1/*
   2 * USB Network driver infrastructure
   3 * Copyright (C) 2000-2005 by David Brownell
   4 * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20/*
  21 * This is a generic "USB networking" framework that works with several
  22 * kinds of full and high speed networking devices:  host-to-host cables,
  23 * smart usb peripherals, and actual Ethernet adapters.
  24 *
  25 * These devices usually differ in terms of control protocols (if they
  26 * even have one!) and sometimes they define new framing to wrap or batch
  27 * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28 * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29 * issues can usefully be addressed by this framework.
  30 */
  31
  32// #define	DEBUG			// error path messages, extra info
  33// #define	VERBOSE			// more; success messages
  34
  35#include <linux/module.h>
  36#include <linux/init.h>
  37#include <linux/netdevice.h>
  38#include <linux/etherdevice.h>
  39#include <linux/ctype.h>
  40#include <linux/ethtool.h>
  41#include <linux/workqueue.h>
  42#include <linux/mii.h>
  43#include <linux/usb.h>
  44#include <linux/usb/usbnet.h>
  45#include <linux/slab.h>
  46#include <linux/kernel.h>
  47#include <linux/pm_runtime.h>
  48
  49#define DRIVER_VERSION		"22-Aug-2005"
  50
  51
  52/*-------------------------------------------------------------------------*/
  53
  54/*
  55 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56 * Several dozen bytes of IPv4 data can fit in two such transactions.
  57 * One maximum size Ethernet packet takes twenty four of them.
  58 * For high speed, each frame comfortably fits almost 36 max size
  59 * Ethernet packets (so queues should be bigger).
  60 *
  61 * The goal is to let the USB host controller be busy for 5msec or
  62 * more before an irq is required, under load.  Jumbograms change
  63 * the equation.
  64 */
  65#define	MAX_QUEUE_MEMORY	(60 * 1518)
  66#define	RX_QLEN(dev)		((dev)->rx_qlen)
  67#define	TX_QLEN(dev)		((dev)->tx_qlen)
  68
  69// reawaken network queue this soon after stopping; else watchdog barks
  70#define TX_TIMEOUT_JIFFIES	(5*HZ)
  71
  72/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73 * us (it polls at HZ/4 usually) before we report too many false errors.
  74 */
  75#define THROTTLE_JIFFIES	(HZ/8)
  76
  77// between wakeups
  78#define UNLINK_TIMEOUT_MS	3
  79
  80/*-------------------------------------------------------------------------*/
  81
  82// randomly generated ethernet address
  83static u8	node_id [ETH_ALEN];
  84
 
 
  85/* use ethtool to change the level for any given device */
  86static int msg_level = -1;
  87module_param (msg_level, int, 0);
  88MODULE_PARM_DESC (msg_level, "Override default message level");
  89
  90/*-------------------------------------------------------------------------*/
  91
  92/* handles CDC Ethernet and many other network "bulk data" interfaces */
  93int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  94{
  95	int				tmp;
  96	struct usb_host_interface	*alt = NULL;
  97	struct usb_host_endpoint	*in = NULL, *out = NULL;
  98	struct usb_host_endpoint	*status = NULL;
  99
 100	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 101		unsigned	ep;
 102
 103		in = out = status = NULL;
 104		alt = intf->altsetting + tmp;
 105
 106		/* take the first altsetting with in-bulk + out-bulk;
 107		 * remember any status endpoint, just in case;
 108		 * ignore other endpoints and altsettings.
 109		 */
 110		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 111			struct usb_host_endpoint	*e;
 112			int				intr = 0;
 113
 114			e = alt->endpoint + ep;
 115			switch (e->desc.bmAttributes) {
 116			case USB_ENDPOINT_XFER_INT:
 117				if (!usb_endpoint_dir_in(&e->desc))
 118					continue;
 119				intr = 1;
 120				/* FALLTHROUGH */
 121			case USB_ENDPOINT_XFER_BULK:
 122				break;
 123			default:
 124				continue;
 125			}
 126			if (usb_endpoint_dir_in(&e->desc)) {
 127				if (!intr && !in)
 128					in = e;
 129				else if (intr && !status)
 130					status = e;
 131			} else {
 132				if (!out)
 133					out = e;
 134			}
 135		}
 136		if (in && out)
 137			break;
 138	}
 139	if (!alt || !in || !out)
 140		return -EINVAL;
 141
 142	if (alt->desc.bAlternateSetting != 0 ||
 143	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 144		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 145				alt->desc.bAlternateSetting);
 146		if (tmp < 0)
 147			return tmp;
 148	}
 149
 150	dev->in = usb_rcvbulkpipe (dev->udev,
 151			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 152	dev->out = usb_sndbulkpipe (dev->udev,
 153			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154	dev->status = status;
 155	return 0;
 156}
 157EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 158
 159int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 160{
 161	int 		tmp = -1, ret;
 162	unsigned char	buf [13];
 163
 164	ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 165	if (ret == 12)
 166		tmp = hex2bin(dev->net->dev_addr, buf, 6);
 167	if (tmp < 0) {
 168		dev_dbg(&dev->udev->dev,
 169			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170		if (ret >= 0)
 171			ret = -EINVAL;
 172		return ret;
 173	}
 174	return 0;
 175}
 176EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 177
 178static void intr_complete (struct urb *urb)
 179{
 180	struct usbnet	*dev = urb->context;
 181	int		status = urb->status;
 182
 183	switch (status) {
 184	/* success */
 185	case 0:
 186		dev->driver_info->status(dev, urb);
 187		break;
 188
 189	/* software-driven interface shutdown */
 190	case -ENOENT:		/* urb killed */
 191	case -ESHUTDOWN:	/* hardware gone */
 192		netif_dbg(dev, ifdown, dev->net,
 193			  "intr shutdown, code %d\n", status);
 194		return;
 195
 196	/* NOTE:  not throttling like RX/TX, since this endpoint
 197	 * already polls infrequently
 198	 */
 199	default:
 200		netdev_dbg(dev->net, "intr status %d\n", status);
 201		break;
 202	}
 203
 204	status = usb_submit_urb (urb, GFP_ATOMIC);
 205	if (status != 0)
 206		netif_err(dev, timer, dev->net,
 207			  "intr resubmit --> %d\n", status);
 208}
 209
 210static int init_status (struct usbnet *dev, struct usb_interface *intf)
 211{
 212	char		*buf = NULL;
 213	unsigned	pipe = 0;
 214	unsigned	maxp;
 215	unsigned	period;
 216
 217	if (!dev->driver_info->status)
 218		return 0;
 219
 220	pipe = usb_rcvintpipe (dev->udev,
 221			dev->status->desc.bEndpointAddress
 222				& USB_ENDPOINT_NUMBER_MASK);
 223	maxp = usb_maxpacket (dev->udev, pipe, 0);
 224
 225	/* avoid 1 msec chatter:  min 8 msec poll rate */
 226	period = max ((int) dev->status->desc.bInterval,
 227		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 228
 229	buf = kmalloc (maxp, GFP_KERNEL);
 230	if (buf) {
 231		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 232		if (!dev->interrupt) {
 233			kfree (buf);
 234			return -ENOMEM;
 235		} else {
 236			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 237				buf, maxp, intr_complete, dev, period);
 238			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 239			dev_dbg(&intf->dev,
 240				"status ep%din, %d bytes period %d\n",
 241				usb_pipeendpoint(pipe), maxp, period);
 242		}
 243	}
 244	return 0;
 245}
 246
 247/* Submit the interrupt URB if not previously submitted, increasing refcount */
 248int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 249{
 250	int ret = 0;
 251
 252	WARN_ON_ONCE(dev->interrupt == NULL);
 253	if (dev->interrupt) {
 254		mutex_lock(&dev->interrupt_mutex);
 255
 256		if (++dev->interrupt_count == 1)
 257			ret = usb_submit_urb(dev->interrupt, mem_flags);
 258
 259		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 260			dev->interrupt_count);
 261		mutex_unlock(&dev->interrupt_mutex);
 262	}
 263	return ret;
 264}
 265EXPORT_SYMBOL_GPL(usbnet_status_start);
 266
 267/* For resume; submit interrupt URB if previously submitted */
 268static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 269{
 270	int ret = 0;
 271
 272	mutex_lock(&dev->interrupt_mutex);
 273	if (dev->interrupt_count) {
 274		ret = usb_submit_urb(dev->interrupt, mem_flags);
 275		dev_dbg(&dev->udev->dev,
 276			"submitted interrupt URB for resume\n");
 277	}
 278	mutex_unlock(&dev->interrupt_mutex);
 279	return ret;
 280}
 281
 282/* Kill the interrupt URB if all submitters want it killed */
 283void usbnet_status_stop(struct usbnet *dev)
 284{
 285	if (dev->interrupt) {
 286		mutex_lock(&dev->interrupt_mutex);
 287		WARN_ON(dev->interrupt_count == 0);
 288
 289		if (dev->interrupt_count && --dev->interrupt_count == 0)
 290			usb_kill_urb(dev->interrupt);
 291
 292		dev_dbg(&dev->udev->dev,
 293			"decremented interrupt URB count to %d\n",
 294			dev->interrupt_count);
 295		mutex_unlock(&dev->interrupt_mutex);
 296	}
 297}
 298EXPORT_SYMBOL_GPL(usbnet_status_stop);
 299
 300/* For suspend; always kill interrupt URB */
 301static void __usbnet_status_stop_force(struct usbnet *dev)
 302{
 303	if (dev->interrupt) {
 304		mutex_lock(&dev->interrupt_mutex);
 305		usb_kill_urb(dev->interrupt);
 306		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 307		mutex_unlock(&dev->interrupt_mutex);
 308	}
 309}
 310
 311/* Passes this packet up the stack, updating its accounting.
