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#define DRIVER_VERSION		"22-Aug-2005"
  38
  39
  40/*-------------------------------------------------------------------------*/
  41
  42/*
  43 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  44 * Several dozen bytes of IPv4 data can fit in two such transactions.
  45 * One maximum size Ethernet packet takes twenty four of them.
  46 * For high speed, each frame comfortably fits almost 36 max size
  47 * Ethernet packets (so queues should be bigger).
  48 *
  49 * The goal is to let the USB host controller be busy for 5msec or
  50 * more before an irq is required, under load.  Jumbograms change
  51 * the equation.
  52 */
  53#define	MAX_QUEUE_MEMORY	(60 * 1518)
  54#define	RX_QLEN(dev)		((dev)->rx_qlen)
  55#define	TX_QLEN(dev)		((dev)->tx_qlen)
  56
  57// reawaken network queue this soon after stopping; else watchdog barks
  58#define TX_TIMEOUT_JIFFIES	(5*HZ)
  59
  60/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  61 * us (it polls at HZ/4 usually) before we report too many false errors.
  62 */
  63#define THROTTLE_JIFFIES	(HZ/8)
  64
  65// between wakeups
  66#define UNLINK_TIMEOUT_MS	3
  67
  68/*-------------------------------------------------------------------------*/
  69
  70// randomly generated ethernet address
  71static u8	node_id [ETH_ALEN];
  72
  73/* use ethtool to change the level for any given device */
  74static int msg_level = -1;
  75module_param (msg_level, int, 0);
  76MODULE_PARM_DESC (msg_level, "Override default message level");
  77
  78/*-------------------------------------------------------------------------*/
  79
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  80/* handles CDC Ethernet and many other network "bulk data" interfaces */
  81int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  82{
  83	int				tmp;
  84	struct usb_host_interface	*alt = NULL;
  85	struct usb_host_endpoint	*in = NULL, *out = NULL;
  86	struct usb_host_endpoint	*status = NULL;
  87
  88	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
  89		unsigned	ep;
  90
  91		in = out = status = NULL;
  92		alt = intf->altsetting + tmp;
  93
  94		/* take the first altsetting with in-bulk + out-bulk;
  95		 * remember any status endpoint, just in case;
  96		 * ignore other endpoints and altsettings.
  97		 */
  98		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
  99			struct usb_host_endpoint	*e;
 100			int				intr = 0;
 101
 102			e = alt->endpoint + ep;
 103
 104			/* ignore endpoints which cannot transfer data */
 105			if (!usb_endpoint_maxp(&e->desc))
 106				continue;
 107
 108			switch (e->desc.bmAttributes) {
 109			case USB_ENDPOINT_XFER_INT:
 110				if (!usb_endpoint_dir_in(&e->desc))
 111					continue;
 112				intr = 1;
 113				fallthrough;
 114			case USB_ENDPOINT_XFER_BULK:
 115				break;
 116			default:
 117				continue;
 118			}
 119			if (usb_endpoint_dir_in(&e->desc)) {
 120				if (!intr && !in)
 121					in = e;
 122				else if (intr && !status)
 123					status = e;
 124			} else {
 125				if (!out)
 126					out = e;
 127			}
 128		}
 129		if (in && out)
 130			break;
 131	}
 132	if (!alt || !in || !out)
 133		return -EINVAL;
 134
 135	if (alt->desc.bAlternateSetting != 0 ||
 136	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 137		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 138				alt->desc.bAlternateSetting);
 139		if (tmp < 0)
 140			return tmp;
 141	}
 142
 143	dev->in = usb_rcvbulkpipe (dev->udev,
 144			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 145	dev->out = usb_sndbulkpipe (dev->udev,
 146			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 147	dev->status = status;
 148	return 0;
 149}
 150EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 151
 152int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 153{
 154	int 		tmp = -1, ret;
 155	unsigned char	buf [13];
 156
 157	ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 158	if (ret == 12)
 159		tmp = hex2bin(dev->net->dev_addr, buf, 6);
 160	if (tmp < 0) {
 161		dev_dbg(&dev->udev->dev,
 162			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 163		if (ret >= 0)
 164			ret = -EINVAL;
 165		return ret;
 166	}
 167	return 0;
 168}
 169EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 170
 171static void intr_complete (struct urb *urb)
 172{
 173	struct usbnet	*dev = urb->context;
 174	int		status = urb->status;
 175
 176	switch (status) {
 177	/* success */
 178	case 0:
 179		dev->driver_info->status(dev, urb);
 180		break;
 181
 182	/* software-driven interface shutdown */
 183	case -ENOENT:		/* urb killed */
 184	case -ESHUTDOWN:	/* hardware gone */
 185		netif_dbg(dev, ifdown, dev->net,
 186			  "intr shutdown, code %d\n", status);
 187		return;
 188
 189	/* NOTE:  not throttling like RX/TX, since this endpoint
 190	 * already polls infrequently
 191	 */
 192	default:
 193		netdev_dbg(dev->net, "intr status %d\n", status);
 194		break;
 195	}
 196
 197	status = usb_submit_urb (urb, GFP_ATOMIC);
 198	if (status != 0)
 199		netif_err(dev, timer, dev->net,
 200			  "intr resubmit --> %d\n", status);
 201}
 202
 203static int init_status (struct usbnet *dev, struct usb_interface *intf)
 204{
 205	char		*buf = NULL;
 206	unsigned	pipe = 0;
 207	unsigned	maxp;
 208	unsigned	period;
 209
 210	if (!dev->driver_info->status)
 211		return 0;
 212
 213	pipe = usb_rcvintpipe (dev->udev,
 214			dev->status->desc.bEndpointAddress
 215				& USB_ENDPOINT_NUMBER_MASK);
 216	maxp = usb_maxpacket (dev->udev, pipe, 0);
 217
 218	/* avoid 1 msec chatter:  min 8 msec poll rate */
 219	period = max ((int) dev->status->desc.bInterval,
 220		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 221
 222	buf = kmalloc (maxp, GFP_KERNEL);
 223	if (buf) {
 224		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 225		if (!dev->interrupt) {
 226			kfree (buf);
 227			return -ENOMEM;
 228		} else {
 229			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 230				buf, maxp, intr_complete, dev, period);
 231			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 232			dev_dbg(&intf->dev,
 233				"status ep%din, %d bytes period %d\n",
 234				usb_pipeendpoint(pipe), maxp, period);
 235		}
 236	}
 237	return 0;
 238}
 239
 240/* Submit the interrupt URB if not previously submitted, increasing refcount */
 241int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 242{
 243	int ret = 0;
 244
 245	WARN_ON_ONCE(dev->interrupt == NULL);
 246	if (dev->interrupt) {
 247		mutex_lock(&dev->interrupt_mutex);
 248
 249		if (++dev->interrupt_count == 1)
 250			ret = usb_submit_urb(dev->interrupt, mem_flags);
 251
 252		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 253			dev->interrupt_count);
 254		mutex_unlock(&dev->interrupt_mutex);
 255	}
 256	return ret;
 257}
 258EXPORT_SYMBOL_GPL(usbnet_status_start);
 259
 260/* For resume; submit interrupt URB if previously submitted */
 261static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 262{
 263	int ret = 0;
 264
 265	mutex_lock(&dev->interrupt_mutex);
 266	if (dev->interrupt_count) {
 267		ret = usb_submit_urb(dev->interrupt, mem_flags);
 268		dev_dbg(&dev->udev->dev,
 269			"submitted interrupt URB for resume\n");
 270	}
 271	mutex_unlock(&dev->interrupt_mutex);
 272	return ret;
 273}
 274
 275/* Kill the interrupt URB if all submitters want it killed */
 276void usbnet_status_stop(struct usbnet *dev)
 277{
 278	if (dev->interrupt) {
 279		mutex_lock(&dev->interrupt_mutex);
 280		WARN_ON(dev->interrupt_count == 0);
 281
 282		if (dev->interrupt_count && --dev->interrupt_count == 0)
 283			usb_kill_urb(dev->interrupt);
 284
 285		dev_dbg(&dev->udev->dev,
 286			"decremented interrupt URB count to %d\n",
 287			dev->interrupt_count);
 288		mutex_unlock(&dev->interrupt_mutex);
 289	}
 290}
 291EXPORT_SYMBOL_GPL(usbnet_status_stop);
 292
 293/* For suspend; always kill interrupt URB */
 294static void __usbnet_status_stop_force(struct usbnet *dev)
 295{
 296	if (dev->interrupt) {
 297		mutex_lock(&dev->interrupt_mutex);
 298		usb_kill_urb(dev->interrupt);
 299		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 300		mutex_unlock(&dev->interrupt_mutex);
 301	}
 302}
 303
 304/* Passes this packet up the stack, updating its accounting.
