1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * USB Network driver infrastructure
   4 * Copyright (C) 2000-2005 by David Brownell
   5 * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
 
 
 
 
 
 
 
 
 
 
 
 
 
   6 */
   7
   8/*
   9 * This is a generic "USB networking" framework that works with several
  10 * kinds of full and high speed networking devices:  host-to-host cables,
  11 * smart usb peripherals, and actual Ethernet adapters.
  12 *
  13 * These devices usually differ in terms of control protocols (if they
  14 * even have one!) and sometimes they define new framing to wrap or batch
  15 * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  16 * so interface (un)binding, endpoint I/O queues, fault handling, and other
  17 * issues can usefully be addressed by this framework.
  18 */
  19
  20// #define	DEBUG			// error path messages, extra info
  21// #define	VERBOSE			// more; success messages
  22
  23#include <linux/module.h>
  24#include <linux/init.h>
  25#include <linux/netdevice.h>
  26#include <linux/etherdevice.h>
  27#include <linux/ctype.h>
  28#include <linux/ethtool.h>
  29#include <linux/workqueue.h>
  30#include <linux/mii.h>
  31#include <linux/usb.h>
  32#include <linux/usb/usbnet.h>
 
  33#include <linux/slab.h>
  34#include <linux/kernel.h>
  35#include <linux/pm_runtime.h>
  36
 
 
 
  37/*-------------------------------------------------------------------------*/
  38
  39/*
  40 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  41 * Several dozen bytes of IPv4 data can fit in two such transactions.
  42 * One maximum size Ethernet packet takes twenty four of them.
  43 * For high speed, each frame comfortably fits almost 36 max size
  44 * Ethernet packets (so queues should be bigger).
  45 *
  46 * The goal is to let the USB host controller be busy for 5msec or
  47 * more before an irq is required, under load.  Jumbograms change
  48 * the equation.
  49 */
  50#define	MAX_QUEUE_MEMORY	(60 * 1518)
  51#define	RX_QLEN(dev)		((dev)->rx_qlen)
  52#define	TX_QLEN(dev)		((dev)->tx_qlen)
  53
  54// reawaken network queue this soon after stopping; else watchdog barks
  55#define TX_TIMEOUT_JIFFIES	(5*HZ)
  56
  57/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  58 * us (it polls at HZ/4 usually) before we report too many false errors.
  59 */
  60#define THROTTLE_JIFFIES	(HZ/8)
  61
  62// between wakeups
  63#define UNLINK_TIMEOUT_MS	3
  64
  65/*-------------------------------------------------------------------------*/
  66
  67// randomly generated ethernet address
  68static u8	node_id [ETH_ALEN];
  69
 
 
  70/* use ethtool to change the level for any given device */
  71static int msg_level = -1;
  72module_param (msg_level, int, 0);
  73MODULE_PARM_DESC (msg_level, "Override default message level");
  74
  75/*-------------------------------------------------------------------------*/
  76
  77static const char * const usbnet_event_names[] = {
  78	[EVENT_TX_HALT]		   = "EVENT_TX_HALT",
  79	[EVENT_RX_HALT]		   = "EVENT_RX_HALT",
  80	[EVENT_RX_MEMORY]	   = "EVENT_RX_MEMORY",
  81	[EVENT_STS_SPLIT]	   = "EVENT_STS_SPLIT",
  82	[EVENT_LINK_RESET]	   = "EVENT_LINK_RESET",
  83	[EVENT_RX_PAUSED]	   = "EVENT_RX_PAUSED",
  84	[EVENT_DEV_ASLEEP]	   = "EVENT_DEV_ASLEEP",
  85	[EVENT_DEV_OPEN]	   = "EVENT_DEV_OPEN",
  86	[EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE",
  87	[EVENT_NO_RUNTIME_PM]	   = "EVENT_NO_RUNTIME_PM",
  88	[EVENT_RX_KILL]		   = "EVENT_RX_KILL",
  89	[EVENT_LINK_CHANGE]	   = "EVENT_LINK_CHANGE",
  90	[EVENT_SET_RX_MODE]	   = "EVENT_SET_RX_MODE",
  91	[EVENT_NO_IP_ALIGN]	   = "EVENT_NO_IP_ALIGN",
  92};
  93
  94/* handles CDC Ethernet and many other network "bulk data" interfaces */
  95int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96{
  97	int				tmp;
  98	struct usb_host_interface	*alt = NULL;
  99	struct usb_host_endpoint	*in = NULL, *out = NULL;
 100	struct usb_host_endpoint	*status = NULL;
 101
 102	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103		unsigned	ep;
 104
 105		in = out = status = NULL;
 106		alt = intf->altsetting + tmp;
 107
 108		/* take the first altsetting with in-bulk + out-bulk;
 109		 * remember any status endpoint, just in case;
 110		 * ignore other endpoints and altsettings.
 111		 */
 112		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113			struct usb_host_endpoint	*e;
 114			int				intr = 0;
 115
 116			e = alt->endpoint + ep;
 117
 118			/* ignore endpoints which cannot transfer data */
 119			if (!usb_endpoint_maxp(&e->desc))
 120				continue;
 121
 122			switch (e->desc.bmAttributes) {
 123			case USB_ENDPOINT_XFER_INT:
 124				if (!usb_endpoint_dir_in(&e->desc))
 125					continue;
 126				intr = 1;
 127				fallthrough;
 128			case USB_ENDPOINT_XFER_BULK:
 129				break;
 130			default:
 131				continue;
 132			}
 133			if (usb_endpoint_dir_in(&e->desc)) {
 134				if (!intr && !in)
 135					in = e;
 136				else if (intr && !status)
 137					status = e;
 138			} else {
 139				if (!out)
 140					out = e;
 141			}
 142		}
 143		if (in && out)
 144			break;
 145	}
 146	if (!alt || !in || !out)
 147		return -EINVAL;
 148
 149	if (alt->desc.bAlternateSetting != 0 ||
 150	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 151		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 152				alt->desc.bAlternateSetting);
 153		if (tmp < 0)
 154			return tmp;
 155	}
 156
 157	dev->in = usb_rcvbulkpipe (dev->udev,
 158			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 159	dev->out = usb_sndbulkpipe (dev->udev,
 160			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 161	dev->status = status;
 162	return 0;
 163}
 164EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 165
 166int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 167{
 168	int 		tmp = -1, ret;
 169	unsigned char	buf [13];
 170
 171	ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 172	if (ret == 12)
 173		tmp = hex2bin(dev->net->dev_addr, buf, 6);
 174	if (tmp < 0) {
 175		dev_dbg(&dev->udev->dev,
 176			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 177		if (ret >= 0)
 178			ret = -EINVAL;
 179		return ret;
 180	}
 181	return 0;
 182}
 183EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 184
 185static void intr_complete (struct urb *urb)
 186{
 187	struct usbnet	*dev = urb->context;
 188	int		status = urb->status;
 189
 190	switch (status) {
 191	/* success */
 192	case 0:
 193		dev->driver_info->status(dev, urb);
 194		break;
 195
 196	/* software-driven interface shutdown */
 197	case -ENOENT:		/* urb killed */
 198	case -ESHUTDOWN:	/* hardware gone */
 199		netif_dbg(dev, ifdown, dev->net,
 200			  "intr shutdown, code %d\n", status);
 201		return;
 202
 203	/* NOTE:  not throttling like RX/TX, since this endpoint
 204	 * already polls infrequently
 205	 */
 206	default:
 207		netdev_dbg(dev->net, "intr status %d\n", status);
 208		break;
 209	}
 210
 211	status = usb_submit_urb (urb, GFP_ATOMIC);
 212	if (status != 0)
 213		netif_err(dev, timer, dev->net,
 214			  "intr resubmit --> %d\n", status);
 215}
 216
 217static int init_status (struct usbnet *dev, struct usb_interface *intf)
 218{
 219	char		*buf = NULL;
 220	unsigned	pipe = 0;
 221	unsigned	maxp;
 222	unsigned	period;
 223
 224	if (!dev->driver_info->status)
 225		return 0;
 226
 227	pipe = usb_rcvintpipe (dev->udev,
 228			dev->status->desc.bEndpointAddress
 229				& USB_ENDPOINT_NUMBER_MASK);
 230	maxp = usb_maxpacket (dev->udev, pipe, 0);
 231
 232	/* avoid 1 msec chatter:  min 8 msec poll rate */
 233	period = max ((int) dev->status->desc.bInterval,
 234		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 235
 236	buf = kmalloc (maxp, GFP_KERNEL);
 237	if (buf) {
 238		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 239		if (!dev->interrupt) {
 240			kfree (buf);
 241			return -ENOMEM;
 242		} else {
 243			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 244				buf, maxp, intr_complete, dev, period);
 245			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 246			dev_dbg(&intf->dev,
 247				"status ep%din, %d bytes period %d\n",
 248				usb_pipeendpoint(pipe), maxp, period);
 249		}
 250	}
 251	return 0;
 252}
 253
 254/* Submit the interrupt URB if not previously submitted, increasing refcount */
 255int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 256{
 257	int ret = 0;
 258
 259	WARN_ON_ONCE(dev->interrupt == NULL);
 260	if (dev->interrupt) {
 261		mutex_lock(&dev->interrupt_mutex);
 262
 263		if (++dev->interrupt_count == 1)
 264			ret = usb_submit_urb(dev->interrupt, mem_flags);
 265
 266		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 267			dev->interrupt_count);
 268		mutex_unlock(&dev->interrupt_mutex);
 269	}
 270	return ret;
 271}
 272EXPORT_SYMBOL_GPL(usbnet_status_start);
 273
 274/* For resume; submit interrupt URB if previously submitted */
 275static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 276{
 277	int ret = 0;
 278
 279	mutex_lock(&dev->interrupt_mutex);
 280	if (dev->interrupt_count) {
 281		ret = usb_submit_urb(dev->interrupt, mem_flags);
 282		dev_dbg(&dev->udev->dev,
 283			"submitted interrupt URB for resume\n");
 284	}
 285	mutex_unlock(&dev->interrupt_mutex);
 286	return ret;
 287}
 288
 289/* Kill the interrupt URB if all submitters want it killed */
 290void usbnet_status_stop(struct usbnet *dev)
 291{
 292	if (dev->interrupt) {
 293		mutex_lock(&dev->interrupt_mutex);
 294		WARN_ON(dev->interrupt_count == 0);
 295
 296		if (dev->interrupt_count && --dev->interrupt_count == 0)
 297			usb_kill_urb(dev->interrupt);
 298
 299		dev_dbg(&dev->udev->dev,
 300			"decremented interrupt URB count to %d\n",
 301			dev->interrupt_count);
 302		mutex_unlock(&dev->interrupt_mutex);
 303	}
 304}
 305EXPORT_SYMBOL_GPL(usbnet_status_stop);
 306
 307/* For suspend; always kill interrupt URB */
 308static void __usbnet_status_stop_force(struct usbnet *dev)
 309{
 310	if (dev->interrupt) {
 311		mutex_lock(&dev->interrupt_mutex);
 312		usb_kill_urb(dev->interrupt);
 313		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 314		mutex_unlock(&dev->interrupt_mutex);
 315	}
 316}
 317
 318/* Passes this packet up the stack, updating its accounting.
 319 * Some link protocols batch packets, so their rx_fixup paths
 320 * can return clones as well as just modify the original skb.
 321 */
 322void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 323{
 324	struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 325	unsigned long flags;
 326	int	status;
 327
 328	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 329		skb_queue_tail(&dev->rxq_pause, skb);
 330		return;
 331	}
 332
 333	/* only update if unset to allow minidriver rx_fixup override */
 334	if (skb->protocol == 0)
 335		skb->protocol = eth_type_trans (skb, dev->net);
 336
 337	flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 338	stats64->rx_packets++;
 339	stats64->rx_bytes += skb->len;
 340	u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 341
 342	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 343		  skb->len + sizeof (struct ethhdr), skb->protocol);
 344	memset (skb->cb, 0, sizeof (struct skb_data));
 345
 346	if (skb_defer_rx_timestamp(skb))
 347		return;
 348
 349	status = netif_rx (skb);
 350	if (status != NET_RX_SUCCESS)
 351		netif_dbg(dev, rx_err, dev->net,
 352			  "netif_rx status %d\n", status);
 353}
 354EXPORT_SYMBOL_GPL(usbnet_skb_return);
 355
 356/* must be called if hard_mtu or rx_urb_size changed */
 357void usbnet_update_max_qlen(struct usbnet *dev)
 358{
 359	enum usb_device_speed speed = dev->udev->speed;
 360
 361	if (!dev->rx_urb_size || !dev->hard_mtu)
 362		goto insanity;
 363	switch (speed) {
 364	case USB_SPEED_HIGH:
 365		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 366		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 367		break;
 368	case USB_SPEED_SUPER:
 369	case USB_SPEED_SUPER_PLUS:
 370		/*
 371		 * Not take default 5ms qlen for super speed HC to
 372		 * save memory, and iperf tests show 2.5ms qlen can
 373		 * work well
 374		 */
 375		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 376		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 377		break;
 378	default:
 379insanity:
 380		dev->rx_qlen = dev->tx_qlen = 4;
 381	}
 382}
 383EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 384
 385
 386/*-------------------------------------------------------------------------
 387 *
 388 * Network Device Driver (peer link to "Host Device", from USB host)
 389 *
 390 *-------------------------------------------------------------------------*/
 391
 392int usbnet_change_mtu (struct net_device *net, int new_mtu)
 393{
 394	struct usbnet	*dev = netdev_priv(net);
 395	int		ll_mtu = new_mtu + net->hard_header_len;
 396	int		old_hard_mtu = dev->hard_mtu;
 397	int		old_rx_urb_size = dev->rx_urb_size;
 398
 