 312 * Some link protocols batch packets, so their rx_fixup paths
 313 * can return clones as well as just modify the original skb.
 314 */
 315void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 316{
 317	struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 318	unsigned long flags;
 319	int	status;
 320
 321	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322		skb_queue_tail(&dev->rxq_pause, skb);
 323		return;
 324	}
 325
 326	/* only update if unset to allow minidriver rx_fixup override */
 327	if (skb->protocol == 0)
 328		skb->protocol = eth_type_trans (skb, dev->net);
 329
 330	flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 331	stats64->rx_packets++;
 332	stats64->rx_bytes += skb->len;
 333	u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 334
 335	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 336		  skb->len + sizeof (struct ethhdr), skb->protocol);
 337	memset (skb->cb, 0, sizeof (struct skb_data));
 338
 339	if (skb_defer_rx_timestamp(skb))
 340		return;
 341
 342	status = netif_rx (skb);
 343	if (status != NET_RX_SUCCESS)
 344		netif_dbg(dev, rx_err, dev->net,
 345			  "netif_rx status %d\n", status);
 346}
 347EXPORT_SYMBOL_GPL(usbnet_skb_return);
 348
 349/* must be called if hard_mtu or rx_urb_size changed */
 350void usbnet_update_max_qlen(struct usbnet *dev)
 351{
 352	enum usb_device_speed speed = dev->udev->speed;
 353
 354	switch (speed) {
 355	case USB_SPEED_HIGH:
 356		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 357		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 358		break;
 359	case USB_SPEED_SUPER:
 360	case USB_SPEED_SUPER_PLUS:
 361		/*
 362		 * Not take default 5ms qlen for super speed HC to
 363		 * save memory, and iperf tests show 2.5ms qlen can
 364		 * work well
 365		 */
 366		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 367		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 368		break;
 369	default:
 370		dev->rx_qlen = dev->tx_qlen = 4;
 371	}
 372}
 373EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 374
 375
 376/*-------------------------------------------------------------------------
 377 *
 378 * Network Device Driver (peer link to "Host Device", from USB host)
 379 *
 380 *-------------------------------------------------------------------------*/
 381
 382int usbnet_change_mtu (struct net_device *net, int new_mtu)
 383{
 384	struct usbnet	*dev = netdev_priv(net);
 385	int		ll_mtu = new_mtu + net->hard_header_len;
 386	int		old_hard_mtu = dev->hard_mtu;
 387	int		old_rx_urb_size = dev->rx_urb_size;
 388
 389	// no second zero-length packet read wanted after mtu-sized packets
 390	if ((ll_mtu % dev->maxpacket) == 0)
 391		return -EDOM;
 392	net->mtu = new_mtu;
 393
 394	dev->hard_mtu = net->mtu + net->hard_header_len;
 395	if (dev->rx_urb_size == old_hard_mtu) {
 396		dev->rx_urb_size = dev->hard_mtu;
 397		if (dev->rx_urb_size > old_rx_urb_size) {
 398			usbnet_pause_rx(dev);
 399			usbnet_unlink_rx_urbs(dev);
 400			usbnet_resume_rx(dev);
 401		}
 402	}
 403
 404	/* max qlen depend on hard_mtu and rx_urb_size */
 405	usbnet_update_max_qlen(dev);
 406
 407	return 0;
 408}
 409EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 410
 411/* The caller must hold list->lock */
 412static void __usbnet_queue_skb(struct sk_buff_head *list,
 413			struct sk_buff *newsk, enum skb_state state)
 414{
 415	struct skb_data *entry = (struct skb_data *) newsk->cb;
 416
 417	__skb_queue_tail(list, newsk);
 418	entry->state = state;
 419}
 420
 421/*-------------------------------------------------------------------------*/
 422
 423/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 424 * completion callbacks.  2.5 should have fixed those bugs...
 425 */
 426
 427static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 428		struct sk_buff_head *list, enum skb_state state)
 429{
 430	unsigned long		flags;
 431	enum skb_state 		old_state;
 432	struct skb_data *entry = (struct skb_data *) skb->cb;
 433
 434	spin_lock_irqsave(&list->lock, flags);
 435	old_state = entry->state;
 436	entry->state = state;
 437	__skb_unlink(skb, list);
 438
 439	/* defer_bh() is never called with list == &dev->done.
 440	 * spin_lock_nested() tells lockdep that it is OK to take
 441	 * dev->done.lock here with list->lock held.
 442	 */
 443	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 444
 445	__skb_queue_tail(&dev->done, skb);
 446	if (dev->done.qlen == 1)
 447		tasklet_schedule(&dev->bh);
 448	spin_unlock(&dev->done.lock);
 449	spin_unlock_irqrestore(&list->lock, flags);
 450	return old_state;
 451}
 452
 453/* some work can't be done in tasklets, so we use keventd
 454 *
 455 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 456 * but tasklet_schedule() doesn't.  hope the failure is rare.
 457 */
 458void usbnet_defer_kevent (struct usbnet *dev, int work)
 459{
 460	set_bit (work, &dev->flags);
 461	if (!schedule_work (&dev->kevent))
 462		netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 463	else
 
 464		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 
 465}
 466EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 467
 468/*-------------------------------------------------------------------------*/
 469
 470static void rx_complete (struct urb *urb);
 471
 472static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 473{
 474	struct sk_buff		*skb;
 475	struct skb_data		*entry;
 476	int			retval = 0;
 477	unsigned long		lockflags;
 478	size_t			size = dev->rx_urb_size;
 479
 480	/* prevent rx skb allocation when error ratio is high */
 481	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 482		usb_free_urb(urb);
 483		return -ENOLINK;
 484	}
 485
 486	if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 487		skb = __netdev_alloc_skb(dev->net, size, flags);
 488	else
 489		skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 490	if (!skb) {
 491		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 492		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 493		usb_free_urb (urb);
 494		return -ENOMEM;
 495	}
 496
 497	entry = (struct skb_data *) skb->cb;
 498	entry->urb = urb;
 499	entry->dev = dev;
 500	entry->length = 0;
 501
 502	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 503		skb->data, size, rx_complete, skb);
 504
 505	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 506
 507	if (netif_running (dev->net) &&
 508	    netif_device_present (dev->net) &&
 509	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 510	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 511		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 512		case -EPIPE:
 513			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 514			break;
 515		case -ENOMEM:
 516			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 517			break;
 518		case -ENODEV:
 519			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 520			netif_device_detach (dev->net);
 521			break;
 522		case -EHOSTUNREACH:
 523			retval = -ENOLINK;
 524			break;
 525		default:
 526			netif_dbg(dev, rx_err, dev->net,
 527				  "rx submit, %d\n", retval);
 528			tasklet_schedule (&dev->bh);
 529			break;
 530		case 0:
 531			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
 532		}
 533	} else {
 534		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 535		retval = -ENOLINK;
 536	}
 537	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 538	if (retval) {
 539		dev_kfree_skb_any (skb);
 540		usb_free_urb (urb);
 541	}
 542	return retval;
 543}
 544
 545
 546/*-------------------------------------------------------------------------*/
 547
 548static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 549{
 550	if (dev->driver_info->rx_fixup &&
 551	    !dev->driver_info->rx_fixup (dev, skb)) {
 552		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 553		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 554			dev->net->stats.rx_errors++;
 555		goto done;
 556	}
 557	// else network stack removes extra byte if we forced a short packet
 558
 559	/* all data was already cloned from skb inside the driver */
 560	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 561		goto done;
 562
 563	if (skb->len < ETH_HLEN) {
 564		dev->net->stats.rx_errors++;
 565		dev->net->stats.rx_length_errors++;
 566		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 567	} else {
 568		usbnet_skb_return(dev, skb);
 569		return;
 570	}
 571
 572done:
 573	skb_queue_tail(&dev->done, skb);
 574}
 575
 576/*-------------------------------------------------------------------------*/
 577
 578static void rx_complete (struct urb *urb)
 579{
 580	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 581	struct skb_data		*entry = (struct skb_data *) skb->cb;
 582	struct usbnet		*dev = entry->dev;
 583	int			urb_status = urb->status;
 584	enum skb_state		state;
 585
 586	skb_put (skb, urb->actual_length);
 587	state = rx_done;
 588	entry->urb = NULL;
 589
 590	switch (urb_status) {
 591	/* success */
 592	case 0:
 593		break;
 594
 595	/* stalls need manual reset. this is rare ... except that
 596	 * when going through USB 2.0 TTs, unplug appears this way.