 305 * Some link protocols batch packets, so their rx_fixup paths
 306 * can return clones as well as just modify the original skb.
 307 */
 308void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 309{
 310	struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 311	unsigned long flags;
 312	int	status;
 313
 314	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 315		skb_queue_tail(&dev->rxq_pause, skb);
 316		return;
 317	}
 318
 319	/* only update if unset to allow minidriver rx_fixup override */
 320	if (skb->protocol == 0)
 321		skb->protocol = eth_type_trans (skb, dev->net);
 322
 323	flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 324	stats64->rx_packets++;
 325	stats64->rx_bytes += skb->len;
 326	u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 327
 328	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 329		  skb->len + sizeof (struct ethhdr), skb->protocol);
 330	memset (skb->cb, 0, sizeof (struct skb_data));
 331
 332	if (skb_defer_rx_timestamp(skb))
 333		return;
 334
 335	status = netif_rx (skb);
 336	if (status != NET_RX_SUCCESS)
 337		netif_dbg(dev, rx_err, dev->net,
 338			  "netif_rx status %d\n", status);
 339}
 340EXPORT_SYMBOL_GPL(usbnet_skb_return);
 341
 342/* must be called if hard_mtu or rx_urb_size changed */
 343void usbnet_update_max_qlen(struct usbnet *dev)
 344{
 345	enum usb_device_speed speed = dev->udev->speed;
 346
 347	if (!dev->rx_urb_size || !dev->hard_mtu)
 348		goto insanity;
 349	switch (speed) {
 350	case USB_SPEED_HIGH:
 351		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 352		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 353		break;
 354	case USB_SPEED_SUPER:
 355	case USB_SPEED_SUPER_PLUS:
 356		/*
 357		 * Not take default 5ms qlen for super speed HC to
 358		 * save memory, and iperf tests show 2.5ms qlen can
 359		 * work well
 360		 */
 361		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 362		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 363		break;
 364	default:
 365insanity:
 366		dev->rx_qlen = dev->tx_qlen = 4;
 367	}
 368}
 369EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 370
 371
 372/*-------------------------------------------------------------------------
 373 *
 374 * Network Device Driver (peer link to "Host Device", from USB host)
 375 *
 376 *-------------------------------------------------------------------------*/
 377
 378int usbnet_change_mtu (struct net_device *net, int new_mtu)
 379{
 380	struct usbnet	*dev = netdev_priv(net);
 381	int		ll_mtu = new_mtu + net->hard_header_len;
 382	int		old_hard_mtu = dev->hard_mtu;
 383	int		old_rx_urb_size = dev->rx_urb_size;
 384
 385	// no second zero-length packet read wanted after mtu-sized packets
 386	if ((ll_mtu % dev->maxpacket) == 0)
 387		return -EDOM;
 388	net->mtu = new_mtu;
 389
 390	dev->hard_mtu = net->mtu + net->hard_header_len;
 391	if (dev->rx_urb_size == old_hard_mtu) {
 392		dev->rx_urb_size = dev->hard_mtu;
 393		if (dev->rx_urb_size > old_rx_urb_size) {
 394			usbnet_pause_rx(dev);
 395			usbnet_unlink_rx_urbs(dev);
 396			usbnet_resume_rx(dev);
 397		}
 398	}
 399
 400	/* max qlen depend on hard_mtu and rx_urb_size */
 401	usbnet_update_max_qlen(dev);
 402
 403	return 0;
 404}
 405EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 406
 407/* The caller must hold list->lock */
 408static void __usbnet_queue_skb(struct sk_buff_head *list,
 409			struct sk_buff *newsk, enum skb_state state)
 410{
 411	struct skb_data *entry = (struct skb_data *) newsk->cb;
 412
 413	__skb_queue_tail(list, newsk);
 414	entry->state = state;
 415}
 416
 417/*-------------------------------------------------------------------------*/
 418
 419/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 420 * completion callbacks.  2.5 should have fixed those bugs...
 421 */
 422
 423static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 424		struct sk_buff_head *list, enum skb_state state)
 425{
 426	unsigned long		flags;
 427	enum skb_state 		old_state;
 428	struct skb_data *entry = (struct skb_data *) skb->cb;
 429
 430	spin_lock_irqsave(&list->lock, flags);
 431	old_state = entry->state;
 432	entry->state = state;
 433	__skb_unlink(skb, list);
 434
 435	/* defer_bh() is never called with list == &dev->done.
 436	 * spin_lock_nested() tells lockdep that it is OK to take
 437	 * dev->done.lock here with list->lock held.
 438	 */
 439	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 440
 441	__skb_queue_tail(&dev->done, skb);
 442	if (dev->done.qlen == 1)
 443		tasklet_schedule(&dev->bh);
 444	spin_unlock(&dev->done.lock);
 445	spin_unlock_irqrestore(&list->lock, flags);
 446	return old_state;
 447}
 448
 449/* some work can't be done in tasklets, so we use keventd
 450 *
 451 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 452 * but tasklet_schedule() doesn't.  hope the failure is rare.
 453 */
 454void usbnet_defer_kevent (struct usbnet *dev, int work)
 455{
 456	set_bit (work, &dev->flags);
 457	if (!schedule_work (&dev->kevent))
 458		netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 459	else
 460		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 461}
 462EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 463
 464/*-------------------------------------------------------------------------*/
 465
 466static void rx_complete (struct urb *urb);
 467
 468static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 469{
 470	struct sk_buff		*skb;
 471	struct skb_data		*entry;
 472	int			retval = 0;
 473	unsigned long		lockflags;
 474	size_t			size = dev->rx_urb_size;
 475
 476	/* prevent rx skb allocation when error ratio is high */
 477	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 478		usb_free_urb(urb);
 479		return -ENOLINK;
 480	}
 481
 482	if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 483		skb = __netdev_alloc_skb(dev->net, size, flags);
 484	else
 485		skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 486	if (!skb) {
 487		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 488		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 489		usb_free_urb (urb);
 490		return -ENOMEM;
 491	}
 492
 493	entry = (struct skb_data *) skb->cb;
 494	entry->urb = urb;
 495	entry->dev = dev;
 496	entry->length = 0;
 497
 498	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 499		skb->data, size, rx_complete, skb);
 500
 501	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 502
 503	if (netif_running (dev->net) &&
 504	    netif_device_present (dev->net) &&
 505	    test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 506	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 507	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 508		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 509		case -EPIPE:
 510			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 511			break;
 512		case -ENOMEM:
 513			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 514			break;
 515		case -ENODEV:
 516			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 517			netif_device_detach (dev->net);
 518			break;
 519		case -EHOSTUNREACH:
 520			retval = -ENOLINK;
 521			break;
 522		default:
 523			netif_dbg(dev, rx_err, dev->net,
 524				  "rx submit, %d\n", retval);
 525			tasklet_schedule (&dev->bh);
 526			break;
 527		case 0:
 528			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
 529		}
 530	} else {
 531		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 532		retval = -ENOLINK;
 533	}
 534	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 535	if (retval) {
 536		dev_kfree_skb_any (skb);
 537		usb_free_urb (urb);
 538	}
 539	return retval;
 540}
 541
 542
 543/*-------------------------------------------------------------------------*/
 544
 545static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 546{
 547	if (dev->driver_info->rx_fixup &&
 548	    !dev->driver_info->rx_fixup (dev, skb)) {
 549		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 550		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 551			dev->net->stats.rx_errors++;
 552		goto done;
 553	}
 554	// else network stack removes extra byte if we forced a short packet
 555
 556	/* all data was already cloned from skb inside the driver */
 557	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 558		goto done;
 559
 560	if (skb->len < ETH_HLEN) {
 561		dev->net->stats.rx_errors++;
 562		dev->net->stats.rx_length_errors++;
 563		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 564	} else {
 565		usbnet_skb_return(dev, skb);
 566		return;
 567	}
 568
 569done:
 570	skb_queue_tail(&dev->done, skb);
 571}
 572
 573/*-------------------------------------------------------------------------*/
 574
 575static void rx_complete (struct urb *urb)
 576{
 577	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 578	struct skb_data		*entry = (struct skb_data *) skb->cb;
 579	struct usbnet		*dev = entry->dev;
 580	int			urb_status = urb->status;
 581	enum skb_state		state;
 582
 583	skb_put (skb, urb->actual_length);
 584	state = rx_done;
 585	entry->urb = NULL;
 586
 587	switch (urb_status) {
 588	/* success */
 589	case 0:
 590		break;
 591
 592	/* stalls need manual reset. this is rare ... except that
 593	 * when going through USB 2.0 TTs, unplug appears this way.