 
 399	// no second zero-length packet read wanted after mtu-sized packets
 400	if ((ll_mtu % dev->maxpacket) == 0)
 401		return -EDOM;
 402	net->mtu = new_mtu;
 403
 404	dev->hard_mtu = net->mtu + net->hard_header_len;
 405	if (dev->rx_urb_size == old_hard_mtu) {
 406		dev->rx_urb_size = dev->hard_mtu;
 407		if (dev->rx_urb_size > old_rx_urb_size) {
 408			usbnet_pause_rx(dev);
 409			usbnet_unlink_rx_urbs(dev);
 410			usbnet_resume_rx(dev);
 411		}
 412	}
 413
 414	/* max qlen depend on hard_mtu and rx_urb_size */
 415	usbnet_update_max_qlen(dev);
 416
 417	return 0;
 418}
 419EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 420
 421/* The caller must hold list->lock */
 422static void __usbnet_queue_skb(struct sk_buff_head *list,
 423			struct sk_buff *newsk, enum skb_state state)
 424{
 425	struct skb_data *entry = (struct skb_data *) newsk->cb;
 426
 427	__skb_queue_tail(list, newsk);
 428	entry->state = state;
 429}
 430
 431/*-------------------------------------------------------------------------*/
 432
 433/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 434 * completion callbacks.  2.5 should have fixed those bugs...
 435 */
 436
 437static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 438		struct sk_buff_head *list, enum skb_state state)
 439{
 440	unsigned long		flags;
 441	enum skb_state 		old_state;
 442	struct skb_data *entry = (struct skb_data *) skb->cb;
 443
 444	spin_lock_irqsave(&list->lock, flags);
 445	old_state = entry->state;
 446	entry->state = state;
 447	__skb_unlink(skb, list);
 448
 449	/* defer_bh() is never called with list == &dev->done.
 450	 * spin_lock_nested() tells lockdep that it is OK to take
 451	 * dev->done.lock here with list->lock held.
 452	 */
 453	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 454
 455	__skb_queue_tail(&dev->done, skb);
 456	if (dev->done.qlen == 1)
 457		tasklet_schedule(&dev->bh);
 458	spin_unlock(&dev->done.lock);
 459	spin_unlock_irqrestore(&list->lock, flags);
 460	return old_state;
 461}
 462
 463/* some work can't be done in tasklets, so we use keventd
 464 *
 465 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 466 * but tasklet_schedule() doesn't.  hope the failure is rare.
 467 */
 468void usbnet_defer_kevent (struct usbnet *dev, int work)
 469{
 470	set_bit (work, &dev->flags);
 471	if (!schedule_work (&dev->kevent))
 472		netdev_dbg(dev->net, "kevent %s may have been dropped\n", usbnet_event_names[work]);
 473	else
 474		netdev_dbg(dev->net, "kevent %s scheduled\n", usbnet_event_names[work]);
 