 597	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 598	 * storm, recovering as needed.
 599	 */
 600	case -EPIPE:
 601		dev->net->stats.rx_errors++;
 602		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 603		// FALLTHROUGH
 604
 605	/* software-driven interface shutdown */
 606	case -ECONNRESET:		/* async unlink */
 607	case -ESHUTDOWN:		/* hardware gone */
 608		netif_dbg(dev, ifdown, dev->net,
 609			  "rx shutdown, code %d\n", urb_status);
 610		goto block;
 611
 612	/* we get controller i/o faults during hub_wq disconnect() delays.
 613	 * throttle down resubmits, to avoid log floods; just temporarily,
 614	 * so we still recover when the fault isn't a hub_wq delay.
 615	 */
 616	case -EPROTO:
 617	case -ETIME:
 618	case -EILSEQ:
 619		dev->net->stats.rx_errors++;
 620		if (!timer_pending (&dev->delay)) {
 621			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 622			netif_dbg(dev, link, dev->net,
 623				  "rx throttle %d\n", urb_status);
 624		}
 625block:
 626		state = rx_cleanup;
 627		entry->urb = urb;
 628		urb = NULL;
 629		break;
 630
 631	/* data overrun ... flush fifo? */
 632	case -EOVERFLOW:
 633		dev->net->stats.rx_over_errors++;
 634		// FALLTHROUGH
 635
 636	default:
 637		state = rx_cleanup;
 638		dev->net->stats.rx_errors++;
 639		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 640		break;
 641	}
 642
 643	/* stop rx if packet error rate is high */
 644	if (++dev->pkt_cnt > 30) {
 645		dev->pkt_cnt = 0;
 646		dev->pkt_err = 0;
 647	} else {
 648		if (state == rx_cleanup)
 649			dev->pkt_err++;
 650		if (dev->pkt_err > 20)
 651			set_bit(EVENT_RX_KILL, &dev->flags);
 652	}
 653
 654	state = defer_bh(dev, skb, &dev->rxq, state);
 655
 656	if (urb) {
 657		if (netif_running (dev->net) &&
 658		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 659		    state != unlink_start) {
 660			rx_submit (dev, urb, GFP_ATOMIC);
 661			usb_mark_last_busy(dev->udev);
 662			return;
 663		}
 664		usb_free_urb (urb);
 665	}
 666	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 667}
 668
 669/*-------------------------------------------------------------------------*/
 670void usbnet_pause_rx(struct usbnet *dev)
 671{
 672	set_bit(EVENT_RX_PAUSED, &dev->flags);
 673
 674	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 675}
 676EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 677
 678void usbnet_resume_rx(struct usbnet *dev)
 679{
 680	struct sk_buff *skb;
 681	int num = 0;
 682
 683	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 686		usbnet_skb_return(dev, skb);
 687		num++;
 688	}
 689
 690	tasklet_schedule(&dev->bh);
 691
 692	netif_dbg(dev, rx_status, dev->net,
 693		  "paused rx queue disabled, %d skbs requeued\n", num);
 694}
 695EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 696
 697void usbnet_purge_paused_rxq(struct usbnet *dev)
 698{
 699	skb_queue_purge(&dev->rxq_pause);
 700}
 701EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 702
 703/*-------------------------------------------------------------------------*/
 704
 705// unlink pending rx/tx; completion handlers do all other cleanup
 706
 707static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 708{
 709	unsigned long		flags;
 710	struct sk_buff		*skb;
 711	int			count = 0;
 712
 713	spin_lock_irqsave (&q->lock, flags);
 714	while (!skb_queue_empty(q)) {
 715		struct skb_data		*entry;
 716		struct urb		*urb;
 717		int			retval;
 718
 719		skb_queue_walk(q, skb) {
 720			entry = (struct skb_data *) skb->cb;
 721			if (entry->state != unlink_start)
 722				goto found;
 723		}
 724		break;
 725found:
 726		entry->state = unlink_start;
 727		urb = entry->urb;
 728
 729		/*
 730		 * Get reference count of the URB to avoid it to be
 731		 * freed during usb_unlink_urb, which may trigger
 732		 * use-after-free problem inside usb_unlink_urb since
 733		 * usb_unlink_urb is always racing with .complete
 734		 * handler(include defer_bh).
 735		 */
 736		usb_get_urb(urb);
 737		spin_unlock_irqrestore(&q->lock, flags);
 738		// during some PM-driven resume scenarios,
 739		// these (async) unlinks complete immediately
 740		retval = usb_unlink_urb (urb);
 741		if (retval != -EINPROGRESS && retval != 0)
 742			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 743		else
 744			count++;
 745		usb_put_urb(urb);
 746		spin_lock_irqsave(&q->lock, flags);
 747	}
 748	spin_unlock_irqrestore (&q->lock, flags);
 749	return count;
 750}
 751
 752// Flush all pending rx urbs
 753// minidrivers may need to do this when the MTU changes
 754
 755void usbnet_unlink_rx_urbs(struct usbnet *dev)
 756{
 757	if (netif_running(dev->net)) {
 758		(void) unlink_urbs (dev, &dev->rxq);
 759		tasklet_schedule(&dev->bh);
 760	}
 761}
 762EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 763
 764/*-------------------------------------------------------------------------*/
 765
 766static void wait_skb_queue_empty(struct sk_buff_head *q)
 767{
 768	unsigned long flags;
 769
 770	spin_lock_irqsave(&q->lock, flags);
 771	while (!skb_queue_empty(q)) {
 772		spin_unlock_irqrestore(&q->lock, flags);
 773		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 774		set_current_state(TASK_UNINTERRUPTIBLE);
 775		spin_lock_irqsave(&q->lock, flags);
 776	}
 777	spin_unlock_irqrestore(&q->lock, flags);
 778}
 779
 780// precondition: never called in_interrupt
 781static void usbnet_terminate_urbs(struct usbnet *dev)
 782{
 783	DECLARE_WAITQUEUE(wait, current);
 784	int temp;
 785
 786	/* ensure there are no more active urbs */
 787	add_wait_queue(&dev->wait, &wait);
 788	set_current_state(TASK_UNINTERRUPTIBLE);
 789	temp = unlink_urbs(dev, &dev->txq) +
 790		unlink_urbs(dev, &dev->rxq);
 791
 792	/* maybe wait for deletions to finish. */
 793	wait_skb_queue_empty(&dev->rxq);
 794	wait_skb_queue_empty(&dev->txq);
 795	wait_skb_queue_empty(&dev->done);
 796	netif_dbg(dev, ifdown, dev->net,
 797		  "waited for %d urb completions\n", temp);
 798	set_current_state(TASK_RUNNING);
 799	remove_wait_queue(&dev->wait, &wait);
 800}
 801
 802int usbnet_stop (struct net_device *net)
 803{
 804	struct usbnet		*dev = netdev_priv(net);
 805	struct driver_info	*info = dev->driver_info;
 806	int			retval, pm, mpn;
 807
 808	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 809	netif_stop_queue (net);
 810
 811	netif_info(dev, ifdown, dev->net,
 812		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 813		   net->stats.rx_packets, net->stats.tx_packets,
 814		   net->stats.rx_errors, net->stats.tx_errors);
 815
 816	/* to not race resume */
 817	pm = usb_autopm_get_interface(dev->intf);
 818	/* allow minidriver to stop correctly (wireless devices to turn off
 819	 * radio etc) */
 820	if (info->stop) {
 821		retval = info->stop(dev);
 822		if (retval < 0)
 823			netif_info(dev, ifdown, dev->net,
 824				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 825				   retval,
 826				   dev->udev->bus->bus_name, dev->udev->devpath,
 827				   info->description);
 828	}
 829
 830	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 831		usbnet_terminate_urbs(dev);
 832
 833	usbnet_status_stop(dev);
 834
 835	usbnet_purge_paused_rxq(dev);
 836
 837	mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 838
 839	/* deferred work (task, timer, softirq) must also stop.
