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v3.1
 
   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, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20
  21/*
  22 * This is a generic "USB networking" framework that works with several
  23 * kinds of full and high speed networking devices:  host-to-host cables,
  24 * smart usb peripherals, and actual Ethernet adapters.
  25 *
  26 * These devices usually differ in terms of control protocols (if they
  27 * even have one!) and sometimes they define new framing to wrap or batch
  28 * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29 * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30 * issues can usefully be addressed by this framework.
  31 */
  32
  33// #define	DEBUG			// error path messages, extra info
  34// #define	VERBOSE			// more; success messages
  35
  36#include <linux/module.h>
  37#include <linux/init.h>
  38#include <linux/netdevice.h>
  39#include <linux/etherdevice.h>
  40#include <linux/ctype.h>
  41#include <linux/ethtool.h>
  42#include <linux/workqueue.h>
  43#include <linux/mii.h>
  44#include <linux/usb.h>
  45#include <linux/usb/usbnet.h>
  46#include <linux/slab.h>
  47#include <linux/kernel.h>
  48#include <linux/pm_runtime.h>
  49
  50#define DRIVER_VERSION		"22-Aug-2005"
  51
  52
  53/*-------------------------------------------------------------------------*/
  54
  55/*
  56 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57 * Several dozen bytes of IPv4 data can fit in two such transactions.
  58 * One maximum size Ethernet packet takes twenty four of them.
  59 * For high speed, each frame comfortably fits almost 36 max size
  60 * Ethernet packets (so queues should be bigger).
  61 *
  62 * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63 * let the USB host controller be busy for 5msec or more before an irq
  64 * is required, under load.  Jumbograms change the equation.
  65 */
  66#define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67#define	RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68			(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69#define	TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70			(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72// reawaken network queue this soon after stopping; else watchdog barks
  73#define TX_TIMEOUT_JIFFIES	(5*HZ)
  74
  75// throttle rx/tx briefly after some faults, so khubd might disconnect()
  76// us (it polls at HZ/4 usually) before we report too many false errors.
 
  77#define THROTTLE_JIFFIES	(HZ/8)
  78
  79// between wakeups
  80#define UNLINK_TIMEOUT_MS	3
  81
  82/*-------------------------------------------------------------------------*/
  83
  84// randomly generated ethernet address
  85static u8	node_id [ETH_ALEN];
  86
  87static const char driver_name [] = "usbnet";
  88
  89/* use ethtool to change the level for any given device */
  90static int msg_level = -1;
  91module_param (msg_level, int, 0);
  92MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94/*-------------------------------------------------------------------------*/
  95
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  96/* handles CDC Ethernet and many other network "bulk data" interfaces */
  97int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98{
  99	int				tmp;
 100	struct usb_host_interface	*alt = NULL;
 101	struct usb_host_endpoint	*in = NULL, *out = NULL;
 102	struct usb_host_endpoint	*status = NULL;
 103
 104	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105		unsigned	ep;
 106
 107		in = out = status = NULL;
 108		alt = intf->altsetting + tmp;
 109
 110		/* take the first altsetting with in-bulk + out-bulk;
 111		 * remember any status endpoint, just in case;
 112		 * ignore other endpoints and altsettings.
 113		 */
 114		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115			struct usb_host_endpoint	*e;
 116			int				intr = 0;
 117
 118			e = alt->endpoint + ep;
 
 
 
 
 
 119			switch (e->desc.bmAttributes) {
 120			case USB_ENDPOINT_XFER_INT:
 121				if (!usb_endpoint_dir_in(&e->desc))
 122					continue;
 123				intr = 1;
 124				/* FALLTHROUGH */
 125			case USB_ENDPOINT_XFER_BULK:
 126				break;
 127			default:
 128				continue;
 129			}
 130			if (usb_endpoint_dir_in(&e->desc)) {
 131				if (!intr && !in)
 132					in = e;
 133				else if (intr && !status)
 134					status = e;
 135			} else {
 136				if (!out)
 137					out = e;
 138			}
 139		}
 140		if (in && out)
 141			break;
 142	}
 143	if (!alt || !in || !out)
 144		return -EINVAL;
 145
 146	if (alt->desc.bAlternateSetting != 0 ||
 147	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149				alt->desc.bAlternateSetting);
 150		if (tmp < 0)
 151			return tmp;
 152	}
 153
 154	dev->in = usb_rcvbulkpipe (dev->udev,
 155			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156	dev->out = usb_sndbulkpipe (dev->udev,
 157			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158	dev->status = status;
 159	return 0;
 160}
 161EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164{
 165	int 		tmp, i;
 