 
 475}
 476EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 477
 478/*-------------------------------------------------------------------------*/
 479
 480static void rx_complete (struct urb *urb);
 481
 482static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 483{
 484	struct sk_buff		*skb;
 485	struct skb_data		*entry;
 486	int			retval = 0;
 487	unsigned long		lockflags;
 488	size_t			size = dev->rx_urb_size;
 489
 490	/* prevent rx skb allocation when error ratio is high */
 491	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 492		usb_free_urb(urb);
 493		return -ENOLINK;
 494	}
 495
 496	if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 497		skb = __netdev_alloc_skb(dev->net, size, flags);
 498	else
 499		skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 500	if (!skb) {
 501		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 502		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 503		usb_free_urb (urb);
 504		return -ENOMEM;
 505	}
 506
 507	entry = (struct skb_data *) skb->cb;
 508	entry->urb = urb;
 509	entry->dev = dev;
 510	entry->length = 0;
 511
 512	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 513		skb->data, size, rx_complete, skb);
 514
 515	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 516
 517	if (netif_running (dev->net) &&
 518	    netif_device_present (dev->net) &&
 519	    test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 520	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 521	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 522		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 523		case -EPIPE:
 524			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 525			break;
 526		case -ENOMEM:
 527			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 528			break;
 529		case -ENODEV:
 530			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 531			netif_device_detach (dev->net);
 532			break;
 533		case -EHOSTUNREACH:
 534			retval = -ENOLINK;
 535			break;
 536		default:
 537			netif_dbg(dev, rx_err, dev->net,
 538				  "rx submit, %d\n", retval);
 539			tasklet_schedule (&dev->bh);
 540			break;
 541		case 0:
 542			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
 543		}
 544	} else {
 545		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 546		retval = -ENOLINK;
 547	}
 548	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 549	if (retval) {
 550		dev_kfree_skb_any (skb);
 551		usb_free_urb (urb);
 552	}
 553	return retval;
 554}
 555
 556
 557/*-------------------------------------------------------------------------*/
 558
 559static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 560{
 561	if (dev->driver_info->rx_fixup &&
 562	    !dev->driver_info->rx_fixup (dev, skb)) {
 563		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 564		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 565			dev->net->stats.rx_errors++;
 566		goto done;
 567	}
 568	// else network stack removes extra byte if we forced a short packet
 569
 570	/* all data was already cloned from skb inside the driver */
 571	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 572		goto done;
 573
 574	if (skb->len < ETH_HLEN) {
 575		dev->net->stats.rx_errors++;
 576		dev->net->stats.rx_length_errors++;
 577		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 578	} else {
 579		usbnet_skb_return(dev, skb);
 580		return;
 581	}
 582
 583done:
 584	skb_queue_tail(&dev->done, skb);
 585}
 586
 587/*-------------------------------------------------------------------------*/
 588
 589static void rx_complete (struct urb *urb)
 590{
 591	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 592	struct skb_data		*entry = (struct skb_data *) skb->cb;
 593	struct usbnet		*dev = entry->dev;
 594	int			urb_status = urb->status;
 595	enum skb_state		state;
 596
 597	skb_put (skb, urb->actual_length);
 598	state = rx_done;
 599	entry->urb = NULL;
 600
 601	switch (urb_status) {
 602	/* success */
 603	case 0:
 604		break;
 605
 606	/* stalls need manual reset. this is rare ... except that
 607	 * when going through USB 2.0 TTs, unplug appears this way.
 608	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 609	 * storm, recovering as needed.
 610	 */
 611	case -EPIPE:
 612		dev->net->stats.rx_errors++;
 613		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 614		fallthrough;
 615
 616	/* software-driven interface shutdown */
 617	case -ECONNRESET:		/* async unlink */
 618	case -ESHUTDOWN:		/* hardware gone */
 619		netif_dbg(dev, ifdown, dev->net,
 620			  "rx shutdown, code %d\n", urb_status);
 621		goto block;
 622
 623	/* we get controller i/o faults during hub_wq disconnect() delays.
 624	 * throttle down resubmits, to avoid log floods; just temporarily,
 625	 * so we still recover when the fault isn't a hub_wq delay.
 626	 */
 627	case -EPROTO:
 628	case -ETIME:
 629	case -EILSEQ:
 630		dev->net->stats.rx_errors++;
 631		if (!timer_pending (&dev->delay)) {
 632			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 633			netif_dbg(dev, link, dev->net,
 634				  "rx throttle %d\n", urb_status);
 635		}
 636block:
 637		state = rx_cleanup;
 638		entry->urb = urb;
 639		urb = NULL;
 640		break;
 641
 642	/* data overrun ... flush fifo? */
 643	case -EOVERFLOW:
 644		dev->net->stats.rx_over_errors++;
 645		fallthrough;
 646
 647	default:
 648		state = rx_cleanup;
 649		dev->net->stats.rx_errors++;
 650		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 651		break;
 652	}
 653
 654	/* stop rx if packet error rate is high */
 655	if (++dev->pkt_cnt > 30) {
 656		dev->pkt_cnt = 0;
 657		dev->pkt_err = 0;
 658	} else {
 659		if (state == rx_cleanup)
 660			dev->pkt_err++;
 661		if (dev->pkt_err > 20)
 662			set_bit(EVENT_RX_KILL, &dev->flags);
 663	}
 664
 665	state = defer_bh(dev, skb, &dev->rxq, state);
 666
 667	if (urb) {
 668		if (netif_running (dev->net) &&
 669		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 670		    state != unlink_start) {
 671			rx_submit (dev, urb, GFP_ATOMIC);
 672			usb_mark_last_busy(dev->udev);
 673			return;
 674		}
 675		usb_free_urb (urb);
 676	}
 677	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 678}
 679
 680/*-------------------------------------------------------------------------*/
 681void usbnet_pause_rx(struct usbnet *dev)
 682{
 683	set_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 686}
 687EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 688
 689void usbnet_resume_rx(struct usbnet *dev)
 690{
 691	struct sk_buff *skb;
 692	int num = 0;
 693
 694	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 695
 696	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 697		usbnet_skb_return(dev, skb);
 698		num++;
 699	}
 700
 701	tasklet_schedule(&dev->bh);
 702
 703	netif_dbg(dev, rx_status, dev->net,
 704		  "paused rx queue disabled, %d skbs requeued\n", num);
 705}
 706EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 707
 708void usbnet_purge_paused_rxq(struct usbnet *dev)
 709{
 710	skb_queue_purge(&dev->rxq_pause);
 711}
 712EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 713
 714/*-------------------------------------------------------------------------*/
 715
 716// unlink pending rx/tx; completion handlers do all other cleanup
 717
 718static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 719{
 720	unsigned long		flags;
 721	struct sk_buff		*skb;
 722	int			count = 0;
 723
 724	spin_lock_irqsave (&q->lock, flags);
 725	while (!skb_queue_empty(q)) {
 726		struct skb_data		*entry;
 727		struct urb		*urb;
 728		int			retval;
 729
 730		skb_queue_walk(q, skb) {
 731			entry = (struct skb_data *) skb->cb;
 732			if (entry->state != unlink_start)
 733				goto found;
 734		}
 735		break;
 736found:
 737		entry->state = unlink_start;
 738		urb = entry->urb;
 739
 740		/*
 741		 * Get reference count of the URB to avoid it to be
 742		 * freed during usb_unlink_urb, which may trigger
 743		 * use-after-free problem inside usb_unlink_urb since
 744		 * usb_unlink_urb is always racing with .complete
 745		 * handler(include defer_bh).
 746		 */
 747		usb_get_urb(urb);
 748		spin_unlock_irqrestore(&q->lock, flags);
 749		// during some PM-driven resume scenarios,
 750		// these (async) unlinks complete immediately
 751		retval = usb_unlink_urb (urb);
 752		if (retval != -EINPROGRESS && retval != 0)
 753			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 754		else
 755			count++;
 756		usb_put_urb(urb);
 757		spin_lock_irqsave(&q->lock, flags);
 758	}
 759	spin_unlock_irqrestore (&q->lock, flags);
 760	return count;
 761}
 762
 763// Flush all pending rx urbs
 764// minidrivers may need to do this when the MTU changes
 765
 766void usbnet_unlink_rx_urbs(struct usbnet *dev)
 767{
 768	if (netif_running(dev->net)) {
 769		(void) unlink_urbs (dev, &dev->rxq);
 770		tasklet_schedule(&dev->bh);
 771	}
 772}
 773EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 774
 775/*-------------------------------------------------------------------------*/
 776
 777static void wait_skb_queue_empty(struct sk_buff_head *q)
 778{
 779	unsigned long flags;
 780
 781	spin_lock_irqsave(&q->lock, flags);
 782	while (!skb_queue_empty(q)) {
 783		spin_unlock_irqrestore(&q->lock, flags);
 784		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 785		set_current_state(TASK_UNINTERRUPTIBLE);
 786		spin_lock_irqsave(&q->lock, flags);
 787	}
 788	spin_unlock_irqrestore(&q->lock, flags);
 789}
 790
 791// precondition: never called in_interrupt
 792static void usbnet_terminate_urbs(struct usbnet *dev)
 793{
 794	DECLARE_WAITQUEUE(wait, current);
 795	int temp;
 796
 797	/* ensure there are no more active urbs */
 798	add_wait_queue(&dev->wait, &wait);
 799	set_current_state(TASK_UNINTERRUPTIBLE);
 800	temp = unlink_urbs(dev, &dev->txq) +
 801		unlink_urbs(dev, &dev->rxq);
 802
 803	/* maybe wait for deletions to finish. */
 804	wait_skb_queue_empty(&dev->rxq);
 805	wait_skb_queue_empty(&dev->txq);
 806	wait_skb_queue_empty(&dev->done);
 807	netif_dbg(dev, ifdown, dev->net,
 808		  "waited for %d urb completions\n", temp);
 809	set_current_state(TASK_RUNNING);
 810	remove_wait_queue(&dev->wait, &wait);
 811}
 812
 813int usbnet_stop (struct net_device *net)
 814{
 815	struct usbnet		*dev = netdev_priv(net);
 816	const struct driver_info *info = dev->driver_info;
 817	int			retval, pm, mpn;
 818
 819	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 820	netif_stop_queue (net);
 821
 822	netif_info(dev, ifdown, dev->net,
 823		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 824		   net->stats.rx_packets, net->stats.tx_packets,
 825		   net->stats.rx_errors, net->stats.tx_errors);
 826
 827	/* to not race resume */
 828	pm = usb_autopm_get_interface(dev->intf);
 829	/* allow minidriver to stop correctly (wireless devices to turn off
 830	 * radio etc) */
 831	if (info->stop) {
 832		retval = info->stop(dev);
 833		if (retval < 0)
 834			netif_info(dev, ifdown, dev->net,
 835				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 836				   retval,
 837				   dev->udev->bus->bus_name, dev->udev->devpath,
 838				   info->description);
 839	}
 840
 841	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 842		usbnet_terminate_urbs(dev);
 843
 844	usbnet_status_stop(dev);
 845
 846	usbnet_purge_paused_rxq(dev);
 847
 848	mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 849
 850	/* deferred work (task, timer, softirq) must also stop.
 851	 * can't flush_scheduled_work() until we drop rtnl (later),
 852	 * else workers could deadlock; so make workers a NOP.
 853	 */
 854	dev->flags = 0;
 855	del_timer_sync (&dev->delay);
 856	tasklet_kill (&dev->bh);
 857	if (!pm)
 858		usb_autopm_put_interface(dev->intf);
 859
 860	if (info->manage_power && mpn)
 861		info->manage_power(dev, 0);
 862	else
 863		usb_autopm_put_interface(dev->intf);
 864
 865	return 0;
 866}
 867EXPORT_SYMBOL_GPL(usbnet_stop);
 868
 869/*-------------------------------------------------------------------------*/
 870
 871// posts reads, and enables write queuing
 872
 873// precondition: never called in_interrupt
 874
 875int usbnet_open (struct net_device *net)
 876{
 877	struct usbnet		*dev = netdev_priv(net);
 878	int			retval;
 879	const struct driver_info *info = dev->driver_info;
 880
 881	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 882		netif_info(dev, ifup, dev->net,
 883			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 884			   retval,
 885			   dev->udev->bus->bus_name,
 886			   dev->udev->devpath,
 887			   info->description);
 888		goto done_nopm;
 889	}
 890
 891	// put into "known safe" state
 892	if (info->reset && (retval = info->reset (dev)) < 0) {
 893		netif_info(dev, ifup, dev->net,
 894			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 895			   retval,
 896			   dev->udev->bus->bus_name,
 897			   dev->udev->devpath,
 898			   info->description);
 899		goto done;
 900	}
 901
 902	/* hard_mtu or rx_urb_size may change in reset() */
 903	usbnet_update_max_qlen(dev);
 904
 905	// insist peer be connected
 906	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 907		netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 908		goto done;
 909	}
 910
 911	/* start any status interrupt transfer */
 912	if (dev->interrupt) {
 913		retval = usbnet_status_start(dev, GFP_KERNEL);
 914		if (retval < 0) {
 915			netif_err(dev, ifup, dev->net,
 916				  "intr submit %d\n", retval);
 917			goto done;
 918		}
 919	}
 920
 921	set_bit(EVENT_DEV_OPEN, &dev->flags);
 922	netif_start_queue (net);
 923	netif_info(dev, ifup, dev->net,
 924		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 925		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 926		   dev->net->mtu,
 927		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 928		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 929		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 930		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 931		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 932		   "simple");
 933
 934	/* reset rx error state */
 935	dev->pkt_cnt = 0;
 936	dev->pkt_err = 0;
 937	clear_bit(EVENT_RX_KILL, &dev->flags);
 938
 939	// delay posting reads until we're fully open
 940	tasklet_schedule (&dev->bh);
 941	if (info->manage_power) {
 942		retval = info->manage_power(dev, 1);
 943		if (retval < 0) {
 944			retval = 0;
 945			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 946		} else {
 947			usb_autopm_put_interface(dev->intf);
 948		}
 949	}
 950	return retval;
 951done:
 952	usb_autopm_put_interface(dev->intf);
 953done_nopm:
 954	return retval;
 955}
 956EXPORT_SYMBOL_GPL(usbnet_open);
 957
 958/*-------------------------------------------------------------------------*/
 959
 960/* ethtool methods; minidrivers may need to add some more, but
 961 * they'll probably want to use this base set.
 962 */
 963
 964/* These methods are written on the assumption that the device
 965 * uses MII
 966 */
 967int usbnet_get_link_ksettings_mii(struct net_device *net,
 968			      struct ethtool_link_ksettings *cmd)
 969{
 970	struct usbnet *dev = netdev_priv(net);
 971
 972	if (!dev->mii.mdio_read)
 973		return -EOPNOTSUPP;
 974
 975	mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 976
 977	return 0;
 978}
 979EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 980
 981int usbnet_get_link_ksettings_internal(struct net_device *net,
 982					struct ethtool_link_ksettings *cmd)
 983{
 984	struct usbnet *dev = netdev_priv(net);
 985
 986	/* the assumption that speed is equal on tx and rx
 987	 * is deeply engrained into the networking layer.
 988	 * For wireless stuff it is not true.
 989	 * We assume that rx_speed matters more.
 990	 */
 991	if (dev->rx_speed != SPEED_UNSET)
 992		cmd->base.speed = dev->rx_speed / 1000000;
 993	else if (dev->tx_speed != SPEED_UNSET)
 994		cmd->base.speed = dev->tx_speed / 1000000;
 995	else
 996		cmd->base.speed = SPEED_UNKNOWN;
 997
 998	return 0;
 999}
1000EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
1001
1002int usbnet_set_link_ksettings_mii(struct net_device *net,
1003			      const struct ethtool_link_ksettings *cmd)
1004{
1005	struct usbnet *dev = netdev_priv(net);
1006	int retval;
1007
1008	if (!dev->mii.mdio_write)
1009		return -EOPNOTSUPP;
1010
1011	retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1012
1013	/* link speed/duplex might have changed */
1014	if (dev->driver_info->link_reset)
1015		dev->driver_info->link_reset(dev);
1016
1017	/* hard_mtu or rx_urb_size may change in link_reset() */
1018	usbnet_update_max_qlen(dev);
1019
1020	return retval;
 