 840	 * can't flush_scheduled_work() until we drop rtnl (later),
 841	 * else workers could deadlock; so make workers a NOP.
 842	 */
 843	dev->flags = 0;
 844	del_timer_sync (&dev->delay);
 845	tasklet_kill (&dev->bh);
 846	if (!pm)
 847		usb_autopm_put_interface(dev->intf);
 848
 849	if (info->manage_power && mpn)
 850		info->manage_power(dev, 0);
 851	else
 852		usb_autopm_put_interface(dev->intf);
 853
 854	return 0;
 855}
 856EXPORT_SYMBOL_GPL(usbnet_stop);
 857
 858/*-------------------------------------------------------------------------*/
 859
 860// posts reads, and enables write queuing
 861
 862// precondition: never called in_interrupt
 863
 864int usbnet_open (struct net_device *net)
 865{
 866	struct usbnet		*dev = netdev_priv(net);
 867	int			retval;
 868	struct driver_info	*info = dev->driver_info;
 869
 870	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 871		netif_info(dev, ifup, dev->net,
 872			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 873			   retval,
 874			   dev->udev->bus->bus_name,
 875			   dev->udev->devpath,
 876			   info->description);
 877		goto done_nopm;
 878	}
 879
 880	// put into "known safe" state
 881	if (info->reset && (retval = info->reset (dev)) < 0) {
 882		netif_info(dev, ifup, dev->net,
 883			   "open reset 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;
 889	}
 890
 891	/* hard_mtu or rx_urb_size may change in reset() */
 892	usbnet_update_max_qlen(dev);
 893
 894	// insist peer be connected
 895	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 896		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 897		goto done;
 898	}
 899
 900	/* start any status interrupt transfer */
 901	if (dev->interrupt) {
 902		retval = usbnet_status_start(dev, GFP_KERNEL);
 903		if (retval < 0) {
 904			netif_err(dev, ifup, dev->net,
 905				  "intr submit %d\n", retval);
 906			goto done;
 907		}
 908	}
 909
 910	set_bit(EVENT_DEV_OPEN, &dev->flags);
 911	netif_start_queue (net);
 912	netif_info(dev, ifup, dev->net,
 913		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 914		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 915		   dev->net->mtu,
 916		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 917		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 918		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 919		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 920		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 921		   "simple");
 922
 923	/* reset rx error state */
 924	dev->pkt_cnt = 0;
 925	dev->pkt_err = 0;
 926	clear_bit(EVENT_RX_KILL, &dev->flags);
 927
 928	// delay posting reads until we're fully open
 929	tasklet_schedule (&dev->bh);
 930	if (info->manage_power) {
 931		retval = info->manage_power(dev, 1);
 932		if (retval < 0) {
 933			retval = 0;
 934			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 935		} else {
 936			usb_autopm_put_interface(dev->intf);
 937		}
 938	}
 939	return retval;
 940done:
 941	usb_autopm_put_interface(dev->intf);
 942done_nopm:
 943	return retval;
 944}
 945EXPORT_SYMBOL_GPL(usbnet_open);
 946
 947/*-------------------------------------------------------------------------*/
 948
 949/* ethtool methods; minidrivers may need to add some more, but
 950 * they'll probably want to use this base set.
 951 */
 952
 953int usbnet_get_link_ksettings(struct net_device *net,
 954			      struct ethtool_link_ksettings *cmd)
 955{
 956	struct usbnet *dev = netdev_priv(net);
 957
 958	if (!dev->mii.mdio_read)
 959		return -EOPNOTSUPP;
 960
 961	mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 962
 963	return 0;
 964}
 965EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 966
 967int usbnet_set_link_ksettings(struct net_device *net,
 968			      const struct ethtool_link_ksettings *cmd)
 969{
 970	struct usbnet *dev = netdev_priv(net);
 971	int retval;
 972
 973	if (!dev->mii.mdio_write)
 974		return -EOPNOTSUPP;
 975
 976	retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 977
 978	/* link speed/duplex might have changed */
 979	if (dev->driver_info->link_reset)
 980		dev->driver_info->link_reset(dev);
 981
 982	/* hard_mtu or rx_urb_size may change in link_reset() */
 983	usbnet_update_max_qlen(dev);
 984
 985	return retval;
 986}
 987EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 988
 989void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 990{
 991	struct usbnet *dev = netdev_priv(net);
 992	unsigned int start;
 993	int cpu;
 994
 995	netdev_stats_to_stats64(stats, &net->stats);
 996
 997	for_each_possible_cpu(cpu) {
 998		struct pcpu_sw_netstats *stats64;
 999		u64 rx_packets, rx_bytes;
1000		u64 tx_packets, tx_bytes;
1001
1002		stats64 = per_cpu_ptr(dev->stats64, cpu);
1003
1004		do {
1005			start = u64_stats_fetch_begin_irq(&stats64->syncp);
1006			rx_packets = stats64->rx_packets;
1007			rx_bytes = stats64->rx_bytes;
1008			tx_packets = stats64->tx_packets;
1009			tx_bytes = stats64->tx_bytes;
1010		} while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1011
1012		stats->rx_packets += rx_packets;
1013		stats->rx_bytes += rx_bytes;
1014		stats->tx_packets += tx_packets;
1015		stats->tx_bytes += tx_bytes;
1016	}
1017}
1018EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1019
1020u32 usbnet_get_link (struct net_device *net)
1021{
1022	struct usbnet *dev = netdev_priv(net);
1023
1024	/* If a check_connect is defined, return its result */
1025	if (dev->driver_info->check_connect)
1026		return dev->driver_info->check_connect (dev) == 0;
1027
1028	/* if the device has mii operations, use those */
1029	if (dev->mii.mdio_read)
1030		return mii_link_ok(&dev->mii);
1031
1032	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1033	return ethtool_op_get_link(net);
1034}
1035EXPORT_SYMBOL_GPL(usbnet_get_link);
1036
1037int usbnet_nway_reset(struct net_device *net)
1038{
1039	struct usbnet *dev = netdev_priv(net);
1040
1041	if (!dev->mii.mdio_write)
1042		return -EOPNOTSUPP;
1043
1044	return mii_nway_restart(&dev->mii);
1045}
1046EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1047
1048void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1049{
1050	struct usbnet *dev = netdev_priv(net);
1051
1052	strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1053	strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1054	strlcpy (info->fw_version, dev->driver_info->description,
1055		sizeof info->fw_version);
1056	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1057}
1058EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1059
1060u32 usbnet_get_msglevel (struct net_device *net)
1061{
1062	struct usbnet *dev = netdev_priv(net);
1063
1064	return dev->msg_enable;
1065}
1066EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1067
1068void usbnet_set_msglevel (struct net_device *net, u32 level)
1069{
1070	struct usbnet *dev = netdev_priv(net);
1071
1072	dev->msg_enable = level;
1073}
1074EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1075
1076/* drivers may override default ethtool_ops in their bind() routine */
1077static const struct ethtool_ops usbnet_ethtool_ops = {
 
 
1078	.get_link		= usbnet_get_link,
1079	.nway_reset		= usbnet_nway_reset,
1080	.get_drvinfo		= usbnet_get_drvinfo,
1081	.get_msglevel		= usbnet_get_msglevel,
1082	.set_msglevel		= usbnet_set_msglevel,
1083	.get_ts_info		= ethtool_op_get_ts_info,
1084	.get_link_ksettings	= usbnet_get_link_ksettings,
1085	.set_link_ksettings	= usbnet_set_link_ksettings,
1086};
1087
1088/*-------------------------------------------------------------------------*/
1089
1090static void __handle_link_change(struct usbnet *dev)
1091{
1092	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1093		return;
1094
1095	if (!netif_carrier_ok(dev->net)) {
1096		/* kill URBs for reading packets to save bus bandwidth */
1097		unlink_urbs(dev, &dev->rxq);
1098
1099		/*
1100		 * tx_timeout will unlink URBs for sending packets and
1101		 * tx queue is stopped by netcore after link becomes off
1102		 */
1103	} else {
1104		/* submitting URBs for reading packets */
1105		tasklet_schedule(&dev->bh);
1106	}
1107
1108	/* hard_mtu or rx_urb_size may change during link change */
1109	usbnet_update_max_qlen(dev);
1110
1111	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1112}
1113
1114static void usbnet_set_rx_mode(struct net_device *net)
1115{
1116	struct usbnet		*dev = netdev_priv(net);
1117
1118	usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1119}
1120
1121static void __handle_set_rx_mode(struct usbnet *dev)
1122{
1123	if (dev->driver_info->set_rx_mode)
1124		(dev->driver_info->set_rx_mode)(dev);
1125
1126	clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1127}
1128
1129/* work that cannot be done in interrupt context uses keventd.