 166	unsigned char	buf [13];
 167
 168	tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169	if (tmp != 12) {
 
 
 170		dev_dbg(&dev->udev->dev,
 171			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172		if (tmp >= 0)
 173			tmp = -EINVAL;
 174		return tmp;
 175	}
 176	for (i = tmp = 0; i < 6; i++, tmp += 2)
 177		dev->net->dev_addr [i] =
 178			(hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179	return 0;
 180}
 181EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183static void intr_complete (struct urb *urb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 184
 185static int init_status (struct usbnet *dev, struct usb_interface *intf)
 186{
 187	char		*buf = NULL;
 188	unsigned	pipe = 0;
 189	unsigned	maxp;
 190	unsigned	period;
 191
 192	if (!dev->driver_info->status)
 193		return 0;
 194
 195	pipe = usb_rcvintpipe (dev->udev,
 196			dev->status->desc.bEndpointAddress
 197				& USB_ENDPOINT_NUMBER_MASK);
 198	maxp = usb_maxpacket (dev->udev, pipe, 0);
 199
 200	/* avoid 1 msec chatter:  min 8 msec poll rate */
 201	period = max ((int) dev->status->desc.bInterval,
 202		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 203
 204	buf = kmalloc (maxp, GFP_KERNEL);
 205	if (buf) {
 206		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 207		if (!dev->interrupt) {
 208			kfree (buf);
 209			return -ENOMEM;
 210		} else {
 211			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 212				buf, maxp, intr_complete, dev, period);
 
 213			dev_dbg(&intf->dev,
 214				"status ep%din, %d bytes period %d\n",
 215				usb_pipeendpoint(pipe), maxp, period);
 216		}
 217	}
 218	return 0;
 219}
 220
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 221/* Passes this packet up the stack, updating its accounting.
 222 * Some link protocols batch packets, so their rx_fixup paths
 223 * can return clones as well as just modify the original skb.
 224 */
 225void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 226{
 
 
 227	int	status;
 228
 229	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 230		skb_queue_tail(&dev->rxq_pause, skb);
 231		return;
 232	}
 233
 234	skb->protocol = eth_type_trans (skb, dev->net);
 235	dev->net->stats.rx_packets++;
 236	dev->net->stats.rx_bytes += skb->len;
 
 
 
 
 
 237
 238	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 239		  skb->len + sizeof (struct ethhdr), skb->protocol);
 240	memset (skb->cb, 0, sizeof (struct skb_data));
 
 
 
 
 241	status = netif_rx (skb);
 242	if (status != NET_RX_SUCCESS)
 243		netif_dbg(dev, rx_err, dev->net,
 244			  "netif_rx status %d\n", status);
 245}
 246EXPORT_SYMBOL_GPL(usbnet_skb_return);
 247
 248
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 249/*-------------------------------------------------------------------------
 250 *
 251 * Network Device Driver (peer link to "Host Device", from USB host)
 252 *
 253 *-------------------------------------------------------------------------*/
 254
 255int usbnet_change_mtu (struct net_device *net, int new_mtu)
 256{
 257	struct usbnet	*dev = netdev_priv(net);
 258	int		ll_mtu = new_mtu + net->hard_header_len;
 259	int		old_hard_mtu = dev->hard_mtu;
 260	int		old_rx_urb_size = dev->rx_urb_size;
 261
 262	if (new_mtu <= 0)
 263		return -EINVAL;
 264	// no second zero-length packet read wanted after mtu-sized packets
 265	if ((ll_mtu % dev->maxpacket) == 0)
 266		return -EDOM;
 267	net->mtu = new_mtu;
 268
 269	dev->hard_mtu = net->mtu + net->hard_header_len;
 270	if (dev->rx_urb_size == old_hard_mtu) {
 271		dev->rx_urb_size = dev->hard_mtu;
 272		if (dev->rx_urb_size > old_rx_urb_size)
 
