clear->clear_list);
 823
 824		/* drop lock so HCD can concurrently report other TT errors */
 825		spin_unlock_irqrestore(&hub->tt.lock, flags);
 826		status = hub_clear_tt_buffer(hdev, clear->devinfo, clear->tt);
 827		if (status && status != -ENODEV)
 828			dev_err(&hdev->dev,
 829				"clear tt %d (%04x) error %d\n",
 830				clear->tt, clear->devinfo, status);
 831
 832		/* Tell the HCD, even if the operation failed */
 833		drv = clear->hcd->driver;
 834		if (drv->clear_tt_buffer_complete)
 835			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
 836
 837		kfree(clear);
 838		spin_lock_irqsave(&hub->tt.lock, flags);
 839	}
 840	spin_unlock_irqrestore(&hub->tt.lock, flags);
 841}
 842
 843/**
 844 * usb_hub_set_port_power - control hub port's power state
 845 * @hdev: USB device belonging to the usb hub
 846 * @hub: target hub
 847 * @port1: port index
 848 * @set: expected status
 849 *
 850 * call this function to control port's power via setting or
 851 * clearing the port's PORT_POWER feature.
 852 *
 853 * Return: 0 if successful. A negative error code otherwise.
 854 */
 855int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
 856			   int port1, bool set)
 857{
 858	int ret;
 859
 860	if (set)
 861		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 862	else
 863		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 864
 865	if (ret)
 866		return ret;
 867
 868	if (set)
 869		set_bit(port1, hub->power_bits);
 870	else
 871		clear_bit(port1, hub->power_bits);
 872	return 0;
 873}
 874
 875/**
 876 * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
 877 * @urb: an URB associated with the failed or incomplete split transaction
 878 *
 879 * High speed HCDs use this to tell the hub driver that some split control or
 880 * bulk transaction failed in a way that requires clearing internal state of
 881 * a transaction translator.  This is normally detected (and reported) from
 882 * interrupt context.
 883 *
 884 * It may not be possible for that hub to handle additional full (or low)
 885 * speed transactions until that state is fully cleared out.
 886 *
 887 * Return: 0 if successful. A negative error code otherwise.
 888 */
 889int usb_hub_clear_tt_buffer(struct urb *urb)
 890{
 891	struct usb_device	*udev = urb->dev;
 892	int			pipe = urb->pipe;
 893	struct usb_tt		*tt = udev->tt;
 894	unsigned long		flags;
 895	struct usb_tt_clear	*clear;
 896
 897	/* we've got to cope with an arbitrary number of pending TT clears,
 898	 * since each TT has "at least two" buffers that can need it (and
 899	 * there can be many TTs per hub).  even if they're uncommon.
 900	 */
 901	clear = kmalloc(sizeof *clear, GFP_ATOMIC);
 902	if (clear == NULL) {
 903		dev_err(&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
 904		/* FIXME recover somehow ... RESET_TT? */
 905		return -ENOMEM;
 906	}
 907
 908	/* info that CLEAR_TT_BUFFER needs */
 909	clear->tt = tt->multi ? udev->ttport : 1;
 910	clear->devinfo = usb_pipeendpoint (pipe);
 911	clear->devinfo |= ((u16)udev->devaddr) << 4;
 912	clear->devinfo |= usb_pipecontrol(pipe)
 913			? (USB_ENDPOINT_XFER_CONTROL << 11)
 914			: (USB_ENDPOINT_XFER_BULK << 11);
 915	if (usb_pipein(pipe))
 916		clear->devinfo |= 1 << 15;
 917
 918	/* info for completion callback */
 919	clear->hcd = bus_to_hcd(udev->bus);
 920	clear->ep = urb->ep;
 921
 922	/* tell keventd to clear state for this TT */
 923	spin_lock_irqsave(&tt->lock, flags);
 924	list_add_tail(&clear->clear_list, &tt->clear_list);
 925	schedule_work(&tt->clear_work);
 926	spin_unlock_irqrestore(&tt->lock, flags);
 927	return 0;
 928}
 929EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
 930
 931static void hub_power_on(struct usb_hub *hub, bool do_delay)
 932{
 933	int port1;
 934
 935	/* Enable power on each port.  Some hubs have reserved values
 936	 * of LPSM (> 2) in their descriptors, even though they are
 937	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
 938	 * but only emulate it.  In all cases, the ports won't work
 939	 * unless we send these messages to the hub.
 940	 */
 941	if (hub_is_port_power_switchable(hub))
 942		dev_dbg(hub->intfdev, "enabling power on all ports\n");
 943	else
 944		dev_dbg(hub->intfdev, "trying to enable port power on "
 945				"non-switchable hub\n");
 946	for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
 947		if (test_bit(port1, hub->power_bits))
 948			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
 949		else
 950			usb_clear_port_feature(hub->hdev, port1,
 951						USB_PORT_FEAT_POWER);
 952	if (do_delay)
 953		msleep(hub_power_on_good_delay(hub));
 954}
 955
 956static int hub_hub_status(struct usb_hub *hub,
 957		u16 *status, u16 *change)
 958{
 959	int ret;
 960
 961	mutex_lock(&hub->status_mutex);
 962	ret = get_hub_status(hub->hdev, &hub->status->hub);
 963	if (ret < 0) {
 964		if (ret != -ENODEV)
 965			dev_err(hub->intfdev,
 966				"%s failed (err = %d)\n", __func__, ret);
 967	} else {
 968		*status = le16_to_cpu(hub->status->hub.wHubStatus);
 969		*change = le16_to_cpu(hub->status->hub.wHubChange);
 970		ret = 0;
 971	}
 972	mutex_unlock(&hub->status_mutex);
 973	return ret;
 974}
 975
 976static int hub_set_port_link_state(struct usb_hub *hub, int port1,
 977			unsigned int link_status)
 978{
 979	return set_port_feature(hub->hdev,
 980			port1 | (link_status << 3),
 981			USB_PORT_FEAT_LINK_STATE);
 982}
 983
 984/*
 985 * Disable a port and mark a logical connect-change event, so that some
 986 * time later hub_wq will disconnect() any existing usb_device on the port
 987 * and will re-enumerate if there actually is a device attached.
 988 */
 989static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
 990{
 991	dev_dbg(&hub->ports[port1 - 1]->dev, "logical disconnect\n");
 992	hub_port_disable(hub, port1, 1);
 993
 994	/* FIXME let caller ask to power down the port:
 995	 *  - some devices won't enumerate without a VBUS power cycle
 996	 *  - SRP saves power that way
 997	 *  - ... new call, TBD ...
 998	 * That's easy if this hub can switch power per-port, and
 999	 * hub_wq reactivates the port later (timer, SRP, etc).
1000	 * Powerdown must be optional, because of reset/DFU.
1001	 */
1002
1003	set_bit(port1, hub->change_bits);
1004	kick_hub_wq(hub);
1005}
1006
1007/**
1008 * usb_remove_device - disable a device's port on its parent hub
1009 * @udev: device to be disabled and removed
1010 * Context: @udev locked, must be able to sleep.
1011 *
1012 * After @udev's port has been disabled, hub_wq is notified and it will
1013 * see that the device has been disconnected.  When the device is
1014 * physically unplugged and something is plugged in, the events will
1015 * be received and processed normally.
1016 *
1017 * Return: 0 if successful. A negative error code otherwise.
1018 */
1019int usb_remove_device(struct usb_device *udev)
1020{
1021	struct usb_hub *hub;
1022	struct usb_interface *intf;
1023	int ret;
1024
1025	if (!udev->parent)	/* Can't remove a root hub */
1026		return -EINVAL;
1027	hub = usb_hub_to_struct_hub(udev->parent);
1028	intf = to_usb_interface(hub->intfdev);
1029
1030	ret = usb_autopm_get_interface(intf);
1031	if (ret < 0)
1032		return ret;
1033
1034	set_bit(udev->portnum, hub->removed_bits);
1035	hub_port_logical_disconnect(hub, udev->portnum);
1036	usb_autopm_put_interface(intf);
1037	return 0;
1038}
1039
1040enum hub_activation_type {
1041	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
1042	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
1043};
1044
1045static void hub_init_func2(struct work_struct *ws);
1046static void hub_init_func3(struct work_struct *ws);
1047
1048static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
1049{
1050	struct usb_device *hdev = hub->hdev;
1051	struct usb_hcd *hcd;
1052	int ret;
1053	int port1;
1054	int status;
1055	bool need_debounce_delay = false;
1056	unsigned delay;
1057
1058	/* Continue a partial initialization */
1059	if (type == HUB_INIT2 || type == HUB_INIT3) {
1060		device_lock(&hdev->dev);
1061
1062		/* Was the hub disconnected while we were waiting? */
1063		if (hub->disconnected)
1064			goto disconnected;
1065		if (type == HUB_INIT2)
1066			goto init2;
1067		goto init3;
1068	}
1069	kref_get(&hub->kref);
1070
1071	/* The superspeed hub except for root hub has to use Hub Depth
1072	 * value as an offset into the route string to locate the bits
1073	 * it uses to determine the downstream port number. So hub driver
1074	 * should send a set hub depth request to superspeed hub after
1075	 * the superspeed hub is set configuration in initialization or
1076	 * reset procedure.
1077	 *
1078	 * After a resume, port power should still be on.
1079	 * For any other type of activation, turn it on.
1080	 */
1081	if (type != HUB_RESUME) {
1082		if (hdev->parent && hub_is_superspeed(hdev)) {
1083			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1084					HUB_SET_DEPTH, USB_RT_HUB,
1085					hdev->level - 1, 0, NULL, 0,
1086					USB_CTRL_SET_TIMEOUT);
1087			if (ret < 0)
1088				dev_err(hub->intfdev,
1089						"set hub depth failed\n");
1090		}
1091
1092		/* Speed up system boot by using a delayed_work for the
1093		 * hub's initial power-up delays.  This is pretty awkward
1094		 * and the implementation looks like a home-brewed sort of
1095		 * setjmp/longjmp, but it saves at least 100 ms for each
1096		 * root hub (assuming usbcore is compiled into the kernel
1097		 * rather than as a module).  It adds up.
1098		 *
1099		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1100		 * because for those activation types the ports have to be
1101		 * operational when we return.  In theory this could be done
1102		 * for HUB_POST_RESET, but it's easier not to.
1103		 */
1104		if (type == HUB_INIT) {
1105			delay = hub_power_on_good_delay(hub);
1106
1107			hub_power_on(hub, false);
1108			INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
1109			queue_delayed_work(system_power_efficient_wq,
1110					&hub->init_work,
1111					msecs_to_jiffies(delay));
1112
1113			/* Suppress autosuspend until init is done */
1114			usb_autopm_get_interface_no_resume(
1115					to_usb_interface(hub->intfdev));
1116			return;		/* Continues at init2: below */
1117		} else if (type == HUB_RESET_RESUME) {
1118			/* The internal host controller state for the hub device
1119			 * may be gone after a host power loss on system resume.
1120			 * Update the device's info so the HW knows it's a hub.
1121			 */
1122			hcd = bus_to_hcd(hdev->bus);
1123			if (hcd->driver->update_hub_device) {
1124				ret = hcd->driver->update_hub_device(hcd, hdev,
1125						&hub->tt, GFP_NOIO);
1126				if (ret < 0) {
1127					dev_err(hub->intfdev,
1128						"Host not accepting hub info update\n");
1129					dev_err(hub->intfdev,
1130						"LS/FS devices and hubs may not work under this hub\n");
1131				}
1132			}
1133			hub_power_on(hub, true);
1134		} else {
1135			hub_power_on(hub, true);
1136		}
1137	/* Give some time on remote wakeup to let links to transit to U0 */
1138	} else if (hub_is_superspeed(hub->hdev))
1139		msleep(20);
1140
1141 init2:
1142
1143	/*
1144	 * Check each port and set hub->change_bits to let hub_wq know
1145	 * which ports need attention.
1146	 */
1147	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1148		struct usb_port *port_dev = hub->ports[port1 - 1];
1149		struct usb_device *udev = port_dev->child;
1150		u16 portstatus, portchange;
1151
1152		portstatus = portchange = 0;
1153		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
1154		if (status)
1155			goto abort;
1156
1157		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1158			dev_dbg(&port_dev->dev, "status %04x change %04x\n",
1159					portstatus, portchange);
1160
1161		/*
1162		 * After anything other than HUB_RESUME (i.e., initialization
1163		 * or any sort of reset), every port should be disabled.
1164		 * Unconnected ports should likewise be disabled (paranoia),
1165		 * and so should ports for which we have no usb_device.
1166		 */
1167		if ((portstatus & USB_PORT_STAT_ENABLE) && (
1168				type != HUB_RESUME ||
1169				!(portstatus & USB_PORT_STAT_CONNECTION) ||
1170				!udev ||
1171				udev->state == USB_STATE_NOTATTACHED)) {
1172			/*
1173			 * USB3 protocol ports will automatically transition
1174			 * to Enabled state when detect an USB3.0 device attach.
1175			 * Do not disable USB3 protocol ports, just pretend
1176			 * power was lost
1177			 */
1178			portstatus &= ~USB_PORT_STAT_ENABLE;
1179			if (!hub_is_superspeed(hdev))
1180				usb_clear_port_feature(hdev, port1,
1181						   USB_PORT_FEAT_ENABLE);
1182		}
1183
1184		/* Make sure a warm-reset request is handled by port_event */
1185		if (type == HUB_RESUME &&
1186		    hub_port_warm_reset_required(hub, port1, portstatus))
1187			set_bit(port1, hub->event_bits);
1188
1189		/*
1190		 * Add debounce if USB3 link is in polling/link training state.
1191		 * Link will automatically transition to Enabled state after
1192		 * link training completes.
1193		 */
1194		if (hub_is_superspeed(hdev) &&
1195		    ((portstatus & USB_PORT_STAT_LINK_STATE) ==
1196						USB_SS_PORT_LS_POLLING))
1197			need_debounce_delay = true;
1198
1199		/* Clear status-change flags; we'll debounce later */
1200		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1201			need_debounce_delay = true;
1202			usb_clear_port_feature(hub->hdev, port1,
1203					USB_PORT_FEAT_C_CONNECTION);
1204		}
1205		if (portchange & USB_PORT_STAT_C_ENABLE) {
1206			need_debounce_delay = true;
1207			usb_clear_port_feature(hub->hdev, port1,
1208					USB_PORT_FEAT_C_ENABLE);
1209		}
1210		if (portchange & USB_PORT_STAT_C_RESET) {
1211			need_debounce_delay = true;
1212			usb_clear_port_feature(hub->hdev, port1,
1213					USB_PORT_FEAT_C_RESET);
1214		}
1215		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1216				hub_is_superspeed(hub->hdev)) {
1217			need_debounce_delay = true;
1218			usb_clear_port_feature(hub->hdev, port1,
1219					USB_PORT_FEAT_C_BH_PORT_RESET);
1220		}
1221		/* We can forget about a "removed" device when there's a
1222		 * physical disconnect or the connect status changes.
1223		 */
1224		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1225				(portchange & USB_PORT_STAT_C_CONNECTION))
1226			clear_bit(port1, hub->removed_bits);
1227
1228		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1229			/* Tell hub_wq to disconnect the device or
1230			 * check for a new connection or over current condition.
1231			 * Based on USB2.0 Spec Section 11.12.5,
1232			 * C_PORT_OVER_CURRENT could be set while
1233			 * PORT_OVER_CURRENT is not. So check for any of them.
1234			 */
1235			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
1236			    (portchange & USB_PORT_STAT_C_CONNECTION) ||
1237			    (portstatus & USB_PORT_STAT_OVERCURRENT) ||
1238			    (portchange & USB_PORT_STAT_C_OVERCURRENT))
1239				set_bit(port1, hub->change_bits);
1240
1241		} else if (portstatus & USB_PORT_STAT_ENABLE) {
1242			bool port_resumed = (portstatus &
1243					USB_PORT_STAT_LINK_STATE) ==
1244				USB_SS_PORT_LS_U0;
1245			/* The power session apparently survived the resume.
1246			 * If there was an overcurrent or suspend change
1247			 * (i.e., remote wakeup request), have hub_wq
1248			 * take care of it.  Look at the port link state
1249			 * for USB 3.0 hubs, since they don't have a suspend
1250			 * change bit, and they don't set the port link change
1251			 * bit on device-initiated resume.
1252			 */
1253			if (portchange || (hub_is_superspeed(hub->hdev) &&
1254						port_resumed))
1255				set_bit(port1, hub->event_bits);
1256
1257		} else if (udev->persist_enabled) {
1258#ifdef CONFIG_PM
1259			udev->reset_resume = 1;
1260#endif
1261			/* Don't set the change_bits when the device
1262			 * was powered off.
1263			 */
1264			if (test_bit(port1, hub->power_bits))
1265				set_bit(port1, hub->change_bits);
1266
1267		} else {
1268			/* The power session is gone; tell hub_wq */
1269			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1270			set_bit(port1, hub->change_bits);
1271		}
1272	}
1273
1274	/* If no port-status-change flags were set, we don't need any
1275	 * debouncing.  If flags were set we can try to debounce the
1276	 * ports all at once right now, instead of letting hub_wq do them
1277	 * one at a time later on.
1278	 *
1279	 * If any port-status changes do occur during this delay, hub_wq
1280	 * will see them later and handle them normally.
1281	 */
1282	if (need_debounce_delay) {
1283		delay = HUB_DEBOUNCE_STABLE;
1284
1285		/* Don't do a long sleep inside a workqueue routine */
1286		if (type == HUB_INIT2) {
1287			INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
1288			queue_delayed_work(system_power_efficient_wq,
1289					&hub->init_work,
1290					msecs_to_jiffies(delay));
1291			device_unlock(&hdev->dev);
1292			return;		/* Continues at init3: below */
1293		} else {
1294			msleep(delay);
1295		}
1296	}
1297 init3:
1298	hub->quiescing = 0;
1299
1300	status = usb_submit_urb(hub->urb, GFP_NOIO);
1301	if (status < 0)
1302		dev_err(hub->intfdev, "activate --> %d\n", status);
1303	if (hub->has_indicators && blinkenlights)
1304		queue_delayed_work(system_power_efficient_wq,
1305				&hub->leds, LED_CYCLE_PERIOD);
1306
1307	/* Scan all ports that need attention */
1308	kick_hub_wq(hub);
1309 abort:
1310	if (type == HUB_INIT2 || type == HUB_INIT3) {
1311		/* Allow autosuspend if it was suppressed */
1312 disconnected:
1313		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1314		device_unlock(&hdev->dev);
1315	}
1316
1317	kref_put(&hub->kref, hub_release);
1318}
1319
1320/* Implement the continuations for the delays above */
1321static void hub_init_func2(struct work_struct *ws)
1322{
1323	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1324
1325	hub_activate(hub, HUB_INIT2);
1326}
1327
1328static void hub_init_func3(struct work_struct *ws)
1329{
1330	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1331
1332	hub_activate(hub, HUB_INIT3);
1333}
1334
1335enum hub_quiescing_type {
1336	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1337};
1338
1339static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1340{
1341	struct usb_device *hdev = hub->hdev;
1342	unsigned long flags;
1343	int i;
1344
1345	/* hub_wq and related activity won't re-trigger */
1346	spin_lock_irqsave(&hub->irq_urb_lock, flags);
1347	hub->quiescing = 1;
1348	spin_unlock_irqrestore(&hub->irq_urb_lock, flags);
1349
1350	if (type != HUB_SUSPEND) {
1351		/* Disconnect all the children */
1352		for (i = 0; i < hdev->maxchild; ++i) {
1353			if (hub->ports[i]->child)
1354				usb_disconnect(&hub->ports[i]->child);
1355		}
1356	}
1357
1358	/* Stop hub_wq and related activity */
1359	del_timer_sync(&hub->irq_urb_retry);
1360	usb_kill_urb(hub->urb);
1361	if (hub->has_indicators)
1362		cancel_delayed_work_sync(&hub->leds);
1363	if (hub->tt.hub)
1364		flush_work(&hub->tt.clear_work);
1365}
1366
1367static void hub_pm_barrier_for_all_ports(struct usb_hub *hub)
1368{
1369	int i;
1370
1371	for (i = 0; i < hub->hdev->maxchild; ++i)
1372		pm_runtime_barrier(&hub->ports[i]->dev);
1373}
1374
1375/* caller has locked the hub device */
1376static int hub_pre_reset(struct usb_interface *intf)
1377{
1378	struct usb_hub *hub = usb_get_intfdata(intf);
1379
1380	hub_quiesce(hub, HUB_PRE_RESET);
1381	hub->in_reset = 1;
1382	hub_pm_barrier_for_all_ports(hub);
1383	return 0;
1384}
1385
1386/* caller has locked the hub device */
1387static int hub_post_reset(struct usb_interface *intf)
1388{
1389	struct usb_hub *hub = usb_get_intfdata(intf);
1390
1391	hub->in_reset = 0;
1392	hub_pm_barrier_for_all_ports(hub);
1393	hub_activate(hub, HUB_POST_RESET);
1394	return 0;
1395}
1396
1397static int hub_configure(struct usb_hub *hub,
1398	struct usb_endpoint_descriptor *endpoint)
1399{
1400	struct usb_hcd *hcd;
1401	struct usb_device *hdev = hub->hdev;
1402	struct device *hub_dev = hub->intfdev;
1403	u16 hubstatus, hubchange;
1404	u16 wHubCharacteristics;
1405	unsigned int pipe;
1406	int maxp, ret, i;
1407	char *message = "out of memory";
1408	unsigned unit_load;
1409	unsigned full_load;
1410	unsigned maxchild;
1411
1412	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1413	if (!hub->buffer) {
1414		ret = -ENOMEM;
1415		goto fail;
1416	}
1417
1418	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1419	if (!hub->status) {
1420		ret = -ENOMEM;
1421		goto fail;
1422	}
1423	mutex_init(&hub->status_mutex);
1424
1425	hub->descriptor = kzalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1426	if (!hub->descriptor) {
1427		ret = -ENOMEM;
1428		goto fail;
1429	}
1430
1431	/* Request the entire hub descriptor.
1432	 * hub->descriptor can handle USB_MAXCHILDREN ports,
1433	 * but a (non-SS) hub can/will return fewer bytes here.
1434	 */
1435	ret = get_hub_descriptor(hdev, hub->descriptor);
1436	if (ret < 0) {
1437		message = "can't read hub descriptor";
1438		goto fail;
1439	}
1440
1441	maxchild = USB_MAXCHILDREN;
1442	if (hub_is_superspeed(hdev))
1443		maxchild = min_t(unsigned, maxchild, USB_SS_MAXPORTS);
1444
1445	if (hub->descriptor->bNbrPorts > maxchild) {
1446		message = "hub has too many ports!";
1447		ret = -ENODEV;
1448		goto fail;
1449	} else if (hub->descriptor->bNbrPorts == 0) {
1450		message = "hub doesn't have any ports!";
1451		ret = -ENODEV;
1452		goto fail;
1453	}
1454
1455	/*
1456	 * Accumulate wHubDelay + 40ns for every hub in the tree of devices.
1457	 * The resulting value will be used for SetIsochDelay() request.
1458	 */
1459	if (hub_is_superspeed(hdev) || hub_is_superspeedplus(hdev)) {
1460		u32 delay = __le16_to_cpu(hub->descriptor->u.ss.wHubDelay);
1461
1462		if (hdev->parent)
1463			delay += hdev->parent->hub_delay;
1464
1465		delay += USB_TP_TRANSMISSION_DELAY;
1466		hdev->hub_delay = min_t(u32, delay, USB_TP_TRANSMISSION_DELAY_MAX);
1467	}
1468
1469	maxchild = hub->descriptor->bNbrPorts;
1470	dev_info(hub_dev, "%d port%s detected\n", maxchild,
1471			(maxchild == 1) ? "" : "s");
1472
1473	hub->ports = kcalloc(maxchild, sizeof(struct usb_port *), GFP_KERNEL);
1474	if (!hub->ports) {
1475		ret = -ENOMEM;
1476		goto fail;
1477	}
1478
1479	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1480	if (hub_is_superspeed(hdev)) {
1481		unit_load = 150;
1482		full_load = 900;
1483	} else {
1484		unit_load = 100;
1485		full_load = 500;