1130 *
1131 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1132 * especially now that control transfers can be queued.
1133 */
1134static void
1135usbnet_deferred_kevent (struct work_struct *work)
1136{
1137	struct usbnet		*dev =
1138		container_of(work, struct usbnet, kevent);
1139	int			status;
1140
1141	/* usb_clear_halt() needs a thread context */
1142	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1143		unlink_urbs (dev, &dev->txq);
1144		status = usb_autopm_get_interface(dev->intf);
1145		if (status < 0)
1146			goto fail_pipe;
1147		status = usb_clear_halt (dev->udev, dev->out);
1148		usb_autopm_put_interface(dev->intf);
1149		if (status < 0 &&
1150		    status != -EPIPE &&
1151		    status != -ESHUTDOWN) {
1152			if (netif_msg_tx_err (dev))
1153fail_pipe:
1154				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1155					   status);
1156		} else {
1157			clear_bit (EVENT_TX_HALT, &dev->flags);
1158			if (status != -ESHUTDOWN)
1159				netif_wake_queue (dev->net);
1160		}
1161	}
1162	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1163		unlink_urbs (dev, &dev->rxq);
1164		status = usb_autopm_get_interface(dev->intf);
1165		if (status < 0)
1166			goto fail_halt;
1167		status = usb_clear_halt (dev->udev, dev->in);
1168		usb_autopm_put_interface(dev->intf);
1169		if (status < 0 &&
1170		    status != -EPIPE &&
1171		    status != -ESHUTDOWN) {
1172			if (netif_msg_rx_err (dev))
1173fail_halt:
1174				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1175					   status);
1176		} else {
1177			clear_bit (EVENT_RX_HALT, &dev->flags);
1178			tasklet_schedule (&dev->bh);
1179		}
1180	}
1181
1182	/* tasklet could resubmit itself forever if memory is tight */
1183	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1184		struct urb	*urb = NULL;
1185		int resched = 1;
1186
1187		if (netif_running (dev->net))
1188			urb = usb_alloc_urb (0, GFP_KERNEL);
1189		else
1190			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1191		if (urb != NULL) {
1192			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1193			status = usb_autopm_get_interface(dev->intf);
1194			if (status < 0) {
1195				usb_free_urb(urb);
1196				goto fail_lowmem;
1197			}
1198			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1199				resched = 0;
1200			usb_autopm_put_interface(dev->intf);
1201fail_lowmem:
1202			if (resched)
1203				tasklet_schedule (&dev->bh);
1204		}
1205	}
1206
1207	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1208		struct driver_info	*info = dev->driver_info;
1209		int			retval = 0;
1210
1211		clear_bit (EVENT_LINK_RESET, &dev->flags);
1212		status = usb_autopm_get_interface(dev->intf);
1213		if (status < 0)
1214			goto skip_reset;
1215		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1216			usb_autopm_put_interface(dev->intf);
1217skip_reset:
1218			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1219				    retval,
1220				    dev->udev->bus->bus_name,
1221				    dev->udev->devpath,
1222				    info->description);
1223		} else {
1224			usb_autopm_put_interface(dev->intf);
1225		}
1226
1227		/* handle link change from link resetting */
1228		__handle_link_change(dev);
1229	}
1230
1231	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1232		__handle_link_change(dev);
1233
1234	if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1235		__handle_set_rx_mode(dev);
1236
1237
1238	if (dev->flags)
1239		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1240}
1241
1242/*-------------------------------------------------------------------------*/
1243
1244static void tx_complete (struct urb *urb)
1245{
1246	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1247	struct skb_data		*entry = (struct skb_data *) skb->cb;
1248	struct usbnet		*dev = entry->dev;
1249
1250	if (urb->status == 0) {
1251		struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1252		unsigned long flags;
1253
1254		flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1255		stats64->tx_packets += entry->packets;
1256		stats64->tx_bytes += entry->length;
1257		u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1258	} else {
1259		dev->net->stats.tx_errors++;
1260
1261		switch (urb->status) {
1262		case -EPIPE:
1263			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1264			break;
1265
1266		/* software-driven interface shutdown */
1267		case -ECONNRESET:		// async unlink
1268		case -ESHUTDOWN:		// hardware gone
1269			break;
1270
1271		/* like rx, tx gets controller i/o faults during hub_wq
1272		 * delays and so it uses the same throttling mechanism.
1273		 */
1274		case -EPROTO:
1275		case -ETIME:
1276		case -EILSEQ:
1277			usb_mark_last_busy(dev->udev);
1278			if (!timer_pending (&dev->delay)) {
1279				mod_timer (&dev->delay,
1280					jiffies + THROTTLE_JIFFIES);
1281				netif_dbg(dev, link, dev->net,
1282					  "tx throttle %d\n", urb->status);
1283			}
1284			netif_stop_queue (dev->net);
1285			break;
1286		default:
1287			netif_dbg(dev, tx_err, dev->net,
1288				  "tx err %d\n", entry->urb->status);
1289			break;
1290		}
1291	}
1292
1293	usb_autopm_put_interface_async(dev->intf);
1294	(void) defer_bh(dev, skb, &dev->txq, tx_done);
1295}
1296
1297/*-------------------------------------------------------------------------*/
1298
1299void usbnet_tx_timeout (struct net_device *net)
1300{
1301	struct usbnet		*dev = netdev_priv(net);
1302
1303	unlink_urbs (dev, &dev->txq);
1304	tasklet_schedule (&dev->bh);
1305	/* this needs to be handled individually because the generic layer
1306	 * doesn't know what is sufficient and could not restore private
1307	 * information if a remedy of an unconditional reset were used.
1308	 */
1309	if (dev->driver_info->recover)
1310		(dev->driver_info->recover)(dev);
1311}
1312EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1313
1314/*-------------------------------------------------------------------------*/
1315
1316static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1317{
1318	unsigned num_sgs, total_len = 0;
1319	int i, s = 0;
1320
1321	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1322	if (num_sgs == 1)
1323		return 0;
1324
1325	/* reserve one for zero packet */
1326	urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1327			  GFP_ATOMIC);
1328	if (!urb->sg)
1329		return -ENOMEM;
1330
1331	urb->num_sgs = num_sgs;
1332	sg_init_table(urb->sg, urb->num_sgs + 1);
1333
1334	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1335	total_len += skb_headlen(skb);
1336
1337	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1338		struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1339
1340		total_len += skb_frag_size(f);
1341		sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1342				f->page_offset);
1343	}
1344	urb->transfer_buffer_length = total_len;
1345
1346	return 1;
1347}
1348
1349netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1350				     struct net_device *net)
1351{
1352	struct usbnet		*dev = netdev_priv(net);
1353	unsigned int			length;
1354	struct urb		*urb = NULL;
1355	struct skb_data		*entry;
1356	struct driver_info	*info = dev->driver_info;
1357	unsigned long		flags;
1358	int retval;
1359
1360	if (skb)
1361		skb_tx_timestamp(skb);
1362
1363	// some devices want funky USB-level framing, for
1364	// win32 driver (usually) and/or hardware quirks
1365	if (info->tx_fixup) {
1366		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1367		if (!skb) {
1368			/* packet collected; minidriver waiting for more */
1369			if (info->flags & FLAG_MULTI_PACKET)
1370				goto not_drop;
1371			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1372			goto drop;
1373		}
1374	}
1375
1376	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1377		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1378		goto drop;
1379	}
1380
1381	entry = (struct skb_data *) skb->cb;
1382	entry->urb = urb;
1383	entry->dev = dev;
1384
1385	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1386			skb->data, skb->len, tx_complete, skb);
1387	if (dev->can_dma_sg) {
1388		if (build_dma_sg(skb, urb) < 0)
1389			goto drop;
1390	}
1391	length = urb->transfer_buffer_length;
1392
1393	/* don't assume the hardware handles USB_ZERO_PACKET
1394	 * NOTE:  strictly conforming cdc-ether devices should expect
1395	 * the ZLP here, but ignore the one-byte packet.