 273			usbnet_unlink_rx_urbs(dev);
 
 
 274	}
 275
 
 
 
 276	return 0;
 277}
 278EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 279
 
 
 
 
 
 
 
 
 
 
 280/*-------------------------------------------------------------------------*/
 281
 282/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 283 * completion callbacks.  2.5 should have fixed those bugs...
 284 */
 285
 286static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
 
 287{
 288	unsigned long		flags;
 
 
 289
 290	spin_lock_irqsave(&list->lock, flags);
 
 
 291	__skb_unlink(skb, list);
 292	spin_unlock(&list->lock);
 293	spin_lock(&dev->done.lock);
 
 
 
 
 
 294	__skb_queue_tail(&dev->done, skb);
 295	if (dev->done.qlen == 1)
 296		tasklet_schedule(&dev->bh);
 297	spin_unlock_irqrestore(&dev->done.lock, flags);
 
 
 298}
 299
 300/* some work can't be done in tasklets, so we use keventd
 301 *
 302 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 303 * but tasklet_schedule() doesn't.  hope the failure is rare.
 304 */
 305void usbnet_defer_kevent (struct usbnet *dev, int work)
 306{
 307	set_bit (work, &dev->flags);
 308	if (!schedule_work (&dev->kevent))
 309		netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 310	else
 311		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 312}
 313EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 314
 315/*-------------------------------------------------------------------------*/
 316
 317static void rx_complete (struct urb *urb);
 318
 319static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 320{
 321	struct sk_buff		*skb;
 322	struct skb_data		*entry;
 323	int			retval = 0;
 324	unsigned long		lockflags;
 325	size_t			size = dev->rx_urb_size;
 326
 327	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
 
 
 
 
 
 
 
 
 
 
 328		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 329		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 330		usb_free_urb (urb);
 331		return -ENOMEM;
 332	}
 333	skb_reserve (skb, NET_IP_ALIGN);
 334
 335	entry = (struct skb_data *) skb->cb;
 336	entry->urb = urb;
 337	entry->dev = dev;
 338	entry->state = rx_start;
 339	entry->length = 0;
 340
 341	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 342		skb->data, size, rx_complete, skb);
 343
 344	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 345
 346	if (netif_running (dev->net) &&
 347	    netif_device_present (dev->net) &&
 
 348	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 349	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 350		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 351		case -EPIPE:
 352			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 353			break;
 354		case -ENOMEM:
 355			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 356			break;
 357		case -ENODEV:
 358			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 359			netif_device_detach (dev->net);
 360			break;
 361		case -EHOSTUNREACH:
 362			retval = -ENOLINK;
 363			break;
 364		default:
 365			netif_dbg(dev, rx_err, dev->net,
 366				  "rx submit, %d\n", retval);
 367			tasklet_schedule (&dev->bh);
 368			break;
 369		case 0:
 370			__skb_queue_tail (&dev->rxq, skb);
 371		}
 372	} else {
 373		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 374		retval = -ENOLINK;
 375	}
 376	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 377	if (retval) {
 378		dev_kfree_skb_any (skb);
 379		usb_free_urb (urb);
 380	}
 381	return retval;
 382}
 383
 384
 385/*-------------------------------------------------------------------------*/
 386
 387static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 388{
 389	if (dev->driver_info->rx_fixup &&
 390	    !dev->driver_info->rx_fixup (dev, skb)) {
 391		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 392		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 393			dev->net->stats.rx_errors++;
 394		goto done;
 395	}
 396	// else network stack removes extra byte if we forced a short packet
 397
 398	if (skb->len) {
 399		/* all data was already cloned from skb inside the driver */
 400		if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 401			dev_kfree_skb_any(skb);
 402		else
 403			usbnet_skb_return(dev, skb);
 