1486	}
1487
1488	/* FIXME for USB 3.0, skip for now */
1489	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1490			!(hub_is_superspeed(hdev))) {
1491		char	portstr[USB_MAXCHILDREN + 1];
1492
1493		for (i = 0; i < maxchild; i++)
1494			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1495				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1496				? 'F' : 'R';
1497		portstr[maxchild] = 0;
1498		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1499	} else
1500		dev_dbg(hub_dev, "standalone hub\n");
1501
1502	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1503	case HUB_CHAR_COMMON_LPSM:
1504		dev_dbg(hub_dev, "ganged power switching\n");
1505		break;
1506	case HUB_CHAR_INDV_PORT_LPSM:
1507		dev_dbg(hub_dev, "individual port power switching\n");
1508		break;
1509	case HUB_CHAR_NO_LPSM:
1510	case HUB_CHAR_LPSM:
1511		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1512		break;
1513	}
1514
1515	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1516	case HUB_CHAR_COMMON_OCPM:
1517		dev_dbg(hub_dev, "global over-current protection\n");
1518		break;
1519	case HUB_CHAR_INDV_PORT_OCPM:
1520		dev_dbg(hub_dev, "individual port over-current protection\n");
1521		break;
1522	case HUB_CHAR_NO_OCPM:
1523	case HUB_CHAR_OCPM:
1524		dev_dbg(hub_dev, "no over-current protection\n");
1525		break;
1526	}
1527
1528	spin_lock_init(&hub->tt.lock);
1529	INIT_LIST_HEAD(&hub->tt.clear_list);
1530	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1531	switch (hdev->descriptor.bDeviceProtocol) {
1532	case USB_HUB_PR_FS:
1533		break;
1534	case USB_HUB_PR_HS_SINGLE_TT:
1535		dev_dbg(hub_dev, "Single TT\n");
1536		hub->tt.hub = hdev;
1537		break;
1538	case USB_HUB_PR_HS_MULTI_TT:
1539		ret = usb_set_interface(hdev, 0, 1);
1540		if (ret == 0) {
1541			dev_dbg(hub_dev, "TT per port\n");
1542			hub->tt.multi = 1;
1543		} else
1544			dev_err(hub_dev, "Using single TT (err %d)\n",
1545				ret);
1546		hub->tt.hub = hdev;
1547		break;
1548	case USB_HUB_PR_SS:
1549		/* USB 3.0 hubs don't have a TT */
1550		break;
1551	default:
1552		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1553			hdev->descriptor.bDeviceProtocol);
1554		break;
1555	}
1556
1557	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1558	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1559	case HUB_TTTT_8_BITS:
1560		if (hdev->descriptor.bDeviceProtocol != 0) {
1561			hub->tt.think_time = 666;
1562			dev_dbg(hub_dev, "TT requires at most %d "
1563					"FS bit times (%d ns)\n",
1564				8, hub->tt.think_time);
1565		}
1566		break;
1567	case HUB_TTTT_16_BITS:
1568		hub->tt.think_time = 666 * 2;
1569		dev_dbg(hub_dev, "TT requires at most %d "
1570				"FS bit times (%d ns)\n",
1571			16, hub->tt.think_time);
1572		break;
1573	case HUB_TTTT_24_BITS:
1574		hub->tt.think_time = 666 * 3;
1575		dev_dbg(hub_dev, "TT requires at most %d "
1576				"FS bit times (%d ns)\n",
1577			24, hub->tt.think_time);
1578		break;
1579	case HUB_TTTT_32_BITS:
1580		hub->tt.think_time = 666 * 4;
1581		dev_dbg(hub_dev, "TT requires at most %d "
1582				"FS bit times (%d ns)\n",
1583			32, hub->tt.think_time);
1584		break;
1585	}
1586
1587	/* probe() zeroes hub->indicator[] */
1588	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1589		hub->has_indicators = 1;
1590		dev_dbg(hub_dev, "Port indicators are supported\n");
1591	}
1592
1593	dev_dbg(hub_dev, "power on to power good time: %dms\n",
1594		hub->descriptor->bPwrOn2PwrGood * 2);
1595
1596	/* power budgeting mostly matters with bus-powered hubs,
1597	 * and battery-powered root hubs (may provide just 8 mA).
1598	 */
1599	ret = usb_get_std_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1600	if (ret) {
1601		message = "can't get hub status";
1602		goto fail;
1603	}
1604	hcd = bus_to_hcd(hdev->bus);
1605	if (hdev == hdev->bus->root_hub) {
1606		if (hcd->power_budget > 0)
1607			hdev->bus_mA = hcd->power_budget;
1608		else
1609			hdev->bus_mA = full_load * maxchild;
1610		if (hdev->bus_mA >= full_load)
1611			hub->mA_per_port = full_load;
1612		else {
1613			hub->mA_per_port = hdev->bus_mA;
1614			hub->limited_power = 1;
1615		}
1616	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1617		int remaining = hdev->bus_mA -
1618			hub->descriptor->bHubContrCurrent;
1619
1620		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1621			hub->descriptor->bHubContrCurrent);
1622		hub->limited_power = 1;
1623
1624		if (remaining < maxchild * unit_load)
1625			dev_warn(hub_dev,
1626					"insufficient power available "
1627					"to use all downstream ports\n");
1628		hub->mA_per_port = unit_load;	/* 7.2.1 */
1629
1630	} else {	/* Self-powered external hub */
1631		/* FIXME: What about battery-powered external hubs that
1632		 * provide less current per port? */
1633		hub->mA_per_port = full_load;
1634	}
1635	if (hub->mA_per_port < full_load)
1636		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1637				hub->mA_per_port);
1638
1639	ret = hub_hub_status(hub, &hubstatus, &hubchange);
1640	if (ret < 0) {
1641		message = "can't get hub status";
1642		goto fail;
1643	}
1644
1645	/* local power status reports aren't always correct */
1646	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1647		dev_dbg(hub_dev, "local power source is %s\n",
1648			(hubstatus & HUB_STATUS_LOCAL_POWER)
1649			? "lost (inactive)" : "good");
1650
1651	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1652		dev_dbg(hub_dev, "%sover-current condition exists\n",
1653			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1654
1655	/* set up the interrupt endpoint
1656	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1657	 * bytes as USB2.0[11.12.3] says because some hubs are known
1658	 * to send more data (and thus cause overflow). For root hubs,
1659	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1660	 * to be big enough for at least USB_MAXCHILDREN ports. */
1661	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1662	maxp = usb_maxpacket(hdev, pipe);
1663
1664	if (maxp > sizeof(*hub->buffer))
1665		maxp = sizeof(*hub->buffer);
1666
1667	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1668	if (!hub->urb) {
1669		ret = -ENOMEM;
1670		goto fail;
1671	}
1672
1673	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1674		hub, endpoint->bInterval);
1675
1676	/* maybe cycle the hub leds */
1677	if (hub->has_indicators && blinkenlights)
1678		hub->indicator[0] = INDICATOR_CYCLE;
1679
1680	mutex_lock(&usb_port_peer_mutex);
1681	for (i = 0; i < maxchild; i++) {
1682		ret = usb_hub_create_port_device(hub, i + 1);
1683		if (ret < 0) {
1684			dev_err(hub->intfdev,
1685				"couldn't create port%d device.\n", i + 1);
1686			break;
1687		}
1688	}
1689	hdev->maxchild = i;
1690	for (i = 0; i < hdev->maxchild; i++) {
1691		struct usb_port *port_dev = hub->ports[i];
1692
1693		pm_runtime_put(&port_dev->dev);
1694	}
1695
1696	mutex_unlock(&usb_port_peer_mutex);
1697	if (ret < 0)
1698		goto fail;
1699
1700	/* Update the HCD's internal representation of this hub before hub_wq
1701	 * starts getting port status changes for devices under the hub.
1702	 */
1703	if (hcd->driver->update_hub_device) {
1704		ret = hcd->driver->update_hub_device(hcd, hdev,
1705				&hub->tt, GFP_KERNEL);
1706		if (ret < 0) {
1707			message = "can't update HCD hub info";
1708			goto fail;
1709		}
1710	}
1711
1712	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1713
1714	hub_activate(hub, HUB_INIT);
1715	return 0;
1716
1717fail:
1718	dev_err(hub_dev, "config failed, %s (err %d)\n",
1719			message, ret);
1720	/* hub_disconnect() frees urb and descriptor */
1721	return ret;
1722}
1723
1724static void hub_release(struct kref *kref)
1725{
1726	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1727
1728	usb_put_dev(hub->hdev);
1729	usb_put_intf(to_usb_interface(hub->intfdev));
1730	kfree(hub);
1731}
1732
1733static unsigned highspeed_hubs;
1734
1735static void hub_disconnect(struct usb_interface *intf)
1736{
1737	struct usb_hub *hub = usb_get_intfdata(intf);
1738	struct usb_device *hdev = interface_to_usbdev(intf);
1739	int port1;
1740
1741	/*
1742	 * Stop adding new hub events. We do not want to block here and thus
1743	 * will not try to remove any pending work item.
1744	 */
1745	hub->disconnected = 1;
1746
1747	/* Disconnect all children and quiesce the hub */
1748	hub->error = 0;
1749	hub_quiesce(hub, HUB_DISCONNECT);
1750
1751	mutex_lock(&usb_port_peer_mutex);
1752
1753	/* Avoid races with recursively_mark_NOTATTACHED() */
1754	spin_lock_irq(&device_state_lock);
1755	port1 = hdev->maxchild;
1756	hdev->maxchild = 0;
1757	usb_set_intfdata(intf, NULL);
1758	spin_unlock_irq(&device_state_lock);
1759
1760	for (; port1 > 0; --port1)
1761		usb_hub_remove_port_device(hub, port1);
1762
1763	mutex_unlock(&usb_port_peer_mutex);
1764
1765	if (hub->hdev->speed == USB_SPEED_HIGH)
1766		highspeed_hubs--;
1767
1768	usb_free_urb(hub->urb);
1769	kfree(hub->ports);
1770	kfree(hub->descriptor);
1771	kfree(hub->status);
1772	kfree(hub->buffer);
1773
1774	pm_suspend_ignore_children(&intf->dev, false);
1775
1776	if (hub->quirk_disable_autosuspend)
1777		usb_autopm_put_interface(intf);
1778
1779	onboard_hub_destroy_pdevs(&hub->onboard_hub_devs);
1780
1781	kref_put(&hub->kref, hub_release);
1782}
1783
1784static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
1785{
1786	/* Some hubs have a subclass of 1, which AFAICT according to the */
1787	/*  specs is not defined, but it works */
1788	if (desc->desc.bInterfaceSubClass != 0 &&
1789	    desc->desc.bInterfaceSubClass != 1)
1790		return false;
1791
1792	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
1793	if (desc->desc.bNumEndpoints != 1)
1794		return false;
1795
1796	/* If the first endpoint is not interrupt IN, we'd better punt! */
1797	if (!usb_endpoint_is_int_in(&desc->endpoint[0].desc))
1798		return false;
1799
1800        return true;
1801}
1802
1803static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1804{
1805	struct usb_host_interface *desc;
1806	struct usb_device *hdev;
1807	struct usb_hub *hub;
1808
1809	desc = intf->cur_altsetting;
1810	hdev = interface_to_usbdev(intf);
1811
1812	/*
1813	 * Set default autosuspend delay as 0 to speedup bus suspend,
1814	 * based on the below considerations:
1815	 *
1816	 * - Unlike other drivers, the hub driver does not rely on the
1817	 *   autosuspend delay to provide enough time to handle a wakeup
1818	 *   event, and the submitted status URB is just to check future
1819	 *   change on hub downstream ports, so it is safe to do it.
1820	 *
1821	 * - The patch might cause one or more auto supend/resume for
1822	 *   below very rare devices when they are plugged into hub
1823	 *   first time:
1824	 *
1825	 *   	devices having trouble initializing, and disconnect
1826	 *   	themselves from the bus and then reconnect a second
1827	 *   	or so later
1828	 *
1829	 *   	devices just for downloading firmware, and disconnects
1830	 *   	themselves after completing it
1831	 *
1832	 *   For these quite rare devices, their drivers may change the
1833	 *   autosuspend delay of their parent hub in the probe() to one
1834	 *   appropriate value to avoid the subtle problem if someone
1835	 *   does care it.
1836	 *
1837	 * - The patch may cause one or more auto suspend/resume on
1838	 *   hub during running 'lsusb', but it is probably too
1839	 *   infrequent to worry about.
1840	 *
1841	 * - Change autosuspend delay of hub can avoid unnecessary auto
1842	 *   suspend timer for hub, also may decrease power consumption
1843	 *   of USB bus.
1844	 *
1845	 * - If user has indicated to prevent autosuspend by passing
1846	 *   usbcore.autosuspend = -1 then keep autosuspend disabled.
1847	 */
1848#ifdef CONFIG_PM
1849	if (hdev->dev.power.autosuspend_delay >= 0)
1850		pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1851#endif
1852
1853	/*
1854	 * Hubs have proper suspend/resume support, except for root hubs
1855	 * where the controller driver doesn't have bus_suspend and
1856	 * bus_resume methods.
1857	 */
1858	if (hdev->parent) {		/* normal device */
1859		usb_enable_autosuspend(hdev);
1860	} else {			/* root hub */
1861		const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;
1862
1863		if (drv->bus_suspend && drv->bus_resume)
1864			usb_enable_autosuspend(hdev);
1865	}
1866
1867	if (hdev->level == MAX_TOPO_LEVEL) {
1868		dev_err(&intf->dev,
1869			"Unsupported bus topology: hub nested too deep\n");
1870		return -E2BIG;
1871	}
1872
1873#ifdef	CONFIG_USB_OTG_DISABLE_EXTERNAL_HUB
1874	if (hdev->parent) {
1875		dev_warn(&intf->dev, "ignoring external hub\n");
1876		return -ENODEV;
1877	}
1878#endif
1879
1880	if (!hub_descriptor_is_sane(desc)) {
1881		dev_err(&intf->dev, "bad descriptor, ignoring hub\n");
1882		return -EIO;
1883	}
1884
1885	/* We found a hub */
1886	dev_info(&intf->dev, "USB hub found\n");
1887
1888	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1889	if (!hub)
1890		return -ENOMEM;
1891
1892	kref_init(&hub->kref);
1893	hub->intfdev = &intf->dev;
1894	hub->hdev = hdev;
1895	INIT_DELAYED_WORK(&hub->leds, led_work);
1896	INIT_DELAYED_WORK(&hub->init_work, NULL);
1897	INIT_WORK(&hub->events, hub_event);
1898	INIT_LIST_HEAD(&hub->onboard_hub_devs);
1899	spin_lock_init(&hub->irq_urb_lock);
1900	timer_setup(&hub->irq_urb_retry, hub_retry_irq_urb, 0);
1901	usb_get_intf(intf);
1902	usb_get_dev(hdev);
1903
1904	usb_set_intfdata(intf, hub);
1905	intf->needs_remote_wakeup = 1;
1906	pm_suspend_ignore_children(&intf->dev, true);
1907
1908	if (hdev->speed == USB_SPEED_HIGH)
1909		highspeed_hubs++;
1910
1911	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1912		hub->quirk_check_port_auto_suspend = 1;
1913
1914	if (id->driver_info & HUB_QUIRK_DISABLE_AUTOSUSPEND) {
1915		hub->quirk_disable_autosuspend = 1;
1916		usb_autopm_get_interface_no_resume(intf);
1917	}
1918
1919	if ((id->driver_info & HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL) &&
1920	    desc->endpoint[0].desc.bInterval > USB_REDUCE_FRAME_INTR_BINTERVAL) {
1921		desc->endpoint[0].desc.bInterval =
1922			USB_REDUCE_FRAME_INTR_BINTERVAL;
1923		/* Tell the HCD about the interrupt ep's new bInterval */
1924		usb_set_interface(hdev, 0, 0);
1925	}
1926
1927	if (hub_configure(hub, &desc->endpoint[0].desc) >= 0) {
1928		onboard_hub_create_pdevs(hdev, &hub->onboard_hub_devs);
1929
1930		return 0;
1931	}
1932
1933	hub_disconnect(intf);
1934	return -ENODEV;
1935}
1936
1937static int
1938hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1939{
1940	struct usb_device *hdev = interface_to_usbdev(intf);
1941	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1942
1943	/* assert ifno == 0 (part of hub spec) */
1944	switch (code) {
1945	case USBDEVFS_HUB_PORTINFO: {
1946		struct usbdevfs_hub_portinfo *info = user_data;
1947		int i;
1948
1949		spin_lock_irq(&device_state_lock);
1950		if (hdev->devnum <= 0)
1951			info->nports = 0;
1952		else {
1953			info->nports = hdev->maxchild;
1954			for (i = 0; i < info->nports; i++) {
1955				if (hub->ports[i]->child == NULL)
1956					info->port[i] = 0;
1957				else
1958					info->port[i] =
1959						hub->ports[i]->child->devnum;
1960			}
1961		}
1962		spin_unlock_irq(&device_state_lock);
1963
1964		return info->nports + 1;
1965		}
1966
1967	default:
1968		return -ENOSYS;
1969	}
1970}
1971
1972/*
1973 * Allow user programs to claim ports on a hub.  When a device is attached
1974 * to one of these "claimed" ports, the program will "own" the device.
1975 */
1976static int find_port_owner(struct usb_device *hdev, unsigned port1,
1977		struct usb_dev_state ***ppowner)
1978{
1979	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1980
1981	if (hdev->state == USB_STATE_NOTATTACHED)
1982		return -ENODEV;
1983	if (port1 == 0 || port1 > hdev->maxchild)
1984		return -EINVAL;
1985
1986	/* Devices not managed by the hub driver
1987	 * will always have maxchild equal to 0.
1988	 */
1989	*ppowner = &(hub->ports[port1 - 1]->port_owner);
1990	return 0;
1991}
1992
1993/* In the following three functions, the caller must hold hdev's lock */
1994int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1995		       struct usb_dev_state *owner)
1996{
1997	int rc;
1998	struct usb_dev_state **powner;
1999
2000	rc = find_port_owner(hdev, port1, &powner);
2001	if (rc)
2002		return rc;
2003	if (*powner)
2004		return -EBUSY;
2005	*powner = owner;
2006	return rc;
2007}
2008EXPORT_SYMBOL_GPL(usb_hub_claim_port);
2009
2010int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
2011			 struct usb_dev_state *owner)
2012{
2013	int rc;
2014	struct usb_dev_state **powner;
2015
2016	rc = find_port_owner(hdev, port1, &powner);
2017	if (rc)
2018		return rc;
2019	if (*powner != owner)
2020		return -ENOENT;
2021	*powner = NULL;
2022	return rc;
2023}
2024EXPORT_SYMBOL_GPL(usb_hub_release_port);
2025
2026void usb_hub_release_all_ports(struct usb_device *hdev, struct usb_dev_state *owner)
2027{
2028	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
2029	int n;
2030
2031	for (n = 0; n < hdev->maxchild; n++) {
2032		if (hub->ports[n]->port_owner == owner)
2033			hub->ports[n]->port_owner = NULL;
2034	}
2035
2036}
2037
2038/* The caller must hold udev's lock */
2039bool usb_device_is_owned(struct usb_device *udev)
2040{
2041	struct usb_hub *hub;
2042
2043	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
2044		return false;
2045	hub = usb_hub_to_struct_hub(udev->parent);
2046	return !!hub->ports[udev->portnum - 1]->port_owner;
2047}
2048
2049static void update_port_device_state(struct usb_device *udev)
2050{
2051	struct usb_hub *hub;
2052	struct usb_port *port_dev;
2053
2054	if (udev->parent) {
2055		hub = usb_hub_to_struct_hub(udev->parent);
2056
2057		/*
2058		 * The Link Layer Validation System Driver (lvstest)
2059		 * has a test step to unbind the hub before running the
2060		 * rest of the procedure. This triggers hub_disconnect
2061		 * which will set the hub's maxchild to 0, further
2062		 * resulting in usb_hub_to_struct_hub returning NULL.
2063		 */
2064		if (hub) {
2065			port_dev = hub->ports[udev->portnum - 1];
2066			WRITE_ONCE(port_dev->state, udev->state);
2067			sysfs_notify_dirent(port_dev->state_kn);
2068		}
2069	}
2070}
2071
2072static void recursively_mark_NOTATTACHED(struct usb_device *udev)
2073{
2074	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2075	int i;
2076
2077	for (i = 0; i < udev->maxchild; ++i) {
2078		if (hub->ports[i]->child)
2079			recursively_mark_NOTATTACHED(hub->ports[i]->child);
2080	}
2081	if (udev->state == USB_STATE_SUSPENDED)
2082		udev->active_duration -= jiffies;
2083	udev->state = USB_STATE_NOTATTACHED;
2084	update_port_device_state(udev);
2085}
2086
2087/**
2088 * usb_set_device_state - change a device's current state (usbcore, hcds)
2089 * @udev: pointer to device whose state should be changed
2090 * @new_state: new state value to be stored
2091 *
2092 * udev->state is _not_ fully protected by the device lock.  Although
2093 * most transitions are made only while holding the lock, the state can
2094 * can change to USB_STATE_NOTATTACHED at almost any time.  This
2095 * is so that devices can be marked as disconnected as soon as possible,
2096 * without having to wait for any semaphores to be released.  As a result,
2097 * all changes to any device's state must be protected by the
2098 * device_state_lock spinlock.
2099 *
2100 * Once a device has been added to the device tree, all changes to its state
2101 * should be made using this routine.  The state should _not_ be set directly.
2102 *
2103 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
2104 * Otherwise udev->state is set to new_state, and if new_state is
2105 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
2106 * to USB_STATE_NOTATTACHED.
2107 */
2108void usb_set_device_state(struct usb_device *udev,
2109		enum usb_device_state new_state)
2110{
2111	unsigned long flags;
2112	int wakeup = -1;
2113
2114	spin_lock_irqsave(&device_state_lock, flags);
2115	if (udev->state == USB_STATE_NOTATTACHED)
2116		;	/* do nothing */
2117	else if (new_state != USB_STATE_NOTATTACHED) {
2118
2119		/* root hub wakeup capabilities are managed out-of-band
2120		 * and may involve silicon errata ... ignore them here.
2121		 */
2122		if (udev->parent) {
2123			if (udev->state == USB_STATE_SUSPENDED
2124					|| new_state == USB_STATE_SUSPENDED)
2125				;	/* No change to wakeup settings */
2126			else if (new_state == USB_STATE_CONFIGURED)
2127				wakeup = (udev->quirks &
2128					USB_QUIRK_IGNORE_REMOTE_WAKEUP) ? 0 :
2129					udev->actconfig->desc.bmAttributes &
2130					USB_CONFIG_ATT_WAKEUP;
2131			else
2132				wakeup = 0;
2133		}
2134		if (udev->state == USB_STATE_SUSPENDED &&
2135			new_state != USB_STATE_SUSPENDED)
2136			udev->active_duration -= jiffies;
2137		else if (new_state == USB_STATE_SUSPENDED &&
2138				udev->state != USB_STATE_SUSPENDED)
2139			udev->active_duration += jiffies;
2140		udev->state = new_state;
2141		update_port_device_state(udev);
2142	} else
2143		recursively_mark_NOTATTACHED(udev);
2144	spin_unlock_irqrestore(&device_state_lock, flags);
2145	if (wakeup >= 0)
2146		device_set_wakeup_capable(&udev->dev, wakeup);
2147}
2148EXPORT_SYMBOL_GPL(usb_set_device_state);
2149
2150/*
2151 * Choose a device number.
2152 *
2153 * Device numbers are used as filenames in usbfs.  On USB-1.1 and
2154 * USB-2.0 buses they are also used as device addresses, however on
2155 * USB-3.0 buses the address is assigned by the controller hardware
2156 * and it usually is not the same as the device number.
2157 *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2158 * Devices connected under xHCI are not as simple.  The host controller
2159 * supports virtualization, so the hardware assigns device addresses and
2160 * the HCD must setup data structures before issuing a set address
2161 * command to the hardware.
2162 */
2163static void choose_devnum(struct usb_device *udev)
2164{
2165	int		devnum;
2166	struct usb_bus	*bus = udev->bus;
2167
2168	/* be safe when more hub events are proceed in parallel */
2169	mutex_lock(&bus->devnum_next_mutex);
2170
2171	/* Try to allocate the next devnum beginning at bus->devnum_next. */
2172	devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2173			bus->devnum_next);
2174	if (devnum >= 128)
2175		devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
2176	bus->devnum_next = (devnum >= 127 ? 1 : devnum + 1);
 