1021}
1022EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1023
1024u32 usbnet_get_link (struct net_device *net)
1025{
1026	struct usbnet *dev = netdev_priv(net);
1027
1028	/* If a check_connect is defined, return its result */
1029	if (dev->driver_info->check_connect)
1030		return dev->driver_info->check_connect (dev) == 0;
1031
1032	/* if the device has mii operations, use those */
1033	if (dev->mii.mdio_read)
1034		return mii_link_ok(&dev->mii);
1035
1036	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1037	return ethtool_op_get_link(net);
1038}
1039EXPORT_SYMBOL_GPL(usbnet_get_link);
1040
1041int usbnet_nway_reset(struct net_device *net)
1042{
1043	struct usbnet *dev = netdev_priv(net);
1044
1045	if (!dev->mii.mdio_write)
1046		return -EOPNOTSUPP;
1047
1048	return mii_nway_restart(&dev->mii);
1049}
1050EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1051
1052void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1053{
1054	struct usbnet *dev = netdev_priv(net);
1055
1056	strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 
1057	strlcpy (info->fw_version, dev->driver_info->description,
1058		sizeof info->fw_version);
1059	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1060}
1061EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1062
1063u32 usbnet_get_msglevel (struct net_device *net)
1064{
1065	struct usbnet *dev = netdev_priv(net);
1066
1067	return dev->msg_enable;
1068}
1069EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1070
1071void usbnet_set_msglevel (struct net_device *net, u32 level)
1072{
1073	struct usbnet *dev = netdev_priv(net);
1074
1075	dev->msg_enable = level;
1076}
1077EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1078
1079/* drivers may override default ethtool_ops in their bind() routine */
1080static const struct ethtool_ops usbnet_ethtool_ops = {
 