 594	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 595	 * storm, recovering as needed.
 596	 */
 597	case -EPIPE:
 598		dev->net->stats.rx_errors++;
 599		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 600		// FALLTHROUGH
 601
 602	/* software-driven interface shutdown */
 603	case -ECONNRESET:		/* async unlink */
 604	case -ESHUTDOWN:		/* hardware gone */
 605		netif_dbg(dev, ifdown, dev->net,
 606			  "rx shutdown, code %d\n", urb_status);
 607		goto block;
 608
 609	/* we get controller i/o faults during hub_wq disconnect() delays.
 610	 * throttle down resubmits, to avoid log floods; just temporarily,
 611	 * so we still recover when the fault isn't a hub_wq delay.
 612	 */
 613	case -EPROTO:
 614	case -ETIME:
 615	case -EILSEQ:
 616		dev->net->stats.rx_errors++;
 617		if (!timer_pending (&dev->delay)) {
 618			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 619			netif_dbg(dev, link, dev->net,
 620				  "rx throttle %d\n", urb_status);
 621		}
 622block:
 623		state = rx_cleanup;
 624		entry->urb = urb;
 625		urb = NULL;
 626		break;
 627
 628	/* data overrun ... flush fifo? */
 629	case -EOVERFLOW:
 630		dev->net->stats.rx_over_errors++;
 631		fallthrough;
 632
 633	default:
 634		state = rx_cleanup;
 635		dev->net->stats.rx_errors++;
 636		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 637		break;
 638	}
 639
 640	/* stop rx if packet error rate is high */
 641	if (++dev->pkt_cnt > 30) {
 642		dev->pkt_cnt = 0;
 643		dev->pkt_err = 0;
 644	} else {
 645		if (state == rx_cleanup)
 646			dev->pkt_err++;
 647		if (dev->pkt_err > 20)
 648			set_bit(EVENT_RX_KILL, &dev->flags);
 649	}
 650
 651	state = defer_bh(dev, skb, &dev->rxq, state);
 652
 653	if (urb) {
 654		if (netif_running (dev->net) &&
 655		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 656		    state != unlink_start) {
 657			rx_submit (dev, urb, GFP_ATOMIC);
 658			usb_mark_last_busy(dev->udev);
 659			return;
 660		}
 661		usb_free_urb (urb);
 662	}
 663	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 664}
 665
 666/*-------------------------------------------------------------------------*/
 667void usbnet_pause_rx(struct usbnet *dev)
 668{
 669	set_bit(EVENT_RX_PAUSED, &dev->flags);
 670
 671	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 672}
 673EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 674
 675void usbnet_resume_rx(struct usbnet *dev)
 676{
 677	struct sk_buff *skb;
 678	int num = 0;
 679
 680	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 681
 682	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 683		usbnet_skb_return(dev, skb);
 684		num++;
 685	}
 686
 687	tasklet_schedule(&dev->bh);
 688
 689	netif_dbg(dev, rx_status, dev->net,
 690		  "paused rx queue disabled, %d skbs requeued\n", num);
 691}
 692EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 693
 694void usbnet_purge_paused_rxq(struct usbnet *dev)
 695{
 696	skb_queue_purge(&dev->rxq_pause);
 697}
 698EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 699
 700/*-------------------------------------------------------------------------*/
 701
 702// unlink pending rx/tx; completion handlers do all other cleanup
 703
 704static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 705{
 706	unsigned long		flags;
 707	struct sk_buff		*skb;
 708	int			count = 0;
 709
 710	spin_lock_irqsave (&q->lock, flags);
 711	while (!skb_queue_empty(q)) {
 712		struct skb_data		*entry;
 713		struct urb		*urb;
 714		int			retval;
 715
 716		skb_queue_walk(q, skb) {
 717			entry = (struct skb_data *) skb->cb;
 718			if (entry->state != unlink_start)
 719				goto found;
 720		}
 721		break;
 722found:
 723		entry->state = unlink_start;
 724		urb = entry->urb;
 725
 726		/*
 727		 * Get reference count of the URB to avoid it to be
 728		 * freed during usb_unlink_urb, which may trigger
 729		 * use-after-free problem inside usb_unlink_urb since
 730		 * usb_unlink_urb is always racing with .complete
 731		 * handler(include defer_bh).
 732		 */
 733		usb_get_urb(urb);
 734		spin_unlock_irqrestore(&q->lock, flags);
 735		// during some PM-driven resume scenarios,
 736		// these (async) unlinks complete immediately
 737		retval = usb_unlink_urb (urb);
 738		if (retval != -EINPROGRESS && retval != 0)
 739			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 740		else
 741			count++;
 742		usb_put_urb(urb);
 743		spin_lock_irqsave(&q->lock, flags);
 744	}
 745	spin_unlock_irqrestore (&q->lock, flags);
 746	return count;
 747}
 748
 749// Flush all pending rx urbs
 750// minidrivers may need to do this when the MTU changes
 751
 752void usbnet_unlink_rx_urbs(struct usbnet *dev)
 753{
 754	if (netif_running(dev->net)) {
 755		(void) unlink_urbs (dev, &dev->rxq);
 756		tasklet_schedule(&dev->bh);
 757	}
 758}
 759EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 760
 761/*-------------------------------------------------------------------------*/
 762
 763static void wait_skb_queue_empty(struct sk_buff_head *q)
 764{
 765	unsigned long flags;
 766
 767	spin_lock_irqsave(&q->lock, flags);
 768	while (!skb_queue_empty(q)) {
 769		spin_unlock_irqrestore(&q->lock, flags);
 770		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 771		set_current_state(TASK_UNINTERRUPTIBLE);
 772		spin_lock_irqsave(&q->lock, flags);
 773	}
 774	spin_unlock_irqrestore(&q->lock, flags);
 775}
 776
 777// precondition: never called in_interrupt
 778static void usbnet_terminate_urbs(struct usbnet *dev)
 779{
 780	DECLARE_WAITQUEUE(wait, current);
 781	int temp;
 782
 783	/* ensure there are no more active urbs */
 784	add_wait_queue(&dev->wait, &wait);
 785	set_current_state(TASK_UNINTERRUPTIBLE);
 786	temp = unlink_urbs(dev, &dev->txq) +
 787		unlink_urbs(dev, &dev->rxq);
 788
 789	/* maybe wait for deletions to finish. */
 790	wait_skb_queue_empty(&dev->rxq);
 791	wait_skb_queue_empty(&dev->txq);
 792	wait_skb_queue_empty(&dev->done);
 793	netif_dbg(dev, ifdown, dev->net,
 794		  "waited for %d urb completions\n", temp);
 795	set_current_state(TASK_RUNNING);
 796	remove_wait_queue(&dev->wait, &wait);
 797}
 798
 799int usbnet_stop (struct net_device *net)
 800{
 801	struct usbnet		*dev = netdev_priv(net);
 802	const struct driver_info *info = dev->driver_info;
 803	int			retval, pm, mpn;
 804
 805	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 806	netif_stop_queue (net);
 807
 808	netif_info(dev, ifdown, dev->net,
 809		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 810		   net->stats.rx_packets, net->stats.tx_packets,
 811		   net->stats.rx_errors, net->stats.tx_errors);
 812
 813	/* to not race resume */
 814	pm = usb_autopm_get_interface(dev->intf);
 815	/* allow minidriver to stop correctly (wireless devices to turn off
 816	 * radio etc) */
 817	if (info->stop) {
 818		retval = info->stop(dev);
 819		if (retval < 0)
 820			netif_info(dev, ifdown, dev->net,
 821				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 822				   retval,
 823				   dev->udev->bus->bus_name, dev->udev->devpath,
 824				   info->description);
 825	}
 826
 827	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 828		usbnet_terminate_urbs(dev);
 829
 830	usbnet_status_stop(dev);
 831
 832	usbnet_purge_paused_rxq(dev);
 833
 834	mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 835
 836	/* deferred work (task, timer, softirq) must also stop.
 837	 * can't flush_scheduled_work() until we drop rtnl (later),
 838	 * else workers could deadlock; so make workers a NOP.