 
 
 
 
 
2177	if (devnum < 128) {
2178		set_bit(devnum, bus->devmap.devicemap);
2179		udev->devnum = devnum;
2180	}
2181	mutex_unlock(&bus->devnum_next_mutex);
2182}
2183
2184static void release_devnum(struct usb_device *udev)
2185{
2186	if (udev->devnum > 0) {
2187		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2188		udev->devnum = -1;
2189	}
2190}
2191
2192static void update_devnum(struct usb_device *udev, int devnum)
2193{
2194	udev->devnum = devnum;
 
 
2195	if (!udev->devaddr)
2196		udev->devaddr = (u8)devnum;
2197}
2198
2199static void hub_free_dev(struct usb_device *udev)
2200{
2201	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2202
2203	/* Root hubs aren't real devices, so don't free HCD resources */
2204	if (hcd->driver->free_dev && udev->parent)
2205		hcd->driver->free_dev(hcd, udev);
2206}
2207
2208static void hub_disconnect_children(struct usb_device *udev)
2209{
2210	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2211	int i;
2212
2213	/* Free up all the children before we remove this device */
2214	for (i = 0; i < udev->maxchild; i++) {
2215		if (hub->ports[i]->child)
2216			usb_disconnect(&hub->ports[i]->child);
2217	}
2218}
2219
2220/**
2221 * usb_disconnect - disconnect a device (usbcore-internal)
2222 * @pdev: pointer to device being disconnected
2223 *
2224 * Context: task context, might sleep
2225 *
2226 * Something got disconnected. Get rid of it and all of its children.
2227 *
2228 * If *pdev is a normal device then the parent hub must already be locked.
2229 * If *pdev is a root hub then the caller must hold the usb_bus_idr_lock,
2230 * which protects the set of root hubs as well as the list of buses.
2231 *
2232 * Only hub drivers (including virtual root hub drivers for host
2233 * controllers) should ever call this.
2234 *
2235 * This call is synchronous, and may not be used in an interrupt context.
2236 */
2237void usb_disconnect(struct usb_device **pdev)
2238{
2239	struct usb_port *port_dev = NULL;
2240	struct usb_device *udev = *pdev;
2241	struct usb_hub *hub = NULL;
2242	int port1 = 1;
2243
2244	/* mark the device as inactive, so any further urb submissions for
2245	 * this device (and any of its children) will fail immediately.
2246	 * this quiesces everything except pending urbs.
2247	 */
2248	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2249	dev_info(&udev->dev, "USB disconnect, device number %d\n",
2250			udev->devnum);
2251
2252	/*
2253	 * Ensure that the pm runtime code knows that the USB device
2254	 * is in the process of being disconnected.
2255	 */
2256	pm_runtime_barrier(&udev->dev);
2257
2258	usb_lock_device(udev);
2259
2260	hub_disconnect_children(udev);
2261
2262	/* deallocate hcd/hardware state ... nuking all pending urbs and
2263	 * cleaning up all state associated with the current configuration
2264	 * so that the hardware is now fully quiesced.
2265	 */
2266	dev_dbg(&udev->dev, "unregistering device\n");
2267	usb_disable_device(udev, 0);
2268	usb_hcd_synchronize_unlinks(udev);
2269
2270	if (udev->parent) {
2271		port1 = udev->portnum;
2272		hub = usb_hub_to_struct_hub(udev->parent);
2273		port_dev = hub->ports[port1 - 1];
2274
2275		sysfs_remove_link(&udev->dev.kobj, "port");
2276		sysfs_remove_link(&port_dev->dev.kobj, "device");
2277
2278		/*
2279		 * As usb_port_runtime_resume() de-references udev, make
2280		 * sure no resumes occur during removal
2281		 */
2282		if (!test_and_set_bit(port1, hub->child_usage_bits))
2283			pm_runtime_get_sync(&port_dev->dev);
2284
2285		typec_deattach(port_dev->connector, &udev->dev);
2286	}
2287
2288	usb_remove_ep_devs(&udev->ep0);
2289	usb_unlock_device(udev);
2290
2291	/* Unregister the device.  The device driver is responsible
2292	 * for de-configuring the device and invoking the remove-device
2293	 * notifier chain (used by usbfs and possibly others).
2294	 */
2295	device_del(&udev->dev);
2296
2297	/* Free the device number and delete the parent's children[]
2298	 * (or root_hub) pointer.
2299	 */
2300	release_devnum(udev);
2301
2302	/* Avoid races with recursively_mark_NOTATTACHED() */
2303	spin_lock_irq(&device_state_lock);
2304	*pdev = NULL;
2305	spin_unlock_irq(&device_state_lock);
2306
2307	if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
2308		pm_runtime_put(&port_dev->dev);
2309
2310	hub_free_dev(udev);
2311
2312	put_device(&udev->dev);
2313}
2314
2315#ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
2316static void show_string(struct usb_device *udev, char *id, char *string)
2317{
2318	if (!string)
2319		return;
2320	dev_info(&udev->dev, "%s: %s\n", id, string);
2321}
2322
2323static void announce_device(struct usb_device *udev)
2324{
2325	u16 bcdDevice = le16_to_cpu(udev->descriptor.bcdDevice);
2326
2327	dev_info(&udev->dev,
2328		"New USB device found, idVendor=%04x, idProduct=%04x, bcdDevice=%2x.%02x\n",
2329		le16_to_cpu(udev->descriptor.idVendor),
2330		le16_to_cpu(udev->descriptor.idProduct),
2331		bcdDevice >> 8, bcdDevice & 0xff);
2332	dev_info(&udev->dev,
2333		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2334		udev->descriptor.iManufacturer,
2335		udev->descriptor.iProduct,
2336		udev->descriptor.iSerialNumber);
2337	show_string(udev, "Product", udev->product);
2338	show_string(udev, "Manufacturer", udev->manufacturer);
2339	show_string(udev, "SerialNumber", udev->serial);
2340}
2341#else
2342static inline void announce_device(struct usb_device *udev) { }
2343#endif
2344
2345
2346/**
2347 * usb_enumerate_device_otg - FIXME (usbcore-internal)
2348 * @udev: newly addressed device (in ADDRESS state)
2349 *
2350 * Finish enumeration for On-The-Go devices
2351 *
2352 * Return: 0 if successful. A negative error code otherwise.
2353 */
2354static int usb_enumerate_device_otg(struct usb_device *udev)
2355{
2356	int err = 0;
2357
2358#ifdef	CONFIG_USB_OTG
2359	/*
2360	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2361	 * to wake us after we've powered off VBUS; and HNP, switching roles
2362	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
2363	 */
2364	if (!udev->bus->is_b_host
2365			&& udev->config
2366			&& udev->parent == udev->bus->root_hub) {
2367		struct usb_otg_descriptor	*desc = NULL;
2368		struct usb_bus			*bus = udev->bus;
2369		unsigned			port1 = udev->portnum;
2370
2371		/* descriptor may appear anywhere in config */
2372		err = __usb_get_extra_descriptor(udev->rawdescriptors[0],
2373				le16_to_cpu(udev->config[0].desc.wTotalLength),
2374				USB_DT_OTG, (void **) &desc, sizeof(*desc));
2375		if (err || !(desc->bmAttributes & USB_OTG_HNP))
2376			return 0;
2377
2378		dev_info(&udev->dev, "Dual-Role OTG device on %sHNP port\n",
2379					(port1 == bus->otg_port) ? "" : "non-");
2380
2381		/* enable HNP before suspend, it's simpler */
2382		if (port1 == bus->otg_port) {
2383			bus->b_hnp_enable = 1;
2384			err = usb_control_msg(udev,
2385				usb_sndctrlpipe(udev, 0),
2386				USB_REQ_SET_FEATURE, 0,
2387				USB_DEVICE_B_HNP_ENABLE,
2388				0, NULL, 0,
2389				USB_CTRL_SET_TIMEOUT);
2390			if (err < 0) {
2391				/*
2392				 * OTG MESSAGE: report errors here,
2393				 * customize to match your product.
2394				 */
2395				dev_err(&udev->dev, "can't set HNP mode: %d\n",
2396									err);
2397				bus->b_hnp_enable = 0;
2398			}
2399		} else if (desc->bLength == sizeof
2400				(struct usb_otg_descriptor)) {
2401			/*
2402			 * We are operating on a legacy OTP device
2403			 * These should be told that they are operating
2404			 * on the wrong port if we have another port that does
2405			 * support HNP
2406			 */
2407			if (bus->otg_port != 0) {
2408				/* Set a_alt_hnp_support for legacy otg device */
2409				err = usb_control_msg(udev,
2410					usb_sndctrlpipe(udev, 0),
2411					USB_REQ_SET_FEATURE, 0,
2412					USB_DEVICE_A_ALT_HNP_SUPPORT,
2413					0, NULL, 0,
2414					USB_CTRL_SET_TIMEOUT);
2415				if (err < 0)
2416					dev_err(&udev->dev,
2417						"set a_alt_hnp_support failed: %d\n",
2418						err);
2419			}
2420		}
2421	}
2422#endif
2423	return err;
2424}
2425
2426
2427/**
2428 * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2429 * @udev: newly addressed device (in ADDRESS state)
2430 *
2431 * This is only called by usb_new_device() -- all comments that apply there
2432 * apply here wrt to environment.
 
2433 *
2434 * If the device is WUSB and not authorized, we don't attempt to read
2435 * the string descriptors, as they will be errored out by the device
2436 * until it has been authorized.
2437 *
2438 * Return: 0 if successful. A negative error code otherwise.
2439 */
2440static int usb_enumerate_device(struct usb_device *udev)
2441{
2442	int err;
2443	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2444
2445	if (udev->config == NULL) {
2446		err = usb_get_configuration(udev);
2447		if (err < 0) {
2448			if (err != -ENODEV)
2449				dev_err(&udev->dev, "can't read configurations, error %d\n",
2450						err);
2451			return err;
2452		}
2453	}
2454
2455	/* read the standard strings and cache them if present */
2456	udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2457	udev->manufacturer = usb_cache_string(udev,
2458					      udev->descriptor.iManufacturer);
2459	udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2460
2461	err = usb_enumerate_device_otg(udev);
2462	if (err < 0)
2463		return err;
2464
2465	if (IS_ENABLED(CONFIG_USB_OTG_PRODUCTLIST) && hcd->tpl_support &&
2466		!is_targeted(udev)) {
2467		/* Maybe it can talk to us, though we can't talk to it.
2468		 * (Includes HNP test device.)
2469		 */
2470		if (IS_ENABLED(CONFIG_USB_OTG) && (udev->bus->b_hnp_enable
2471			|| udev->bus->is_b_host)) {
2472			err = usb_port_suspend(udev, PMSG_AUTO_SUSPEND);
2473			if (err < 0)
2474				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2475		}
2476		return -ENOTSUPP;
2477	}
2478
2479	usb_detect_interface_quirks(udev);
2480
2481	return 0;
2482}
2483
2484static void set_usb_port_removable(struct usb_device *udev)
2485{
2486	struct usb_device *hdev = udev->parent;
2487	struct usb_hub *hub;
2488	u8 port = udev->portnum;
2489	u16 wHubCharacteristics;
2490	bool removable = true;
2491
2492	dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN);
2493
2494	if (!hdev)
2495		return;
2496
2497	hub = usb_hub_to_struct_hub(udev->parent);
2498
2499	/*
2500	 * If the platform firmware has provided information about a port,
2501	 * use that to determine whether it's removable.
2502	 */
2503	switch (hub->ports[udev->portnum - 1]->connect_type) {
2504	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
2505		dev_set_removable(&udev->dev, DEVICE_REMOVABLE);
2506		return;
2507	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
2508	case USB_PORT_NOT_USED:
2509		dev_set_removable(&udev->dev, DEVICE_FIXED);
2510		return;
2511	default:
2512		break;
2513	}
2514
2515	/*
2516	 * Otherwise, check whether the hub knows whether a port is removable
2517	 * or not
2518	 */
2519	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2520
2521	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2522		return;
2523
2524	if (hub_is_superspeed(hdev)) {
2525		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2526				& (1 << port))
2527			removable = false;
2528	} else {
2529		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2530			removable = false;
2531	}
2532
2533	if (removable)
2534		dev_set_removable(&udev->dev, DEVICE_REMOVABLE);
2535	else
2536		dev_set_removable(&udev->dev, DEVICE_FIXED);
2537
2538}
2539
2540/**
2541 * usb_new_device - perform initial device setup (usbcore-internal)
2542 * @udev: newly addressed device (in ADDRESS state)
2543 *
2544 * This is called with devices which have been detected but not fully
2545 * enumerated.  The device descriptor is available, but not descriptors
2546 * for any device configuration.  The caller must have locked either
2547 * the parent hub (if udev is a normal device) or else the
2548 * usb_bus_idr_lock (if udev is a root hub).  The parent's pointer to
2549 * udev has already been installed, but udev is not yet visible through
2550 * sysfs or other filesystem code.
2551 *
2552 * This call is synchronous, and may not be used in an interrupt context.
2553 *
2554 * Only the hub driver or root-hub registrar should ever call this.
2555 *
2556 * Return: Whether the device is configured properly or not. Zero if the
2557 * interface was registered with the driver core; else a negative errno
2558 * value.
2559 *
2560 */
2561int usb_new_device(struct usb_device *udev)
2562{
2563	int err;
2564
2565	if (udev->parent) {
2566		/* Initialize non-root-hub device wakeup to disabled;
2567		 * device (un)configuration controls wakeup capable
2568		 * sysfs power/wakeup controls wakeup enabled/disabled
2569		 */
2570		device_init_wakeup(&udev->dev, 0);
2571	}
2572
2573	/* Tell the runtime-PM framework the device is active */
2574	pm_runtime_set_active(&udev->dev);
2575	pm_runtime_get_noresume(&udev->dev);
2576	pm_runtime_use_autosuspend(&udev->dev);
2577	pm_runtime_enable(&udev->dev);
2578
2579	/* By default, forbid autosuspend for all devices.  It will be
2580	 * allowed for hubs during binding.
2581	 */
2582	usb_disable_autosuspend(udev);
2583
2584	err = usb_enumerate_device(udev);	/* Read descriptors */
2585	if (err < 0)
2586		goto fail;
2587	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2588			udev->devnum, udev->bus->busnum,
2589			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2590	/* export the usbdev device-node for libusb */
2591	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2592			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2593
2594	/* Tell the world! */
2595	announce_device(udev);
2596
2597	if (udev->serial)
2598		add_device_randomness(udev->serial, strlen(udev->serial));
2599	if (udev->product)
2600		add_device_randomness(udev->product, strlen(udev->product));
2601	if (udev->manufacturer)
2602		add_device_randomness(udev->manufacturer,
2603				      strlen(udev->manufacturer));
2604
2605	device_enable_async_suspend(&udev->dev);
2606
2607	/* check whether the hub or firmware marks this port as non-removable */
2608	set_usb_port_removable(udev);
2609
2610	/* Register the device.  The device driver is responsible
2611	 * for configuring the device and invoking the add-device
2612	 * notifier chain (used by usbfs and possibly others).
2613	 */
2614	err = device_add(&udev->dev);
2615	if (err) {
2616		dev_err(&udev->dev, "can't device_add, error %d\n", err);
2617		goto fail;
2618	}
2619
2620	/* Create link files between child device and usb port device. */
2621	if (udev->parent) {
2622		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2623		int port1 = udev->portnum;
2624		struct usb_port	*port_dev = hub->ports[port1 - 1];
2625
2626		err = sysfs_create_link(&udev->dev.kobj,
2627				&port_dev->dev.kobj, "port");
2628		if (err)
2629			goto fail;
2630
2631		err = sysfs_create_link(&port_dev->dev.kobj,
2632				&udev->dev.kobj, "device");
2633		if (err) {
2634			sysfs_remove_link(&udev->dev.kobj, "port");
2635			goto fail;
2636		}
2637
2638		if (!test_and_set_bit(port1, hub->child_usage_bits))
2639			pm_runtime_get_sync(&port_dev->dev);
2640
2641		typec_attach(port_dev->connector, &udev->dev);
2642	}
2643
2644	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2645	usb_mark_last_busy(udev);
2646	pm_runtime_put_sync_autosuspend(&udev->dev);
2647	return err;
2648
2649fail:
2650	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2651	pm_runtime_disable(&udev->dev);
2652	pm_runtime_set_suspended(&udev->dev);
2653	return err;
2654}
2655
2656
2657/**
2658 * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2659 * @usb_dev: USB device
2660 *
2661 * Move the USB device to a very basic state where interfaces are disabled
2662 * and the device is in fact unconfigured and unusable.
2663 *
2664 * We share a lock (that we have) with device_del(), so we need to
2665 * defer its call.
2666 *
2667 * Return: 0.
2668 */
2669int usb_deauthorize_device(struct usb_device *usb_dev)
2670{
2671	usb_lock_device(usb_dev);
2672	if (usb_dev->authorized == 0)
2673		goto out_unauthorized;
2674
2675	usb_dev->authorized = 0;
2676	usb_set_configuration(usb_dev, -1);
2677
2678out_unauthorized:
2679	usb_unlock_device(usb_dev);
2680	return 0;
2681}
2682
2683
2684int usb_authorize_device(struct usb_device *usb_dev)
2685{
2686	int result = 0, c;
2687
2688	usb_lock_device(usb_dev);
2689	if (usb_dev->authorized == 1)
2690		goto out_authorized;
2691
2692	result = usb_autoresume_device(usb_dev);
2693	if (result < 0) {
2694		dev_err(&usb_dev->dev,
2695			"can't autoresume for authorization: %d\n", result);
2696		goto error_autoresume;
2697	}
2698
 
 
 
 
 
 
 
 
 
2699	usb_dev->authorized = 1;
2700	/* Choose and set the configuration.  This registers the interfaces
2701	 * with the driver core and lets interface drivers bind to them.
2702	 */
2703	c = usb_choose_configuration(usb_dev);
2704	if (c >= 0) {
2705		result = usb_set_configuration(usb_dev, c);
2706		if (result) {
2707			dev_err(&usb_dev->dev,
2708				"can't set config #%d, error %d\n", c, result);
2709			/* This need not be fatal.  The user can try to
2710			 * set other configurations. */
2711		}
2712	}
2713	dev_info(&usb_dev->dev, "authorized to connect\n");
2714
 
2715	usb_autosuspend_device(usb_dev);
2716error_autoresume:
2717out_authorized:
2718	usb_unlock_device(usb_dev);	/* complements locktree */
2719	return result;
2720}
2721
2722/**
2723 * get_port_ssp_rate - Match the extended port status to SSP rate
2724 * @hdev: The hub device
2725 * @ext_portstatus: extended port status
2726 *
2727 * Match the extended port status speed id to the SuperSpeed Plus sublink speed
2728 * capability attributes. Base on the number of connected lanes and speed,
2729 * return the corresponding enum usb_ssp_rate.
2730 */
2731static enum usb_ssp_rate get_port_ssp_rate(struct usb_device *hdev,
2732					   u32 ext_portstatus)
2733{
2734	struct usb_ssp_cap_descriptor *ssp_cap;
2735	u32 attr;
2736	u8 speed_id;
2737	u8 ssac;
2738	u8 lanes;
2739	int i;
2740
2741	if (!hdev->bos)
2742		goto out;
2743
2744	ssp_cap = hdev->bos->ssp_cap;
2745	if (!ssp_cap)
2746		goto out;
2747
2748	speed_id = ext_portstatus & USB_EXT_PORT_STAT_RX_SPEED_ID;
2749	lanes = USB_EXT_PORT_RX_LANES(ext_portstatus) + 1;
2750
2751	ssac = le32_to_cpu(ssp_cap->bmAttributes) &
2752		USB_SSP_SUBLINK_SPEED_ATTRIBS;
2753
2754	for (i = 0; i <= ssac; i++) {
2755		u8 ssid;
2756
2757		attr = le32_to_cpu(ssp_cap->bmSublinkSpeedAttr[i]);
2758		ssid = FIELD_GET(USB_SSP_SUBLINK_SPEED_SSID, attr);
2759		if (speed_id == ssid) {
2760			u16 mantissa;
2761			u8 lse;
2762			u8 type;
2763
2764			/*
2765			 * Note: currently asymmetric lane types are only
2766			 * applicable for SSIC operate in SuperSpeed protocol
2767			 */
2768			type = FIELD_GET(USB_SSP_SUBLINK_SPEED_ST, attr);
2769			if (type == USB_SSP_SUBLINK_SPEED_ST_ASYM_RX ||
2770			    type == USB_SSP_SUBLINK_SPEED_ST_ASYM_TX)
2771				goto out;
2772
2773			if (FIELD_GET(USB_SSP_SUBLINK_SPEED_LP, attr) !=
2774			    USB_SSP_SUBLINK_SPEED_LP_SSP)
2775				goto out;
2776
2777			lse = FIELD_GET(USB_SSP_SUBLINK_SPEED_LSE, attr);
2778			mantissa = FIELD_GET(USB_SSP_SUBLINK_SPEED_LSM, attr);
2779
2780			/* Convert to Gbps */
2781			for (; lse < USB_SSP_SUBLINK_SPEED_LSE_GBPS; lse++)
2782				mantissa /= 1000;
2783
2784			if (mantissa >= 10 && lanes == 1)
2785				return USB_SSP_GEN_2x1;
2786
2787			if (mantissa >= 10 && lanes == 2)
2788				return USB_SSP_GEN_2x2;
2789
2790			if (mantissa >= 5 && lanes == 2)
2791				return USB_SSP_GEN_1x2;
2792
2793			goto out;
2794		}
2795	}
2796
2797out:
2798	return USB_SSP_GEN_UNKNOWN;
2799}
2800
 
 
 
 
 
 
 
 
 
 
 
2801#ifdef CONFIG_USB_FEW_INIT_RETRIES
2802#define PORT_RESET_TRIES	2
2803#define SET_ADDRESS_TRIES	1
2804#define GET_DESCRIPTOR_TRIES	1
2805#define GET_MAXPACKET0_TRIES	1
2806#define PORT_INIT_TRIES		4
2807
2808#else
2809#define PORT_RESET_TRIES	5
2810#define SET_ADDRESS_TRIES	2
2811#define GET_DESCRIPTOR_TRIES	2
2812#define GET_MAXPACKET0_TRIES	3
2813#define PORT_INIT_TRIES		4
2814#endif	/* CONFIG_USB_FEW_INIT_RETRIES */
2815
2816#define DETECT_DISCONNECT_TRIES 5
2817
2818#define HUB_ROOT_RESET_TIME	60	/* times are in msec */
2819#define HUB_SHORT_RESET_TIME	10
2820#define HUB_BH_RESET_TIME	50
2821#define HUB_LONG_RESET_TIME	200
2822#define HUB_RESET_TIMEOUT	800
2823
2824static bool use_new_scheme(struct usb_device *udev, int retry,
2825			   struct usb_port *port_dev)
2826{
2827	int old_scheme_first_port =
2828		(port_dev->quirks & USB_PORT_QUIRK_OLD_SCHEME) ||
2829		old_scheme_first;
2830
2831	/*
2832	 * "New scheme" enumeration causes an extra state transition to be
2833	 * exposed to an xhci host and causes USB3 devices to receive control
2834	 * commands in the default state.  This has been seen to cause
2835	 * enumeration failures, so disable this enumeration scheme for USB3
2836	 * devices.
2837	 */
2838	if (udev->speed >= USB_SPEED_SUPER)
2839		return false;
2840
2841	/*
2842	 * If use_both_schemes is set, use the first scheme (whichever
2843	 * it is) for the larger half of the retries, then use the other
2844	 * scheme.  Otherwise, use the first scheme for all the retries.
2845	 */
2846	if (use_both_schemes && retry >= (PORT_INIT_TRIES + 1) / 2)
2847		return old_scheme_first_port;	/* Second half */
2848	return !old_scheme_first_port;		/* First half or all */
2849}
2850
2851/* Is a USB 3.0 port in the Inactive or Compliance Mode state?
2852 * Port warm reset is required to recover
2853 */
2854static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
2855		u16 portstatus)
2856{
2857	u16 link_state;
2858
2859	if (!hub_is_superspeed(hub->hdev))
2860		return false;
2861
2862	if (test_bit(port1, hub->warm_reset_bits))
2863		return true;
2864
2865	link_state = portstatus & USB_PORT_STAT_LINK_STATE;
2866	return link_state == USB_SS_PORT_LS_SS_INACTIVE
2867		|| link_state == USB_SS_PORT_LS_COMP_MOD;
2868}
2869
2870static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2871			struct usb_device *udev, unsigned int delay, bool warm)
2872{
2873	int delay_time, ret;
2874	u16 portstatus;
2875	u16 portchange;
2876	u32 ext_portstatus = 0;
2877
2878	for (delay_time = 0;
2879			delay_time < HUB_RESET_TIMEOUT;
2880			delay_time += delay) {
2881		/* wait to give the device a chance to reset */
2882		msleep(delay);
2883
2884		/* read and decode port status */
2885		if (hub_is_superspeedplus(hub->hdev))
2886			ret = hub_ext_port_status(hub, port1,
2887						  HUB_EXT_PORT_STATUS,
2888						  &portstatus, &portchange,
2889						  &ext_portstatus);
2890		else
2891			ret = usb_hub_port_status(hub, port1, &portstatus,
2892					      &portchange);
2893		if (ret < 0)
2894			return ret;
2895
2896		/*
2897		 * The port state is unknown until the reset completes.
2898		 *
2899		 * On top of that, some chips may require additional time
2900		 * to re-establish a connection after the reset is complete,
2901		 * so also wait for the connection to be re-established.
2902		 */
2903		if (!(portstatus & USB_PORT_STAT_RESET) &&
2904		    (portstatus & USB_PORT_STAT_CONNECTION))
2905			break;
2906
2907		/* switch to the long delay after two short delay failures */
2908		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2909			delay = HUB_LONG_RESET_TIME;
2910
2911		dev_dbg(&hub->ports[port1 - 1]->dev,
2912				"not %sreset yet, waiting %dms\n",
2913				warm ? "warm " : "", delay);
2914	}
2915
2916	if ((portstatus & USB_PORT_STAT_RESET))
2917		return -EBUSY;
2918
2919	if (hub_port_warm_reset_required(hub, port1, portstatus))
2920		return -ENOTCONN;
2921
2922	/* Device went away? */
2923	if (!(portstatus & USB_PORT_STAT_CONNECTION))
2924		return -ENOTCONN;
2925
2926	/* Retry if connect change is set but status is still connected.
2927	 * A USB 3.0 connection may bounce if multiple warm resets were issued,
2928	 * but the device may have successfully re-connected. Ignore it.
2929	 */
2930	if (!hub_is_superspeed(hub->hdev) &&
2931	    (portchange & USB_PORT_STAT_C_CONNECTION)) {
2932		usb_clear_port_feature(hub->hdev, port1,
2933				       USB_PORT_FEAT_C_CONNECTION);
2934		return -EAGAIN;
2935	}
2936
2937	if (!(portstatus & USB_PORT_STAT_ENABLE))
2938		return -EBUSY;
2939
2940	if (!udev)
2941		return 0;
2942
2943	if (hub_is_superspeedplus(hub->hdev)) {
2944		/* extended portstatus Rx and Tx lane count are zero based */
2945		udev->rx_lanes = USB_EXT_PORT_RX_LANES(ext_portstatus) + 1;
2946		udev->tx_lanes = USB_EXT_PORT_TX_LANES(ext_portstatus) + 1;
2947		udev->ssp_rate = get_port_ssp_rate(hub->hdev, ext_portstatus);
2948	} else {
2949		udev->rx_lanes = 1;
2950		udev->tx_lanes = 1;
2951		udev->ssp_rate = USB_SSP_GEN_UNKNOWN;
2952	}
2953	if (udev->ssp_rate != USB_SSP_GEN_UNKNOWN)
 