 
1081	.get_link		= usbnet_get_link,
1082	.nway_reset		= usbnet_nway_reset,
1083	.get_drvinfo		= usbnet_get_drvinfo,
1084	.get_msglevel		= usbnet_get_msglevel,
1085	.set_msglevel		= usbnet_set_msglevel,
1086	.get_ts_info		= ethtool_op_get_ts_info,
1087	.get_link_ksettings	= usbnet_get_link_ksettings_mii,
1088	.set_link_ksettings	= usbnet_set_link_ksettings_mii,
1089};
1090
1091/*-------------------------------------------------------------------------*/
1092
1093static void __handle_link_change(struct usbnet *dev)
1094{
1095	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1096		return;
1097
1098	if (!netif_carrier_ok(dev->net)) {
1099		/* kill URBs for reading packets to save bus bandwidth */
1100		unlink_urbs(dev, &dev->rxq);
1101
1102		/*
1103		 * tx_timeout will unlink URBs for sending packets and
1104		 * tx queue is stopped by netcore after link becomes off
1105		 */
1106	} else {
1107		/* submitting URBs for reading packets */
1108		tasklet_schedule(&dev->bh);
1109	}
1110
1111	/* hard_mtu or rx_urb_size may change during link change */
1112	usbnet_update_max_qlen(dev);
1113
1114	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1115}
1116
1117void usbnet_set_rx_mode(struct net_device *net)
1118{
1119	struct usbnet		*dev = netdev_priv(net);
1120
1121	usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1122}
1123EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1124
1125static void __handle_set_rx_mode(struct usbnet *dev)
1126{
1127	if (dev->driver_info->set_rx_mode)
1128		(dev->driver_info->set_rx_mode)(dev);
1129
1130	clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1131}
1132
1133/* work that cannot be done in interrupt context uses keventd.
1134 *
1135 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1136 * especially now that control transfers can be queued.
1137 */
1138static void
1139usbnet_deferred_kevent (struct work_struct *work)
1140{
1141	struct usbnet		*dev =
1142		container_of(work, struct usbnet, kevent);
1143	int			status;
1144
1145	/* usb_clear_halt() needs a thread context */
1146	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1147		unlink_urbs (dev, &dev->txq);
1148		status = usb_autopm_get_interface(dev->intf);
1149		if (status < 0)
1150			goto fail_pipe;
1151		status = usb_clear_halt (dev->udev, dev->out);
1152		usb_autopm_put_interface(dev->intf);
1153		if (status < 0 &&
1154		    status != -EPIPE &&
1155		    status != -ESHUTDOWN) {
1156			if (netif_msg_tx_err (dev))
1157fail_pipe:
1158				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1159					   status);
1160		} else {
1161			clear_bit (EVENT_TX_HALT, &dev->flags);
1162			if (status != -ESHUTDOWN)
1163				netif_wake_queue (dev->net);
1164		}
1165	}
1166	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1167		unlink_urbs (dev, &dev->rxq);
1168		status = usb_autopm_get_interface(dev->intf);
1169		if (status < 0)
1170			goto fail_halt;
1171		status = usb_clear_halt (dev->udev, dev->in);
1172		usb_autopm_put_interface(dev->intf);
1173		if (status < 0 &&
1174		    status != -EPIPE &&
1175		    status != -ESHUTDOWN) {
1176			if (netif_msg_rx_err (dev))
1177fail_halt:
1178				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1179					   status);
1180		} else {
1181			clear_bit (EVENT_RX_HALT, &dev->flags);
1182			tasklet_schedule (&dev->bh);
1183		}
1184	}
1185
1186	/* tasklet could resubmit itself forever if memory is tight */
1187	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1188		struct urb	*urb = NULL;
1189		int resched = 1;
1190
1191		if (netif_running (dev->net))
1192			urb = usb_alloc_urb (0, GFP_KERNEL);
1193		else
1194			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1195		if (urb != NULL) {
1196			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1197			status = usb_autopm_get_interface(dev->intf);
1198			if (status < 0) {
1199				usb_free_urb(urb);
1200				goto fail_lowmem;
1201			}
1202			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1203				resched = 0;
1204			usb_autopm_put_interface(dev->intf);
1205fail_lowmem:
1206			if (resched)
1207				tasklet_schedule (&dev->bh);
1208		}
1209	}
1210
1211	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1212		const struct driver_info *info = dev->driver_info;
1213		int			retval = 0;
1214
1215		clear_bit (EVENT_LINK_RESET, &dev->flags);
1216		status = usb_autopm_get_interface(dev->intf);
1217		if (status < 0)
1218			goto skip_reset;
1219		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1220			usb_autopm_put_interface(dev->intf);
1221skip_reset:
1222			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1223				    retval,
1224				    dev->udev->bus->bus_name,
1225				    dev->udev->devpath,
1226				    info->description);
1227		} else {
1228			usb_autopm_put_interface(dev->intf);
1229		}
1230
1231		/* handle link change from link resetting */
1232		__handle_link_change(dev);
1233	}
1234
1235	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1236		__handle_link_change(dev);
1237
1238	if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1239		__handle_set_rx_mode(dev);
1240
1241
1242	if (dev->flags)
1243		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1244}
1245
1246/*-------------------------------------------------------------------------*/
1247
1248static void tx_complete (struct urb *urb)
1249{
1250	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1251	struct skb_data		*entry = (struct skb_data *) skb->cb;
1252	struct usbnet		*dev = entry->dev;
1253
1254	if (urb->status == 0) {
1255		struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1256		unsigned long flags;
1257
1258		flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1259		stats64->tx_packets += entry->packets;
1260		stats64->tx_bytes += entry->length;
1261		u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1262	} else {
1263		dev->net->stats.tx_errors++;
1264
1265		switch (urb->status) {
1266		case -EPIPE:
1267			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1268			break;
1269
1270		/* software-driven interface shutdown */
1271		case -ECONNRESET:		// async unlink
1272		case -ESHUTDOWN:		// hardware gone
1273			break;
1274
1275		/* like rx, tx gets controller i/o faults during hub_wq
1276		 * delays and so it uses the same throttling mechanism.
1277		 */
1278		case -EPROTO:
1279		case -ETIME:
1280		case -EILSEQ:
1281			usb_mark_last_busy(dev->udev);
1282			if (!timer_pending (&dev->delay)) {
1283				mod_timer (&dev->delay,
1284					jiffies + THROTTLE_JIFFIES);
1285				netif_dbg(dev, link, dev->net,
1286					  "tx throttle %d\n", urb->status);
1287			}
1288			netif_stop_queue (dev->net);
1289			break;
1290		default:
1291			netif_dbg(dev, tx_err, dev->net,
1292				  "tx err %d\n", entry->urb->status);
1293			break;
1294		}
1295	}
1296
1297	usb_autopm_put_interface_async(dev->intf);
1298	(void) defer_bh(dev, skb, &dev->txq, tx_done);
1299}
1300
1301/*-------------------------------------------------------------------------*/
1302
1303void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1304{
1305	struct usbnet		*dev = netdev_priv(net);
1306
1307	unlink_urbs (dev, &dev->txq);
1308	tasklet_schedule (&dev->bh);
1309	/* this needs to be handled individually because the generic layer
1310	 * doesn't know what is sufficient and could not restore private
1311	 * information if a remedy of an unconditional reset were used.
1312	 */
1313	if (dev->driver_info->recover)
1314		(dev->driver_info->recover)(dev);
1315}
1316EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1317
1318/*-------------------------------------------------------------------------*/
1319
1320static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1321{
1322	unsigned num_sgs, total_len = 0;
1323	int i, s = 0;
1324
1325	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1326	if (num_sgs == 1)
1327		return 0;
1328
1329	/* reserve one for zero packet */
1330	urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1331				GFP_ATOMIC);
1332	if (!urb->sg)
1333		return -ENOMEM;
1334
1335	urb->num_sgs = num_sgs;
1336	sg_init_table(urb->sg, urb->num_sgs + 1);
1337
1338	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1339	total_len += skb_headlen(skb);
1340
1341	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1342		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1343
1344		total_len += skb_frag_size(f);