1396	 * NOTE2: CDC NCM specification is different from CDC ECM when
1397	 * handling ZLP/short packets, so cdc_ncm driver will make short
1398	 * packet itself if needed.
1399	 */
1400	if (length % dev->maxpacket == 0) {
1401		if (!(info->flags & FLAG_SEND_ZLP)) {
1402			if (!(info->flags & FLAG_MULTI_PACKET)) {
1403				length++;
1404				if (skb_tailroom(skb) && !urb->num_sgs) {
1405					skb->data[skb->len] = 0;
1406					__skb_put(skb, 1);
1407				} else if (urb->num_sgs)
1408					sg_set_buf(&urb->sg[urb->num_sgs++],
1409							dev->padding_pkt, 1);
1410			}
1411		} else
1412			urb->transfer_flags |= URB_ZERO_PACKET;
1413	}
1414	urb->transfer_buffer_length = length;
1415
1416	if (info->flags & FLAG_MULTI_PACKET) {
1417		/* Driver has set number of packets and a length delta.
1418		 * Calculate the complete length and ensure that it's
1419		 * positive.
1420		 */
1421		entry->length += length;
1422		if (WARN_ON_ONCE(entry->length <= 0))
1423			entry->length = length;
1424	} else {
1425		usbnet_set_skb_tx_stats(skb, 1, length);
1426	}
1427
1428	spin_lock_irqsave(&dev->txq.lock, flags);
1429	retval = usb_autopm_get_interface_async(dev->intf);
1430	if (retval < 0) {
1431		spin_unlock_irqrestore(&dev->txq.lock, flags);
1432		goto drop;
1433	}
1434
1435#ifdef CONFIG_PM
1436	/* if this triggers the device is still a sleep */
1437	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1438		/* transmission will be done in resume */
1439		usb_anchor_urb(urb, &dev->deferred);
1440		/* no use to process more packets */
1441		netif_stop_queue(net);
1442		usb_put_urb(urb);
1443		spin_unlock_irqrestore(&dev->txq.lock, flags);
1444		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1445		goto deferred;
1446	}
1447#endif
1448
1449	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1450	case -EPIPE:
1451		netif_stop_queue (net);
1452		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1453		usb_autopm_put_interface_async(dev->intf);
1454		break;
1455	default:
1456		usb_autopm_put_interface_async(dev->intf);
1457		netif_dbg(dev, tx_err, dev->net,
1458			  "tx: submit urb err %d\n", retval);
1459		break;
1460	case 0:
1461		netif_trans_update(net);
1462		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1463		if (dev->txq.qlen >= TX_QLEN (dev))
1464			netif_stop_queue (net);
1465	}
1466	spin_unlock_irqrestore (&dev->txq.lock, flags);
1467
1468	if (retval) {
1469		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1470drop:
1471		dev->net->stats.tx_dropped++;
1472not_drop:
1473		if (skb)
1474			dev_kfree_skb_any (skb);
1475		if (urb) {
1476			kfree(urb->sg);
1477			usb_free_urb(urb);
1478		}
1479	} else
1480		netif_dbg(dev, tx_queued, dev->net,
1481			  "> tx, len %u, type 0x%x\n", length, skb->protocol);
1482#ifdef CONFIG_PM
1483deferred:
1484#endif
1485	return NETDEV_TX_OK;
1486}
1487EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1488
1489static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1490{
1491	struct urb	*urb;
1492	int		i;
1493	int		ret = 0;
1494
1495	/* don't refill the queue all at once */
1496	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1497		urb = usb_alloc_urb(0, flags);
1498		if (urb != NULL) {
1499			ret = rx_submit(dev, urb, flags);
1500			if (ret)
1501				goto err;
1502		} else {
1503			ret = -ENOMEM;
1504			goto err;
1505		}
1506	}
1507err:
1508	return ret;
1509}
1510
1511/*-------------------------------------------------------------------------*/
1512
1513// tasklet (work deferred from completions, in_irq) or timer
1514
1515static void usbnet_bh (struct timer_list *t)
1516{
1517	struct usbnet		*dev = from_timer(dev, t, delay);
1518	struct sk_buff		*skb;
1519	struct skb_data		*entry;
1520
1521	while ((skb = skb_dequeue (&dev->done))) {
1522		entry = (struct skb_data *) skb->cb;
1523		switch (entry->state) {
1524		case rx_done:
1525			entry->state = rx_cleanup;
1526			rx_process (dev, skb);
1527			continue;
1528		case tx_done:
1529			kfree(entry->urb->sg);
1530		case rx_cleanup:
1531			usb_free_urb (entry->urb);
1532			dev_kfree_skb (skb);
1533			continue;
1534		default:
1535			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1536		}
1537	}
1538
1539	/* restart RX again after disabling due to high error rate */
1540	clear_bit(EVENT_RX_KILL, &dev->flags);
1541
1542	/* waiting for all pending urbs to complete?
1543	 * only then can we forgo submitting anew
1544	 */
1545	if (waitqueue_active(&dev->wait)) {
1546		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1547			wake_up_all(&dev->wait);
1548
1549	// or are we maybe short a few urbs?
1550	} else if (netif_running (dev->net) &&
1551		   netif_device_present (dev->net) &&
1552		   netif_carrier_ok(dev->net) &&
1553		   !timer_pending(&dev->delay) &&
1554		   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1555		   !test_bit(EVENT_RX_HALT, &dev->flags)) {
1556		int	temp = dev->rxq.qlen;
1557
1558		if (temp < RX_QLEN(dev)) {
1559			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1560				return;
1561			if (temp != dev->rxq.qlen)
1562				netif_dbg(dev, link, dev->net,
1563					  "rxqlen %d --> %d\n",
1564					  temp, dev->rxq.qlen);
1565			if (dev->rxq.qlen < RX_QLEN(dev))
1566				tasklet_schedule (&dev->bh);
1567		}
1568		if (dev->txq.qlen < TX_QLEN (dev))
1569			netif_wake_queue (dev->net);
1570	}
1571}
1572
1573
1574/*-------------------------------------------------------------------------
1575 *
1576 * USB Device Driver support
1577 *
1578 *-------------------------------------------------------------------------*/
1579
1580// precondition: never called in_interrupt
1581
1582void usbnet_disconnect (struct usb_interface *intf)
1583{
1584	struct usbnet		*dev;
1585	struct usb_device	*xdev;
1586	struct net_device	*net;
1587
1588	dev = usb_get_intfdata(intf);
1589	usb_set_intfdata(intf, NULL);
1590	if (!dev)
1591		return;
1592
1593	xdev = interface_to_usbdev (intf);
1594
1595	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1596		   intf->dev.driver->name,
1597		   xdev->bus->bus_name, xdev->devpath,
1598		   dev->driver_info->description);
1599
1600	net = dev->net;
1601	unregister_netdev (net);
1602
1603	cancel_work_sync(&dev->kevent);
1604
1605	usb_scuttle_anchored_urbs(&dev->deferred);
1606
1607	if (dev->driver_info->unbind)
1608		dev->driver_info->unbind (dev, intf);
1609
1610	usb_kill_urb(dev->interrupt);
1611	usb_free_urb(dev->interrupt);
1612	kfree(dev->padding_pkt);
1613
1614	free_percpu(dev->stats64);
1615	free_netdev(net);
1616}
1617EXPORT_SYMBOL_GPL(usbnet_disconnect);
1618
1619static const struct net_device_ops usbnet_netdev_ops = {
1620	.ndo_open		= usbnet_open,
1621	.ndo_stop		= usbnet_stop,
1622	.ndo_start_xmit		= usbnet_start_xmit,
1623	.ndo_tx_timeout		= usbnet_tx_timeout,
1624	.ndo_set_rx_mode	= usbnet_set_rx_mode,
1625	.ndo_change_mtu		= usbnet_change_mtu,
1626	.ndo_get_stats64	= usbnet_get_stats64,
1627	.ndo_set_mac_address 	= eth_mac_addr,
1628	.ndo_validate_addr	= eth_validate_addr,
1629};
1630
1631/*-------------------------------------------------------------------------*/
1632
1633// precondition: never called in_interrupt
1634
1635static struct device_type wlan_type = {
1636	.name	= "wlan",
1637};
1638
1639static struct device_type wwan_type = {
1640	.name	= "wwan",
1641};
1642
1643int
1644usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1645{
1646	struct usbnet			*dev;
1647	struct net_device		*net;
1648	struct usb_host_interface	*interface;
1649	struct driver_info		*info;
1650	struct usb_device		*xdev;
1651	int				status;
1652	const char			*name;
1653	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1654
1655	/* usbnet already took usb runtime pm, so have to enable the feature
1656	 * for usb interface, otherwise usb_autopm_get_interface may return
1657	 * failure if RUNTIME_PM is enabled.