 839	 */
 840	dev->flags = 0;
 841	del_timer_sync (&dev->delay);
 842	tasklet_kill (&dev->bh);
 843	if (!pm)
 844		usb_autopm_put_interface(dev->intf);
 845
 846	if (info->manage_power && mpn)
 847		info->manage_power(dev, 0);
 848	else
 849		usb_autopm_put_interface(dev->intf);
 850
 851	return 0;
 852}
 853EXPORT_SYMBOL_GPL(usbnet_stop);
 854
 855/*-------------------------------------------------------------------------*/
 856
 857// posts reads, and enables write queuing
 858
 859// precondition: never called in_interrupt
 860
 861int usbnet_open (struct net_device *net)
 862{
 863	struct usbnet		*dev = netdev_priv(net);
 864	int			retval;
 865	const struct driver_info *info = dev->driver_info;
 866
 867	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 868		netif_info(dev, ifup, dev->net,
 869			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 870			   retval,
 871			   dev->udev->bus->bus_name,
 872			   dev->udev->devpath,
 873			   info->description);
 874		goto done_nopm;
 875	}
 876
 877	// put into "known safe" state
 878	if (info->reset && (retval = info->reset (dev)) < 0) {
 879		netif_info(dev, ifup, dev->net,
 880			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 881			   retval,
 882			   dev->udev->bus->bus_name,
 883			   dev->udev->devpath,
 884			   info->description);
 885		goto done;
 886	}
 887
 888	/* hard_mtu or rx_urb_size may change in reset() */
 889	usbnet_update_max_qlen(dev);
 890
 891	// insist peer be connected
 892	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 893		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 894		goto done;
 895	}
 896
 897	/* start any status interrupt transfer */
 898	if (dev->interrupt) {
 899		retval = usbnet_status_start(dev, GFP_KERNEL);
 900		if (retval < 0) {
 901			netif_err(dev, ifup, dev->net,
 902				  "intr submit %d\n", retval);
 903			goto done;
 904		}
 905	}
 906
 907	set_bit(EVENT_DEV_OPEN, &dev->flags);
 908	netif_start_queue (net);
 909	netif_info(dev, ifup, dev->net,
 910		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 911		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 912		   dev->net->mtu,
 913		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 914		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 915		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 916		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 917		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 918		   "simple");
 919
 920	/* reset rx error state */
 921	dev->pkt_cnt = 0;
 922	dev->pkt_err = 0;
 923	clear_bit(EVENT_RX_KILL, &dev->flags);
 924
 925	// delay posting reads until we're fully open
 926	tasklet_schedule (&dev->bh);
 927	if (info->manage_power) {
 928		retval = info->manage_power(dev, 1);
 929		if (retval < 0) {
 930			retval = 0;
 931			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 932		} else {
 933			usb_autopm_put_interface(dev->intf);
 934		}
 935	}
 936	return retval;
 937done:
 938	usb_autopm_put_interface(dev->intf);
 939done_nopm:
 940	return retval;
 941}
 942EXPORT_SYMBOL_GPL(usbnet_open);
 943
 944/*-------------------------------------------------------------------------*/
 945
 946/* ethtool methods; minidrivers may need to add some more, but
 947 * they'll probably want to use this base set.
 948 */
 949
 950int usbnet_get_link_ksettings(struct net_device *net,
 
 
 
 951			      struct ethtool_link_ksettings *cmd)
 952{
 953	struct usbnet *dev = netdev_priv(net);
 954
 955	if (!dev->mii.mdio_read)
 956		return -EOPNOTSUPP;
 957
 958	mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 959
 960	return 0;
 961}
 962EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 963
 964int usbnet_set_link_ksettings(struct net_device *net,
 965			      const struct ethtool_link_ksettings *cmd)
 966{
 967	struct usbnet *dev = netdev_priv(net);
 968	int retval;
 969
 970	if (!dev->mii.mdio_write)
 971		return -EOPNOTSUPP;
 972
 973	retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 974
 975	/* link speed/duplex might have changed */
 976	if (dev->driver_info->link_reset)
 977		dev->driver_info->link_reset(dev);
 978
 979	/* hard_mtu or rx_urb_size may change in link_reset() */
 980	usbnet_update_max_qlen(dev);
 981
 982	return retval;
 983}
 984EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 985
 986void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 987{
 988	struct usbnet *dev = netdev_priv(net);
 989	unsigned int start;
 990	int cpu;
 991
 992	netdev_stats_to_stats64(stats, &net->stats);
 993
 994	for_each_possible_cpu(cpu) {
 995		struct pcpu_sw_netstats *stats64;
 996		u64 rx_packets, rx_bytes;
 997		u64 tx_packets, tx_bytes;
 998
 999		stats64 = per_cpu_ptr(dev->stats64, cpu);
1000
1001		do {
1002			start = u64_stats_fetch_begin_irq(&stats64->syncp);
1003			rx_packets = stats64->rx_packets;
1004			rx_bytes = stats64->rx_bytes;
1005			tx_packets = stats64->tx_packets;
1006			tx_bytes = stats64->tx_bytes;
1007		} while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1008
1009		stats->rx_packets += rx_packets;
1010		stats->rx_bytes += rx_bytes;
1011		stats->tx_packets += tx_packets;
1012		stats->tx_bytes += tx_bytes;
1013	}
1014}
1015EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1016
1017u32 usbnet_get_link (struct net_device *net)
1018{
1019	struct usbnet *dev = netdev_priv(net);
1020
1021	/* If a check_connect is defined, return its result */
1022	if (dev->driver_info->check_connect)
1023		return dev->driver_info->check_connect (dev) == 0;
1024
1025	/* if the device has mii operations, use those */
1026	if (dev->mii.mdio_read)
1027		return mii_link_ok(&dev->mii);
1028
1029	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1030	return ethtool_op_get_link(net);
1031}
1032EXPORT_SYMBOL_GPL(usbnet_get_link);
1033
1034int usbnet_nway_reset(struct net_device *net)
1035{
1036	struct usbnet *dev = netdev_priv(net);
1037
1038	if (!dev->mii.mdio_write)
1039		return -EOPNOTSUPP;
1040
1041	return mii_nway_restart(&dev->mii);
1042}
1043EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1044
1045void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1046{
1047	struct usbnet *dev = netdev_priv(net);
1048
1049	strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1050	strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1051	strlcpy (info->fw_version, dev->driver_info->description,
1052		sizeof info->fw_version);
1053	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1054}
1055EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1056
1057u32 usbnet_get_msglevel (struct net_device *net)
1058{
1059	struct usbnet *dev = netdev_priv(net);
1060
1061	return dev->msg_enable;
1062}
1063EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1064
1065void usbnet_set_msglevel (struct net_device *net, u32 level)
1066{
1067	struct usbnet *dev = netdev_priv(net);
1068
1069	dev->msg_enable = level;
1070}
1071EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1072
1073/* drivers may override default ethtool_ops in their bind() routine */
1074static const struct ethtool_ops usbnet_ethtool_ops = {
1075	.get_link		= usbnet_get_link,
1076	.nway_reset		= usbnet_nway_reset,
1077	.get_drvinfo		= usbnet_get_drvinfo,
1078	.get_msglevel		= usbnet_get_msglevel,
1079	.set_msglevel		= usbnet_set_msglevel,
1080	.get_ts_info		= ethtool_op_get_ts_info,
1081	.get_link_ksettings	= usbnet_get_link_ksettings,
1082	.set_link_ksettings	= usbnet_set_link_ksettings,
1083};
1084
1085/*-------------------------------------------------------------------------*/
1086
1087static void __handle_link_change(struct usbnet *dev)
1088{
1089	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1090		return;
1091
1092	if (!netif_carrier_ok(dev->net)) {
1093		/* kill URBs for reading packets to save bus bandwidth */
1094		unlink_urbs(dev, &dev->rxq);
1095
1096		/*
1097		 * tx_timeout will unlink URBs for sending packets and
1098		 * tx queue is stopped by netcore after link becomes off
1099		 */
1100	} else {
1101		/* submitting URBs for reading packets */
1102		tasklet_schedule(&dev->bh);
1103	}
1104
1105	/* hard_mtu or rx_urb_size may change during link change */
1106	usbnet_update_max_qlen(dev);
1107
1108	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1109}
1110
1111void usbnet_set_rx_mode(struct net_device *net)
1112{
1113	struct usbnet		*dev = netdev_priv(net);
1114
1115	usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1116}
1117EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1118
1119static void __handle_set_rx_mode(struct usbnet *dev)
1120{
1121	if (dev->driver_info->set_rx_mode)
1122		(dev->driver_info->set_rx_mode)(dev);
1123
1124	clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1125}
1126
1127/* work that cannot be done in interrupt context uses keventd.