 
 
 
 404		return;
 405	}
 406
 407	netif_dbg(dev, rx_err, dev->net, "drop\n");
 408	dev->net->stats.rx_errors++;
 409done:
 410	skb_queue_tail(&dev->done, skb);
 411}
 412
 413/*-------------------------------------------------------------------------*/
 414
 415static void rx_complete (struct urb *urb)
 416{
 417	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 418	struct skb_data		*entry = (struct skb_data *) skb->cb;
 419	struct usbnet		*dev = entry->dev;
 420	int			urb_status = urb->status;
 
 421
 422	skb_put (skb, urb->actual_length);
 423	entry->state = rx_done;
 424	entry->urb = NULL;
 425
 426	switch (urb_status) {
 427	/* success */
 428	case 0:
 429		if (skb->len < dev->net->hard_header_len) {
 430			entry->state = rx_cleanup;
 431			dev->net->stats.rx_errors++;
 432			dev->net->stats.rx_length_errors++;
 433			netif_dbg(dev, rx_err, dev->net,
 434				  "rx length %d\n", skb->len);
 435		}
 436		break;
 437
 438	/* stalls need manual reset. this is rare ... except that
 439	 * when going through USB 2.0 TTs, unplug appears this way.
 440	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 441	 * storm, recovering as needed.
 442	 */
 443	case -EPIPE:
 444		dev->net->stats.rx_errors++;
 445		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 446		// FALLTHROUGH
 447
 448	/* software-driven interface shutdown */
 449	case -ECONNRESET:		/* async unlink */
 450	case -ESHUTDOWN:		/* hardware gone */
 451		netif_dbg(dev, ifdown, dev->net,
 452			  "rx shutdown, code %d\n", urb_status);
 453		goto block;
 454
 455	/* we get controller i/o faults during khubd disconnect() delays.
 456	 * throttle down resubmits, to avoid log floods; just temporarily,
 457	 * so we still recover when the fault isn't a khubd delay.
 458	 */
 459	case -EPROTO:
 460	case -ETIME:
 461	case -EILSEQ:
 462		dev->net->stats.rx_errors++;
 463		if (!timer_pending (&dev->delay)) {
 464			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 465			netif_dbg(dev, link, dev->net,
 466				  "rx throttle %d\n", urb_status);
 467		}
 468block:
 469		entry->state = rx_cleanup;
 470		entry->urb = urb;
 471		urb = NULL;
 472		break;
 473
 474	/* data overrun ... flush fifo? */
 475	case -EOVERFLOW:
 476		dev->net->stats.rx_over_errors++;
 477		// FALLTHROUGH
 478
 479	default:
 480		entry->state = rx_cleanup;
 481		dev->net->stats.rx_errors++;
 482		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 483		break;
 484	}
 485
 486	defer_bh(dev, skb, &dev->rxq);
 
 
 
 
 
 
 
 
 
 
 
 487
 488	if (urb) {
 489		if (netif_running (dev->net) &&
 490		    !test_bit (EVENT_RX_HALT, &dev->flags)) {
 
 491			rx_submit (dev, urb, GFP_ATOMIC);
 