 
2954		udev->speed = USB_SPEED_SUPER_PLUS;
2955	else if (hub_is_superspeed(hub->hdev))
2956		udev->speed = USB_SPEED_SUPER;
2957	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2958		udev->speed = USB_SPEED_HIGH;
2959	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2960		udev->speed = USB_SPEED_LOW;
2961	else
2962		udev->speed = USB_SPEED_FULL;
2963	return 0;
2964}
2965
2966/* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
2967static int hub_port_reset(struct usb_hub *hub, int port1,
2968			struct usb_device *udev, unsigned int delay, bool warm)
2969{
2970	int i, status;
2971	u16 portchange, portstatus;
2972	struct usb_port *port_dev = hub->ports[port1 - 1];
2973	int reset_recovery_time;
2974
2975	if (!hub_is_superspeed(hub->hdev)) {
2976		if (warm) {
2977			dev_err(hub->intfdev, "only USB3 hub support "
2978						"warm reset\n");
2979			return -EINVAL;
2980		}
2981		/* Block EHCI CF initialization during the port reset.
2982		 * Some companion controllers don't like it when they mix.
2983		 */
2984		down_read(&ehci_cf_port_reset_rwsem);
2985	} else if (!warm) {
2986		/*
2987		 * If the caller hasn't explicitly requested a warm reset,
2988		 * double check and see if one is needed.
2989		 */
2990		if (usb_hub_port_status(hub, port1, &portstatus,
2991					&portchange) == 0)
2992			if (hub_port_warm_reset_required(hub, port1,
2993							portstatus))
2994				warm = true;
2995	}
2996	clear_bit(port1, hub->warm_reset_bits);
2997
2998	/* Reset the port */
2999	for (i = 0; i < PORT_RESET_TRIES; i++) {
3000		status = set_port_feature(hub->hdev, port1, (warm ?
3001					USB_PORT_FEAT_BH_PORT_RESET :
3002					USB_PORT_FEAT_RESET));
3003		if (status == -ENODEV) {
3004			;	/* The hub is gone */
3005		} else if (status) {
3006			dev_err(&port_dev->dev,
3007					"cannot %sreset (err = %d)\n",
3008					warm ? "warm " : "", status);
3009		} else {
3010			status = hub_port_wait_reset(hub, port1, udev, delay,
3011								warm);
3012			if (status && status != -ENOTCONN && status != -ENODEV)
3013				dev_dbg(hub->intfdev,
3014						"port_wait_reset: err = %d\n",
3015						status);
3016		}
3017
3018		/*
3019		 * Check for disconnect or reset, and bail out after several
3020		 * reset attempts to avoid warm reset loop.
3021		 */
3022		if (status == 0 || status == -ENOTCONN || status == -ENODEV ||
3023		    (status == -EBUSY && i == PORT_RESET_TRIES - 1)) {
3024			usb_clear_port_feature(hub->hdev, port1,
3025					USB_PORT_FEAT_C_RESET);
3026
3027			if (!hub_is_superspeed(hub->hdev))
3028				goto done;
3029
3030			usb_clear_port_feature(hub->hdev, port1,
3031					USB_PORT_FEAT_C_BH_PORT_RESET);
3032			usb_clear_port_feature(hub->hdev, port1,
3033					USB_PORT_FEAT_C_PORT_LINK_STATE);
3034
3035			if (udev)
3036				usb_clear_port_feature(hub->hdev, port1,
3037					USB_PORT_FEAT_C_CONNECTION);
3038
3039			/*
3040			 * If a USB 3.0 device migrates from reset to an error
3041			 * state, re-issue the warm reset.
3042			 */
3043			if (usb_hub_port_status(hub, port1,
3044					&portstatus, &portchange) < 0)
3045				goto done;
3046
3047			if (!hub_port_warm_reset_required(hub, port1,
3048					portstatus))
3049				goto done;
3050
3051			/*
3052			 * If the port is in SS.Inactive or Compliance Mode, the
3053			 * hot or warm reset failed.  Try another warm reset.
3054			 */
3055			if (!warm) {
3056				dev_dbg(&port_dev->dev,
3057						"hot reset failed, warm reset\n");
3058				warm = true;
3059			}
3060		}
3061
3062		dev_dbg(&port_dev->dev,
3063				"not enabled, trying %sreset again...\n",
3064				warm ? "warm " : "");
3065		delay = HUB_LONG_RESET_TIME;
3066	}
3067
3068	dev_err(&port_dev->dev, "Cannot enable. Maybe the USB cable is bad?\n");
3069
3070done:
3071	if (status == 0) {
3072		if (port_dev->quirks & USB_PORT_QUIRK_FAST_ENUM)
3073			usleep_range(10000, 12000);
3074		else {
3075			/* TRSTRCY = 10 ms; plus some extra */
3076			reset_recovery_time = 10 + 40;
3077
3078			/* Hub needs extra delay after resetting its port. */
3079			if (hub->hdev->quirks & USB_QUIRK_HUB_SLOW_RESET)
3080				reset_recovery_time += 100;
3081
3082			msleep(reset_recovery_time);
3083		}
3084
3085		if (udev) {
3086			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3087
3088			update_devnum(udev, 0);
3089			/* The xHC may think the device is already reset,
3090			 * so ignore the status.
3091			 */
3092			if (hcd->driver->reset_device)
3093				hcd->driver->reset_device(hcd, udev);
3094
3095			usb_set_device_state(udev, USB_STATE_DEFAULT);
3096		}
3097	} else {
3098		if (udev)
3099			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
3100	}
3101
3102	if (!hub_is_superspeed(hub->hdev))
3103		up_read(&ehci_cf_port_reset_rwsem);
3104
3105	return status;
3106}
3107
3108/*
3109 * hub_port_stop_enumerate - stop USB enumeration or ignore port events
3110 * @hub: target hub
3111 * @port1: port num of the port
3112 * @retries: port retries number of hub_port_init()
3113 *
3114 * Return:
3115 *    true: ignore port actions/events or give up connection attempts.
3116 *    false: keep original behavior.
3117 *
3118 * This function will be based on retries to check whether the port which is
3119 * marked with early_stop attribute would stop enumeration or ignore events.
3120 *
3121 * Note:
3122 * This function didn't change anything if early_stop is not set, and it will
3123 * prevent all connection attempts when early_stop is set and the attempts of
3124 * the port are more than 1.
3125 */
3126static bool hub_port_stop_enumerate(struct usb_hub *hub, int port1, int retries)
3127{
3128	struct usb_port *port_dev = hub->ports[port1 - 1];
3129
3130	if (port_dev->early_stop) {
3131		if (port_dev->ignore_event)
3132			return true;
3133
3134		/*
3135		 * We want unsuccessful attempts to fail quickly.
3136		 * Since some devices may need one failure during
3137		 * port initialization, we allow two tries but no
3138		 * more.
3139		 */
3140		if (retries < 2)
3141			return false;
3142
3143		port_dev->ignore_event = 1;
3144	} else
3145		port_dev->ignore_event = 0;
3146
3147	return port_dev->ignore_event;
3148}
3149
3150/* Check if a port is power on */
3151int usb_port_is_power_on(struct usb_hub *hub, unsigned int portstatus)
3152{
3153	int ret = 0;
3154
3155	if (hub_is_superspeed(hub->hdev)) {
3156		if (portstatus & USB_SS_PORT_STAT_POWER)
3157			ret = 1;
3158	} else {
3159		if (portstatus & USB_PORT_STAT_POWER)
3160			ret = 1;
3161	}
3162
3163	return ret;
3164}
3165
3166static void usb_lock_port(struct usb_port *port_dev)
3167		__acquires(&port_dev->status_lock)
3168{
3169	mutex_lock(&port_dev->status_lock);
3170	__acquire(&port_dev->status_lock);
3171}
3172
3173static void usb_unlock_port(struct usb_port *port_dev)
3174		__releases(&port_dev->status_lock)
3175{
3176	mutex_unlock(&port_dev->status_lock);
3177	__release(&port_dev->status_lock);
3178}
3179
3180#ifdef	CONFIG_PM
3181
3182/* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
3183static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
3184{
3185	int ret = 0;
3186
3187	if (hub_is_superspeed(hub->hdev)) {
3188		if ((portstatus & USB_PORT_STAT_LINK_STATE)
3189				== USB_SS_PORT_LS_U3)
3190			ret = 1;
3191	} else {
3192		if (portstatus & USB_PORT_STAT_SUSPEND)
3193			ret = 1;
3194	}
3195
3196	return ret;
3197}
3198
3199/* Determine whether the device on a port is ready for a normal resume,
3200 * is ready for a reset-resume, or should be disconnected.
3201 */
3202static int check_port_resume_type(struct usb_device *udev,
3203		struct usb_hub *hub, int port1,
3204		int status, u16 portchange, u16 portstatus)
3205{
3206	struct usb_port *port_dev = hub->ports[port1 - 1];
3207	int retries = 3;
3208
3209 retry:
3210	/* Is a warm reset needed to recover the connection? */
3211	if (status == 0 && udev->reset_resume
3212		&& hub_port_warm_reset_required(hub, port1, portstatus)) {
3213		/* pass */;
3214	}
3215	/* Is the device still present? */
3216	else if (status || port_is_suspended(hub, portstatus) ||
3217			!usb_port_is_power_on(hub, portstatus)) {
3218		if (status >= 0)
3219			status = -ENODEV;
3220	} else if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
3221		if (retries--) {
3222			usleep_range(200, 300);
3223			status = usb_hub_port_status(hub, port1, &portstatus,
3224							     &portchange);
3225			goto retry;
3226		}
3227		status = -ENODEV;
3228	}
3229
3230	/* Can't do a normal resume if the port isn't enabled,
3231	 * so try a reset-resume instead.
3232	 */
3233	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
3234		if (udev->persist_enabled)
3235			udev->reset_resume = 1;
3236		else
3237			status = -ENODEV;
3238	}
3239
3240	if (status) {
3241		dev_dbg(&port_dev->dev, "status %04x.%04x after resume, %d\n",
3242				portchange, portstatus, status);
3243	} else if (udev->reset_resume) {
3244
3245		/* Late port handoff can set status-change bits */
3246		if (portchange & USB_PORT_STAT_C_CONNECTION)
3247			usb_clear_port_feature(hub->hdev, port1,
3248					USB_PORT_FEAT_C_CONNECTION);
3249		if (portchange & USB_PORT_STAT_C_ENABLE)
3250			usb_clear_port_feature(hub->hdev, port1,
3251					USB_PORT_FEAT_C_ENABLE);
3252
3253		/*
3254		 * Whatever made this reset-resume necessary may have
3255		 * turned on the port1 bit in hub->change_bits.  But after
3256		 * a successful reset-resume we want the bit to be clear;
3257		 * if it was on it would indicate that something happened
3258		 * following the reset-resume.
3259		 */
3260		clear_bit(port1, hub->change_bits);
3261	}
3262
3263	return status;
3264}
3265
3266int usb_disable_ltm(struct usb_device *udev)
3267{
3268	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3269
3270	/* Check if the roothub and device supports LTM. */
3271	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
3272			!usb_device_supports_ltm(udev))
3273		return 0;
3274
3275	/* Clear Feature LTM Enable can only be sent if the device is
3276	 * configured.
3277	 */
3278	if (!udev->actconfig)
3279		return 0;
3280
3281	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3282			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3283			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
3284			USB_CTRL_SET_TIMEOUT);
3285}
3286EXPORT_SYMBOL_GPL(usb_disable_ltm);
3287
3288void usb_enable_ltm(struct usb_device *udev)
3289{
3290	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3291
3292	/* Check if the roothub and device supports LTM. */
3293	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
3294			!usb_device_supports_ltm(udev))
3295		return;
3296
3297	/* Set Feature LTM Enable can only be sent if the device is
3298	 * configured.
3299	 */
3300	if (!udev->actconfig)
3301		return;
3302
3303	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3304			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3305			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
3306			USB_CTRL_SET_TIMEOUT);
3307}
3308EXPORT_SYMBOL_GPL(usb_enable_ltm);
3309
3310/*
3311 * usb_enable_remote_wakeup - enable remote wakeup for a device
3312 * @udev: target device
3313 *
3314 * For USB-2 devices: Set the device's remote wakeup feature.
3315 *
3316 * For USB-3 devices: Assume there's only one function on the device and
3317 * enable remote wake for the first interface.  FIXME if the interface
3318 * association descriptor shows there's more than one function.
3319 */
3320static int usb_enable_remote_wakeup(struct usb_device *udev)
3321{
3322	if (udev->speed < USB_SPEED_SUPER)
3323		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3324				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3325				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3326				USB_CTRL_SET_TIMEOUT);
3327	else
3328		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3329				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3330				USB_INTRF_FUNC_SUSPEND,
3331				USB_INTRF_FUNC_SUSPEND_RW |
3332					USB_INTRF_FUNC_SUSPEND_LP,
3333				NULL, 0, USB_CTRL_SET_TIMEOUT);
3334}
3335
3336/*
3337 * usb_disable_remote_wakeup - disable remote wakeup for a device
3338 * @udev: target device
3339 *
3340 * For USB-2 devices: Clear the device's remote wakeup feature.
3341 *
3342 * For USB-3 devices: Assume there's only one function on the device and
3343 * disable remote wake for the first interface.  FIXME if the interface
3344 * association descriptor shows there's more than one function.
3345 */
3346static int usb_disable_remote_wakeup(struct usb_device *udev)
3347{
3348	if (udev->speed < USB_SPEED_SUPER)
3349		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3350				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3351				USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3352				USB_CTRL_SET_TIMEOUT);
3353	else
3354		return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3355				USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3356				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
3357				USB_CTRL_SET_TIMEOUT);
3358}
3359
3360/* Count of wakeup-enabled devices at or below udev */
3361unsigned usb_wakeup_enabled_descendants(struct usb_device *udev)
3362{
3363	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
3364
3365	return udev->do_remote_wakeup +
3366			(hub ? hub->wakeup_enabled_descendants : 0);
3367}
3368EXPORT_SYMBOL_GPL(usb_wakeup_enabled_descendants);
3369
3370/*
3371 * usb_port_suspend - suspend a usb device's upstream port
3372 * @udev: device that's no longer in active use, not a root hub
3373 * Context: must be able to sleep; device not locked; pm locks held
3374 *
3375 * Suspends a USB device that isn't in active use, conserving power.
3376 * Devices may wake out of a suspend, if anything important happens,
3377 * using the remote wakeup mechanism.  They may also be taken out of
3378 * suspend by the host, using usb_port_resume().  It's also routine
3379 * to disconnect devices while they are suspended.
3380 *
3381 * This only affects the USB hardware for a device; its interfaces
3382 * (and, for hubs, child devices) must already have been suspended.
3383 *
3384 * Selective port suspend reduces power; most suspended devices draw
3385 * less than 500 uA.  It's also used in OTG, along with remote wakeup.
3386 * All devices below the suspended port are also suspended.
3387 *
3388 * Devices leave suspend state when the host wakes them up.  Some devices
3389 * also support "remote wakeup", where the device can activate the USB
3390 * tree above them to deliver data, such as a keypress or packet.  In
3391 * some cases, this wakes the USB host.
3392 *
3393 * Suspending OTG devices may trigger HNP, if that's been enabled
3394 * between a pair of dual-role devices.  That will change roles, such
3395 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
3396 *
3397 * Devices on USB hub ports have only one "suspend" state, corresponding
3398 * to ACPI D2, "may cause the device to lose some context".
3399 * State transitions include:
3400 *
3401 *   - suspend, resume ... when the VBUS power link stays live
3402 *   - suspend, disconnect ... VBUS lost
3403 *
3404 * Once VBUS drop breaks the circuit, the port it's using has to go through
3405 * normal re-enumeration procedures, starting with enabling VBUS power.
3406 * Other than re-initializing the hub (plug/unplug, except for root hubs),
3407 * Linux (2.6) currently has NO mechanisms to initiate that:  no hub_wq
3408 * timer, no SRP, no requests through sysfs.
3409 *
3410 * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
3411 * suspended until their bus goes into global suspend (i.e., the root
3412 * hub is suspended).  Nevertheless, we change @udev->state to
3413 * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
3414 * upstream port setting is stored in @udev->port_is_suspended.
3415 *
3416 * Returns 0 on success, else negative errno.
3417 */
3418int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
3419{
3420	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3421	struct usb_port *port_dev = hub->ports[udev->portnum - 1];
3422	int		port1 = udev->portnum;
3423	int		status;
3424	bool		really_suspend = true;
3425
3426	usb_lock_port(port_dev);
3427
3428	/* enable remote wakeup when appropriate; this lets the device
3429	 * wake up the upstream hub (including maybe the root hub).
3430	 *
3431	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
3432	 * we don't explicitly enable it here.
3433	 */
3434	if (udev->do_remote_wakeup) {
3435		status = usb_enable_remote_wakeup(udev);
3436		if (status) {
3437			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
3438					status);
3439			/* bail if autosuspend is requested */
3440			if (PMSG_IS_AUTO(msg))
3441				goto err_wakeup;
3442		}
3443	}
3444
3445	/* disable USB2 hardware LPM */
3446	usb_disable_usb2_hardware_lpm(udev);
3447
3448	if (usb_disable_ltm(udev)) {
3449		dev_err(&udev->dev, "Failed to disable LTM before suspend\n");
3450		status = -ENOMEM;
3451		if (PMSG_IS_AUTO(msg))
3452			goto err_ltm;
3453	}
3454
3455	/* see 7.1.7.6 */
3456	if (hub_is_superspeed(hub->hdev))
3457		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
3458
3459	/*
3460	 * For system suspend, we do not need to enable the suspend feature
3461	 * on individual USB-2 ports.  The devices will automatically go
3462	 * into suspend a few ms after the root hub stops sending packets.
3463	 * The USB 2.0 spec calls this "global suspend".
3464	 *
3465	 * However, many USB hubs have a bug: They don't relay wakeup requests
3466	 * from a downstream port if the port's suspend feature isn't on.
3467	 * Therefore we will turn on the suspend feature if udev or any of its
3468	 * descendants is enabled for remote wakeup.
3469	 */
3470	else if (PMSG_IS_AUTO(msg) || usb_wakeup_enabled_descendants(udev) > 0)
3471		status = set_port_feature(hub->hdev, port1,
3472				USB_PORT_FEAT_SUSPEND);
3473	else {
3474		really_suspend = false;
3475		status = 0;
3476	}
3477	if (status) {
3478		/* Check if the port has been suspended for the timeout case
3479		 * to prevent the suspended port from incorrect handling.
3480		 */
3481		if (status == -ETIMEDOUT) {
3482			int ret;
3483			u16 portstatus, portchange;
3484
3485			portstatus = portchange = 0;
3486			ret = usb_hub_port_status(hub, port1, &portstatus,
3487					&portchange);
3488
3489			dev_dbg(&port_dev->dev,
3490				"suspend timeout, status %04x\n", portstatus);
3491
3492			if (ret == 0 && port_is_suspended(hub, portstatus)) {
3493				status = 0;
3494				goto suspend_done;
3495			}
3496		}
3497
3498		dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
3499
3500		/* Try to enable USB3 LTM again */
3501		usb_enable_ltm(udev);
3502 err_ltm:
3503		/* Try to enable USB2 hardware LPM again */
3504		usb_enable_usb2_hardware_lpm(udev);
3505
3506		if (udev->do_remote_wakeup)
3507			(void) usb_disable_remote_wakeup(udev);
3508 err_wakeup:
3509
3510		/* System sleep transitions should never fail */
3511		if (!PMSG_IS_AUTO(msg))
3512			status = 0;
3513	} else {
3514 suspend_done:
3515		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3516				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
3517				udev->do_remote_wakeup);
3518		if (really_suspend) {
3519			udev->port_is_suspended = 1;
3520
3521			/* device has up to 10 msec to fully suspend */
3522			msleep(10);
3523		}
3524		usb_set_device_state(udev, USB_STATE_SUSPENDED);
3525	}
3526
3527	if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
3528			&& test_and_clear_bit(port1, hub->child_usage_bits))
3529		pm_runtime_put_sync(&port_dev->dev);
3530
3531	usb_mark_last_busy(hub->hdev);
3532
3533	usb_unlock_port(port_dev);
3534	return status;
3535}
3536
3537/*
3538 * If the USB "suspend" state is in use (rather than "global suspend"),
3539 * many devices will be individually taken out of suspend state using
3540 * special "resume" signaling.  This routine kicks in shortly after
3541 * hardware resume signaling is finished, either because of selective
3542 * resume (by host) or remote wakeup (by device) ... now see what changed
3543 * in the tree that's rooted at this device.
3544 *
3545 * If @udev->reset_resume is set then the device is reset before the
3546 * status check is done.
3547 */
3548static int finish_port_resume(struct usb_device *udev)
3549{
3550	int	status = 0;
3551	u16	devstatus = 0;
3552
3553	/* caller owns the udev device lock */
3554	dev_dbg(&udev->dev, "%s\n",
3555		udev->reset_resume ? "finish reset-resume" : "finish resume");
3556
3557	/* usb ch9 identifies four variants of SUSPENDED, based on what
3558	 * state the device resumes to.  Linux currently won't see the
3559	 * first two on the host side; they'd be inside hub_port_init()
3560	 * during many timeouts, but hub_wq can't suspend until later.
3561	 */
3562	usb_set_device_state(udev, udev->actconfig
3563			? USB_STATE_CONFIGURED
3564			: USB_STATE_ADDRESS);
3565
3566	/* 10.5.4.5 says not to reset a suspended port if the attached
3567	 * device is enabled for remote wakeup.  Hence the reset
3568	 * operation is carried out here, after the port has been
3569	 * resumed.
3570	 */
3571	if (udev->reset_resume) {
3572		/*
3573		 * If the device morphs or switches modes when it is reset,
3574		 * we don't want to perform a reset-resume.  We'll fail the
3575		 * resume, which will cause a logical disconnect, and then
3576		 * the device will be rediscovered.
3577		 */
3578 retry_reset_resume:
3579		if (udev->quirks & USB_QUIRK_RESET)
3580			status = -ENODEV;
3581		else
3582			status = usb_reset_and_verify_device(udev);
3583	}
3584
3585	/* 10.5.4.5 says be sure devices in the tree are still there.
3586	 * For now let's assume the device didn't go crazy on resume,
3587	 * and device drivers will know about any resume quirks.
3588	 */
3589	if (status == 0) {
3590		devstatus = 0;
3591		status = usb_get_std_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3592
3593		/* If a normal resume failed, try doing a reset-resume */
3594		if (status && !udev->reset_resume && udev->persist_enabled) {
3595			dev_dbg(&udev->dev, "retry with reset-resume\n");
3596			udev->reset_resume = 1;
3597			goto retry_reset_resume;
3598		}
3599	}
3600
3601	if (status) {
3602		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3603				status);
3604	/*
3605	 * There are a few quirky devices which violate the standard
3606	 * by claiming to have remote wakeup enabled after a reset,
3607	 * which crash if the feature is cleared, hence check for
3608	 * udev->reset_resume
3609	 */
3610	} else if (udev->actconfig && !udev->reset_resume) {
3611		if (udev->speed < USB_SPEED_SUPER) {
3612			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3613				status = usb_disable_remote_wakeup(udev);
3614		} else {
3615			status = usb_get_std_status(udev, USB_RECIP_INTERFACE, 0,
3616					&devstatus);
3617			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3618					| USB_INTRF_STAT_FUNC_RW))
3619				status = usb_disable_remote_wakeup(udev);
3620		}
3621
3622		if (status)
3623			dev_dbg(&udev->dev,
3624				"disable remote wakeup, status %d\n",
3625				status);
3626		status = 0;
3627	}
3628	return status;
3629}
3630
3631/*
3632 * There are some SS USB devices which take longer time for link training.
3633 * XHCI specs 4.19.4 says that when Link training is successful, port
3634 * sets CCS bit to 1. So if SW reads port status before successful link
3635 * training, then it will not find device to be present.
3636 * USB Analyzer log with such buggy devices show that in some cases
3637 * device switch on the RX termination after long delay of host enabling
3638 * the VBUS. In few other cases it has been seen that device fails to
3639 * negotiate link training in first attempt. It has been
3640 * reported till now that few devices take as long as 2000 ms to train
3641 * the link after host enabling its VBUS and termination. Following
3642 * routine implements a 2000 ms timeout for link training. If in a case
3643 * link trains before timeout, loop will exit earlier.
3644 *
3645 * There are also some 2.0 hard drive based devices and 3.0 thumb
3646 * drives that, when plugged into a 2.0 only port, take a long
3647 * time to set CCS after VBUS enable.
3648 *
3649 * FIXME: If a device was connected before suspend, but was removed
3650 * while system was asleep, then the loop in the following routine will
3651 * only exit at timeout.
3652 *
3653 * This routine should only be called when persist is enabled.
3654 */
3655static int wait_for_connected(struct usb_device *udev,
3656		struct usb_hub *hub, int port1,
3657		u16 *portchange, u16 *portstatus)
3658{
3659	int status = 0, delay_ms = 0;
3660
3661	while (delay_ms < 2000) {
3662		if (status || *portstatus & USB_PORT_STAT_CONNECTION)
3663			break;
3664		if (!usb_port_is_power_on(hub, *portstatus)) {
3665			status = -ENODEV;
3666			break;
3667		}
3668		msleep(20);
3669		delay_ms += 20;
3670		status = usb_hub_port_status(hub, port1, portstatus, portchange);
3671	}
3672	dev_dbg(&udev->dev, "Waited %dms for CONNECT\n", delay_ms);
3673	return status;
3674}
3675
3676/*
3677 * usb_port_resume - re-activate a suspended usb device's upstream port
3678 * @udev: device to re-activate, not a root hub
3679 * Context: must be able to sleep; device not locked; pm locks held
3680 *
3681 * This will re-activate the suspended device, increasing power usage
3682 * while letting drivers communicate again with its endpoints.
3683 * USB resume explicitly guarantees that the power session between
3684 * the host and the device is the same as it was when the device
3685 * suspended.
3686 *
3687 * If @udev->reset_resume is set then this routine won't check that the
3688 * port is still enabled.  Furthermore, finish_port_resume() above will
3689 * reset @udev.  The end result is that a broken power session can be
3690 * recovered and @udev will appear to persist across a loss of VBUS power.
3691 *
3692 * For example, if a host controller doesn't maintain VBUS suspend current
3693 * during a system sleep or is reset when the system wakes up, all the USB
3694 * power sessions below it will be broken.  This is especially troublesome
3695 * for mass-storage devices containing mounted filesystems, since the
3696 * device will appear to have disconnected and all the memory mappings
3697 * to it will be lost.  Using the USB_PERSIST facility, the device can be
3698 * made to appear as if it had not disconnected.
3699 *
3700 * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3701 * every effort to insure that the same device is present after the
3702 * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3703 * quite possible for a device to remain unaltered but its media to be
3704 * changed.  If the user replaces a flash memory card while the system is
3705 * asleep, he will have only himself to blame when the filesystem on the
3706 * new card is corrupted and the system crashes.
3707 *
3708 * Returns 0 on success, else negative errno.
3709 */
3710int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3711{
3712	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3713	struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3714	int		port1 = udev->portnum;
3715	int		status;
3716	u16		portchange, portstatus;
3717
3718	if (!test_and_set_bit(port1, hub->child_usage_bits)) {
3719		status = pm_runtime_resume_and_get(&port_dev->dev);
3720		if (status < 0) {
3721			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3722					status);
3723			return status;
3724		}
3725	}
3726
3727	usb_lock_port(port_dev);
3728
3729	/* Skip the initial Clear-Suspend step for a remote wakeup */
3730	status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3731	if (status == 0 && !port_is_suspended(hub, portstatus)) {
3732		if (portchange & USB_PORT_STAT_C_SUSPEND)
3733			pm_wakeup_event(&udev->dev, 0);
3734		goto SuspendCleared;
3735	}
3736
3737	/* see 7.1.7.7; affects power usage, but not budgeting */
3738	if (hub_is_superspeed(hub->hdev))
3739		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3740	else
3741		status = usb_clear_port_feature(hub->hdev,
3742				port1, USB_PORT_FEAT_SUSPEND);
3743	if (status) {
3744		dev_dbg(&port_dev->dev, "can't resume, status %d\n", status);
3745	} else {
3746		/* drive resume for USB_RESUME_TIMEOUT msec */
3747		dev_dbg(&udev->dev, "usb %sresume\n",
3748				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
3749		msleep(USB_RESUME_TIMEOUT);
3750
3751		/* Virtual root hubs can trigger on GET_PORT_STATUS to
3752		 * stop resume signaling.  Then finish the resume
3753		 * sequence.
3754		 */
3755		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3756	}
3757
3758 SuspendCleared:
3759	if (status == 0) {
3760		udev->port_is_suspended = 0;
3761		if (hub_is_superspeed(hub->hdev)) {
3762			if (portchange & USB_PORT_STAT_C_LINK_STATE)
3763				usb_clear_port_feature(hub->hdev, port1,
3764					USB_PORT_FEAT_C_PORT_LINK_STATE);
3765		} else {
3766			if (portchange & USB_PORT_STAT_C_SUSPEND)
3767				usb_clear_port_feature(hub->hdev, port1,
3768						USB_PORT_FEAT_C_SUSPEND);
3769		}
3770
3771		/* TRSMRCY = 10 msec */
3772		msleep(10);
3773	}
3774
3775	if (udev->persist_enabled)
3776		status = wait_for_connected(udev, hub, port1, &portchange,
3777				&portstatus);
3778
3779	status = check_port_resume_type(udev,
3780			hub, port1, status, portchange, portstatus);
3781	if (status == 0)
3782		status = finish_port_resume(udev);
3783	if (status < 0) {
3784		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3785		hub_port_logical_disconnect(hub, port1);
3786	} else  {
3787		/* Try to enable USB2 hardware LPM */
3788		usb_enable_usb2_hardware_lpm(udev);
3789
3790		/* Try to enable USB3 LTM */
3791		usb_enable_ltm(udev);
3792	}
3793
3794	usb_unlock_port(port_dev);
3795
3796	return status;
3797}
3798
3799int usb_remote_wakeup(struct usb_device *udev)
3800{
3801	int	status = 0;
3802
3803	usb_lock_device(udev);
3804	if (udev->state == USB_STATE_SUSPENDED) {
3805		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3806		status = usb_autoresume_device(udev);
3807		if (status == 0) {
3808			/* Let the drivers do their thing, then... */
3809			usb_autosuspend_device(udev);
3810		}
3811	}
3812	usb_unlock_device(udev);
3813	return status;
3814}
3815
3816/* Returns 1 if there was a remote wakeup and a connect status change. */
3817static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3818		u16 portstatus, u16 portchange)
3819		__must_hold(&port_dev->status_lock)
3820{
3821	struct usb_port *port_dev = hub->ports[port - 1];
3822	struct usb_device *hdev;
3823	struct usb_device *udev;
3824	int connect_change = 0;
3825	u16 link_state;
3826	int ret;
3827
3828	hdev = hub->hdev;
3829	udev = port_dev->child;
3830	if (!hub_is_superspeed(hdev)) {
3831		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
3832			return 0;
3833		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
3834	} else {
3835		link_state = portstatus & USB_PORT_STAT_LINK_STATE;
3836		if (!udev || udev->state != USB_STATE_SUSPENDED ||
3837				(link_state != USB_SS_PORT_LS_U0 &&
3838				 link_state != USB_SS_PORT_LS_U1 &&
3839				 link_state != USB_SS_PORT_LS_U2))
3840			return 0;
3841	}
3842
3843	if (udev) {
3844		/* TRSMRCY = 10 msec */
3845		msleep(10);
3846
3847		usb_unlock_port(port_dev);
3848		ret = usb_remote_wakeup(udev);
3849		usb_lock_port(port_dev);
3850		if (ret < 0)
3851			connect_change = 1;
3852	} else {
3853		ret = -ENODEV;
3854		hub_port_disable(hub, port, 1);
3855	}
3856	dev_dbg(&port_dev->dev, "resume, status %d\n", ret);
3857	return connect_change;
3858}
3859
3860static int check_ports_changed(struct usb_hub *hub)
3861{
3862	int port1;
3863
3864	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3865		u16 portstatus, portchange;
3866		int status;
3867
3868		status = usb_hub_port_status(hub, port1, &portstatus, &portchange);
3869		if (!status && portchange)
3870			return 1;
3871	}
3872	return 0;
3873}
3874
3875static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3876{
3877	struct usb_hub		*hub = usb_get_intfdata(intf);
3878	struct usb_device	*hdev = hub->hdev;
3879	unsigned		port1;
3880
3881	/*
3882	 * Warn if children aren't already suspended.
3883	 * Also, add up the number of wakeup-enabled descendants.
3884	 */
3885	hub->wakeup_enabled_descendants = 0;
3886	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3887		struct usb_port *port_dev = hub->ports[port1 - 1];
3888		struct usb_device *udev = port_dev->child;
3889
3890		if (udev && udev->can_submit) {
3891			dev_warn(&port_dev->dev, "device %s not suspended yet\n",
3892					dev_name(&udev->dev));
3893			if (PMSG_IS_AUTO(msg))
3894				return -EBUSY;
3895		}
3896		if (udev)
3897			hub->wakeup_enabled_descendants +=
3898					usb_wakeup_enabled_descendants(udev);
3899	}
3900
3901	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3902		/* check if there are changes pending on hub ports */