1128 *
1129 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1130 * especially now that control transfers can be queued.
1131 */
1132static void
1133usbnet_deferred_kevent (struct work_struct *work)
1134{
1135	struct usbnet		*dev =
1136		container_of(work, struct usbnet, kevent);
1137	int			status;
1138
1139	/* usb_clear_halt() needs a thread context */
1140	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1141		unlink_urbs (dev, &dev->txq);
1142		status = usb_autopm_get_interface(dev->intf);
1143		if (status < 0)
1144			goto fail_pipe;
1145		status = usb_clear_halt (dev->udev, dev->out);
1146		usb_autopm_put_interface(dev->intf);
1147		if (status < 0 &&
1148		    status != -EPIPE &&
1149		    status != -ESHUTDOWN) {
1150			if (netif_msg_tx_err (dev))
1151fail_pipe:
1152				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1153					   status);
1154		} else {
1155			clear_bit (EVENT_TX_HALT, &dev->flags);
1156			if (status != -ESHUTDOWN)
1157				netif_wake_queue (dev->net);
1158		}
1159	}
1160	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1161		unlink_urbs (dev, &dev->rxq);
1162		status = usb_autopm_get_interface(dev->intf);
1163		if (status < 0)
1164			goto fail_halt;
1165		status = usb_clear_halt (dev->udev, dev->in);
1166		usb_autopm_put_interface(dev->intf);
1167		if (status < 0 &&
1168		    status != -EPIPE &&
1169		    status != -ESHUTDOWN) {
1170			if (netif_msg_rx_err (dev))
1171fail_halt:
1172				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1173					   status);
1174		} else {
1175			clear_bit (EVENT_RX_HALT, &dev->flags);
1176			tasklet_schedule (&dev->bh);
1177		}
1178	}
1179
1180	/* tasklet could resubmit itself forever if memory is tight */
1181	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1182		struct urb	*urb = NULL;
1183		int resched = 1;
1184
1185		if (netif_running (dev->net))
1186			urb = usb_alloc_urb (0, GFP_KERNEL);
1187		else
1188			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1189		if (urb != NULL) {
1190			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1191			status = usb_autopm_get_interface(dev->intf);
1192			if (status < 0) {
1193				usb_free_urb(urb);
1194				goto fail_lowmem;
1195			}
1196			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1197				resched = 0;
1198			usb_autopm_put_interface(dev->intf);
1199fail_lowmem:
1200			if (resched)
1201				tasklet_schedule (&dev->bh);
1202		}
1203	}
1204
1205	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1206		const struct driver_info *info = dev->driver_info;
1207		int			retval = 0;
1208
1209		clear_bit (EVENT_LINK_RESET, &dev->flags);
1210		status = usb_autopm_get_interface(dev->intf);
1211		if (status < 0)
1212			goto skip_reset;
1213		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1214			usb_autopm_put_interface(dev->intf);
1215skip_reset:
1216			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1217				    retval,
1218				    dev->udev->bus->bus_name,
1219				    dev->udev->devpath,
1220				    info->description);
1221		} else {
1222			usb_autopm_put_interface(dev->intf);
1223		}
1224
1225		/* handle link change from link resetting */
1226		__handle_link_change(dev);
1227	}
1228
1229	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1230		__handle_link_change(dev);
1231
1232	if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1233		__handle_set_rx_mode(dev);
1234
1235
1236	if (dev->flags)
1237		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1238}
1239
1240/*-------------------------------------------------------------------------*/
1241
1242static void tx_complete (struct urb *urb)
1243{
1244	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1245	struct skb_data		*entry = (struct skb_data *) skb->cb;
1246	struct usbnet		*dev = entry->dev;
1247
1248	if (urb->status == 0) {
1249		struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1250		unsigned long flags;
1251
1252		flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1253		stats64->tx_packets += entry->packets;
1254		stats64->tx_bytes += entry->length;
1255		u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1256	} else {
1257		dev->net->stats.tx_errors++;
1258
1259		switch (urb->status) {
1260		case -EPIPE:
1261			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1262			break;
1263
1264		/* software-driven interface shutdown */
1265		case -ECONNRESET:		// async unlink
1266		case -ESHUTDOWN:		// hardware gone
1267			break;
1268
1269		/* like rx, tx gets controller i/o faults during hub_wq
1270		 * delays and so it uses the same throttling mechanism.
1271		 */
1272		case -EPROTO:
1273		case -ETIME:
1274		case -EILSEQ:
1275			usb_mark_last_busy(dev->udev);
1276			if (!timer_pending (&dev->delay)) {
1277				mod_timer (&dev->delay,
1278					jiffies + THROTTLE_JIFFIES);
1279				netif_dbg(dev, link, dev->net,
1280					  "tx throttle %d\n", urb->status);
1281			}
1282			netif_stop_queue (dev->net);
1283			break;
1284		default:
1285			netif_dbg(dev, tx_err, dev->net,
1286				  "tx err %d\n", entry->urb->status);
1287			break;
1288		}
1289	}
1290
1291	usb_autopm_put_interface_async(dev->intf);
1292	(void) defer_bh(dev, skb, &dev->txq, tx_done);
1293}
1294
1295/*-------------------------------------------------------------------------*/
1296
1297void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1298{
1299	struct usbnet		*dev = netdev_priv(net);
1300
1301	unlink_urbs (dev, &dev->txq);
1302	tasklet_schedule (&dev->bh);
1303	/* this needs to be handled individually because the generic layer
1304	 * doesn't know what is sufficient and could not restore private
1305	 * information if a remedy of an unconditional reset were used.
1306	 */
1307	if (dev->driver_info->recover)
1308		(dev->driver_info->recover)(dev);
1309}
1310EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1311
1312/*-------------------------------------------------------------------------*/
1313
1314static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1315{
1316	unsigned num_sgs, total_len = 0;
1317	int i, s = 0;
1318
1319	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1320	if (num_sgs == 1)
1321		return 0;
1322
1323	/* reserve one for zero packet */
1324	urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1325				GFP_ATOMIC);
1326	if (!urb->sg)
1327		return -ENOMEM;
1328
1329	urb->num_sgs = num_sgs;
1330	sg_init_table(urb->sg, urb->num_sgs + 1);
1331
1332	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1333	total_len += skb_headlen(skb);
1334
1335	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1336		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1337
1338		total_len += skb_frag_size(f);
1339		sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1340			    skb_frag_off(f));
1341	}
1342	urb->transfer_buffer_length = total_len;
1343
1344	return 1;
1345}
1346
1347netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1348				     struct net_device *net)
1349{
1350	struct usbnet		*dev = netdev_priv(net);
1351	unsigned int			length;
1352	struct urb		*urb = NULL;
1353	struct skb_data		*entry;
1354	const struct driver_info *info = dev->driver_info;
1355	unsigned long		flags;
1356	int retval;
1357
1358	if (skb)
1359		skb_tx_timestamp(skb);
1360
1361	// some devices want funky USB-level framing, for
1362	// win32 driver (usually) and/or hardware quirks
1363	if (info->tx_fixup) {
1364		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1365		if (!skb) {
1366			/* packet collected; minidriver waiting for more */
1367			if (info->flags & FLAG_MULTI_PACKET)
1368				goto not_drop;
1369			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1370			goto drop;
1371		}
1372	}
1373
1374	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1375		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1376		goto drop;
1377	}
1378
1379	entry = (struct skb_data *) skb->cb;
1380	entry->urb = urb;
1381	entry->dev = dev;
1382
1383	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1384			skb->data, skb->len, tx_complete, skb);
1385	if (dev->can_dma_sg) {
1386		if (build_dma_sg(skb, urb) < 0)
1387			goto drop;
1388	}
1389	length = urb->transfer_buffer_length;
1390
1391	/* don't assume the hardware handles USB_ZERO_PACKET
1392	 * NOTE:  strictly conforming cdc-ether devices should expect
1393	 * the ZLP here, but ignore the one-byte packet.
1394	 * NOTE2: CDC NCM specification is different from CDC ECM when
1395	 * handling ZLP/short packets, so cdc_ncm driver will make short
1396	 * packet itself if needed.