 492			return;
 493		}
 494		usb_free_urb (urb);
 495	}
 496	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 497}
 498
 499static void intr_complete (struct urb *urb)
 500{
 501	struct usbnet	*dev = urb->context;
 502	int		status = urb->status;
 503
 504	switch (status) {
 505	/* success */
 506	case 0:
 507		dev->driver_info->status(dev, urb);
 508		break;
 509
 510	/* software-driven interface shutdown */
 511	case -ENOENT:		/* urb killed */
 512	case -ESHUTDOWN:	/* hardware gone */
 513		netif_dbg(dev, ifdown, dev->net,
 514			  "intr shutdown, code %d\n", status);
 515		return;
 516
 517	/* NOTE:  not throttling like RX/TX, since this endpoint
 518	 * already polls infrequently
 519	 */
 520	default:
 521		netdev_dbg(dev->net, "intr status %d\n", status);
 522		break;
 523	}
 524
 525	if (!netif_running (dev->net))
 526		return;
 527
 528	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 529	status = usb_submit_urb (urb, GFP_ATOMIC);
 530	if (status != 0)
 531		netif_err(dev, timer, dev->net,
 532			  "intr resubmit --> %d\n", status);
 533}
 534
 535/*-------------------------------------------------------------------------*/
 536void usbnet_pause_rx(struct usbnet *dev)
 537{
 538	set_bit(EVENT_RX_PAUSED, &dev->flags);
 539
 540	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 541}
 542EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 543
 544void usbnet_resume_rx(struct usbnet *dev)
 545{
 546	struct sk_buff *skb;
 547	int num = 0;
 548
 549	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 550
 551	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 552		usbnet_skb_return(dev, skb);
 553		num++;
 554	}
 555
 556	tasklet_schedule(&dev->bh);
 557
 558	netif_dbg(dev, rx_status, dev->net,
 559		  "paused rx queue disabled, %d skbs requeued\n", num);
 560}
 561EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 562
 563void usbnet_purge_paused_rxq(struct usbnet *dev)
 564{
 565	skb_queue_purge(&dev->rxq_pause);
 566}
 567EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 568
 569/*-------------------------------------------------------------------------*/
 570
 571// unlink pending rx/tx; completion handlers do all other cleanup
 572
 573static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 574{
 575	unsigned long		flags;
 576	struct sk_buff		*skb, *skbnext;
 577	int			count = 0;
 578
 579	spin_lock_irqsave (&q->lock, flags);
 580	skb_queue_walk_safe(q, skb, skbnext) {
 581		struct skb_data		*entry;
 582		struct urb		*urb;
 583		int			retval;
 584
 585		entry = (struct skb_data *) skb->cb;
 
 
 
 
 
 
 
 586		urb = entry->urb;
 587
 
 
 
 
 
 
 
 
 
 588		// during some PM-driven resume scenarios,
 589		// these (async) unlinks complete immediately
 590		retval = usb_unlink_urb (urb);
 591		if (retval != -EINPROGRESS && retval != 0)
 592			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 593		else
 594			count++;
 
 
 595	}
 596	spin_unlock_irqrestore (&q->lock, flags);
 597	return count;
 598}
 599
 600// Flush all pending rx urbs
 601// minidrivers may need to do this when the MTU changes
 602
 603void usbnet_unlink_rx_urbs(struct usbnet *dev)
 604{
 605	if (netif_running(dev->net)) {
 606		(void) unlink_urbs (dev, &dev->rxq);
 607		tasklet_schedule(&dev->bh);
 608	}
 609}
 610EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 611
 612/*-------------------------------------------------------------------------*/
 613
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 614// precondition: never called in_interrupt
 615static void usbnet_terminate_urbs(struct usbnet *dev)
 616{
 617	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 618	DECLARE_WAITQUEUE(wait, current);
 619	int temp;
 620
 621	/* ensure there are no more active urbs */
 622	add_wait_queue(&unlink_wakeup, &wait);
 623	set_current_state(TASK_UNINTERRUPTIBLE);
 624	dev->wait = &unlink_wakeup;
 625	temp = unlink_urbs(dev, &dev->txq) +
 626		unlink_urbs(dev, &dev->rxq);
 627
 628	/* maybe wait for deletions to finish. */
 629	while (!skb_queue_empty(&dev->rxq)
 630		&& !skb_queue_empty(&dev->txq)
 631		&& !skb_queue_empty(&dev->done)) {
 632			schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 633			set_current_state(TASK_UNINTERRUPTIBLE);
 634			netif_dbg(dev, ifdown, dev->net,
 635				  "waited for %d urb completions\n", temp);
 636	}
 637	set_current_state(TASK_RUNNING);
 638	dev->wait = NULL;
 639	remove_wait_queue(&unlink_wakeup, &wait);
 640}
 641
 642int usbnet_stop (struct net_device *net)
 643{
 644	struct usbnet		*dev = netdev_priv(net);
 645	struct driver_info	*info = dev->driver_info;
 646	int			retval;
 647
 648	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 649	netif_stop_queue (net);
 650
 651	netif_info(dev, ifdown, dev->net,
 652		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 653		   net->stats.rx_packets, net->stats.tx_packets,
 654		   net->stats.rx_errors, net->stats.tx_errors);
 655
 