3903		if (check_ports_changed(hub)) {
3904			if (PMSG_IS_AUTO(msg))
3905				return -EBUSY;
3906			pm_wakeup_event(&hdev->dev, 2000);
3907		}
3908	}
3909
3910	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3911		/* Enable hub to send remote wakeup for all ports. */
3912		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3913			set_port_feature(hdev,
3914					 port1 |
3915					 USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3916					 USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3917					 USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3918					 USB_PORT_FEAT_REMOTE_WAKE_MASK);
3919		}
3920	}
3921
3922	dev_dbg(&intf->dev, "%s\n", __func__);
3923
3924	/* stop hub_wq and related activity */
3925	hub_quiesce(hub, HUB_SUSPEND);
3926	return 0;
3927}
3928
3929/* Report wakeup requests from the ports of a resuming root hub */
3930static void report_wakeup_requests(struct usb_hub *hub)
3931{
3932	struct usb_device	*hdev = hub->hdev;
3933	struct usb_device	*udev;
3934	struct usb_hcd		*hcd;
3935	unsigned long		resuming_ports;
3936	int			i;
3937
3938	if (hdev->parent)
3939		return;		/* Not a root hub */
3940
3941	hcd = bus_to_hcd(hdev->bus);
3942	if (hcd->driver->get_resuming_ports) {
3943
3944		/*
3945		 * The get_resuming_ports() method returns a bitmap (origin 0)
3946		 * of ports which have started wakeup signaling but have not
3947		 * yet finished resuming.  During system resume we will
3948		 * resume all the enabled ports, regardless of any wakeup
3949		 * signals, which means the wakeup requests would be lost.
3950		 * To prevent this, report them to the PM core here.
3951		 */
3952		resuming_ports = hcd->driver->get_resuming_ports(hcd);
3953		for (i = 0; i < hdev->maxchild; ++i) {
3954			if (test_bit(i, &resuming_ports)) {
3955				udev = hub->ports[i]->child;
3956				if (udev)
3957					pm_wakeup_event(&udev->dev, 0);
3958			}
3959		}
3960	}
3961}
3962
3963static int hub_resume(struct usb_interface *intf)
3964{
3965	struct usb_hub *hub = usb_get_intfdata(intf);
3966
3967	dev_dbg(&intf->dev, "%s\n", __func__);
3968	hub_activate(hub, HUB_RESUME);
3969
3970	/*
3971	 * This should be called only for system resume, not runtime resume.
3972	 * We can't tell the difference here, so some wakeup requests will be
3973	 * reported at the wrong time or more than once.  This shouldn't
3974	 * matter much, so long as they do get reported.
3975	 */
3976	report_wakeup_requests(hub);
3977	return 0;
3978}
3979
3980static int hub_reset_resume(struct usb_interface *intf)
3981{
3982	struct usb_hub *hub = usb_get_intfdata(intf);
3983
3984	dev_dbg(&intf->dev, "%s\n", __func__);
3985	hub_activate(hub, HUB_RESET_RESUME);
3986	return 0;
3987}
3988
3989/**
3990 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3991 * @rhdev: struct usb_device for the root hub
3992 *
3993 * The USB host controller driver calls this function when its root hub
3994 * is resumed and Vbus power has been interrupted or the controller
3995 * has been reset.  The routine marks @rhdev as having lost power.
3996 * When the hub driver is resumed it will take notice and carry out
3997 * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3998 * the others will be disconnected.
3999 */
4000void usb_root_hub_lost_power(struct usb_device *rhdev)
4001{
4002	dev_notice(&rhdev->dev, "root hub lost power or was reset\n");
4003	rhdev->reset_resume = 1;
4004}
4005EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
4006
4007static const char * const usb3_lpm_names[]  = {
4008	"U0",
4009	"U1",
4010	"U2",
4011	"U3",
4012};
4013
4014/*
4015 * Send a Set SEL control transfer to the device, prior to enabling
4016 * device-initiated U1 or U2.  This lets the device know the exit latencies from
4017 * the time the device initiates a U1 or U2 exit, to the time it will receive a
4018 * packet from the host.
4019 *
4020 * This function will fail if the SEL or PEL values for udev are greater than
4021 * the maximum allowed values for the link state to be enabled.
4022 */
4023static int usb_req_set_sel(struct usb_device *udev)
4024{
4025	struct usb_set_sel_req *sel_values;
4026	unsigned long long u1_sel;
4027	unsigned long long u1_pel;
4028	unsigned long long u2_sel;
4029	unsigned long long u2_pel;
4030	int ret;
4031
4032	if (!udev->parent || udev->speed < USB_SPEED_SUPER || !udev->lpm_capable)
4033		return 0;
4034
4035	/* Convert SEL and PEL stored in ns to us */
4036	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
4037	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
4038	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
4039	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
4040
4041	/*
4042	 * Make sure that the calculated SEL and PEL values for the link
4043	 * state we're enabling aren't bigger than the max SEL/PEL
4044	 * value that will fit in the SET SEL control transfer.
4045	 * Otherwise the device would get an incorrect idea of the exit
4046	 * latency for the link state, and could start a device-initiated
4047	 * U1/U2 when the exit latencies are too high.
4048	 */
4049	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
4050	    u1_pel > USB3_LPM_MAX_U1_SEL_PEL ||
4051	    u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
4052	    u2_pel > USB3_LPM_MAX_U2_SEL_PEL) {
4053		dev_dbg(&udev->dev, "Device-initiated U1/U2 disabled due to long SEL or PEL\n");
4054		return -EINVAL;
4055	}
4056
4057	/*
4058	 * usb_enable_lpm() can be called as part of a failed device reset,
4059	 * which may be initiated by an error path of a mass storage driver.
4060	 * Therefore, use GFP_NOIO.
4061	 */
4062	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
4063	if (!sel_values)
4064		return -ENOMEM;
4065
4066	sel_values->u1_sel = u1_sel;
4067	sel_values->u1_pel = u1_pel;
4068	sel_values->u2_sel = cpu_to_le16(u2_sel);
4069	sel_values->u2_pel = cpu_to_le16(u2_pel);
4070
4071	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4072			USB_REQ_SET_SEL,
4073			USB_RECIP_DEVICE,
4074			0, 0,
4075			sel_values, sizeof *(sel_values),
4076			USB_CTRL_SET_TIMEOUT);
4077	kfree(sel_values);
4078
4079	if (ret > 0)
4080		udev->lpm_devinit_allow = 1;
4081
4082	return ret;
4083}
4084
4085/*
4086 * Enable or disable device-initiated U1 or U2 transitions.
4087 */
4088static int usb_set_device_initiated_lpm(struct usb_device *udev,
4089		enum usb3_link_state state, bool enable)
4090{
4091	int ret;
4092	int feature;
4093
4094	switch (state) {
4095	case USB3_LPM_U1:
4096		feature = USB_DEVICE_U1_ENABLE;
4097		break;
4098	case USB3_LPM_U2:
4099		feature = USB_DEVICE_U2_ENABLE;
4100		break;
4101	default:
4102		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
4103				__func__, enable ? "enable" : "disable");
4104		return -EINVAL;
4105	}
4106
4107	if (udev->state != USB_STATE_CONFIGURED) {
4108		dev_dbg(&udev->dev, "%s: Can't %s %s state "
4109				"for unconfigured device.\n",
4110				__func__, enable ? "enable" : "disable",
4111				usb3_lpm_names[state]);
4112		return 0;
4113	}
4114
4115	if (enable) {
4116		/*
4117		 * Now send the control transfer to enable device-initiated LPM
4118		 * for either U1 or U2.
4119		 */
4120		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4121				USB_REQ_SET_FEATURE,
4122				USB_RECIP_DEVICE,
4123				feature,
4124				0, NULL, 0,
4125				USB_CTRL_SET_TIMEOUT);
4126	} else {
4127		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
4128				USB_REQ_CLEAR_FEATURE,
4129				USB_RECIP_DEVICE,
4130				feature,
4131				0, NULL, 0,
4132				USB_CTRL_SET_TIMEOUT);
4133	}
4134	if (ret < 0) {
4135		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
4136				enable ? "Enable" : "Disable",
4137				usb3_lpm_names[state]);
4138		return -EBUSY;
4139	}
4140	return 0;
4141}
4142
4143static int usb_set_lpm_timeout(struct usb_device *udev,
4144		enum usb3_link_state state, int timeout)
4145{
4146	int ret;
4147	int feature;
4148
4149	switch (state) {
4150	case USB3_LPM_U1:
4151		feature = USB_PORT_FEAT_U1_TIMEOUT;
4152		break;
4153	case USB3_LPM_U2:
4154		feature = USB_PORT_FEAT_U2_TIMEOUT;
4155		break;
4156	default:
4157		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
4158				__func__);
4159		return -EINVAL;
4160	}
4161
4162	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
4163			timeout != USB3_LPM_DEVICE_INITIATED) {
4164		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
4165				"which is a reserved value.\n",
4166				usb3_lpm_names[state], timeout);
4167		return -EINVAL;
4168	}
4169
4170	ret = set_port_feature(udev->parent,
4171			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
4172			feature);
4173	if (ret < 0) {
4174		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
4175				"error code %i\n", usb3_lpm_names[state],
4176				timeout, ret);
4177		return -EBUSY;
4178	}
4179	if (state == USB3_LPM_U1)
4180		udev->u1_params.timeout = timeout;
4181	else
4182		udev->u2_params.timeout = timeout;
4183	return 0;
4184}
4185
4186/*
4187 * Don't allow device intiated U1/U2 if the system exit latency + one bus
4188 * interval is greater than the minimum service interval of any active
4189 * periodic endpoint. See USB 3.2 section 9.4.9
4190 */
4191static bool usb_device_may_initiate_lpm(struct usb_device *udev,
4192					enum usb3_link_state state)
4193{
4194	unsigned int sel;		/* us */
4195	int i, j;
4196
4197	if (!udev->lpm_devinit_allow)
4198		return false;
4199
4200	if (state == USB3_LPM_U1)
4201		sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
4202	else if (state == USB3_LPM_U2)
4203		sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
4204	else
4205		return false;
4206
4207	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
4208		struct usb_interface *intf;
4209		struct usb_endpoint_descriptor *desc;
4210		unsigned int interval;
4211
4212		intf = udev->actconfig->interface[i];
4213		if (!intf)
4214			continue;
4215
4216		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++) {
4217			desc = &intf->cur_altsetting->endpoint[j].desc;
4218
4219			if (usb_endpoint_xfer_int(desc) ||
4220			    usb_endpoint_xfer_isoc(desc)) {
4221				interval = (1 << (desc->bInterval - 1)) * 125;
4222				if (sel + 125 > interval)
4223					return false;
4224			}
4225		}
4226	}
4227	return true;
4228}
4229
4230/*
4231 * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
4232 * U1/U2 entry.
4233 *
4234 * We will attempt to enable U1 or U2, but there are no guarantees that the
4235 * control transfers to set the hub timeout or enable device-initiated U1/U2
4236 * will be successful.
4237 *
4238 * If the control transfer to enable device-initiated U1/U2 entry fails, then
4239 * hub-initiated U1/U2 will be disabled.
4240 *
4241 * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
4242 * driver know about it.  If that call fails, it should be harmless, and just
4243 * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
4244 */
4245static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
4246		enum usb3_link_state state)
4247{
4248	int timeout;
4249	__u8 u1_mel;
4250	__le16 u2_mel;
4251
4252	/* Skip if the device BOS descriptor couldn't be read */
4253	if (!udev->bos)
4254		return;
4255
4256	u1_mel = udev->bos->ss_cap->bU1devExitLat;
4257	u2_mel = udev->bos->ss_cap->bU2DevExitLat;
4258
4259	/* If the device says it doesn't have *any* exit latency to come out of
4260	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
4261	 * state.
4262	 */
4263	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
4264			(state == USB3_LPM_U2 && u2_mel == 0))
4265		return;
4266
4267	/* We allow the host controller to set the U1/U2 timeout internally
4268	 * first, so that it can change its schedule to account for the
4269	 * additional latency to send data to a device in a lower power
4270	 * link state.
4271	 */
4272	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
4273
4274	/* xHCI host controller doesn't want to enable this LPM state. */
4275	if (timeout == 0)
4276		return;
4277
4278	if (timeout < 0) {
4279		dev_warn(&udev->dev, "Could not enable %s link state, "
4280				"xHCI error %i.\n", usb3_lpm_names[state],
4281				timeout);
4282		return;
4283	}
4284
4285	if (usb_set_lpm_timeout(udev, state, timeout)) {
4286		/* If we can't set the parent hub U1/U2 timeout,
4287		 * device-initiated LPM won't be allowed either, so let the xHCI
4288		 * host know that this link state won't be enabled.
4289		 */
4290		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
4291		return;
4292	}
4293
4294	/* Only a configured device will accept the Set Feature
4295	 * U1/U2_ENABLE
4296	 */
4297	if (udev->actconfig &&
4298	    usb_device_may_initiate_lpm(udev, state)) {
4299		if (usb_set_device_initiated_lpm(udev, state, true)) {
4300			/*
4301			 * Request to enable device initiated U1/U2 failed,
4302			 * better to turn off lpm in this case.
4303			 */
4304			usb_set_lpm_timeout(udev, state, 0);
4305			hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
4306			return;
4307		}
4308	}
4309
4310	if (state == USB3_LPM_U1)
4311		udev->usb3_lpm_u1_enabled = 1;
4312	else if (state == USB3_LPM_U2)
4313		udev->usb3_lpm_u2_enabled = 1;
4314}
4315/*
4316 * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
4317 * U1/U2 entry.
4318 *
4319 * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
4320 * If zero is returned, the parent will not allow the link to go into U1/U2.
4321 *
4322 * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
4323 * it won't have an effect on the bus link state because the parent hub will
4324 * still disallow device-initiated U1/U2 entry.
4325 *
4326 * If zero is returned, the xHCI host controller may still think U1/U2 entry is
4327 * possible.  The result will be slightly more bus bandwidth will be taken up
4328 * (to account for U1/U2 exit latency), but it should be harmless.
4329 */
4330static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
4331		enum usb3_link_state state)
4332{
4333	switch (state) {
4334	case USB3_LPM_U1:
4335	case USB3_LPM_U2:
4336		break;
4337	default:
4338		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
4339				__func__);
4340		return -EINVAL;
4341	}
4342
4343	if (usb_set_lpm_timeout(udev, state, 0))
4344		return -EBUSY;
4345
4346	usb_set_device_initiated_lpm(udev, state, false);
4347
4348	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
4349		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
4350				"bus schedule bandwidth may be impacted.\n",
4351				usb3_lpm_names[state]);
4352
4353	/* As soon as usb_set_lpm_timeout(0) return 0, hub initiated LPM
4354	 * is disabled. Hub will disallows link to enter U1/U2 as well,
4355	 * even device is initiating LPM. Hence LPM is disabled if hub LPM
4356	 * timeout set to 0, no matter device-initiated LPM is disabled or
4357	 * not.
4358	 */
4359	if (state == USB3_LPM_U1)
4360		udev->usb3_lpm_u1_enabled = 0;
4361	else if (state == USB3_LPM_U2)
4362		udev->usb3_lpm_u2_enabled = 0;
4363
4364	return 0;
4365}
4366
4367/*
4368 * Disable hub-initiated and device-initiated U1 and U2 entry.
4369 * Caller must own the bandwidth_mutex.
4370 *
4371 * This will call usb_enable_lpm() on failure, which will decrement
4372 * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
4373 */
4374int usb_disable_lpm(struct usb_device *udev)
4375{
4376	struct usb_hcd *hcd;
4377
4378	if (!udev || !udev->parent ||
4379			udev->speed < USB_SPEED_SUPER ||
4380			!udev->lpm_capable ||
4381			udev->state < USB_STATE_CONFIGURED)
4382		return 0;
4383
4384	hcd = bus_to_hcd(udev->bus);
4385	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
4386		return 0;
4387
4388	udev->lpm_disable_count++;
4389	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
4390		return 0;
4391
4392	/* If LPM is enabled, attempt to disable it. */
4393	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
4394		goto enable_lpm;
4395	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
4396		goto enable_lpm;
4397
4398	return 0;
4399
4400enable_lpm:
4401	usb_enable_lpm(udev);
4402	return -EBUSY;
4403}
4404EXPORT_SYMBOL_GPL(usb_disable_lpm);
4405
4406/* Grab the bandwidth_mutex before calling usb_disable_lpm() */
4407int usb_unlocked_disable_lpm(struct usb_device *udev)
4408{
4409	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4410	int ret;
4411
4412	if (!hcd)
4413		return -EINVAL;
4414
4415	mutex_lock(hcd->bandwidth_mutex);
4416	ret = usb_disable_lpm(udev);
4417	mutex_unlock(hcd->bandwidth_mutex);
4418
4419	return ret;
4420}
4421EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4422
4423/*
4424 * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
4425 * xHCI host policy may prevent U1 or U2 from being enabled.
4426 *
4427 * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
4428 * until the lpm_disable_count drops to zero.  Caller must own the
4429 * bandwidth_mutex.
4430 */
4431void usb_enable_lpm(struct usb_device *udev)
4432{
4433	struct usb_hcd *hcd;
4434	struct usb_hub *hub;
4435	struct usb_port *port_dev;
4436
4437	if (!udev || !udev->parent ||
4438			udev->speed < USB_SPEED_SUPER ||
4439			!udev->lpm_capable ||
4440			udev->state < USB_STATE_CONFIGURED)
4441		return;
4442
4443	udev->lpm_disable_count--;
4444	hcd = bus_to_hcd(udev->bus);
4445	/* Double check that we can both enable and disable LPM.
4446	 * Device must be configured to accept set feature U1/U2 timeout.
4447	 */
4448	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
4449			!hcd->driver->disable_usb3_lpm_timeout)
4450		return;
4451
4452	if (udev->lpm_disable_count > 0)
4453		return;
4454
4455	hub = usb_hub_to_struct_hub(udev->parent);
4456	if (!hub)
4457		return;
4458
4459	port_dev = hub->ports[udev->portnum - 1];
4460
4461	if (port_dev->usb3_lpm_u1_permit)
4462		usb_enable_link_state(hcd, udev, USB3_LPM_U1);
4463
4464	if (port_dev->usb3_lpm_u2_permit)
4465		usb_enable_link_state(hcd, udev, USB3_LPM_U2);
4466}
4467EXPORT_SYMBOL_GPL(usb_enable_lpm);
4468
4469/* Grab the bandwidth_mutex before calling usb_enable_lpm() */
4470void usb_unlocked_enable_lpm(struct usb_device *udev)
4471{
4472	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4473
4474	if (!hcd)
4475		return;
4476
4477	mutex_lock(hcd->bandwidth_mutex);
4478	usb_enable_lpm(udev);
4479	mutex_unlock(hcd->bandwidth_mutex);
4480}
4481EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4482
4483/* usb3 devices use U3 for disabled, make sure remote wakeup is disabled */
4484static void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4485					  struct usb_port *port_dev)
4486{
4487	struct usb_device *udev = port_dev->child;
4488	int ret;
4489
4490	if (udev && udev->port_is_suspended && udev->do_remote_wakeup) {
4491		ret = hub_set_port_link_state(hub, port_dev->portnum,
4492					      USB_SS_PORT_LS_U0);
4493		if (!ret) {
4494			msleep(USB_RESUME_TIMEOUT);
4495			ret = usb_disable_remote_wakeup(udev);
4496		}
4497		if (ret)
4498			dev_warn(&udev->dev,
4499				 "Port disable: can't disable remote wake\n");
4500		udev->do_remote_wakeup = 0;
4501	}
4502}
4503
4504#else	/* CONFIG_PM */
4505
4506#define hub_suspend		NULL
4507#define hub_resume		NULL
4508#define hub_reset_resume	NULL
4509
4510static inline void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4511						 struct usb_port *port_dev) { }
4512
4513int usb_disable_lpm(struct usb_device *udev)
4514{
4515	return 0;
4516}
4517EXPORT_SYMBOL_GPL(usb_disable_lpm);
4518
4519void usb_enable_lpm(struct usb_device *udev) { }
4520EXPORT_SYMBOL_GPL(usb_enable_lpm);
4521
4522int usb_unlocked_disable_lpm(struct usb_device *udev)
4523{
4524	return 0;
4525}
4526EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4527
4528void usb_unlocked_enable_lpm(struct usb_device *udev) { }
4529EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4530
4531int usb_disable_ltm(struct usb_device *udev)
4532{
4533	return 0;
4534}
4535EXPORT_SYMBOL_GPL(usb_disable_ltm);
4536
4537void usb_enable_ltm(struct usb_device *udev) { }
4538EXPORT_SYMBOL_GPL(usb_enable_ltm);
4539
4540static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
4541		u16 portstatus, u16 portchange)
4542{
4543	return 0;
4544}
4545
4546static int usb_req_set_sel(struct usb_device *udev)
4547{
4548	return 0;
4549}
4550
4551#endif	/* CONFIG_PM */
4552
4553/*
4554 * USB-3 does not have a similar link state as USB-2 that will avoid negotiating
4555 * a connection with a plugged-in cable but will signal the host when the cable
4556 * is unplugged. Disable remote wake and set link state to U3 for USB-3 devices
4557 */
4558static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
4559{
4560	struct usb_port *port_dev = hub->ports[port1 - 1];
4561	struct usb_device *hdev = hub->hdev;
4562	int ret = 0;
4563
4564	if (!hub->error) {
4565		if (hub_is_superspeed(hub->hdev)) {
4566			hub_usb3_port_prepare_disable(hub, port_dev);
4567			ret = hub_set_port_link_state(hub, port_dev->portnum,
4568						      USB_SS_PORT_LS_U3);
4569		} else {
4570			ret = usb_clear_port_feature(hdev, port1,
4571					USB_PORT_FEAT_ENABLE);
4572		}
4573	}
4574	if (port_dev->child && set_state)
4575		usb_set_device_state(port_dev->child, USB_STATE_NOTATTACHED);
4576	if (ret && ret != -ENODEV)
4577		dev_err(&port_dev->dev, "cannot disable (err = %d)\n", ret);
4578	return ret;
4579}
4580
4581/*
4582 * usb_port_disable - disable a usb device's upstream port
4583 * @udev: device to disable
4584 * Context: @udev locked, must be able to sleep.
4585 *
4586 * Disables a USB device that isn't in active use.
4587 */
4588int usb_port_disable(struct usb_device *udev)
4589{
4590	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4591
4592	return hub_port_disable(hub, udev->portnum, 0);
4593}
4594
4595/* USB 2.0 spec, 7.1.7.3 / fig 7-29:
4596 *
4597 * Between connect detection and reset signaling there must be a delay
4598 * of 100ms at least for debounce and power-settling.  The corresponding
4599 * timer shall restart whenever the downstream port detects a disconnect.
4600 *
4601 * Apparently there are some bluetooth and irda-dongles and a number of
4602 * low-speed devices for which this debounce period may last over a second.
4603 * Not covered by the spec - but easy to deal with.
4604 *
4605 * This implementation uses a 1500ms total debounce timeout; if the
4606 * connection isn't stable by then it returns -ETIMEDOUT.  It checks
4607 * every 25ms for transient disconnects.  When the port status has been
4608 * unchanged for 100ms it returns the port status.
4609 */
4610int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
4611{
4612	int ret;
4613	u16 portchange, portstatus;
4614	unsigned connection = 0xffff;
4615	int total_time, stable_time = 0;
4616	struct usb_port *port_dev = hub->ports[port1 - 1];
4617
4618	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
4619		ret = usb_hub_port_status(hub, port1, &portstatus, &portchange);
4620		if (ret < 0)
4621			return ret;
4622
4623		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
4624		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
4625			if (!must_be_connected ||
4626			     (connection == USB_PORT_STAT_CONNECTION))
4627				stable_time += HUB_DEBOUNCE_STEP;
4628			if (stable_time >= HUB_DEBOUNCE_STABLE)
4629				break;
4630		} else {
4631			stable_time = 0;
4632			connection = portstatus & USB_PORT_STAT_CONNECTION;
4633		}
4634
4635		if (portchange & USB_PORT_STAT_C_CONNECTION) {
4636			usb_clear_port_feature(hub->hdev, port1,
4637					USB_PORT_FEAT_C_CONNECTION);
4638		}
4639
4640		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
4641			break;
4642		msleep(HUB_DEBOUNCE_STEP);
4643	}
4644
4645	dev_dbg(&port_dev->dev, "debounce total %dms stable %dms status 0x%x\n",
4646			total_time, stable_time, portstatus);
4647
4648	if (stable_time < HUB_DEBOUNCE_STABLE)
4649		return -ETIMEDOUT;
4650	return portstatus;
4651}
4652
4653void usb_ep0_reinit(struct usb_device *udev)
4654{
4655	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
4656	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
4657	usb_enable_endpoint(udev, &udev->ep0, true);
4658}
4659EXPORT_SYMBOL_GPL(usb_ep0_reinit);
4660
4661#define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
4662#define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
4663
4664static int hub_set_address(struct usb_device *udev, int devnum)
4665{
4666	int retval;
4667	unsigned int timeout_ms = USB_CTRL_SET_TIMEOUT;
4668	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4669	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4670
4671	if (hub->hdev->quirks & USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT)
4672		timeout_ms = USB_SHORT_SET_ADDRESS_REQ_TIMEOUT;
4673
4674	/*
4675	 * The host controller will choose the device address,
4676	 * instead of the core having chosen it earlier
4677	 */
4678	if (!hcd->driver->address_device && devnum <= 1)
4679		return -EINVAL;
4680	if (udev->state == USB_STATE_ADDRESS)
4681		return 0;
4682	if (udev->state != USB_STATE_DEFAULT)
4683		return -EINVAL;
4684	if (hcd->driver->address_device)
4685		retval = hcd->driver->address_device(hcd, udev, timeout_ms);
4686	else
4687		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
4688				USB_REQ_SET_ADDRESS, 0, devnum, 0,
4689				NULL, 0, timeout_ms);
4690	if (retval == 0) {
4691		update_devnum(udev, devnum);
4692		/* Device now using proper address. */
4693		usb_set_device_state(udev, USB_STATE_ADDRESS);
4694		usb_ep0_reinit(udev);
4695	}
4696	return retval;
4697}
4698
4699/*
4700 * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
4701 * when they're plugged into a USB 2.0 port, but they don't work when LPM is
4702 * enabled.
4703 *
4704 * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
4705 * device says it supports the new USB 2.0 Link PM errata by setting the BESL
4706 * support bit in the BOS descriptor.
4707 */
4708static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
4709{
4710	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4711	int connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
4712
4713	if (!udev->usb2_hw_lpm_capable || !udev->bos)
4714		return;
4715
4716	if (hub)
4717		connect_type = hub->ports[udev->portnum - 1]->connect_type;
4718
4719	if ((udev->bos->ext_cap->bmAttributes & cpu_to_le32(USB_BESL_SUPPORT)) ||
4720			connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
4721		udev->usb2_hw_lpm_allowed = 1;
4722		usb_enable_usb2_hardware_lpm(udev);
4723	}
4724}
4725
4726static int hub_enable_device(struct usb_device *udev)
4727{
4728	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4729
4730	if (!hcd->driver->enable_device)
4731		return 0;
4732	if (udev->state == USB_STATE_ADDRESS)
4733		return 0;
4734	if (udev->state != USB_STATE_DEFAULT)
4735		return -EINVAL;
4736
4737	return hcd->driver->enable_device(hcd, udev);
4738}
4739
4740/*
4741 * Get the bMaxPacketSize0 value during initialization by reading the
4742 * device's device descriptor.  Since we don't already know this value,
4743 * the transfer is unsafe and it ignores I/O errors, only testing for
4744 * reasonable received values.
4745 *
4746 * For "old scheme" initialization, size will be 8 so we read just the
4747 * start of the device descriptor, which should work okay regardless of
4748 * the actual bMaxPacketSize0 value.  For "new scheme" initialization,
4749 * size will be 64 (and buf will point to a sufficiently large buffer),
4750 * which might not be kosher according to the USB spec but it's what
4751 * Windows does and what many devices expect.
4752 *
4753 * Returns: bMaxPacketSize0 or a negative error code.
4754 */
4755static int get_bMaxPacketSize0(struct usb_device *udev,
4756		struct usb_device_descriptor *buf, int size, bool first_time)
4757{
4758	int i, rc;
4759
4760	/*
4761	 * Retry on all errors; some devices are flakey.
4762	 * 255 is for WUSB devices, we actually need to use
4763	 * 512 (WUSB1.0[4.8.1]).
4764	 */
4765	for (i = 0; i < GET_MAXPACKET0_TRIES; ++i) {
4766		/* Start with invalid values in case the transfer fails */
4767		buf->bDescriptorType = buf->bMaxPacketSize0 = 0;
4768		rc = usb_control_msg(udev, usb_rcvaddr0pipe(),
4769				USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4770				USB_DT_DEVICE << 8, 0,
4771				buf, size,
4772				initial_descriptor_timeout);
4773		switch (buf->bMaxPacketSize0) {
4774		case 8: case 16: case 32: case 64: case 9:
4775			if (buf->bDescriptorType == USB_DT_DEVICE) {
4776				rc = buf->bMaxPacketSize0;
4777				break;
4778			}
4779			fallthrough;
4780		default:
4781			if (rc >= 0)
4782				rc = -EPROTO;
4783			break;
4784		}
4785
4786		/*
4787		 * Some devices time out if they are powered on
4788		 * when already connected. They need a second
4789		 * reset, so return early. But only on the first
4790		 * attempt, lest we get into a time-out/reset loop.
4791		 */
4792		if (rc > 0 || (rc == -ETIMEDOUT && first_time &&
4793				udev->speed > USB_SPEED_FULL))
4794			break;
4795	}
4796	return rc;
4797}
4798
4799#define GET_DESCRIPTOR_BUFSIZE	64
4800
4801/* Reset device, (re)assign address, get device descriptor.
4802 * Device connection must be stable, no more debouncing needed.
4803 * Returns device in USB_STATE_ADDRESS, except on error.
4804 *
4805 * If this is called for an already-existing device (as part of
4806 * usb_reset_and_verify_device), the caller must own the device lock and
4807 * the port lock.  For a newly detected device that is not accessible
4808 * through any global pointers, it's not necessary to lock the device,
4809 * but it is still necessary to lock the port.
4810 *
4811 * For a newly detected device, @dev_descr must be NULL.  The device
4812 * descriptor retrieved from the device will then be stored in
4813 * @udev->descriptor.  For an already existing device, @dev_descr
4814 * must be non-NULL.  The device descriptor will be stored there,
4815 * not in @udev->descriptor, because descriptors for registered
4816 * devices are meant to be immutable.
4817 */
4818static int
4819hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
4820		int retry_counter, struct usb_device_descriptor *dev_descr)
4821{
4822	struct usb_device	*hdev = hub->hdev;
4823	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
4824	struct usb_port		*port_dev = hub->ports[port1 - 1];
4825	int			retries, operations, retval, i;
4826	unsigned		delay = HUB_SHORT_RESET_TIME;
4827	enum usb_device_speed	oldspeed = udev->speed;
4828	const char		*speed;
4829	int			devnum = udev->devnum;
4830	const char		*driver_name;
4831	bool			do_new_scheme;
4832	const bool		initial = !dev_descr;
4833	int			maxp0;
4834	struct usb_device_descriptor	*buf, *descr;
4835
4836	buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4837	if (!buf)
4838		return -ENOMEM;
4839
4840	/* root hub ports have a slightly longer reset period
4841	 * (from USB 2.0 spec, section 7.1.7.5)
4842	 */
4843	if (!hdev->parent) {
4844		delay = HUB_ROOT_RESET_TIME;
4845		if (port1 == hdev->bus->otg_port)
4846			hdev->bus->b_hnp_enable = 0;
4847	}
4848
4849	/* Some low speed devices have problems with the quick delay, so */
4850	/*  be a bit pessimistic with those devices. RHbug #23670 */
4851	if (oldspeed == USB_SPEED_LOW)
4852		delay = HUB_LONG_RESET_TIME;
4853
4854	/* Reset the device; full speed may morph to high speed */
4855	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
4856	retval = hub_port_reset(hub, port1, udev, delay, false);
4857	if (retval < 0)		/* error or disconnect */
4858		goto fail;
4859	/* success, speed is known */
4860
4861	retval = -ENODEV;
4862
4863	/* Don't allow speed changes at reset, except usb 3.0 to faster */
4864	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed &&
4865	    !(oldspeed == USB_SPEED_SUPER && udev->speed > oldspeed)) {
4866		dev_dbg(&udev->dev, "device reset changed speed!\n");
4867		goto fail;
4868	}
4869	oldspeed = udev->speed;
4870
4871	if (initial) {
4872		/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
4873		 * it's fixed size except for full speed devices.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4874		 */
4875		switch (udev->speed) {
4876		case USB_SPEED_SUPER_PLUS:
4877		case USB_SPEED_SUPER:
4878			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
4879			break;
4880		case USB_SPEED_HIGH:		/* fixed at 64 */
4881			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4882			break;
4883		case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
4884			/* to determine the ep0 maxpacket size, try to read
4885			 * the device descriptor to get bMaxPacketSize0 and
4886			 * then correct our initial guess.
4887			 */
4888			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4889			break;
4890		case USB_SPEED_LOW:		/* fixed at 8 */
4891			udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4892			break;
4893		default:
4894			goto fail;
4895		}
4896	}
4897
4898	speed = usb_speed_string(udev->speed);
 