1397	 */
1398	if (length % dev->maxpacket == 0) {
1399		if (!(info->flags & FLAG_SEND_ZLP)) {
1400			if (!(info->flags & FLAG_MULTI_PACKET)) {
1401				length++;
1402				if (skb_tailroom(skb) && !urb->num_sgs) {
1403					skb->data[skb->len] = 0;
1404					__skb_put(skb, 1);
1405				} else if (urb->num_sgs)
1406					sg_set_buf(&urb->sg[urb->num_sgs++],
1407							dev->padding_pkt, 1);
1408			}
1409		} else
1410			urb->transfer_flags |= URB_ZERO_PACKET;
1411	}
1412	urb->transfer_buffer_length = length;
1413
1414	if (info->flags & FLAG_MULTI_PACKET) {
1415		/* Driver has set number of packets and a length delta.
1416		 * Calculate the complete length and ensure that it's
1417		 * positive.
1418		 */
1419		entry->length += length;
1420		if (WARN_ON_ONCE(entry->length <= 0))
1421			entry->length = length;
1422	} else {
1423		usbnet_set_skb_tx_stats(skb, 1, length);
1424	}
1425
1426	spin_lock_irqsave(&dev->txq.lock, flags);
1427	retval = usb_autopm_get_interface_async(dev->intf);
1428	if (retval < 0) {
1429		spin_unlock_irqrestore(&dev->txq.lock, flags);
1430		goto drop;
1431	}
1432	if (netif_queue_stopped(net)) {
1433		usb_autopm_put_interface_async(dev->intf);
1434		spin_unlock_irqrestore(&dev->txq.lock, flags);
1435		goto drop;
1436	}
1437
1438#ifdef CONFIG_PM
1439	/* if this triggers the device is still a sleep */
1440	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1441		/* transmission will be done in resume */
1442		usb_anchor_urb(urb, &dev->deferred);
1443		/* no use to process more packets */
1444		netif_stop_queue(net);
1445		usb_put_urb(urb);
1446		spin_unlock_irqrestore(&dev->txq.lock, flags);
1447		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1448		goto deferred;
1449	}
1450#endif
1451
1452	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1453	case -EPIPE:
1454		netif_stop_queue (net);
1455		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1456		usb_autopm_put_interface_async(dev->intf);
1457		break;
1458	default:
1459		usb_autopm_put_interface_async(dev->intf);
1460		netif_dbg(dev, tx_err, dev->net,
1461			  "tx: submit urb err %d\n", retval);
1462		break;
1463	case 0:
1464		netif_trans_update(net);
1465		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1466		if (dev->txq.qlen >= TX_QLEN (dev))
1467			netif_stop_queue (net);
1468	}
1469	spin_unlock_irqrestore (&dev->txq.lock, flags);
1470
1471	if (retval) {
1472		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1473drop:
1474		dev->net->stats.tx_dropped++;
1475not_drop:
1476		if (skb)
1477			dev_kfree_skb_any (skb);
1478		if (urb) {
1479			kfree(urb->sg);
1480			usb_free_urb(urb);
1481		}
1482	} else
1483		netif_dbg(dev, tx_queued, dev->net,
1484			  "> tx, len %u, type 0x%x\n", length, skb->protocol);
1485#ifdef CONFIG_PM
1486deferred:
1487#endif
1488	return NETDEV_TX_OK;
1489}
1490EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1491
1492static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1493{
1494	struct urb	*urb;
1495	int		i;
1496	int		ret = 0;
1497
1498	/* don't refill the queue all at once */
1499	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1500		urb = usb_alloc_urb(0, flags);
1501		if (urb != NULL) {
1502			ret = rx_submit(dev, urb, flags);
1503			if (ret)
1504				goto err;
1505		} else {
1506			ret = -ENOMEM;
1507			goto err;
1508		}
1509	}
1510err:
1511	return ret;
1512}
1513
1514/*-------------------------------------------------------------------------*/
1515
1516// tasklet (work deferred from completions, in_irq) or timer
1517
1518static void usbnet_bh (struct timer_list *t)
1519{
1520	struct usbnet		*dev = from_timer(dev, t, delay);
1521	struct sk_buff		*skb;
1522	struct skb_data		*entry;
1523
1524	while ((skb = skb_dequeue (&dev->done))) {
1525		entry = (struct skb_data *) skb->cb;
1526		switch (entry->state) {
1527		case rx_done:
1528			entry->state = rx_cleanup;
1529			rx_process (dev, skb);
1530			continue;
1531		case tx_done:
1532			kfree(entry->urb->sg);
1533			fallthrough;
1534		case rx_cleanup:
1535			usb_free_urb (entry->urb);
1536			dev_kfree_skb (skb);
1537			continue;
1538		default:
1539			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1540		}
1541	}
1542
1543	/* restart RX again after disabling due to high error rate */
1544	clear_bit(EVENT_RX_KILL, &dev->flags);
1545
1546	/* waiting for all pending urbs to complete?
1547	 * only then can we forgo submitting anew
1548	 */
1549	if (waitqueue_active(&dev->wait)) {
1550		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1551			wake_up_all(&dev->wait);
1552
1553	// or are we maybe short a few urbs?
1554	} else if (netif_running (dev->net) &&
1555		   netif_device_present (dev->net) &&
1556		   netif_carrier_ok(dev->net) &&
1557		   !timer_pending(&dev->delay) &&
1558		   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1559		   !test_bit(EVENT_RX_HALT, &dev->flags)) {
1560		int	temp = dev->rxq.qlen;
1561
1562		if (temp < RX_QLEN(dev)) {
1563			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1564				return;
1565			if (temp != dev->rxq.qlen)
1566				netif_dbg(dev, link, dev->net,
1567					  "rxqlen %d --> %d\n",
1568					  temp, dev->rxq.qlen);
1569			if (dev->rxq.qlen < RX_QLEN(dev))
1570				tasklet_schedule (&dev->bh);
1571		}
1572		if (dev->txq.qlen < TX_QLEN (dev))
1573			netif_wake_queue (dev->net);
1574	}
1575}
1576
1577static void usbnet_bh_tasklet(unsigned long data)
1578{
1579	struct timer_list *t = (struct timer_list *)data;
1580
1581	usbnet_bh(t);
1582}
1583
1584
1585/*-------------------------------------------------------------------------
1586 *
1587 * USB Device Driver support
1588 *
1589 *-------------------------------------------------------------------------*/
1590
1591// precondition: never called in_interrupt
1592
1593void usbnet_disconnect (struct usb_interface *intf)
1594{
1595	struct usbnet		*dev;
1596	struct usb_device	*xdev;
1597	struct net_device	*net;
1598
1599	dev = usb_get_intfdata(intf);
1600	usb_set_intfdata(intf, NULL);
1601	if (!dev)
1602		return;
1603
1604	xdev = interface_to_usbdev (intf);
1605
1606	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1607		   intf->dev.driver->name,
1608		   xdev->bus->bus_name, xdev->devpath,
1609		   dev->driver_info->description);
1610
 
 
 
1611	net = dev->net;
1612	unregister_netdev (net);
1613
1614	cancel_work_sync(&dev->kevent);
1615
1616	usb_scuttle_anchored_urbs(&dev->deferred);
1617
1618	if (dev->driver_info->unbind)
1619		dev->driver_info->unbind (dev, intf);
1620
1621	usb_kill_urb(dev->interrupt);
1622	usb_free_urb(dev->interrupt);
1623	kfree(dev->padding_pkt);
1624
1625	free_percpu(dev->stats64);
1626	free_netdev(net);
1627}
1628EXPORT_SYMBOL_GPL(usbnet_disconnect);
1629
1630static const struct net_device_ops usbnet_netdev_ops = {
1631	.ndo_open		= usbnet_open,
1632	.ndo_stop		= usbnet_stop,
1633	.ndo_start_xmit		= usbnet_start_xmit,
1634	.ndo_tx_timeout		= usbnet_tx_timeout,
1635	.ndo_set_rx_mode	= usbnet_set_rx_mode,
1636	.ndo_change_mtu		= usbnet_change_mtu,
1637	.ndo_get_stats64	= usbnet_get_stats64,
1638	.ndo_set_mac_address 	= eth_mac_addr,
1639	.ndo_validate_addr	= eth_validate_addr,
1640};
1641
1642/*-------------------------------------------------------------------------*/
1643
1644// precondition: never called in_interrupt
1645
1646static struct device_type wlan_type = {
1647	.name	= "wlan",
1648};
1649
1650static struct device_type wwan_type = {
1651	.name	= "wwan",
1652};
1653
1654int
1655usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1656{
1657	struct usbnet			*dev;
1658	struct net_device		*net;
1659	struct usb_host_interface	*interface;
1660	const struct driver_info	*info;
1661	struct usb_device		*xdev;
1662	int				status;
1663	const char			*name;
1664	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1665
1666	/* usbnet already took usb runtime pm, so have to enable the feature
1667	 * for usb interface, otherwise usb_autopm_get_interface may return
1668	 * failure if RUNTIME_PM is enabled.