1345		sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1346			    skb_frag_off(f));
1347	}
1348	urb->transfer_buffer_length = total_len;
1349
1350	return 1;
1351}
1352
1353netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1354				     struct net_device *net)
1355{
1356	struct usbnet		*dev = netdev_priv(net);
1357	unsigned int			length;
1358	struct urb		*urb = NULL;
1359	struct skb_data		*entry;
1360	const struct driver_info *info = dev->driver_info;
1361	unsigned long		flags;
1362	int retval;
1363
1364	if (skb)
1365		skb_tx_timestamp(skb);
1366
1367	// some devices want funky USB-level framing, for
1368	// win32 driver (usually) and/or hardware quirks
1369	if (info->tx_fixup) {
1370		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1371		if (!skb) {
1372			/* packet collected; minidriver waiting for more */
1373			if (info->flags & FLAG_MULTI_PACKET)
1374				goto not_drop;
1375			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1376			goto drop;
1377		}
1378	}
1379
1380	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1381		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1382		goto drop;
1383	}
1384
1385	entry = (struct skb_data *) skb->cb;
1386	entry->urb = urb;
1387	entry->dev = dev;
1388
1389	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1390			skb->data, skb->len, tx_complete, skb);
1391	if (dev->can_dma_sg) {
1392		if (build_dma_sg(skb, urb) < 0)
1393			goto drop;
1394	}
1395	length = urb->transfer_buffer_length;
1396
1397	/* don't assume the hardware handles USB_ZERO_PACKET
1398	 * NOTE:  strictly conforming cdc-ether devices should expect
1399	 * the ZLP here, but ignore the one-byte packet.
1400	 * NOTE2: CDC NCM specification is different from CDC ECM when
1401	 * handling ZLP/short packets, so cdc_ncm driver will make short
1402	 * packet itself if needed.
1403	 */
1404	if (length % dev->maxpacket == 0) {
1405		if (!(info->flags & FLAG_SEND_ZLP)) {
1406			if (!(info->flags & FLAG_MULTI_PACKET)) {
1407				length++;
1408				if (skb_tailroom(skb) && !urb->num_sgs) {
1409					skb->data[skb->len] = 0;
1410					__skb_put(skb, 1);
1411				} else if (urb->num_sgs)
1412					sg_set_buf(&urb->sg[urb->num_sgs++],
1413							dev->padding_pkt, 1);
1414			}
1415		} else
1416			urb->transfer_flags |= URB_ZERO_PACKET;
1417	}
1418	urb->transfer_buffer_length = length;
1419
1420	if (info->flags & FLAG_MULTI_PACKET) {
1421		/* Driver has set number of packets and a length delta.
1422		 * Calculate the complete length and ensure that it's
1423		 * positive.
1424		 */
1425		entry->length += length;
1426		if (WARN_ON_ONCE(entry->length <= 0))
1427			entry->length = length;
1428	} else {
1429		usbnet_set_skb_tx_stats(skb, 1, length);
1430	}
1431
1432	spin_lock_irqsave(&dev->txq.lock, flags);
1433	retval = usb_autopm_get_interface_async(dev->intf);
1434	if (retval < 0) {
1435		spin_unlock_irqrestore(&dev->txq.lock, flags);
1436		goto drop;
1437	}
1438	if (netif_queue_stopped(net)) {
1439		usb_autopm_put_interface_async(dev->intf);
1440		spin_unlock_irqrestore(&dev->txq.lock, flags);
1441		goto drop;
1442	}
1443
1444#ifdef CONFIG_PM
1445	/* if this triggers the device is still a sleep */
1446	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1447		/* transmission will be done in resume */
1448		usb_anchor_urb(urb, &dev->deferred);
1449		/* no use to process more packets */
1450		netif_stop_queue(net);
1451		usb_put_urb(urb);
1452		spin_unlock_irqrestore(&dev->txq.lock, flags);
1453		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1454		goto deferred;
1455	}
1456#endif
1457
1458	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1459	case -EPIPE:
1460		netif_stop_queue (net);
1461		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1462		usb_autopm_put_interface_async(dev->intf);
1463		break;
1464	default:
1465		usb_autopm_put_interface_async(dev->intf);
1466		netif_dbg(dev, tx_err, dev->net,
1467			  "tx: submit urb err %d\n", retval);
1468		break;
1469	case 0:
1470		netif_trans_update(net);
1471		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1472		if (dev->txq.qlen >= TX_QLEN (dev))
1473			netif_stop_queue (net);
1474	}
1475	spin_unlock_irqrestore (&dev->txq.lock, flags);
1476
1477	if (retval) {
1478		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1479drop:
1480		dev->net->stats.tx_dropped++;
1481not_drop:
1482		if (skb)
1483			dev_kfree_skb_any (skb);
1484		if (urb) {
1485			kfree(urb->sg);
1486			usb_free_urb(urb);
1487		}
1488	} else
1489		netif_dbg(dev, tx_queued, dev->net,
1490			  "> tx, len %u, type 0x%x\n", length, skb->protocol);
1491#ifdef CONFIG_PM
1492deferred:
1493#endif
1494	return NETDEV_TX_OK;
1495}
1496EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1497
1498static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1499{
1500	struct urb	*urb;
1501	int		i;
1502	int		ret = 0;
1503
1504	/* don't refill the queue all at once */
1505	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1506		urb = usb_alloc_urb(0, flags);
1507		if (urb != NULL) {
1508			ret = rx_submit(dev, urb, flags);
1509			if (ret)
1510				goto err;
1511		} else {
1512			ret = -ENOMEM;
1513			goto err;
1514		}
1515	}
1516err:
1517	return ret;
1518}
1519
1520/*-------------------------------------------------------------------------*/
1521
1522// tasklet (work deferred from completions, in_irq) or timer
1523
1524static void usbnet_bh (struct timer_list *t)
1525{
1526	struct usbnet		*dev = from_timer(dev, t, delay);
1527	struct sk_buff		*skb;
1528	struct skb_data		*entry;
1529
1530	while ((skb = skb_dequeue (&dev->done))) {
1531		entry = (struct skb_data *) skb->cb;
1532		switch (entry->state) {
1533		case rx_done:
1534			entry->state = rx_cleanup;
1535			rx_process (dev, skb);
1536			continue;
1537		case tx_done:
1538			kfree(entry->urb->sg);
1539			fallthrough;
1540		case rx_cleanup:
1541			usb_free_urb (entry->urb);
1542			dev_kfree_skb (skb);
1543			continue;
1544		default:
1545			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1546		}
1547	}
1548
1549	/* restart RX again after disabling due to high error rate */
1550	clear_bit(EVENT_RX_KILL, &dev->flags);
1551
1552	/* waiting for all pending urbs to complete?
1553	 * only then can we forgo submitting anew
1554	 */
1555	if (waitqueue_active(&dev->wait)) {
1556		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1557			wake_up_all(&dev->wait);
1558
1559	// or are we maybe short a few urbs?
1560	} else if (netif_running (dev->net) &&
1561		   netif_device_present (dev->net) &&
1562		   netif_carrier_ok(dev->net) &&
1563		   !timer_pending(&dev->delay) &&
1564		   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1565		   !test_bit(EVENT_RX_HALT, &dev->flags)) {
1566		int	temp = dev->rxq.qlen;
1567
1568		if (temp < RX_QLEN(dev)) {
1569			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1570				return;
1571			if (temp != dev->rxq.qlen)
1572				netif_dbg(dev, link, dev->net,
1573					  "rxqlen %d --> %d\n",
1574					  temp, dev->rxq.qlen);
1575			if (dev->rxq.qlen < RX_QLEN(dev))
1576				tasklet_schedule (&dev->bh);
1577		}
1578		if (dev->txq.qlen < TX_QLEN (dev))
1579			netif_wake_queue (dev->net);
1580	}
1581}
1582
1583static void usbnet_bh_tasklet(struct tasklet_struct *t)
1584{
1585	struct usbnet *dev = from_tasklet(dev, t, bh);
1586
1587	usbnet_bh(&dev->delay);
1588}
1589
1590
1591/*-------------------------------------------------------------------------
1592 *
1593 * USB Device Driver support
1594 *
1595 *-------------------------------------------------------------------------*/
1596
1597// precondition: never called in_interrupt
1598
1599void usbnet_disconnect (struct usb_interface *intf)
1600{
1601	struct usbnet		*dev;
1602	struct usb_device	*xdev;
1603	struct net_device	*net;
1604
1605	dev = usb_get_intfdata(intf);
1606	usb_set_intfdata(intf, NULL);
1607	if (!dev)
1608		return;
1609
1610	xdev = interface_to_usbdev (intf);
1611
1612	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1613		   intf->dev.driver->name,
1614		   xdev->bus->bus_name, xdev->devpath,
1615		   dev->driver_info->description);
1616
1617	if (dev->driver_info->unbind)
1618		dev->driver_info->unbind(dev, intf);
1619
1620	net = dev->net;
1621	unregister_netdev (net);
1622
1623	cancel_work_sync(&dev->kevent);
1624
1625	usb_scuttle_anchored_urbs(&dev->deferred);
1626
 