 
 656	/* allow minidriver to stop correctly (wireless devices to turn off
 657	 * radio etc) */
 658	if (info->stop) {
 659		retval = info->stop(dev);
 660		if (retval < 0)
 661			netif_info(dev, ifdown, dev->net,
 662				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 663				   retval,
 664				   dev->udev->bus->bus_name, dev->udev->devpath,
 665				   info->description);
 666	}
 667
 668	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 669		usbnet_terminate_urbs(dev);
 670
 671	usb_kill_urb(dev->interrupt);
 672
 673	usbnet_purge_paused_rxq(dev);
 674
 675	/* deferred work (task, timer, softirq) must also stop.
 676	 * can't flush_scheduled_work() until we drop rtnl (later),
 677	 * else workers could deadlock; so make workers a NOP.
 678	 */
 679	dev->flags = 0;
 680	del_timer_sync (&dev->delay);
 681	tasklet_kill (&dev->bh);
 682	if (info->manage_power)
 
 
 
 
 683		info->manage_power(dev, 0);
 684	else
 685		usb_autopm_put_interface(dev->intf);
 686
 687	return 0;
 688}
 689EXPORT_SYMBOL_GPL(usbnet_stop);
 690
 691/*-------------------------------------------------------------------------*/
 692
 693// posts reads, and enables write queuing
 694
 695// precondition: never called in_interrupt
 696
 697int usbnet_open (struct net_device *net)
 698{
 699	struct usbnet		*dev = netdev_priv(net);
 700	int			retval;
 701	struct driver_info	*info = dev->driver_info;
 702
 703	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 704		netif_info(dev, ifup, dev->net,
 705			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 706			   retval,
 707			   dev->udev->bus->bus_name,
 708			   dev->udev->devpath,
 709			   info->description);
 710		goto done_nopm;
 711	}
 712
 713	// put into "known safe" state
 714	if (info->reset && (retval = info->reset (dev)) < 0) {
 715		netif_info(dev, ifup, dev->net,
 716			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 717			   retval,
 718			   dev->udev->bus->bus_name,
 719			   dev->udev->devpath,
 720			   info->description);
 721		goto done;
 722	}
 723
 
 
 
 724	// insist peer be connected
 725	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 726		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 727		goto done;
 728	}
 729
 730	/* start any status interrupt transfer */
 731	if (dev->interrupt) {
 732		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 733		if (retval < 0) {
 734			netif_err(dev, ifup, dev->net,
 735				  "intr submit %d\n", retval);
 736			goto done;
 737		}
 738	}
 739
 740	set_bit(EVENT_DEV_OPEN, &dev->flags);
 741	netif_start_queue (net);
 742	netif_info(dev, ifup, dev->net,
 743		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 744		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 745		   dev->net->mtu,
 746		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 747		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 748		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 749		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 750		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 751		   "simple");
 752
 
 
 
 
 
 753	// delay posting reads until we're fully open
 754	tasklet_schedule (&dev->bh);
 755	if (info->manage_power) {
 756		retval = info->manage_power(dev, 1);
 757		if (retval < 0)
 758			goto done;
 759		usb_autopm_put_interface(dev->intf);
 
 
 
 760	}
 761	return retval;
 762
 763done:
 764	usb_autopm_put_interface(dev->intf);
 765done_nopm:
 766	return retval;
 767}
 768EXPORT_SYMBOL_GPL(usbnet_open);
 769
 770/*-------------------------------------------------------------------------*/
 771
 772/* ethtool methods; minidrivers may need to add some more, but
 773 * they'll probably want to use this base set.
 774 */
 775
 776int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 
 
 
 