 
 
4899
4900	/*
4901	 * The controller driver may be NULL if the controller device
4902	 * is the middle device between platform device and roothub.
4903	 * This middle device may not need a device driver due to
4904	 * all hardware control can be at platform device driver, this
4905	 * platform device is usually a dual-role USB controller device.
4906	 */
4907	if (udev->bus->controller->driver)
4908		driver_name = udev->bus->controller->driver->name;
4909	else
4910		driver_name = udev->bus->sysdev->driver->name;
4911
4912	if (udev->speed < USB_SPEED_SUPER)
4913		dev_info(&udev->dev,
4914				"%s %s USB device number %d using %s\n",
4915				(initial ? "new" : "reset"), speed,
4916				devnum, driver_name);
4917
4918	if (initial) {
4919		/* Set up TT records, if needed  */
4920		if (hdev->tt) {
4921			udev->tt = hdev->tt;
4922			udev->ttport = hdev->ttport;
4923		} else if (udev->speed != USB_SPEED_HIGH
4924				&& hdev->speed == USB_SPEED_HIGH) {
4925			if (!hub->tt.hub) {
4926				dev_err(&udev->dev, "parent hub has no TT\n");
4927				retval = -EINVAL;
4928				goto fail;
4929			}
4930			udev->tt = &hub->tt;
4931			udev->ttport = port1;
4932		}
 
 
4933	}
4934
4935	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4936	 * Because device hardware and firmware is sometimes buggy in
4937	 * this area, and this is how Linux has done it for ages.
4938	 * Change it cautiously.
4939	 *
4940	 * NOTE:  If use_new_scheme() is true we will start by issuing
4941	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4942	 * so it may help with some non-standards-compliant devices.
4943	 * Otherwise we start with SET_ADDRESS and then try to read the
4944	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
4945	 * value.
4946	 */
4947	do_new_scheme = use_new_scheme(udev, retry_counter, port_dev);
4948
4949	for (retries = 0; retries < GET_DESCRIPTOR_TRIES; (++retries, msleep(100))) {
4950		if (hub_port_stop_enumerate(hub, port1, retries)) {
4951			retval = -ENODEV;
4952			break;
4953		}
4954
4955		if (do_new_scheme) {
 
 
 
4956			retval = hub_enable_device(udev);
4957			if (retval < 0) {
4958				dev_err(&udev->dev,
4959					"hub failed to enable device, error %d\n",
4960					retval);
4961				goto fail;
4962			}
4963
4964			maxp0 = get_bMaxPacketSize0(udev, buf,
4965					GET_DESCRIPTOR_BUFSIZE, retries == 0);
4966			if (maxp0 > 0 && !initial &&
4967					maxp0 != udev->descriptor.bMaxPacketSize0) {
4968				dev_err(&udev->dev, "device reset changed ep0 maxpacket size!\n");
4969				retval = -ENODEV;
4970				goto fail;
4971			}
4972
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4973			retval = hub_port_reset(hub, port1, udev, delay, false);
4974			if (retval < 0)		/* error or disconnect */
4975				goto fail;
4976			if (oldspeed != udev->speed) {
4977				dev_dbg(&udev->dev,
4978					"device reset changed speed!\n");
4979				retval = -ENODEV;
4980				goto fail;
4981			}
4982			if (maxp0 < 0) {
4983				if (maxp0 != -ENODEV)
4984					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4985							maxp0);
4986				retval = maxp0;
4987				continue;
4988			}
4989		}
4990
4991		for (operations = 0; operations < SET_ADDRESS_TRIES; ++operations) {
4992			retval = hub_set_address(udev, devnum);
4993			if (retval >= 0)
4994				break;
4995			msleep(200);
4996		}
4997		if (retval < 0) {
4998			if (retval != -ENODEV)
4999				dev_err(&udev->dev, "device not accepting address %d, error %d\n",
5000						devnum, retval);
5001			goto fail;
5002		}
5003		if (udev->speed >= USB_SPEED_SUPER) {
5004			devnum = udev->devnum;
5005			dev_info(&udev->dev,
5006					"%s SuperSpeed%s%s USB device number %d using %s\n",
5007					(udev->config) ? "reset" : "new",
5008				 (udev->speed == USB_SPEED_SUPER_PLUS) ?
5009						" Plus" : "",
5010				 (udev->ssp_rate == USB_SSP_GEN_2x2) ?
5011						" Gen 2x2" :
5012				 (udev->ssp_rate == USB_SSP_GEN_2x1) ?
5013						" Gen 2x1" :
5014				 (udev->ssp_rate == USB_SSP_GEN_1x2) ?
5015						" Gen 1x2" : "",
5016				 devnum, driver_name);
5017		}
5018
5019		/*
5020		 * cope with hardware quirkiness:
5021		 *  - let SET_ADDRESS settle, some device hardware wants it
5022		 *  - read ep0 maxpacket even for high and low speed,
5023		 */
5024		msleep(10);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5025
5026		if (do_new_scheme)
5027			break;
 
 
 
 
 
 
5028
5029		maxp0 = get_bMaxPacketSize0(udev, buf, 8, retries == 0);
5030		if (maxp0 < 0) {
5031			retval = maxp0;
5032			if (retval != -ENODEV)
5033				dev_err(&udev->dev,
5034					"device descriptor read/8, error %d\n",
5035					retval);
 