 
 
1627	usb_kill_urb(dev->interrupt);
1628	usb_free_urb(dev->interrupt);
1629	kfree(dev->padding_pkt);
1630
1631	free_percpu(net->tstats);
1632	free_netdev(net);
1633}
1634EXPORT_SYMBOL_GPL(usbnet_disconnect);
1635
1636static const struct net_device_ops usbnet_netdev_ops = {
1637	.ndo_open		= usbnet_open,
1638	.ndo_stop		= usbnet_stop,
1639	.ndo_start_xmit		= usbnet_start_xmit,
1640	.ndo_tx_timeout		= usbnet_tx_timeout,
1641	.ndo_set_rx_mode	= usbnet_set_rx_mode,
1642	.ndo_change_mtu		= usbnet_change_mtu,
1643	.ndo_get_stats64	= dev_get_tstats64,
1644	.ndo_set_mac_address 	= eth_mac_addr,
1645	.ndo_validate_addr	= eth_validate_addr,
1646};
1647
1648/*-------------------------------------------------------------------------*/
1649
1650// precondition: never called in_interrupt
1651
1652static struct device_type wlan_type = {
1653	.name	= "wlan",
1654};
1655
1656static struct device_type wwan_type = {
1657	.name	= "wwan",
1658};
1659
1660int
1661usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1662{
1663	struct usbnet			*dev;
1664	struct net_device		*net;
1665	struct usb_host_interface	*interface;
1666	const struct driver_info	*info;
1667	struct usb_device		*xdev;
1668	int				status;
1669	const char			*name;
1670	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1671
1672	/* usbnet already took usb runtime pm, so have to enable the feature
1673	 * for usb interface, otherwise usb_autopm_get_interface may return
1674	 * failure if RUNTIME_PM is enabled.
1675	 */
1676	if (!driver->supports_autosuspend) {
1677		driver->supports_autosuspend = 1;
1678		pm_runtime_enable(&udev->dev);
1679	}
1680
1681	name = udev->dev.driver->name;
1682	info = (const struct driver_info *) prod->driver_info;
1683	if (!info) {
1684		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1685		return -ENODEV;
1686	}
1687	xdev = interface_to_usbdev (udev);
1688	interface = udev->cur_altsetting;
1689
1690	status = -ENOMEM;
1691
1692	// set up our own records
1693	net = alloc_etherdev(sizeof(*dev));
1694	if (!net)
1695		goto out;
1696
1697	/* netdev_printk() needs this so do it as early as possible */
1698	SET_NETDEV_DEV(net, &udev->dev);
1699
1700	dev = netdev_priv(net);
1701	dev->udev = xdev;
1702	dev->intf = udev;
1703	dev->driver_info = info;
1704	dev->driver_name = name;
1705	dev->rx_speed = SPEED_UNSET;
1706	dev->tx_speed = SPEED_UNSET;
1707
1708	net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1709	if (!net->tstats)
1710		goto out0;
1711
1712	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1713				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1714	init_waitqueue_head(&dev->wait);
1715	skb_queue_head_init (&dev->rxq);
1716	skb_queue_head_init (&dev->txq);
1717	skb_queue_head_init (&dev->done);
1718	skb_queue_head_init(&dev->rxq_pause);
1719	tasklet_setup(&dev->bh, usbnet_bh_tasklet);
 
1720	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1721	init_usb_anchor(&dev->deferred);
1722	timer_setup(&dev->delay, usbnet_bh, 0);
 