1658	 */
1659	if (!driver->supports_autosuspend) {
1660		driver->supports_autosuspend = 1;
1661		pm_runtime_enable(&udev->dev);
1662	}
1663
1664	name = udev->dev.driver->name;
1665	info = (struct driver_info *) prod->driver_info;
1666	if (!info) {
1667		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1668		return -ENODEV;
1669	}
1670	xdev = interface_to_usbdev (udev);
1671	interface = udev->cur_altsetting;
1672
1673	status = -ENOMEM;
1674
1675	// set up our own records
1676	net = alloc_etherdev(sizeof(*dev));
1677	if (!net)
1678		goto out;
1679
1680	/* netdev_printk() needs this so do it as early as possible */
1681	SET_NETDEV_DEV(net, &udev->dev);
1682
1683	dev = netdev_priv(net);
1684	dev->udev = xdev;
1685	dev->intf = udev;
1686	dev->driver_info = info;
1687	dev->driver_name = name;
1688
1689	dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1690	if (!dev->stats64)
1691		goto out0;
1692
1693	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1694				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1695	init_waitqueue_head(&dev->wait);
1696	skb_queue_head_init (&dev->rxq);
1697	skb_queue_head_init (&dev->txq);
1698	skb_queue_head_init (&dev->done);
1699	skb_queue_head_init(&dev->rxq_pause);
1700	dev->bh.func = (void (*)(unsigned long))usbnet_bh;
1701	dev->bh.data = (unsigned long)&dev->delay;
1702	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1703	init_usb_anchor(&dev->deferred);
1704	timer_setup(&dev->delay, usbnet_bh, 0);
 
 
1705	mutex_init (&dev->phy_mutex);
1706	mutex_init(&dev->interrupt_mutex);
1707	dev->interrupt_count = 0;
1708
1709	dev->net = net;
1710	strcpy (net->name, "usb%d");
1711	memcpy (net->dev_addr, node_id, sizeof node_id);
1712
1713	/* rx and tx sides can use different message sizes;
1714	 * bind() should set rx_urb_size in that case.
1715	 */
1716	dev->hard_mtu = net->mtu + net->hard_header_len;
1717	net->min_mtu = 0;
1718	net->max_mtu = ETH_MAX_MTU;
1719
1720	net->netdev_ops = &usbnet_netdev_ops;
1721	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1722	net->ethtool_ops = &usbnet_ethtool_ops;
1723
1724	// allow device-specific bind/init procedures
1725	// NOTE net->name still not usable ...
1726	if (info->bind) {
1727		status = info->bind (dev, udev);
1728		if (status < 0)
1729			goto out1;
1730
1731		// heuristic:  "usb%d" for links we know are two-host,
1732		// else "eth%d" when there's reasonable doubt.  userspace
1733		// can rename the link if it knows better.
1734		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1735		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1736		     (net->dev_addr [0] & 0x02) == 0))
1737			strcpy (net->name, "eth%d");
1738		/* WLAN devices should always be named "wlan%d" */
1739		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1740			strcpy(net->name, "wlan%d");
1741		/* WWAN devices should always be named "wwan%d" */
1742		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1743			strcpy(net->name, "wwan%d");
1744
1745		/* devices that cannot do ARP */
1746		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1747			net->flags |= IFF_NOARP;
1748
1749		/* maybe the remote can't receive an Ethernet MTU */
1750		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1751			net->mtu = dev->hard_mtu - net->hard_header_len;
1752	} else if (!info->in || !info->out)
1753		status = usbnet_get_endpoints (dev, udev);
1754	else {
1755		dev->in = usb_rcvbulkpipe (xdev, info->in);
1756		dev->out = usb_sndbulkpipe (xdev, info->out);
1757		if (!(info->flags & FLAG_NO_SETINT))
1758			status = usb_set_interface (xdev,
1759				interface->desc.bInterfaceNumber,
1760				interface->desc.bAlternateSetting);
1761		else
1762			status = 0;
1763
1764	}
1765	if (status >= 0 && dev->status)
1766		status = init_status (dev, udev);
1767	if (status < 0)
1768		goto out3;
1769
1770	if (!dev->rx_urb_size)
1771		dev->rx_urb_size = dev->hard_mtu;
1772	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1773
1774	/* let userspace know we have a random address */
1775	if (ether_addr_equal(net->dev_addr, node_id))
1776		net->addr_assign_type = NET_ADDR_RANDOM;
1777
1778	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1779		SET_NETDEV_DEVTYPE(net, &wlan_type);
1780	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1781		SET_NETDEV_DEVTYPE(net, &wwan_type);
1782
1783	/* initialize max rx_qlen and tx_qlen */
1784	usbnet_update_max_qlen(dev);
1785
1786	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1787		!(info->flags & FLAG_MULTI_PACKET)) {
1788		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1789		if (!dev->padding_pkt) {
1790			status = -ENOMEM;
1791			goto out4;
1792		}
1793	}
1794
1795	status = register_netdev (net);
1796	if (status)
1797		goto out5;
1798	netif_info(dev, probe, dev->net,
1799		   "register '%s' at usb-%s-%s, %s, %pM\n",
1800		   udev->dev.driver->name,
1801		   xdev->bus->bus_name, xdev->devpath,
1802		   dev->driver_info->description,
1803		   net->dev_addr);
1804
1805	// ok, it's ready to go.
1806	usb_set_intfdata (udev, dev);
1807
1808	netif_device_attach (net);
1809
1810	if (dev->driver_info->flags & FLAG_LINK_INTR)
1811		usbnet_link_change(dev, 0, 0);
1812
1813	return 0;
1814
1815out5:
1816	kfree(dev->padding_pkt);
1817out4:
1818	usb_free_urb(dev->interrupt);
1819out3:
1820	if (info->unbind)
1821		info->unbind (dev, udev);
1822out1:
1823	/* subdrivers must undo all they did in bind() if they
1824	 * fail it, but we may fail later and a deferred kevent
1825	 * may trigger an error resubmitting itself and, worse,
1826	 * schedule a timer. So we kill it all just in case.
1827	 */
1828	cancel_work_sync(&dev->kevent);
1829	del_timer_sync(&dev->delay);
1830	free_percpu(dev->stats64);
1831out0:
1832	free_netdev(net);
1833out:
1834	return status;
1835}
1836EXPORT_SYMBOL_GPL(usbnet_probe);
1837
1838/*-------------------------------------------------------------------------*/
1839
1840/*
1841 * suspend the whole driver as soon as the first interface is suspended
1842 * resume only when the last interface is resumed
1843 */
1844
1845int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1846{
1847	struct usbnet		*dev = usb_get_intfdata(intf);
1848
1849	if (!dev->suspend_count++) {
1850		spin_lock_irq(&dev->txq.lock);
1851		/* don't autosuspend while transmitting */
1852		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1853			dev->suspend_count--;
1854			spin_unlock_irq(&dev->txq.lock);
1855			return -EBUSY;
1856		} else {
1857			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1858			spin_unlock_irq(&dev->txq.lock);
1859		}
1860		/*
1861		 * accelerate emptying of the rx and queues, to avoid
1862		 * having everything error out.