 
5036		} else {
5037			u32 delay;
5038
5039			if (!initial && maxp0 != udev->descriptor.bMaxPacketSize0) {
5040				dev_err(&udev->dev, "device reset changed ep0 maxpacket size!\n");
5041				retval = -ENODEV;
5042				goto fail;
5043			}
5044
5045			delay = udev->parent->hub_delay;
5046			udev->hub_delay = min_t(u32, delay,
5047						USB_TP_TRANSMISSION_DELAY_MAX);
5048			retval = usb_set_isoch_delay(udev);
5049			if (retval) {
5050				dev_dbg(&udev->dev,
5051					"Failed set isoch delay, error %d\n",
5052					retval);
5053				retval = 0;
5054			}
5055			break;
5056		}
5057	}
5058	if (retval)
5059		goto fail;
5060
5061	/*
5062	 * Check the ep0 maxpacket guess and correct it if necessary.
5063	 * maxp0 is the value stored in the device descriptor;
5064	 * i is the value it encodes (logarithmic for SuperSpeed or greater).
5065	 */
5066	i = maxp0;
5067	if (udev->speed >= USB_SPEED_SUPER) {
5068		if (maxp0 <= 16)
5069			i = 1 << maxp0;
5070		else
5071			i = 0;		/* Invalid */
 
 
 
5072	}
5073	if (usb_endpoint_maxp(&udev->ep0.desc) == i) {
5074		;	/* Initial ep0 maxpacket guess is right */
5075	} else if ((udev->speed == USB_SPEED_FULL ||
5076				udev->speed == USB_SPEED_HIGH) &&
5077			(i == 8 || i == 16 || i == 32 || i == 64)) {
5078		/* Initial guess is wrong; use the descriptor's value */
 
 
 
 
 
 
 
5079		if (udev->speed == USB_SPEED_FULL)
5080			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
5081		else
5082			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
5083		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
5084		usb_ep0_reinit(udev);
5085	} else {
5086		/* Initial guess is wrong and descriptor's value is invalid */
5087		dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", maxp0);
5088		retval = -EMSGSIZE;
5089		goto fail;
5090	}
5091
5092	descr = usb_get_device_descriptor(udev);
5093	if (IS_ERR(descr)) {
5094		retval = PTR_ERR(descr);
5095		if (retval != -ENODEV)
5096			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
5097					retval);
5098		goto fail;
5099	}
5100	if (initial)
5101		udev->descriptor = *descr;
5102	else
5103		*dev_descr = *descr;
5104	kfree(descr);
5105
5106	/*
5107	 * Some superspeed devices have finished the link training process
5108	 * and attached to a superspeed hub port, but the device descriptor
5109	 * got from those devices show they aren't superspeed devices. Warm
5110	 * reset the port attached by the devices can fix them.
5111	 */
5112	if ((udev->speed >= USB_SPEED_SUPER) &&
5113			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
5114		dev_err(&udev->dev, "got a wrong device descriptor, warm reset device\n");
5115		hub_port_reset(hub, port1, udev, HUB_BH_RESET_TIME, true);
5116		retval = -EINVAL;
5117		goto fail;
5118	}
5119
5120	usb_detect_quirks(udev);
5121
5122	if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
5123		retval = usb_get_bos_descriptor(udev);
5124		if (!retval) {
5125			udev->lpm_capable = usb_device_supports_lpm(udev);
5126			udev->lpm_disable_count = 1;
5127			usb_set_lpm_parameters(udev);
5128			usb_req_set_sel(udev);
5129		}
5130	}
5131
5132	retval = 0;
5133	/* notify HCD that we have a device connected and addressed */
5134	if (hcd->driver->update_device)
5135		hcd->driver->update_device(hcd, udev);
5136	hub_set_initial_usb2_lpm_policy(udev);
5137fail:
5138	if (retval) {
5139		hub_port_disable(hub, port1, 0);
5140		update_devnum(udev, devnum);	/* for disconnect processing */
5141	}
5142	kfree(buf);
5143	return retval;
5144}
5145
5146static void
5147check_highspeed(struct usb_hub *hub, struct usb_device *udev, int port1)
5148{
5149	struct usb_qualifier_descriptor	*qual;
5150	int				status;
5151
5152	if (udev->quirks & USB_QUIRK_DEVICE_QUALIFIER)
5153		return;
5154
5155	qual = kmalloc(sizeof *qual, GFP_KERNEL);
5156	if (qual == NULL)
5157		return;
5158
5159	status = usb_get_descriptor(udev, USB_DT_DEVICE_QUALIFIER, 0,
5160			qual, sizeof *qual);
5161	if (status == sizeof *qual) {
5162		dev_info(&udev->dev, "not running at top speed; "
5163			"connect to a high speed hub\n");
5164		/* hub LEDs are probably harder to miss than syslog */
5165		if (hub->has_indicators) {
5166			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
5167			queue_delayed_work(system_power_efficient_wq,
5168					&hub->leds, 0);
5169		}
5170	}
5171	kfree(qual);
5172}
5173
5174static unsigned
5175hub_power_remaining(struct usb_hub *hub)
5176{
5177	struct usb_device *hdev = hub->hdev;
5178	int remaining;
5179	int port1;
5180
5181	if (!hub->limited_power)
5182		return 0;
5183
5184	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
5185	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
5186		struct usb_port *port_dev = hub->ports[port1 - 1];
5187		struct usb_device *udev = port_dev->child;
5188		unsigned unit_load;
5189		int delta;
5190
5191		if (!udev)
5192			continue;
5193		if (hub_is_superspeed(udev))
5194			unit_load = 150;
5195		else
5196			unit_load = 100;
5197
5198		/*
5199		 * Unconfigured devices may not use more than one unit load,
5200		 * or 8mA for OTG ports
5201		 */
5202		if (udev->actconfig)
5203			delta = usb_get_max_power(udev, udev->actconfig);
5204		else if (port1 != udev->bus->otg_port || hdev->parent)
5205			delta = unit_load;
5206		else
5207			delta = 8;
5208		if (delta > hub->mA_per_port)
5209			dev_warn(&port_dev->dev, "%dmA is over %umA budget!\n",
5210					delta, hub->mA_per_port);
5211		remaining -= delta;
5212	}
5213	if (remaining < 0) {
5214		dev_warn(hub->intfdev, "%dmA over power budget!\n",
5215			-remaining);
5216		remaining = 0;
5217	}
5218	return remaining;
5219}
5220
5221
5222static int descriptors_changed(struct usb_device *udev,
5223		struct usb_device_descriptor *new_device_descriptor,
5224		struct usb_host_bos *old_bos)
5225{
5226	int		changed = 0;
5227	unsigned	index;
5228	unsigned	serial_len = 0;
5229	unsigned	len;
5230	unsigned	old_length;
5231	int		length;
5232	char		*buf;
5233
5234	if (memcmp(&udev->descriptor, new_device_descriptor,
5235			sizeof(*new_device_descriptor)) != 0)
5236		return 1;
5237
5238	if ((old_bos && !udev->bos) || (!old_bos && udev->bos))
5239		return 1;
5240	if (udev->bos) {
5241		len = le16_to_cpu(udev->bos->desc->wTotalLength);
5242		if (len != le16_to_cpu(old_bos->desc->wTotalLength))
5243			return 1;
5244		if (memcmp(udev->bos->desc, old_bos->desc, len))
5245			return 1;
5246	}
5247
5248	/* Since the idVendor, idProduct, and bcdDevice values in the
5249	 * device descriptor haven't changed, we will assume the
5250	 * Manufacturer and Product strings haven't changed either.
5251	 * But the SerialNumber string could be different (e.g., a
5252	 * different flash card of the same brand).
5253	 */
5254	if (udev->serial)
5255		serial_len = strlen(udev->serial) + 1;
5256
5257	len = serial_len;
5258	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5259		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5260		len = max(len, old_length);
5261	}
5262
5263	buf = kmalloc(len, GFP_NOIO);
5264	if (!buf)
5265		/* assume the worst */
5266		return 1;
5267
5268	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5269		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5270		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
5271				old_length);
5272		if (length != old_length) {
5273			dev_dbg(&udev->dev, "config index %d, error %d\n",
5274					index, length);
5275			changed = 1;
5276			break;
5277		}
5278		if (memcmp(buf, udev->rawdescriptors[index], old_length)
5279				!= 0) {
5280			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
5281				index,
5282				((struct usb_config_descriptor *) buf)->
5283					bConfigurationValue);
5284			changed = 1;
5285			break;
5286		}
5287	}
5288
5289	if (!changed && serial_len) {
5290		length = usb_string(udev, udev->descriptor.iSerialNumber,
5291				buf, serial_len);
5292		if (length + 1 != serial_len) {
5293			dev_dbg(&udev->dev, "serial string error %d\n",
5294					length);
5295			changed = 1;
5296		} else if (memcmp(buf, udev->serial, length) != 0) {
5297			dev_dbg(&udev->dev, "serial string changed\n");
5298			changed = 1;
5299		}
5300	}
5301
5302	kfree(buf);
5303	return changed;
5304}
5305
5306static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
5307		u16 portchange)
5308{
5309	int status = -ENODEV;
5310	int i;
5311	unsigned unit_load;
5312	struct usb_device *hdev = hub->hdev;
5313	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
5314	struct usb_port *port_dev = hub->ports[port1 - 1];
5315	struct usb_device *udev = port_dev->child;
5316	static int unreliable_port = -1;
5317	bool retry_locked;
5318
5319	/* Disconnect any existing devices under this port */
5320	if (udev) {
5321		if (hcd->usb_phy && !hdev->parent)
5322			usb_phy_notify_disconnect(hcd->usb_phy, udev->speed);
5323		usb_disconnect(&port_dev->child);
5324	}
5325
5326	/* We can forget about a "removed" device when there's a physical
5327	 * disconnect or the connect status changes.
5328	 */
5329	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
5330			(portchange & USB_PORT_STAT_C_CONNECTION))
5331		clear_bit(port1, hub->removed_bits);
5332
5333	if (portchange & (USB_PORT_STAT_C_CONNECTION |
5334				USB_PORT_STAT_C_ENABLE)) {
5335		status = hub_port_debounce_be_stable(hub, port1);
5336		if (status < 0) {
5337			if (status != -ENODEV &&
5338				port1 != unreliable_port &&
5339				printk_ratelimit())
5340				dev_err(&port_dev->dev, "connect-debounce failed\n");
5341			portstatus &= ~USB_PORT_STAT_CONNECTION;
5342			unreliable_port = port1;
5343		} else {
5344			portstatus = status;
5345		}
5346	}
5347
5348	/* Return now if debouncing failed or nothing is connected or
5349	 * the device was "removed".
5350	 */
5351	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
5352			test_bit(port1, hub->removed_bits)) {
5353
5354		/*
5355		 * maybe switch power back on (e.g. root hub was reset)
5356		 * but only if the port isn't owned by someone else.
5357		 */
5358		if (hub_is_port_power_switchable(hub)
5359				&& !usb_port_is_power_on(hub, portstatus)
5360				&& !port_dev->port_owner)
5361			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
5362
5363		if (portstatus & USB_PORT_STAT_ENABLE)
5364			goto done;
5365		return;
5366	}
5367	if (hub_is_superspeed(hub->hdev))
5368		unit_load = 150;
5369	else
5370		unit_load = 100;
5371
5372	status = 0;
5373
5374	for (i = 0; i < PORT_INIT_TRIES; i++) {
5375		if (hub_port_stop_enumerate(hub, port1, i)) {
5376			status = -ENODEV;
5377			break;
5378		}
5379
5380		usb_lock_port(port_dev);
5381		mutex_lock(hcd->address0_mutex);
5382		retry_locked = true;
5383		/* reallocate for each attempt, since references
5384		 * to the previous one can escape in various ways
5385		 */
5386		udev = usb_alloc_dev(hdev, hdev->bus, port1);
5387		if (!udev) {
5388			dev_err(&port_dev->dev,
5389					"couldn't allocate usb_device\n");
5390			mutex_unlock(hcd->address0_mutex);
5391			usb_unlock_port(port_dev);
5392			goto done;
5393		}
5394
5395		usb_set_device_state(udev, USB_STATE_POWERED);
5396		udev->bus_mA = hub->mA_per_port;
5397		udev->level = hdev->level + 1;
 
5398
5399		/* Devices connected to SuperSpeed hubs are USB 3.0 or later */
5400		if (hub_is_superspeed(hub->hdev))
5401			udev->speed = USB_SPEED_SUPER;
5402		else
5403			udev->speed = USB_SPEED_UNKNOWN;
5404
5405		choose_devnum(udev);
5406		if (udev->devnum <= 0) {
5407			status = -ENOTCONN;	/* Don't retry */
5408			goto loop;
5409		}
5410
5411		/* reset (non-USB 3.0 devices) and get descriptor */
5412		status = hub_port_init(hub, udev, port1, i, NULL);
5413		if (status < 0)
5414			goto loop;
5415
5416		mutex_unlock(hcd->address0_mutex);
5417		usb_unlock_port(port_dev);
5418		retry_locked = false;
5419
5420		if (udev->quirks & USB_QUIRK_DELAY_INIT)
5421			msleep(2000);
5422
5423		/* consecutive bus-powered hubs aren't reliable; they can
5424		 * violate the voltage drop budget.  if the new child has
5425		 * a "powered" LED, users should notice we didn't enable it
5426		 * (without reading syslog), even without per-port LEDs
5427		 * on the parent.
5428		 */
5429		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
5430				&& udev->bus_mA <= unit_load) {
5431			u16	devstat;
5432
5433			status = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
5434					&devstat);
5435			if (status) {
5436				dev_dbg(&udev->dev, "get status %d ?\n", status);
5437				goto loop_disable;
5438			}
5439			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
5440				dev_err(&udev->dev,
5441					"can't connect bus-powered hub "
5442					"to this port\n");
5443				if (hub->has_indicators) {
5444					hub->indicator[port1-1] =
5445						INDICATOR_AMBER_BLINK;
5446					queue_delayed_work(
5447						system_power_efficient_wq,
5448						&hub->leds, 0);
5449				}
5450				status = -ENOTCONN;	/* Don't retry */
5451				goto loop_disable;
5452			}
5453		}
5454
5455		/* check for devices running slower than they could */
5456		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
5457				&& udev->speed == USB_SPEED_FULL
5458				&& highspeed_hubs != 0)
5459			check_highspeed(hub, udev, port1);
5460
5461		/* Store the parent's children[] pointer.  At this point
5462		 * udev becomes globally accessible, although presumably
5463		 * no one will look at it until hdev is unlocked.
5464		 */
5465		status = 0;
5466
5467		mutex_lock(&usb_port_peer_mutex);
5468
5469		/* We mustn't add new devices if the parent hub has
5470		 * been disconnected; we would race with the
5471		 * recursively_mark_NOTATTACHED() routine.
5472		 */
5473		spin_lock_irq(&device_state_lock);
5474		if (hdev->state == USB_STATE_NOTATTACHED)
5475			status = -ENOTCONN;
5476		else
5477			port_dev->child = udev;
5478		spin_unlock_irq(&device_state_lock);
5479		mutex_unlock(&usb_port_peer_mutex);
5480
5481		/* Run it through the hoops (find a driver, etc) */
5482		if (!status) {
5483			status = usb_new_device(udev);
5484			if (status) {
5485				mutex_lock(&usb_port_peer_mutex);
5486				spin_lock_irq(&device_state_lock);
5487				port_dev->child = NULL;
5488				spin_unlock_irq(&device_state_lock);
5489				mutex_unlock(&usb_port_peer_mutex);
5490			} else {
5491				if (hcd->usb_phy && !hdev->parent)
5492					usb_phy_notify_connect(hcd->usb_phy,
5493							udev->speed);
5494			}
5495		}
5496
5497		if (status)
5498			goto loop_disable;
5499
5500		status = hub_power_remaining(hub);
5501		if (status)
5502			dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
5503
5504		return;
5505
5506loop_disable:
5507		hub_port_disable(hub, port1, 1);
5508loop:
5509		usb_ep0_reinit(udev);
5510		release_devnum(udev);
5511		hub_free_dev(udev);
5512		if (retry_locked) {
5513			mutex_unlock(hcd->address0_mutex);
5514			usb_unlock_port(port_dev);
5515		}
5516		usb_put_dev(udev);
5517		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
5518			break;
5519
5520		/* When halfway through our retry count, power-cycle the port */
5521		if (i == (PORT_INIT_TRIES - 1) / 2) {
5522			dev_info(&port_dev->dev, "attempt power cycle\n");
5523			usb_hub_set_port_power(hdev, hub, port1, false);
5524			msleep(2 * hub_power_on_good_delay(hub));
5525			usb_hub_set_port_power(hdev, hub, port1, true);
5526			msleep(hub_power_on_good_delay(hub));
5527		}
5528	}
5529	if (hub->hdev->parent ||
5530			!hcd->driver->port_handed_over ||
5531			!(hcd->driver->port_handed_over)(hcd, port1)) {
5532		if (status != -ENOTCONN && status != -ENODEV)
5533			dev_err(&port_dev->dev,
5534					"unable to enumerate USB device\n");
5535	}
5536
5537done:
5538	hub_port_disable(hub, port1, 1);
5539	if (hcd->driver->relinquish_port && !hub->hdev->parent) {
5540		if (status != -ENOTCONN && status != -ENODEV)
5541			hcd->driver->relinquish_port(hcd, port1);
5542	}
5543}
5544
5545/* Handle physical or logical connection change events.
5546 * This routine is called when:
5547 *	a port connection-change occurs;
5548 *	a port enable-change occurs (often caused by EMI);
5549 *	usb_reset_and_verify_device() encounters changed descriptors (as from
5550 *		a firmware download)
5551 * caller already locked the hub
5552 */
5553static void hub_port_connect_change(struct usb_hub *hub, int port1,
5554					u16 portstatus, u16 portchange)
5555		__must_hold(&port_dev->status_lock)
5556{
5557	struct usb_port *port_dev = hub->ports[port1 - 1];
5558	struct usb_device *udev = port_dev->child;
5559	struct usb_device_descriptor *descr;
5560	int status = -ENODEV;
 
5561
5562	dev_dbg(&port_dev->dev, "status %04x, change %04x, %s\n", portstatus,
5563			portchange, portspeed(hub, portstatus));
5564
5565	if (hub->has_indicators) {
5566		set_port_led(hub, port1, HUB_LED_AUTO);
5567		hub->indicator[port1-1] = INDICATOR_AUTO;
5568	}
5569
5570#ifdef	CONFIG_USB_OTG
5571	/* during HNP, don't repeat the debounce */
5572	if (hub->hdev->bus->is_b_host)
5573		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
5574				USB_PORT_STAT_C_ENABLE);
5575#endif
5576
5577	/* Try to resuscitate an existing device */
5578	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
5579			udev->state != USB_STATE_NOTATTACHED) {
5580		if (portstatus & USB_PORT_STAT_ENABLE) {
5581			/*
5582			 * USB-3 connections are initialized automatically by
5583			 * the hostcontroller hardware. Therefore check for
5584			 * changed device descriptors before resuscitating the
5585			 * device.
5586			 */
5587			descr = usb_get_device_descriptor(udev);
5588			if (IS_ERR(descr)) {
 
 
5589				dev_dbg(&udev->dev,
5590						"can't read device descriptor %ld\n",
5591						PTR_ERR(descr));
5592			} else {
5593				if (descriptors_changed(udev, descr,
5594						udev->bos)) {
5595					dev_dbg(&udev->dev,
5596							"device descriptor has changed\n");
 