1669	 */
1670	if (!driver->supports_autosuspend) {
1671		driver->supports_autosuspend = 1;
1672		pm_runtime_enable(&udev->dev);
1673	}
1674
1675	name = udev->dev.driver->name;
1676	info = (const struct driver_info *) prod->driver_info;
1677	if (!info) {
1678		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1679		return -ENODEV;
1680	}
1681	xdev = interface_to_usbdev (udev);
1682	interface = udev->cur_altsetting;
1683
1684	status = -ENOMEM;
1685
1686	// set up our own records
1687	net = alloc_etherdev(sizeof(*dev));
1688	if (!net)
1689		goto out;
1690
1691	/* netdev_printk() needs this so do it as early as possible */
1692	SET_NETDEV_DEV(net, &udev->dev);
1693
1694	dev = netdev_priv(net);
1695	dev->udev = xdev;
1696	dev->intf = udev;
1697	dev->driver_info = info;
1698	dev->driver_name = name;
 
 
1699
1700	dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1701	if (!dev->stats64)
1702		goto out0;
1703
1704	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1705				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1706	init_waitqueue_head(&dev->wait);
1707	skb_queue_head_init (&dev->rxq);
1708	skb_queue_head_init (&dev->txq);
1709	skb_queue_head_init (&dev->done);
1710	skb_queue_head_init(&dev->rxq_pause);
1711	dev->bh.func = usbnet_bh_tasklet;
1712	dev->bh.data = (unsigned long)&dev->delay;
1713	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1714	init_usb_anchor(&dev->deferred);
1715	timer_setup(&dev->delay, usbnet_bh, 0);
1716	mutex_init (&dev->phy_mutex);
1717	mutex_init(&dev->interrupt_mutex);
1718	dev->interrupt_count = 0;
1719
1720	dev->net = net;
1721	strcpy (net->name, "usb%d");
1722	memcpy (net->dev_addr, node_id, sizeof node_id);
1723
1724	/* rx and tx sides can use different message sizes;
1725	 * bind() should set rx_urb_size in that case.
1726	 */
1727	dev->hard_mtu = net->mtu + net->hard_header_len;
1728	net->min_mtu = 0;
1729	net->max_mtu = ETH_MAX_MTU;
1730
1731	net->netdev_ops = &usbnet_netdev_ops;
1732	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1733	net->ethtool_ops = &usbnet_ethtool_ops;
1734
1735	// allow device-specific bind/init procedures
1736	// NOTE net->name still not usable ...
1737	if (info->bind) {
1738		status = info->bind (dev, udev);
1739		if (status < 0)
1740			goto out1;
1741
1742		// heuristic:  "usb%d" for links we know are two-host,
1743		// else "eth%d" when there's reasonable doubt.  userspace
1744		// can rename the link if it knows better.
1745		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1746		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1747		     (net->dev_addr [0] & 0x02) == 0))
1748			strcpy (net->name, "eth%d");
1749		/* WLAN devices should always be named "wlan%d" */
1750		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1751			strcpy(net->name, "wlan%d");
1752		/* WWAN devices should always be named "wwan%d" */
1753		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1754			strcpy(net->name, "wwan%d");
1755
1756		/* devices that cannot do ARP */
1757		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1758			net->flags |= IFF_NOARP;
1759
1760		/* maybe the remote can't receive an Ethernet MTU */
1761		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1762			net->mtu = dev->hard_mtu - net->hard_header_len;
1763	} else if (!info->in || !info->out)
1764		status = usbnet_get_endpoints (dev, udev);
1765	else {
1766		dev->in = usb_rcvbulkpipe (xdev, info->in);
1767		dev->out = usb_sndbulkpipe (xdev, info->out);
1768		if (!(info->flags & FLAG_NO_SETINT))
1769			status = usb_set_interface (xdev,
1770				interface->desc.bInterfaceNumber,
1771				interface->desc.bAlternateSetting);
1772		else
1773			status = 0;
1774
1775	}
1776	if (status >= 0 && dev->status)
1777		status = init_status (dev, udev);
1778	if (status < 0)
1779		goto out3;
1780
1781	if (!dev->rx_urb_size)
1782		dev->rx_urb_size = dev->hard_mtu;
1783	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1784
1785	/* let userspace know we have a random address */
1786	if (ether_addr_equal(net->dev_addr, node_id))
1787		net->addr_assign_type = NET_ADDR_RANDOM;
1788
1789	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1790		SET_NETDEV_DEVTYPE(net, &wlan_type);
1791	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1792		SET_NETDEV_DEVTYPE(net, &wwan_type);
1793
1794	/* initialize max rx_qlen and tx_qlen */
1795	usbnet_update_max_qlen(dev);
1796
1797	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1798		!(info->flags & FLAG_MULTI_PACKET)) {
1799		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1800		if (!dev->padding_pkt) {
1801			status = -ENOMEM;
1802			goto out4;
1803		}
1804	}
1805
1806	status = register_netdev (net);
1807	if (status)
1808		goto out5;
1809	netif_info(dev, probe, dev->net,
1810		   "register '%s' at usb-%s-%s, %s, %pM\n",
1811		   udev->dev.driver->name,
1812		   xdev->bus->bus_name, xdev->devpath,
1813		   dev->driver_info->description,
1814		   net->dev_addr);
1815
1816	// ok, it's ready to go.
1817	usb_set_intfdata (udev, dev);
1818
1819	netif_device_attach (net);
1820
1821	if (dev->driver_info->flags & FLAG_LINK_INTR)
1822		usbnet_link_change(dev, 0, 0);
1823
1824	return 0;
1825
1826out5:
1827	kfree(dev->padding_pkt);
1828out4:
1829	usb_free_urb(dev->interrupt);
1830out3:
1831	if (info->unbind)
1832		info->unbind (dev, udev);
1833out1:
1834	/* subdrivers must undo all they did in bind() if they
1835	 * fail it, but we may fail later and a deferred kevent
1836	 * may trigger an error resubmitting itself and, worse,
1837	 * schedule a timer. So we kill it all just in case.
1838	 */
1839	cancel_work_sync(&dev->kevent);
1840	del_timer_sync(&dev->delay);
1841	free_percpu(dev->stats64);
1842out0:
1843	free_netdev(net);
1844out:
1845	return status;
1846}
1847EXPORT_SYMBOL_GPL(usbnet_probe);
1848
1849/*-------------------------------------------------------------------------*/
1850
1851/*
1852 * suspend the whole driver as soon as the first interface is suspended
1853 * resume only when the last interface is resumed
1854 */
1855
1856int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1857{
1858	struct usbnet		*dev = usb_get_intfdata(intf);
1859
1860	if (!dev->suspend_count++) {
1861		spin_lock_irq(&dev->txq.lock);
1862		/* don't autosuspend while transmitting */
1863		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1864			dev->suspend_count--;
1865			spin_unlock_irq(&dev->txq.lock);
1866			return -EBUSY;
1867		} else {
1868			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1869			spin_unlock_irq(&dev->txq.lock);
1870		}
1871		/*
1872		 * accelerate emptying of the rx and queues, to avoid
1873		 * having everything error out.