1863		 */
1864		netif_device_detach (dev->net);
1865		usbnet_terminate_urbs(dev);
1866		__usbnet_status_stop_force(dev);
1867
1868		/*
1869		 * reattach so runtime management can use and
1870		 * wake the device
1871		 */
1872		netif_device_attach (dev->net);
1873	}
1874	return 0;
1875}
1876EXPORT_SYMBOL_GPL(usbnet_suspend);
1877
1878int usbnet_resume (struct usb_interface *intf)
1879{
1880	struct usbnet		*dev = usb_get_intfdata(intf);
1881	struct sk_buff          *skb;
1882	struct urb              *res;
1883	int                     retval;
1884
1885	if (!--dev->suspend_count) {
1886		/* resume interrupt URB if it was previously submitted */
1887		__usbnet_status_start_force(dev, GFP_NOIO);
1888
1889		spin_lock_irq(&dev->txq.lock);
1890		while ((res = usb_get_from_anchor(&dev->deferred))) {
1891
1892			skb = (struct sk_buff *)res->context;
1893			retval = usb_submit_urb(res, GFP_ATOMIC);
1894			if (retval < 0) {
1895				dev_kfree_skb_any(skb);
1896				kfree(res->sg);
1897				usb_free_urb(res);
1898				usb_autopm_put_interface_async(dev->intf);
1899			} else {
1900				netif_trans_update(dev->net);
1901				__skb_queue_tail(&dev->txq, skb);
1902			}
1903		}
1904
1905		smp_mb();
1906		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1907		spin_unlock_irq(&dev->txq.lock);
1908
1909		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1910			/* handle remote wakeup ASAP
1911			 * we cannot race against stop
1912			 */
1913			if (netif_device_present(dev->net) &&
1914				!timer_pending(&dev->delay) &&
1915				!test_bit(EVENT_RX_HALT, &dev->flags))
1916					rx_alloc_submit(dev, GFP_NOIO);
1917
1918			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1919				netif_tx_wake_all_queues(dev->net);
1920			tasklet_schedule (&dev->bh);
1921		}
1922	}
1923
1924	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1925		usb_autopm_get_interface_no_resume(intf);
1926
1927	return 0;
1928}
1929EXPORT_SYMBOL_GPL(usbnet_resume);
1930
1931/*
1932 * Either a subdriver implements manage_power, then it is assumed to always
1933 * be ready to be suspended or it reports the readiness to be suspended
1934 * explicitly
1935 */
1936void usbnet_device_suggests_idle(struct usbnet *dev)
1937{
1938	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1939		dev->intf->needs_remote_wakeup = 1;
1940		usb_autopm_put_interface_async(dev->intf);
1941	}
1942}
1943EXPORT_SYMBOL(usbnet_device_suggests_idle);
1944
1945/*
1946 * For devices that can do without special commands
1947 */
1948int usbnet_manage_power(struct usbnet *dev, int on)
1949{
1950	dev->intf->needs_remote_wakeup = on;
1951	return 0;
1952}
1953EXPORT_SYMBOL(usbnet_manage_power);
1954
1955void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1956{
1957	/* update link after link is reseted */
1958	if (link && !need_reset)
1959		netif_carrier_on(dev->net);
1960	else
1961		netif_carrier_off(dev->net);
1962
1963	if (need_reset && link)
1964		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1965	else
1966		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1967}
1968EXPORT_SYMBOL(usbnet_link_change);
1969
1970/*-------------------------------------------------------------------------*/
1971static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1972			     u16 value, u16 index, void *data, u16 size)
1973{
1974	void *buf = NULL;
1975	int err = -ENOMEM;
1976
1977	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1978		   " value=0x%04x index=0x%04x size=%d\n",
1979		   cmd, reqtype, value, index, size);
1980
1981	if (size) {
1982		buf = kmalloc(size, GFP_KERNEL);
1983		if (!buf)
1984			goto out;
1985	}
1986
1987	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1988			      cmd, reqtype, value, index, buf, size,
1989			      USB_CTRL_GET_TIMEOUT);
1990	if (err > 0 && err <= size) {
1991        if (data)
1992            memcpy(data, buf, err);
1993        else
1994            netdev_dbg(dev->net,
1995                "Huh? Data requested but thrown away.\n");
1996    }
1997	kfree(buf);
1998out:
1999	return err;
2000}
2001
2002static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2003			      u16 value, u16 index, const void *data,
2004			      u16 size)
2005{
2006	void *buf = NULL;
2007	int err = -ENOMEM;
2008
2009	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2010		   " value=0x%04x index=0x%04x size=%d\n",
2011		   cmd, reqtype, value, index, size);
2012
2013	if (data) {
2014		buf = kmemdup(data, size, GFP_KERNEL);
2015		if (!buf)
2016			goto out;
2017	} else {
2018        if (size) {
2019            WARN_ON_ONCE(1);
2020            err = -EINVAL;
2021            goto out;
2022        }
2023    }
2024
2025	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2026			      cmd, reqtype, value, index, buf, size,
2027			      USB_CTRL_SET_TIMEOUT);
2028	kfree(buf);
2029
2030out:
2031	return err;
2032}
2033
2034/*
2035 * The function can't be called inside suspend/resume callback,
2036 * otherwise deadlock will be caused.
2037 */
2038int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2039		    u16 value, u16 index, void *data, u16 size)
2040{
2041	int ret;
2042
2043	if (usb_autopm_get_interface(dev->intf) < 0)
2044		return -ENODEV;
2045	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2046				data, size);
2047	usb_autopm_put_interface(dev->intf);
2048	return ret;
2049}
2050EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2051
2052/*
2053 * The function can't be called inside suspend/resume callback,
2054 * otherwise deadlock will be caused.
2055 */
2056int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2057		     u16 value, u16 index, const void *data, u16 size)
2058{
2059	int ret;
2060
2061	if (usb_autopm_get_interface(dev->intf) < 0)
2062		return -ENODEV;
2063	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2064				 data, size);
2065	usb_autopm_put_interface(dev->intf);
2066	return ret;
2067}
2068EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2069
2070/*
2071 * The function can be called inside suspend/resume callback safely
2072 * and should only be called by suspend/resume callback generally.
2073 */
2074int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2075			  u16 value, u16 index, void *data, u16 size)
2076{
2077	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2078				 data, size);
2079}
2080EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2081
2082/*
2083 * The function can be called inside suspend/resume callback safely
2084 * and should only be called by suspend/resume callback generally.
2085 */
2086int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2087			  u16 value, u16 index, const void *data,
2088			  u16 size)
2089{
2090	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2091				  data, size);
2092}
2093EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2094
2095static void usbnet_async_cmd_cb(struct urb *urb)
2096{
2097	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2098	int status = urb->status;
2099
2100	if (status < 0)
2101		dev_dbg(&urb->dev->dev, "%s failed with %d",
2102			__func__, status);
2103
2104	kfree(req);
2105	usb_free_urb(urb);
2106}
2107
2108/*
2109 * The caller must make sure that device can't be put into suspend
2110 * state until the control URB completes.
2111 */
2112int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2113			   u16 value, u16 index, const void *data, u16 size)
2114{
2115	struct usb_ctrlrequest *req = NULL;
2116	struct urb *urb;
2117	int err = -ENOMEM;
2118	void *buf = NULL;
2119
2120	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2121		   " value=0x%04x index=0x%04x size=%d\n",
2122		   cmd, reqtype, value, index, size);
2123
2124	urb = usb_alloc_urb(0, GFP_ATOMIC);
2125	if (!urb)
2126		goto fail;
2127
2128	if (data) {
2129		buf = kmemdup(data, size, GFP_ATOMIC);
2130		if (!buf) {
2131			netdev_err(dev->net, "Error allocating buffer"
2132				   " in %s!\n", __func__);
2133			goto fail_free;
2134		}
2135	}
2136
2137	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2138	if (!req)
2139		goto fail_free_buf;
2140
2141	req->bRequestType = reqtype;
2142	req->bRequest = cmd;
2143	req->wValue = cpu_to_le16(value);
2144	req->wIndex = cpu_to_le16(index);
2145	req->wLength = cpu_to_le16(size);
2146
2147	usb_fill_control_urb(urb, dev->udev,
2148			     usb_sndctrlpipe(dev->udev, 0),
2149			     (void *)req, buf, size,
2150			     usbnet_async_cmd_cb, req);
2151	urb->transfer_flags |= URB_FREE_BUFFER;
2152
2153	err = usb_submit_urb(urb, GFP_ATOMIC);
2154	if (err < 0) {
2155		netdev_err(dev->net, "Error submitting the control"
2156			   " message: status=%d\n", err);
2157		goto fail_free;
2158	}
2159	return 0;
2160
2161fail_free_buf:
2162	kfree(buf);
2163fail_free:
2164	kfree(req);
2165	usb_free_urb(urb);
2166fail:
2167	return err;
2168
2169}
2170EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2171/*-------------------------------------------------------------------------*/
2172
2173static int __init usbnet_init(void)
2174{
2175	/* Compiler should optimize this out. */
2176	BUILD_BUG_ON(
2177		FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2178
2179	eth_random_addr(node_id);
2180	return 0;
2181}
2182module_init(usbnet_init);
2183
2184static void __exit usbnet_exit(void)
2185{
2186}
2187module_exit(usbnet_exit);
2188
2189MODULE_AUTHOR("David Brownell");
2190MODULE_DESCRIPTION("USB network driver framework");
2191MODULE_LICENSE("GPL");