 777{
 778	struct usbnet *dev = netdev_priv(net);
 779
 780	if (!dev->mii.mdio_read)
 781		return -EOPNOTSUPP;
 782
 783	return mii_ethtool_gset(&dev->mii, cmd);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 784}
 785EXPORT_SYMBOL_GPL(usbnet_get_settings);
 786
 787int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 
 788{
 789	struct usbnet *dev = netdev_priv(net);
 790	int retval;
 791
 792	if (!dev->mii.mdio_write)
 793		return -EOPNOTSUPP;
 794
 795	retval = mii_ethtool_sset(&dev->mii, cmd);
 796
 797	/* link speed/duplex might have changed */
 798	if (dev->driver_info->link_reset)
 799		dev->driver_info->link_reset(dev);
 800
 801	return retval;
 
 802
 
 803}
 804EXPORT_SYMBOL_GPL(usbnet_set_settings);
 805
 806u32 usbnet_get_link (struct net_device *net)
 807{
 808	struct usbnet *dev = netdev_priv(net);
 809
 810	/* If a check_connect is defined, return its result */
 811	if (dev->driver_info->check_connect)
 812		return dev->driver_info->check_connect (dev) == 0;
 813
 814	/* if the device has mii operations, use those */
 815	if (dev->mii.mdio_read)
 816		return mii_link_ok(&dev->mii);
 817
 818	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 819	return ethtool_op_get_link(net);
 820}
 821EXPORT_SYMBOL_GPL(usbnet_get_link);
 822
 823int usbnet_nway_reset(struct net_device *net)
 824{
 825	struct usbnet *dev = netdev_priv(net);
 826
 827	if (!dev->mii.mdio_write)
 828		return -EOPNOTSUPP;
 829
 830	return mii_nway_restart(&dev->mii);
 831}
 832EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 833
 834void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 835{
 836	struct usbnet *dev = netdev_priv(net);
 837
 838	strncpy (info->driver, dev->driver_name, sizeof info->driver);
 839	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 840	strncpy (info->fw_version, dev->driver_info->description,
 841		sizeof info->fw_version);
 842	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 843}
 844EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 845
 846u32 usbnet_get_msglevel (struct net_device *net)
 847{
 848	struct usbnet *dev = netdev_priv(net);
 849
 850	return dev->msg_enable;
 851}
 852EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 853
 854void usbnet_set_msglevel (struct net_device *net, u32 level)
 855{
 856	struct usbnet *dev = netdev_priv(net);
 857
 858	dev->msg_enable = level;
 859}
 860EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 861
 862/* drivers may override default ethtool_ops in their bind() routine */
 863static const struct ethtool_ops usbnet_ethtool_ops = {
 864	.get_settings		= usbnet_get_settings,
 865	.set_settings		= usbnet_set_settings,
 866	.get_link		= usbnet_get_link,
 867	.nway_reset		= usbnet_nway_reset,
 868	.get_drvinfo		= usbnet_get_drvinfo,
 869	.get_msglevel		= usbnet_get_msglevel,
 870	.set_msglevel		= usbnet_set_msglevel,
 
 
 