1874		 */
1875		netif_device_detach (dev->net);
1876		usbnet_terminate_urbs(dev);
1877		__usbnet_status_stop_force(dev);
1878
1879		/*
1880		 * reattach so runtime management can use and
1881		 * wake the device
1882		 */
1883		netif_device_attach (dev->net);
1884	}
1885	return 0;
1886}
1887EXPORT_SYMBOL_GPL(usbnet_suspend);
1888
1889int usbnet_resume (struct usb_interface *intf)
1890{
1891	struct usbnet		*dev = usb_get_intfdata(intf);
1892	struct sk_buff          *skb;
1893	struct urb              *res;
1894	int                     retval;
1895
1896	if (!--dev->suspend_count) {
1897		/* resume interrupt URB if it was previously submitted */
1898		__usbnet_status_start_force(dev, GFP_NOIO);
1899
1900		spin_lock_irq(&dev->txq.lock);
1901		while ((res = usb_get_from_anchor(&dev->deferred))) {
1902
1903			skb = (struct sk_buff *)res->context;
1904			retval = usb_submit_urb(res, GFP_ATOMIC);
1905			if (retval < 0) {
1906				dev_kfree_skb_any(skb);
1907				kfree(res->sg);
1908				usb_free_urb(res);
1909				usb_autopm_put_interface_async(dev->intf);
1910			} else {
1911				netif_trans_update(dev->net);
1912				__skb_queue_tail(&dev->txq, skb);
1913			}
1914		}
1915
1916		smp_mb();
1917		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1918		spin_unlock_irq(&dev->txq.lock);
1919
1920		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1921			/* handle remote wakeup ASAP
1922			 * we cannot race against stop
1923			 */
1924			if (netif_device_present(dev->net) &&
1925				!timer_pending(&dev->delay) &&
1926				!test_bit(EVENT_RX_HALT, &dev->flags))
1927					rx_alloc_submit(dev, GFP_NOIO);
1928
1929			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1930				netif_tx_wake_all_queues(dev->net);
1931			tasklet_schedule (&dev->bh);
1932		}
1933	}
1934
1935	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1936		usb_autopm_get_interface_no_resume(intf);
1937
1938	return 0;
1939}
1940EXPORT_SYMBOL_GPL(usbnet_resume);
1941
1942/*
1943 * Either a subdriver implements manage_power, then it is assumed to always
1944 * be ready to be suspended or it reports the readiness to be suspended
1945 * explicitly
1946 */
1947void usbnet_device_suggests_idle(struct usbnet *dev)
1948{
1949	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1950		dev->intf->needs_remote_wakeup = 1;
1951		usb_autopm_put_interface_async(dev->intf);
1952	}
1953}
1954EXPORT_SYMBOL(usbnet_device_suggests_idle);
1955
1956/*
1957 * For devices that can do without special commands
1958 */
1959int usbnet_manage_power(struct usbnet *dev, int on)
1960{
1961	dev->intf->needs_remote_wakeup = on;
1962	return 0;
1963}
1964EXPORT_SYMBOL(usbnet_manage_power);
1965
1966void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1967{
1968	/* update link after link is reseted */
1969	if (link && !need_reset)
1970		netif_carrier_on(dev->net);
1971	else
1972		netif_carrier_off(dev->net);
1973
1974	if (need_reset && link)
1975		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1976	else
1977		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1978}
1979EXPORT_SYMBOL(usbnet_link_change);
1980
1981/*-------------------------------------------------------------------------*/
1982static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1983			     u16 value, u16 index, void *data, u16 size)
1984{
1985	void *buf = NULL;
1986	int err = -ENOMEM;
1987
1988	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1989		   " value=0x%04x index=0x%04x size=%d\n",
1990		   cmd, reqtype, value, index, size);
1991
1992	if (size) {
1993		buf = kmalloc(size, GFP_KERNEL);
1994		if (!buf)
1995			goto out;
1996	}
1997
1998	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1999			      cmd, reqtype, value, index, buf, size,
2000			      USB_CTRL_GET_TIMEOUT);
2001	if (err > 0 && err <= size) {
2002        if (data)
2003            memcpy(data, buf, err);
2004        else
2005            netdev_dbg(dev->net,
2006                "Huh? Data requested but thrown away.\n");
2007    }
2008	kfree(buf);
2009out:
2010	return err;
2011}
2012
2013static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2014			      u16 value, u16 index, const void *data,
2015			      u16 size)
2016{
2017	void *buf = NULL;
2018	int err = -ENOMEM;
2019
2020	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2021		   " value=0x%04x index=0x%04x size=%d\n",
2022		   cmd, reqtype, value, index, size);
2023
2024	if (data) {
2025		buf = kmemdup(data, size, GFP_KERNEL);
2026		if (!buf)
2027			goto out;
2028	} else {
2029        if (size) {
2030            WARN_ON_ONCE(1);
2031            err = -EINVAL;
2032            goto out;
2033        }
2034    }
2035
2036	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2037			      cmd, reqtype, value, index, buf, size,
2038			      USB_CTRL_SET_TIMEOUT);
2039	kfree(buf);
2040
2041out:
2042	return err;
2043}
2044
2045/*
2046 * The function can't be called inside suspend/resume callback,
2047 * otherwise deadlock will be caused.
2048 */
2049int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2050		    u16 value, u16 index, void *data, u16 size)
2051{
2052	int ret;
2053
2054	if (usb_autopm_get_interface(dev->intf) < 0)
2055		return -ENODEV;
2056	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2057				data, size);
2058	usb_autopm_put_interface(dev->intf);
2059	return ret;
2060}
2061EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2062
2063/*
2064 * The function can't be called inside suspend/resume callback,
2065 * otherwise deadlock will be caused.
2066 */
2067int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2068		     u16 value, u16 index, const void *data, u16 size)
2069{
2070	int ret;
2071
2072	if (usb_autopm_get_interface(dev->intf) < 0)
2073		return -ENODEV;
2074	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2075				 data, size);
2076	usb_autopm_put_interface(dev->intf);
2077	return ret;
2078}
2079EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2080
2081/*
2082 * The function can be called inside suspend/resume callback safely
2083 * and should only be called by suspend/resume callback generally.
2084 */
2085int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2086			  u16 value, u16 index, void *data, u16 size)
2087{
2088	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2089				 data, size);
2090}
2091EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2092
2093/*
2094 * The function can be called inside suspend/resume callback safely
2095 * and should only be called by suspend/resume callback generally.
2096 */
2097int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2098			  u16 value, u16 index, const void *data,
2099			  u16 size)
2100{
2101	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2102				  data, size);
2103}
2104EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2105
2106static void usbnet_async_cmd_cb(struct urb *urb)
2107{
2108	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2109	int status = urb->status;
2110
2111	if (status < 0)
2112		dev_dbg(&urb->dev->dev, "%s failed with %d",
2113			__func__, status);
2114
2115	kfree(req);
2116	usb_free_urb(urb);
2117}
2118
2119/*
2120 * The caller must make sure that device can't be put into suspend
2121 * state until the control URB completes.
2122 */
2123int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2124			   u16 value, u16 index, const void *data, u16 size)
2125{
2126	struct usb_ctrlrequest *req = NULL;
2127	struct urb *urb;
2128	int err = -ENOMEM;
2129	void *buf = NULL;
2130
2131	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2132		   " value=0x%04x index=0x%04x size=%d\n",
2133		   cmd, reqtype, value, index, size);
2134
2135	urb = usb_alloc_urb(0, GFP_ATOMIC);
2136	if (!urb)
2137		goto fail;
2138
2139	if (data) {
2140		buf = kmemdup(data, size, GFP_ATOMIC);
2141		if (!buf) {
2142			netdev_err(dev->net, "Error allocating buffer"
2143				   " in %s!\n", __func__);
2144			goto fail_free;
2145		}
2146	}
2147
2148	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2149	if (!req)
2150		goto fail_free_buf;
2151
2152	req->bRequestType = reqtype;
2153	req->bRequest = cmd;
2154	req->wValue = cpu_to_le16(value);
2155	req->wIndex = cpu_to_le16(index);
2156	req->wLength = cpu_to_le16(size);
2157
2158	usb_fill_control_urb(urb, dev->udev,
2159			     usb_sndctrlpipe(dev->udev, 0),
2160			     (void *)req, buf, size,
2161			     usbnet_async_cmd_cb, req);
2162	urb->transfer_flags |= URB_FREE_BUFFER;
2163
2164	err = usb_submit_urb(urb, GFP_ATOMIC);
2165	if (err < 0) {
2166		netdev_err(dev->net, "Error submitting the control"
2167			   " message: status=%d\n", err);
2168		goto fail_free;
2169	}
2170	return 0;
2171
2172fail_free_buf:
2173	kfree(buf);
2174fail_free:
2175	kfree(req);
2176	usb_free_urb(urb);
2177fail:
2178	return err;
2179
2180}
2181EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2182/*-------------------------------------------------------------------------*/
2183
2184static int __init usbnet_init(void)
2185{
2186	/* Compiler should optimize this out. */
2187	BUILD_BUG_ON(
2188		sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2189
2190	eth_random_addr(node_id);
2191	return 0;
2192}
2193module_init(usbnet_init);
2194
2195static void __exit usbnet_exit(void)
2196{
2197}
2198module_exit(usbnet_exit);
2199
2200MODULE_AUTHOR("David Brownell");
2201MODULE_DESCRIPTION("USB network driver framework");
2202MODULE_LICENSE("GPL");