 
1723	mutex_init (&dev->phy_mutex);
1724	mutex_init(&dev->interrupt_mutex);
1725	dev->interrupt_count = 0;
1726
1727	dev->net = net;
1728	strcpy (net->name, "usb%d");
1729	memcpy (net->dev_addr, node_id, sizeof node_id);
1730
1731	/* rx and tx sides can use different message sizes;
1732	 * bind() should set rx_urb_size in that case.
1733	 */
1734	dev->hard_mtu = net->mtu + net->hard_header_len;
1735	net->min_mtu = 0;
1736	net->max_mtu = ETH_MAX_MTU;
1737
1738	net->netdev_ops = &usbnet_netdev_ops;
1739	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1740	net->ethtool_ops = &usbnet_ethtool_ops;
1741
1742	// allow device-specific bind/init procedures
1743	// NOTE net->name still not usable ...
1744	if (info->bind) {
1745		status = info->bind (dev, udev);
1746		if (status < 0)
1747			goto out1;
1748
1749		// heuristic:  "usb%d" for links we know are two-host,
1750		// else "eth%d" when there's reasonable doubt.  userspace
1751		// can rename the link if it knows better.
1752		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1753		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1754		     (net->dev_addr [0] & 0x02) == 0))
1755			strcpy (net->name, "eth%d");
1756		/* WLAN devices should always be named "wlan%d" */
1757		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1758			strcpy(net->name, "wlan%d");
1759		/* WWAN devices should always be named "wwan%d" */
1760		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1761			strcpy(net->name, "wwan%d");
1762
1763		/* devices that cannot do ARP */
1764		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1765			net->flags |= IFF_NOARP;
1766
1767		/* maybe the remote can't receive an Ethernet MTU */
1768		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1769			net->mtu = dev->hard_mtu - net->hard_header_len;
1770	} else if (!info->in || !info->out)
1771		status = usbnet_get_endpoints (dev, udev);
1772	else {
1773		dev->in = usb_rcvbulkpipe (xdev, info->in);
1774		dev->out = usb_sndbulkpipe (xdev, info->out);
1775		if (!(info->flags & FLAG_NO_SETINT))
1776			status = usb_set_interface (xdev,
1777				interface->desc.bInterfaceNumber,
1778				interface->desc.bAlternateSetting);
1779		else
1780			status = 0;
1781
1782	}
1783	if (status >= 0 && dev->status)
1784		status = init_status (dev, udev);
1785	if (status < 0)
1786		goto out3;
1787
1788	if (!dev->rx_urb_size)
1789		dev->rx_urb_size = dev->hard_mtu;
1790	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1791
1792	/* let userspace know we have a random address */
1793	if (ether_addr_equal(net->dev_addr, node_id))
1794		net->addr_assign_type = NET_ADDR_RANDOM;
1795
1796	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1797		SET_NETDEV_DEVTYPE(net, &wlan_type);
1798	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1799		SET_NETDEV_DEVTYPE(net, &wwan_type);
1800
1801	/* initialize max rx_qlen and tx_qlen */
1802	usbnet_update_max_qlen(dev);
1803
1804	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1805		!(info->flags & FLAG_MULTI_PACKET)) {
1806		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1807		if (!dev->padding_pkt) {
1808			status = -ENOMEM;
1809			goto out4;
1810		}
1811	}
1812
1813	status = register_netdev (net);
1814	if (status)
1815		goto out5;
1816	netif_info(dev, probe, dev->net,
1817		   "register '%s' at usb-%s-%s, %s, %pM\n",
1818		   udev->dev.driver->name,
1819		   xdev->bus->bus_name, xdev->devpath,
1820		   dev->driver_info->description,
1821		   net->dev_addr);
1822
1823	// ok, it's ready to go.
1824	usb_set_intfdata (udev, dev);
1825
1826	netif_device_attach (net);
1827
1828	if (dev->driver_info->flags & FLAG_LINK_INTR)
1829		usbnet_link_change(dev, 0, 0);
1830
1831	return 0;
1832
1833out5:
1834	kfree(dev->padding_pkt);
1835out4:
1836	usb_free_urb(dev->interrupt);
1837out3:
1838	if (info->unbind)
1839		info->unbind (dev, udev);
1840out1:
1841	/* subdrivers must undo all they did in bind() if they
1842	 * fail it, but we may fail later and a deferred kevent
1843	 * may trigger an error resubmitting itself and, worse,
1844	 * schedule a timer. So we kill it all just in case.
1845	 */
1846	cancel_work_sync(&dev->kevent);
1847	del_timer_sync(&dev->delay);
1848	free_percpu(net->tstats);
1849out0:
1850	free_netdev(net);
1851out:
1852	return status;
1853}
1854EXPORT_SYMBOL_GPL(usbnet_probe);
1855
1856/*-------------------------------------------------------------------------*/
1857
1858/*
1859 * suspend the whole driver as soon as the first interface is suspended
1860 * resume only when the last interface is resumed
1861 */
1862
1863int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1864{
1865	struct usbnet		*dev = usb_get_intfdata(intf);
1866
1867	if (!dev->suspend_count++) {
1868		spin_lock_irq(&dev->txq.lock);
1869		/* don't autosuspend while transmitting */
1870		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1871			dev->suspend_count--;
1872			spin_unlock_irq(&dev->txq.lock);
1873			return -EBUSY;
1874		} else {
1875			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1876			spin_unlock_irq(&dev->txq.lock);
1877		}
1878		/*
1879		 * accelerate emptying of the rx and queues, to avoid
1880		 * having everything error out.
1881		 */
1882		netif_device_detach (dev->net);
1883		usbnet_terminate_urbs(dev);
1884		__usbnet_status_stop_force(dev);
1885
1886		/*
1887		 * reattach so runtime management can use and
1888		 * wake the device
1889		 */
1890		netif_device_attach (dev->net);
1891	}
1892	return 0;
1893}
1894EXPORT_SYMBOL_GPL(usbnet_suspend);
1895
1896int usbnet_resume (struct usb_interface *intf)
1897{
1898	struct usbnet		*dev = usb_get_intfdata(intf);
1899	struct sk_buff          *skb;
1900	struct urb              *res;
1901	int                     retval;
1902
1903	if (!--dev->suspend_count) {
1904		/* resume interrupt URB if it was previously submitted */
1905		__usbnet_status_start_force(dev, GFP_NOIO);
1906
1907		spin_lock_irq(&dev->txq.lock);
1908		while ((res = usb_get_from_anchor(&dev->deferred))) {
1909
1910			skb = (struct sk_buff *)res->context;
1911			retval = usb_submit_urb(res, GFP_ATOMIC);
1912			if (retval < 0) {
1913				dev_kfree_skb_any(skb);
1914				kfree(res->sg);
1915				usb_free_urb(res);
1916				usb_autopm_put_interface_async(dev->intf);
1917			} else {
1918				netif_trans_update(dev->net);
1919				__skb_queue_tail(&dev->txq, skb);
1920			}
1921		}
1922
1923		smp_mb();
1924		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1925		spin_unlock_irq(&dev->txq.lock);
1926
1927		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1928			/* handle remote wakeup ASAP
1929			 * we cannot race against stop
1930			 */
1931			if (netif_device_present(dev->net) &&
1932				!timer_pending(&dev->delay) &&
1933				!test_bit(EVENT_RX_HALT, &dev->flags))
1934					rx_alloc_submit(dev, GFP_NOIO);
1935
1936			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1937				netif_tx_wake_all_queues(dev->net);
1938			tasklet_schedule (&dev->bh);
1939		}
1940	}
1941
1942	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1943		usb_autopm_get_interface_no_resume(intf);
1944
1945	return 0;
1946}
1947EXPORT_SYMBOL_GPL(usbnet_resume);
1948
1949/*
1950 * Either a subdriver implements manage_power, then it is assumed to always
1951 * be ready to be suspended or it reports the readiness to be suspended
1952 * explicitly
1953 */
1954void usbnet_device_suggests_idle(struct usbnet *dev)
1955{
1956	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1957		dev->intf->needs_remote_wakeup = 1;
1958		usb_autopm_put_interface_async(dev->intf);
1959	}
1960}
1961EXPORT_SYMBOL(usbnet_device_suggests_idle);
1962
1963/*
1964 * For devices that can do without special commands
1965 */
1966int usbnet_manage_power(struct usbnet *dev, int on)
1967{
1968	dev->intf->needs_remote_wakeup = on;
1969	return 0;
1970}
1971EXPORT_SYMBOL(usbnet_manage_power);
1972
1973void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1974{
1975	/* update link after link is reseted */
1976	if (link && !need_reset)
1977		netif_carrier_on(dev->net);
1978	else
1979		netif_carrier_off(dev->net);
1980
1981	if (need_reset && link)
1982		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1983	else
1984		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1985}
1986EXPORT_SYMBOL(usbnet_link_change);
1987
1988/*-------------------------------------------------------------------------*/
1989static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1990			     u16 value, u16 index, void *data, u16 size)
1991{
1992	void *buf = NULL;
1993	int err = -ENOMEM;
1994
1995	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1996		   " value=0x%04x index=0x%04x size=%d\n",
1997		   cmd, reqtype, value, index, size);
1998
1999	if (size) {
2000		buf = kmalloc(size, GFP_KERNEL);
2001		if (!buf)
2002			goto out;
2003	}
2004
2005	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2006			      cmd, reqtype, value, index, buf, size,
2007			      USB_CTRL_GET_TIMEOUT);
2008	if (err > 0 && err <= size) {
2009		if (data)
2010			memcpy(data, buf, err);
2011		else
2012			netdev_dbg(dev->net,
2013				   "Huh? Data requested but thrown away.\n");
2014	}
2015	kfree(buf);
2016out:
2017	return err;
2018}
2019
2020static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2021			      u16 value, u16 index, const void *data,
2022			      u16 size)
2023{
2024	void *buf = NULL;
2025	int err = -ENOMEM;
2026
2027	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2028		   " value=0x%04x index=0x%04x size=%d\n",
2029		   cmd, reqtype, value, index, size);
2030
2031	if (data) {
2032		buf = kmemdup(data, size, GFP_KERNEL);
2033		if (!buf)
2034			goto out;
2035	} else {
2036        if (size) {
2037            WARN_ON_ONCE(1);
2038            err = -EINVAL;
2039            goto out;
2040        }
2041    }
2042
2043	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2044			      cmd, reqtype, value, index, buf, size,
2045			      USB_CTRL_SET_TIMEOUT);
2046	kfree(buf);
2047
2048out:
2049	return err;
2050}
2051
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2052/*
2053 * The function can't be called inside suspend/resume callback,
2054 * otherwise deadlock will be caused.
2055 */
2056int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2057		    u16 value, u16 index, void *data, u16 size)
2058{
2059	int ret;
2060
2061	if (usb_autopm_get_interface(dev->intf) < 0)
2062		return -ENODEV;
2063	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2064				data, size);
2065	usb_autopm_put_interface(dev->intf);
2066	return ret;
2067}
2068EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2069
2070/*
2071 * The function can't be called inside suspend/resume callback,
2072 * otherwise deadlock will be caused.
2073 */
2074int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2075		     u16 value, u16 index, const void *data, u16 size)
2076{
2077	int ret;
2078
2079	if (usb_autopm_get_interface(dev->intf) < 0)
2080		return -ENODEV;
2081	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2082				 data, size);
2083	usb_autopm_put_interface(dev->intf);
2084	return ret;
2085}
2086EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2087
2088/*
2089 * The function can be called inside suspend/resume callback safely
2090 * and should only be called by suspend/resume callback generally.
2091 */
2092int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2093			  u16 value, u16 index, void *data, u16 size)
2094{
2095	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2096				 data, size);
2097}
2098EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2099
2100/*
2101 * The function can be called inside suspend/resume callback safely
2102 * and should only be called by suspend/resume callback generally.
2103 */
2104int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2105			  u16 value, u16 index, const void *data,
2106			  u16 size)
2107{
2108	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2109				  data, size);
2110}
2111EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2112
2113static void usbnet_async_cmd_cb(struct urb *urb)
2114{
2115	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2116	int status = urb->status;
2117
2118	if (status < 0)
2119		dev_dbg(&urb->dev->dev, "%s failed with %d",
2120			__func__, status);
2121
2122	kfree(req);
2123	usb_free_urb(urb);
2124}
2125
2126/*
2127 * The caller must make sure that device can't be put into suspend
2128 * state until the control URB completes.
2129 */
2130int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2131			   u16 value, u16 index, const void *data, u16 size)
2132{
2133	struct usb_ctrlrequest *req = NULL;
2134	struct urb *urb;
2135	int err = -ENOMEM;
2136	void *buf = NULL;
2137
2138	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2139		   " value=0x%04x index=0x%04x size=%d\n",
2140		   cmd, reqtype, value, index, size);
2141
2142	urb = usb_alloc_urb(0, GFP_ATOMIC);
2143	if (!urb)
 
 
2144		goto fail;
 
2145
2146	if (data) {
2147		buf = kmemdup(data, size, GFP_ATOMIC);
2148		if (!buf) {
2149			netdev_err(dev->net, "Error allocating buffer"
2150				   " in %s!\n", __func__);
2151			goto fail_free;
2152		}
2153	}
2154
2155	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2156	if (!req)
2157		goto fail_free_buf;
2158
2159	req->bRequestType = reqtype;
2160	req->bRequest = cmd;
2161	req->wValue = cpu_to_le16(value);
2162	req->wIndex = cpu_to_le16(index);
2163	req->wLength = cpu_to_le16(size);
2164
2165	usb_fill_control_urb(urb, dev->udev,
2166			     usb_sndctrlpipe(dev->udev, 0),
2167			     (void *)req, buf, size,
2168			     usbnet_async_cmd_cb, req);
2169	urb->transfer_flags |= URB_FREE_BUFFER;
2170
2171	err = usb_submit_urb(urb, GFP_ATOMIC);
2172	if (err < 0) {
2173		netdev_err(dev->net, "Error submitting the control"
2174			   " message: status=%d\n", err);
2175		goto fail_free;
2176	}
2177	return 0;
2178
2179fail_free_buf:
2180	kfree(buf);
2181fail_free:
2182	kfree(req);
2183	usb_free_urb(urb);
2184fail:
2185	return err;
2186
2187}
2188EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2189/*-------------------------------------------------------------------------*/
2190
2191static int __init usbnet_init(void)
2192{
2193	/* Compiler should optimize this out. */
2194	BUILD_BUG_ON(
2195		sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2196
2197	eth_random_addr(node_id);
2198	return 0;
2199}
2200module_init(usbnet_init);
2201
2202static void __exit usbnet_exit(void)
2203{
2204}
2205module_exit(usbnet_exit);
2206
2207MODULE_AUTHOR("David Brownell");
2208MODULE_DESCRIPTION("USB network driver framework");
2209MODULE_LICENSE("GPL");