 
5597				} else {
5598					status = 0; /* Nothing to do */
5599				}
5600				kfree(descr);
5601			}
5602#ifdef CONFIG_PM
5603		} else if (udev->state == USB_STATE_SUSPENDED &&
5604				udev->persist_enabled) {
5605			/* For a suspended device, treat this as a
5606			 * remote wakeup event.
5607			 */
5608			usb_unlock_port(port_dev);
5609			status = usb_remote_wakeup(udev);
5610			usb_lock_port(port_dev);
5611#endif
5612		} else {
5613			/* Don't resuscitate */;
5614		}
5615	}
5616	clear_bit(port1, hub->change_bits);
5617
5618	/* successfully revalidated the connection */
5619	if (status == 0)
5620		return;
5621
5622	usb_unlock_port(port_dev);
5623	hub_port_connect(hub, port1, portstatus, portchange);
5624	usb_lock_port(port_dev);
5625}
5626
5627/* Handle notifying userspace about hub over-current events */
5628static void port_over_current_notify(struct usb_port *port_dev)
5629{
5630	char *envp[3] = { NULL, NULL, NULL };
5631	struct device *hub_dev;
5632	char *port_dev_path;
5633
5634	sysfs_notify(&port_dev->dev.kobj, NULL, "over_current_count");
5635
5636	hub_dev = port_dev->dev.parent;
5637
5638	if (!hub_dev)
5639		return;
5640
5641	port_dev_path = kobject_get_path(&port_dev->dev.kobj, GFP_KERNEL);
5642	if (!port_dev_path)
5643		return;
5644
5645	envp[0] = kasprintf(GFP_KERNEL, "OVER_CURRENT_PORT=%s", port_dev_path);
5646	if (!envp[0])
5647		goto exit;
5648
5649	envp[1] = kasprintf(GFP_KERNEL, "OVER_CURRENT_COUNT=%u",
5650			port_dev->over_current_count);
5651	if (!envp[1])
5652		goto exit;
5653
5654	kobject_uevent_env(&hub_dev->kobj, KOBJ_CHANGE, envp);
5655
5656exit:
5657	kfree(envp[1]);
5658	kfree(envp[0]);
5659	kfree(port_dev_path);
5660}
5661
5662static void port_event(struct usb_hub *hub, int port1)
5663		__must_hold(&port_dev->status_lock)
5664{
5665	int connect_change;
5666	struct usb_port *port_dev = hub->ports[port1 - 1];
5667	struct usb_device *udev = port_dev->child;
5668	struct usb_device *hdev = hub->hdev;
5669	u16 portstatus, portchange;
5670	int i = 0;
5671
5672	connect_change = test_bit(port1, hub->change_bits);
5673	clear_bit(port1, hub->event_bits);
5674	clear_bit(port1, hub->wakeup_bits);
5675
5676	if (usb_hub_port_status(hub, port1, &portstatus, &portchange) < 0)
5677		return;
5678
5679	if (portchange & USB_PORT_STAT_C_CONNECTION) {
5680		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
5681		connect_change = 1;
5682	}
5683
5684	if (portchange & USB_PORT_STAT_C_ENABLE) {
5685		if (!connect_change)
5686			dev_dbg(&port_dev->dev, "enable change, status %08x\n",
5687					portstatus);
5688		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
5689
5690		/*
5691		 * EM interference sometimes causes badly shielded USB devices
5692		 * to be shutdown by the hub, this hack enables them again.
5693		 * Works at least with mouse driver.
5694		 */
5695		if (!(portstatus & USB_PORT_STAT_ENABLE)
5696		    && !connect_change && udev) {
5697			dev_err(&port_dev->dev, "disabled by hub (EMI?), re-enabling...\n");
5698			connect_change = 1;
5699		}
5700	}
5701
5702	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
5703		u16 status = 0, unused;
5704		port_dev->over_current_count++;
5705		port_over_current_notify(port_dev);
5706
5707		dev_dbg(&port_dev->dev, "over-current change #%u\n",
5708			port_dev->over_current_count);
5709		usb_clear_port_feature(hdev, port1,
5710				USB_PORT_FEAT_C_OVER_CURRENT);
5711		msleep(100);	/* Cool down */
5712		hub_power_on(hub, true);
5713		usb_hub_port_status(hub, port1, &status, &unused);
5714		if (status & USB_PORT_STAT_OVERCURRENT)
5715			dev_err(&port_dev->dev, "over-current condition\n");
5716	}
5717
5718	if (portchange & USB_PORT_STAT_C_RESET) {
5719		dev_dbg(&port_dev->dev, "reset change\n");
5720		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_RESET);
5721	}
5722	if ((portchange & USB_PORT_STAT_C_BH_RESET)
5723	    && hub_is_superspeed(hdev)) {
5724		dev_dbg(&port_dev->dev, "warm reset change\n");
5725		usb_clear_port_feature(hdev, port1,
5726				USB_PORT_FEAT_C_BH_PORT_RESET);
5727	}
5728	if (portchange & USB_PORT_STAT_C_LINK_STATE) {
5729		dev_dbg(&port_dev->dev, "link state change\n");
5730		usb_clear_port_feature(hdev, port1,
5731				USB_PORT_FEAT_C_PORT_LINK_STATE);
5732	}
5733	if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
5734		dev_warn(&port_dev->dev, "config error\n");
5735		usb_clear_port_feature(hdev, port1,
5736				USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
5737	}
5738
5739	/* skip port actions that require the port to be powered on */
5740	if (!pm_runtime_active(&port_dev->dev))
5741		return;
5742
5743	/* skip port actions if ignore_event and early_stop are true */
5744	if (port_dev->ignore_event && port_dev->early_stop)
5745		return;
5746
5747	if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
5748		connect_change = 1;
5749
5750	/*
5751	 * Avoid trying to recover a USB3 SS.Inactive port with a warm reset if
5752	 * the device was disconnected. A 12ms disconnect detect timer in
5753	 * SS.Inactive state transitions the port to RxDetect automatically.
5754	 * SS.Inactive link error state is common during device disconnect.
5755	 */
5756	while (hub_port_warm_reset_required(hub, port1, portstatus)) {
5757		if ((i++ < DETECT_DISCONNECT_TRIES) && udev) {
5758			u16 unused;
5759
5760			msleep(20);
5761			usb_hub_port_status(hub, port1, &portstatus, &unused);
5762			dev_dbg(&port_dev->dev, "Wait for inactive link disconnect detect\n");
5763			continue;
5764		} else if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
5765				|| udev->state == USB_STATE_NOTATTACHED) {
5766			dev_dbg(&port_dev->dev, "do warm reset, port only\n");
5767			if (hub_port_reset(hub, port1, NULL,
5768					HUB_BH_RESET_TIME, true) < 0)
5769				hub_port_disable(hub, port1, 1);
5770		} else {
5771			dev_dbg(&port_dev->dev, "do warm reset, full device\n");
5772			usb_unlock_port(port_dev);
5773			usb_lock_device(udev);
5774			usb_reset_device(udev);
5775			usb_unlock_device(udev);
5776			usb_lock_port(port_dev);
5777			connect_change = 0;
5778		}
5779		break;
5780	}
5781
5782	if (connect_change)
5783		hub_port_connect_change(hub, port1, portstatus, portchange);
5784}
5785
5786static void hub_event(struct work_struct *work)
5787{
5788	struct usb_device *hdev;
5789	struct usb_interface *intf;
5790	struct usb_hub *hub;
5791	struct device *hub_dev;
5792	u16 hubstatus;
5793	u16 hubchange;
5794	int i, ret;
5795
5796	hub = container_of(work, struct usb_hub, events);
5797	hdev = hub->hdev;
5798	hub_dev = hub->intfdev;
5799	intf = to_usb_interface(hub_dev);
5800
5801	kcov_remote_start_usb((u64)hdev->bus->busnum);
5802
5803	dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
5804			hdev->state, hdev->maxchild,
5805			/* NOTE: expects max 15 ports... */
5806			(u16) hub->change_bits[0],
5807			(u16) hub->event_bits[0]);
5808
5809	/* Lock the device, then check to see if we were
5810	 * disconnected while waiting for the lock to succeed. */
5811	usb_lock_device(hdev);
5812	if (unlikely(hub->disconnected))
5813		goto out_hdev_lock;
5814
5815	/* If the hub has died, clean up after it */
5816	if (hdev->state == USB_STATE_NOTATTACHED) {
5817		hub->error = -ENODEV;
5818		hub_quiesce(hub, HUB_DISCONNECT);
5819		goto out_hdev_lock;
5820	}
5821
5822	/* Autoresume */
5823	ret = usb_autopm_get_interface(intf);
5824	if (ret) {
5825		dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
5826		goto out_hdev_lock;
5827	}
5828
5829	/* If this is an inactive hub, do nothing */
5830	if (hub->quiescing)
5831		goto out_autopm;
5832
5833	if (hub->error) {
5834		dev_dbg(hub_dev, "resetting for error %d\n", hub->error);
5835
5836		ret = usb_reset_device(hdev);
5837		if (ret) {
5838			dev_dbg(hub_dev, "error resetting hub: %d\n", ret);
5839			goto out_autopm;
5840		}
5841
5842		hub->nerrors = 0;
5843		hub->error = 0;
5844	}
5845
5846	/* deal with port status changes */
5847	for (i = 1; i <= hdev->maxchild; i++) {
5848		struct usb_port *port_dev = hub->ports[i - 1];
5849
5850		if (test_bit(i, hub->event_bits)
5851				|| test_bit(i, hub->change_bits)
5852				|| test_bit(i, hub->wakeup_bits)) {
5853			/*
5854			 * The get_noresume and barrier ensure that if
5855			 * the port was in the process of resuming, we
5856			 * flush that work and keep the port active for
5857			 * the duration of the port_event().  However,
5858			 * if the port is runtime pm suspended
5859			 * (powered-off), we leave it in that state, run
5860			 * an abbreviated port_event(), and move on.
5861			 */
5862			pm_runtime_get_noresume(&port_dev->dev);
5863			pm_runtime_barrier(&port_dev->dev);
5864			usb_lock_port(port_dev);
5865			port_event(hub, i);
5866			usb_unlock_port(port_dev);
5867			pm_runtime_put_sync(&port_dev->dev);
5868		}
5869	}
5870
5871	/* deal with hub status changes */
5872	if (test_and_clear_bit(0, hub->event_bits) == 0)
5873		;	/* do nothing */
5874	else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
5875		dev_err(hub_dev, "get_hub_status failed\n");
5876	else {
5877		if (hubchange & HUB_CHANGE_LOCAL_POWER) {
5878			dev_dbg(hub_dev, "power change\n");
5879			clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
5880			if (hubstatus & HUB_STATUS_LOCAL_POWER)
5881				/* FIXME: Is this always true? */
5882				hub->limited_power = 1;
5883			else
5884				hub->limited_power = 0;
5885		}
5886		if (hubchange & HUB_CHANGE_OVERCURRENT) {
5887			u16 status = 0;
5888			u16 unused;
5889
5890			dev_dbg(hub_dev, "over-current change\n");
5891			clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
5892			msleep(500);	/* Cool down */
5893			hub_power_on(hub, true);
5894			hub_hub_status(hub, &status, &unused);
5895			if (status & HUB_STATUS_OVERCURRENT)
5896				dev_err(hub_dev, "over-current condition\n");
5897		}
5898	}
5899
5900out_autopm:
5901	/* Balance the usb_autopm_get_interface() above */
5902	usb_autopm_put_interface_no_suspend(intf);
5903out_hdev_lock:
5904	usb_unlock_device(hdev);
5905
5906	/* Balance the stuff in kick_hub_wq() and allow autosuspend */
5907	usb_autopm_put_interface(intf);
5908	kref_put(&hub->kref, hub_release);
5909
5910	kcov_remote_stop();
5911}
5912
5913static const struct usb_device_id hub_id_table[] = {
5914    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5915                   | USB_DEVICE_ID_MATCH_PRODUCT
5916                   | USB_DEVICE_ID_MATCH_INT_CLASS,
5917      .idVendor = USB_VENDOR_SMSC,
5918      .idProduct = USB_PRODUCT_USB5534B,
5919      .bInterfaceClass = USB_CLASS_HUB,
5920      .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5921    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5922                   | USB_DEVICE_ID_MATCH_PRODUCT,
5923      .idVendor = USB_VENDOR_CYPRESS,
5924      .idProduct = USB_PRODUCT_CY7C65632,
5925      .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5926    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5927			| USB_DEVICE_ID_MATCH_INT_CLASS,
5928      .idVendor = USB_VENDOR_GENESYS_LOGIC,
5929      .bInterfaceClass = USB_CLASS_HUB,
5930      .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
5931    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5932			| USB_DEVICE_ID_MATCH_PRODUCT,
5933      .idVendor = USB_VENDOR_TEXAS_INSTRUMENTS,
5934      .idProduct = USB_PRODUCT_TUSB8041_USB2,
5935      .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5936    { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5937			| USB_DEVICE_ID_MATCH_PRODUCT,
5938      .idVendor = USB_VENDOR_TEXAS_INSTRUMENTS,
5939      .idProduct = USB_PRODUCT_TUSB8041_USB3,
5940      .driver_info = HUB_QUIRK_DISABLE_AUTOSUSPEND},
5941	{ .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5942			| USB_DEVICE_ID_MATCH_PRODUCT,
5943	  .idVendor = USB_VENDOR_MICROCHIP,
5944	  .idProduct = USB_PRODUCT_USB4913,
5945	  .driver_info = HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL},
5946	{ .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5947			| USB_DEVICE_ID_MATCH_PRODUCT,
5948	  .idVendor = USB_VENDOR_MICROCHIP,
5949	  .idProduct = USB_PRODUCT_USB4914,
5950	  .driver_info = HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL},
5951	{ .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5952			| USB_DEVICE_ID_MATCH_PRODUCT,
5953	  .idVendor = USB_VENDOR_MICROCHIP,
5954	  .idProduct = USB_PRODUCT_USB4915,
5955	  .driver_info = HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL},
5956    { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
5957      .bDeviceClass = USB_CLASS_HUB},
5958    { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
5959      .bInterfaceClass = USB_CLASS_HUB},
5960    { }						/* Terminating entry */
5961};
5962
5963MODULE_DEVICE_TABLE(usb, hub_id_table);
5964
5965static struct usb_driver hub_driver = {
5966	.name =		"hub",
5967	.probe =	hub_probe,
5968	.disconnect =	hub_disconnect,
5969	.suspend =	hub_suspend,
5970	.resume =	hub_resume,
5971	.reset_resume =	hub_reset_resume,
5972	.pre_reset =	hub_pre_reset,
5973	.post_reset =	hub_post_reset,
5974	.unlocked_ioctl = hub_ioctl,
5975	.id_table =	hub_id_table,
5976	.supports_autosuspend =	1,
5977};
5978
5979int usb_hub_init(void)
5980{
5981	if (usb_register(&hub_driver) < 0) {
5982		printk(KERN_ERR "%s: can't register hub driver\n",
5983			usbcore_name);
5984		return -1;
5985	}
5986
5987	/*
5988	 * The workqueue needs to be freezable to avoid interfering with
5989	 * USB-PERSIST port handover. Otherwise it might see that a full-speed
5990	 * device was gone before the EHCI controller had handed its port
5991	 * over to the companion full-speed controller.
5992	 */
5993	hub_wq = alloc_workqueue("usb_hub_wq", WQ_FREEZABLE, 0);
5994	if (hub_wq)
5995		return 0;
5996
5997	/* Fall through if kernel_thread failed */
5998	usb_deregister(&hub_driver);
5999	pr_err("%s: can't allocate workqueue for usb hub\n", usbcore_name);
6000
6001	return -1;
6002}
6003
6004void usb_hub_cleanup(void)
6005{
6006	destroy_workqueue(hub_wq);
6007
6008	/*
6009	 * Hub resources are freed for us by usb_deregister. It calls
6010	 * usb_driver_purge on every device which in turn calls that
6011	 * devices disconnect function if it is using this driver.
6012	 * The hub_disconnect function takes care of releasing the
6013	 * individual hub resources. -greg
6014	 */
6015	usb_deregister(&hub_driver);
6016} /* usb_hub_cleanup() */
6017
6018/**
6019 * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
6020 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
6021 *
6022 * WARNING - don't use this routine to reset a composite device
6023 * (one with multiple interfaces owned by separate drivers)!
6024 * Use usb_reset_device() instead.
6025 *
6026 * Do a port reset, reassign the device's address, and establish its
6027 * former operating configuration.  If the reset fails, or the device's
6028 * descriptors change from their values before the reset, or the original
6029 * configuration and altsettings cannot be restored, a flag will be set
6030 * telling hub_wq to pretend the device has been disconnected and then
6031 * re-connected.  All drivers will be unbound, and the device will be
6032 * re-enumerated and probed all over again.
6033 *
6034 * Return: 0 if the reset succeeded, -ENODEV if the device has been
6035 * flagged for logical disconnection, or some other negative error code
6036 * if the reset wasn't even attempted.
6037 *
6038 * Note:
6039 * The caller must own the device lock and the port lock, the latter is
6040 * taken by usb_reset_device().  For example, it's safe to use
6041 * usb_reset_device() from a driver probe() routine after downloading
6042 * new firmware.  For calls that might not occur during probe(), drivers
6043 * should lock the device using usb_lock_device_for_reset().
6044 *
6045 * Locking exception: This routine may also be called from within an
6046 * autoresume handler.  Such usage won't conflict with other tasks
6047 * holding the device lock because these tasks should always call
6048 * usb_autopm_resume_device(), thereby preventing any unwanted
6049 * autoresume.  The autoresume handler is expected to have already
6050 * acquired the port lock before calling this routine.
6051 */
6052static int usb_reset_and_verify_device(struct usb_device *udev)
6053{
6054	struct usb_device		*parent_hdev = udev->parent;
6055	struct usb_hub			*parent_hub;
6056	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
6057	struct usb_device_descriptor	descriptor;
6058	struct usb_host_bos		*bos;
6059	int				i, j, ret = 0;
6060	int				port1 = udev->portnum;
6061
6062	if (udev->state == USB_STATE_NOTATTACHED ||
6063			udev->state == USB_STATE_SUSPENDED) {
6064		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
6065				udev->state);
6066		return -EINVAL;
6067	}
6068
6069	if (!parent_hdev)
6070		return -EISDIR;
6071
6072	parent_hub = usb_hub_to_struct_hub(parent_hdev);
6073
6074	/* Disable USB2 hardware LPM.
6075	 * It will be re-enabled by the enumeration process.
6076	 */
6077	usb_disable_usb2_hardware_lpm(udev);
6078
6079	bos = udev->bos;
6080	udev->bos = NULL;
6081
6082	mutex_lock(hcd->address0_mutex);
6083
6084	for (i = 0; i < PORT_INIT_TRIES; ++i) {
6085		if (hub_port_stop_enumerate(parent_hub, port1, i)) {
6086			ret = -ENODEV;
6087			break;
6088		}
6089
6090		/* ep0 maxpacket size may change; let the HCD know about it.
6091		 * Other endpoints will be handled by re-enumeration. */
6092		usb_ep0_reinit(udev);
6093		ret = hub_port_init(parent_hub, udev, port1, i, &descriptor);
6094		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
6095			break;
6096	}
6097	mutex_unlock(hcd->address0_mutex);
6098
6099	if (ret < 0)
6100		goto re_enumerate;
6101
6102	/* Device might have changed firmware (DFU or similar) */
6103	if (descriptors_changed(udev, &descriptor, bos)) {
6104		dev_info(&udev->dev, "device firmware changed\n");
 
6105		goto re_enumerate;
6106	}
6107
6108	/* Restore the device's previous configuration */
6109	if (!udev->actconfig)
6110		goto done;
6111
6112	mutex_lock(hcd->bandwidth_mutex);
6113	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
6114	if (ret < 0) {
6115		dev_warn(&udev->dev,
6116				"Busted HC?  Not enough HCD resources for "
6117				"old configuration.\n");
6118		mutex_unlock(hcd->bandwidth_mutex);
6119		goto re_enumerate;
6120	}
6121	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
6122			USB_REQ_SET_CONFIGURATION, 0,
6123			udev->actconfig->desc.bConfigurationValue, 0,
6124			NULL, 0, USB_CTRL_SET_TIMEOUT);
6125	if (ret < 0) {
6126		dev_err(&udev->dev,
6127			"can't restore configuration #%d (error=%d)\n",
6128			udev->actconfig->desc.bConfigurationValue, ret);
6129		mutex_unlock(hcd->bandwidth_mutex);
6130		goto re_enumerate;
6131	}
6132	mutex_unlock(hcd->bandwidth_mutex);
6133	usb_set_device_state(udev, USB_STATE_CONFIGURED);
6134
6135	/* Put interfaces back into the same altsettings as before.
6136	 * Don't bother to send the Set-Interface request for interfaces
6137	 * that were already in altsetting 0; besides being unnecessary,
6138	 * many devices can't handle it.  Instead just reset the host-side
6139	 * endpoint state.
6140	 */
6141	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
6142		struct usb_host_config *config = udev->actconfig;
6143		struct usb_interface *intf = config->interface[i];
6144		struct usb_interface_descriptor *desc;
6145
6146		desc = &intf->cur_altsetting->desc;
6147		if (desc->bAlternateSetting == 0) {
6148			usb_disable_interface(udev, intf, true);
6149			usb_enable_interface(udev, intf, true);
6150			ret = 0;
6151		} else {
6152			/* Let the bandwidth allocation function know that this
6153			 * device has been reset, and it will have to use
6154			 * alternate setting 0 as the current alternate setting.
6155			 */
6156			intf->resetting_device = 1;
6157			ret = usb_set_interface(udev, desc->bInterfaceNumber,
6158					desc->bAlternateSetting);
6159			intf->resetting_device = 0;
6160		}
6161		if (ret < 0) {
6162			dev_err(&udev->dev, "failed to restore interface %d "
6163				"altsetting %d (error=%d)\n",
6164				desc->bInterfaceNumber,
6165				desc->bAlternateSetting,
6166				ret);
6167			goto re_enumerate;
6168		}
6169		/* Resetting also frees any allocated streams */
6170		for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
6171			intf->cur_altsetting->endpoint[j].streams = 0;
6172	}
6173
6174done:
6175	/* Now that the alt settings are re-installed, enable LTM and LPM. */
6176	usb_enable_usb2_hardware_lpm(udev);
6177	usb_unlocked_enable_lpm(udev);
6178	usb_enable_ltm(udev);
6179	usb_release_bos_descriptor(udev);
6180	udev->bos = bos;
6181	return 0;
6182
6183re_enumerate:
6184	usb_release_bos_descriptor(udev);
6185	udev->bos = bos;
6186	hub_port_logical_disconnect(parent_hub, port1);
6187	return -ENODEV;
6188}
6189
6190/**
6191 * usb_reset_device - warn interface drivers and perform a USB port reset
6192 * @udev: device to reset (not in NOTATTACHED state)
6193 *
6194 * Warns all drivers bound to registered interfaces (using their pre_reset
6195 * method), performs the port reset, and then lets the drivers know that
6196 * the reset is over (using their post_reset method).
6197 *
6198 * Return: The same as for usb_reset_and_verify_device().
6199 * However, if a reset is already in progress (for instance, if a
6200 * driver doesn't have pre_reset() or post_reset() callbacks, and while
6201 * being unbound or re-bound during the ongoing reset its disconnect()
6202 * or probe() routine tries to perform a second, nested reset), the
6203 * routine returns -EINPROGRESS.
6204 *
6205 * Note:
6206 * The caller must own the device lock.  For example, it's safe to use
6207 * this from a driver probe() routine after downloading new firmware.
6208 * For calls that might not occur during probe(), drivers should lock
6209 * the device using usb_lock_device_for_reset().
6210 *
6211 * If an interface is currently being probed or disconnected, we assume
6212 * its driver knows how to handle resets.  For all other interfaces,
6213 * if the driver doesn't have pre_reset and post_reset methods then
6214 * we attempt to unbind it and rebind afterward.
6215 */
6216int usb_reset_device(struct usb_device *udev)
6217{
6218	int ret;
6219	int i;
6220	unsigned int noio_flag;
6221	struct usb_port *port_dev;
6222	struct usb_host_config *config = udev->actconfig;
6223	struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
6224
6225	if (udev->state == USB_STATE_NOTATTACHED) {
6226		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
6227				udev->state);
6228		return -EINVAL;
6229	}
6230
6231	if (!udev->parent) {
6232		/* this requires hcd-specific logic; see ohci_restart() */
6233		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
6234		return -EISDIR;
6235	}
6236
6237	if (udev->reset_in_progress)
6238		return -EINPROGRESS;
6239	udev->reset_in_progress = 1;
6240
6241	port_dev = hub->ports[udev->portnum - 1];
6242
6243	/*
6244	 * Don't allocate memory with GFP_KERNEL in current
6245	 * context to avoid possible deadlock if usb mass
6246	 * storage interface or usbnet interface(iSCSI case)
6247	 * is included in current configuration. The easist
6248	 * approach is to do it for every device reset,
6249	 * because the device 'memalloc_noio' flag may have
6250	 * not been set before reseting the usb device.
6251	 */
6252	noio_flag = memalloc_noio_save();
6253
6254	/* Prevent autosuspend during the reset */
6255	usb_autoresume_device(udev);
6256
6257	if (config) {
6258		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
6259			struct usb_interface *cintf = config->interface[i];
6260			struct usb_driver *drv;
6261			int unbind = 0;
6262
6263			if (cintf->dev.driver) {
6264				drv = to_usb_driver(cintf->dev.driver);
6265				if (drv->pre_reset && drv->post_reset)
6266					unbind = (drv->pre_reset)(cintf);
6267				else if (cintf->condition ==
6268						USB_INTERFACE_BOUND)
6269					unbind = 1;
6270				if (unbind)
6271					usb_forced_unbind_intf(cintf);
6272			}
6273		}
6274	}
6275
6276	usb_lock_port(port_dev);
6277	ret = usb_reset_and_verify_device(udev);
6278	usb_unlock_port(port_dev);
6279
6280	if (config) {
6281		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
6282			struct usb_interface *cintf = config->interface[i];
6283			struct usb_driver *drv;
6284			int rebind = cintf->needs_binding;
6285
6286			if (!rebind && cintf->dev.driver) {
6287				drv = to_usb_driver(cintf->dev.driver);
6288				if (drv->post_reset)
6289					rebind = (drv->post_reset)(cintf);
6290				else if (cintf->condition ==
6291						USB_INTERFACE_BOUND)
6292					rebind = 1;
6293				if (rebind)
6294					cintf->needs_binding = 1;
6295			}
6296		}
6297
6298		/* If the reset failed, hub_wq will unbind drivers later */
6299		if (ret == 0)
6300			usb_unbind_and_rebind_marked_interfaces(udev);
6301	}
6302
6303	usb_autosuspend_device(udev);
6304	memalloc_noio_restore(noio_flag);
6305	udev->reset_in_progress = 0;
6306	return ret;
6307}
6308EXPORT_SYMBOL_GPL(usb_reset_device);
6309
6310
6311/**
6312 * usb_queue_reset_device - Reset a USB device from an atomic context
6313 * @iface: USB interface belonging to the device to reset
6314 *
6315 * This function can be used to reset a USB device from an atomic
6316 * context, where usb_reset_device() won't work (as it blocks).
6317 *
6318 * Doing a reset via this method is functionally equivalent to calling
6319 * usb_reset_device(), except for the fact that it is delayed to a
6320 * workqueue. This means that any drivers bound to other interfaces
6321 * might be unbound, as well as users from usbfs in user space.
6322 *
6323 * Corner cases:
6324 *
6325 * - Scheduling two resets at the same time from two different drivers
6326 *   attached to two different interfaces of the same device is
6327 *   possible; depending on how the driver attached to each interface
6328 *   handles ->pre_reset(), the second reset might happen or not.
6329 *
6330 * - If the reset is delayed so long that the interface is unbound from
6331 *   its driver, the reset will be skipped.
6332 *
6333 * - This function can be called during .probe().  It can also be called
6334 *   during .disconnect(), but doing so is pointless because the reset
6335 *   will not occur.  If you really want to reset the device during
6336 *   .disconnect(), call usb_reset_device() directly -- but watch out
6337 *   for nested unbinding issues!
6338 */
6339void usb_queue_reset_device(struct usb_interface *iface)
6340{
6341	if (schedule_work(&iface->reset_ws))
6342		usb_get_intf(iface);
6343}
6344EXPORT_SYMBOL_GPL(usb_queue_reset_device);
6345
6346/**
6347 * usb_hub_find_child - Get the pointer of child device
6348 * attached to the port which is specified by @port1.
6349 * @hdev: USB device belonging to the usb hub
6350 * @port1: port num to indicate which port the child device
6351 *	is attached to.
6352 *
6353 * USB drivers call this function to get hub's child device
6354 * pointer.
6355 *
6356 * Return: %NULL if input param is invalid and
6357 * child's usb_device pointer if non-NULL.
6358 */
6359struct usb_device *usb_hub_find_child(struct usb_device *hdev,
6360		int port1)
6361{
6362	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6363
6364	if (port1 < 1 || port1 > hdev->maxchild)
6365		return NULL;
6366	return hub->ports[port1 - 1]->child;
6367}
6368EXPORT_SYMBOL_GPL(usb_hub_find_child);
6369
6370void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
6371		struct usb_hub_descriptor *desc)
6372{
6373	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6374	enum usb_port_connect_type connect_type;
6375	int i;
6376
6377	if (!hub)
6378		return;
6379
6380	if (!hub_is_superspeed(hdev)) {
6381		for (i = 1; i <= hdev->maxchild; i++) {
6382			struct usb_port *port_dev = hub->ports[i - 1];
6383
6384			connect_type = port_dev->connect_type;
6385			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
6386				u8 mask = 1 << (i%8);
6387
6388				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
6389					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
6390					desc->u.hs.DeviceRemovable[i/8]	|= mask;
6391				}
6392			}
6393		}
6394	} else {
6395		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
6396
6397		for (i = 1; i <= hdev->maxchild; i++) {
6398			struct usb_port *port_dev = hub->ports[i - 1];
6399
6400			connect_type = port_dev->connect_type;
6401			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
6402				u16 mask = 1 << i;
6403
6404				if (!(port_removable & mask)) {
6405					dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
6406					port_removable |= mask;
6407				}
6408			}
6409		}
6410
6411		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
6412	}
6413}
6414
6415#ifdef CONFIG_ACPI
6416/**
6417 * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
6418 * @hdev: USB device belonging to the usb hub
6419 * @port1: port num of the port
6420 *
6421 * Return: Port's acpi handle if successful, %NULL if params are
6422 * invalid.
6423 */
6424acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
6425	int port1)
6426{
6427	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
6428
6429	if (!hub)
6430		return NULL;
6431
6432	return ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
6433}
6434#endif