 871};
 872
 873/*-------------------------------------------------------------------------*/
 874
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 875/* work that cannot be done in interrupt context uses keventd.
 876 *
 877 * NOTE:  with 2.5 we could do more of this using completion callbacks,
 878 * especially now that control transfers can be queued.
 879 */
 880static void
 881kevent (struct work_struct *work)
 882{
 883	struct usbnet		*dev =
 884		container_of(work, struct usbnet, kevent);
 885	int			status;
 886
 887	/* usb_clear_halt() needs a thread context */
 888	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 889		unlink_urbs (dev, &dev->txq);
 890		status = usb_autopm_get_interface(dev->intf);
 891		if (status < 0)
 892			goto fail_pipe;
 893		status = usb_clear_halt (dev->udev, dev->out);
 894		usb_autopm_put_interface(dev->intf);
 895		if (status < 0 &&
 896		    status != -EPIPE &&
 897		    status != -ESHUTDOWN) {
 898			if (netif_msg_tx_err (dev))
 899fail_pipe:
 900				netdev_err(dev->net, "can't clear tx halt, status %d\n",
 901					   status);
 902		} else {
 903			clear_bit (EVENT_TX_HALT, &dev->flags);
 904			if (status != -ESHUTDOWN)
 905				netif_wake_queue (dev->net);
 906		}
 907	}
 908	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 909		unlink_urbs (dev, &dev->rxq);
 910		status = usb_autopm_get_interface(dev->intf);
 911		if (status < 0)
 912			goto fail_halt;
 913		status = usb_clear_halt (dev->udev, dev->in);
 914		usb_autopm_put_interface(dev->intf);
 915		if (status < 0 &&
 916		    status != -EPIPE &&
 917		    status != -ESHUTDOWN) {
 918			if (netif_msg_rx_err (dev))
 919fail_halt:
 920				netdev_err(dev->net, "can't clear rx halt, status %d\n",
 921					   status);
 922		} else {
 923			clear_bit (EVENT_RX_HALT, &dev->flags);
 924			tasklet_schedule (&dev->bh);
 925		}
 926	}
 927
 928	/* tasklet could resubmit itself forever if memory is tight */
 929	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 930		struct urb	*urb = NULL;
 931		int resched = 1;
 932
 933		if (netif_running (dev->net))
 934			urb = usb_alloc_urb (0, GFP_KERNEL);
 935		else
 936			clear_bit (EVENT_RX_MEMORY, &dev->flags);
 937		if (urb != NULL) {
 938			clear_bit (EVENT_RX_MEMORY, &dev->flags);
 939			status = usb_autopm_get_interface(dev->intf);
 940			if (status < 0) {
 941				usb_free_urb(urb);
 942				goto fail_lowmem;
 943			}
 944			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 945				resched = 0;
 946			usb_autopm_put_interface(dev->intf);
 947fail_lowmem:
 948			if (resched)
 949				tasklet_schedule (&dev->bh);
 950		}
 951	}
 952
 953	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 954		struct driver_info	*info = dev->driver_info;
 955		int			retval = 0;
 956
 957		clear_bit (EVENT_LINK_RESET, &dev->flags);
 958		status = usb_autopm_get_interface(dev->intf);
 959		if (status < 0)
 960			goto skip_reset;
 961		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 962			usb_autopm_put_interface(dev->intf);
 963skip_reset:
 964			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
 965				    retval,
 966				    dev->udev->bus->bus_name,
 967				    dev->udev->devpath,
 968				    info->description);
 969		} else {
 970			usb_autopm_put_interface(dev->intf);
 971		}
 
 
 
 972	}
 973
 
 
 
 
 
 
 
 974	if (dev->flags)
 975		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
 976}
 977
 978/*-------------------------------------------------------------------------*/
 979
 980static void tx_complete (struct urb *urb)
 981{
 982	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 983	struct skb_data		*entry = (struct skb_data *) skb->cb;
 984	struct usbnet		*dev = entry->dev;
 985
 986	if (urb->status == 0) {
 987		if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
 988			dev->net->stats.tx_packets++;
 989		dev->net->stats.tx_bytes += entry->length;
 
 
 
 
 990	} else {
 991		dev->net->stats.tx_errors++;
 992
 993		switch (urb->status) {
 994		case -EPIPE:
 995			usbnet_defer_kevent (dev, EVENT_TX_HALT);
 996			break;
 997
 998		/* software-driven interface shutdown */
 999		case -ECONNRESET:		// async unlink
1000		case -ESHUTDOWN:		// hardware gone
1001			break;
1002
1003		// like rx, tx gets controller i/o faults during khubd delays
1004		// and so it uses the same throttling mechanism.
 
1005		case -EPROTO:
1006		case -ETIME:
1007		case -EILSEQ:
1008			usb_mark_last_busy(dev->udev);
1009			if (!timer_pending (&dev->delay)) {
1010				mod_timer (&dev->delay,
1011					jiffies + THROTTLE_JIFFIES);
1012				netif_dbg(dev, link, dev->net,
1013					  "tx throttle %d\n", urb->status);
1014			}
1015			netif_stop_queue (dev->net);
1016			break;
1017		default:
1018			netif_dbg(dev, tx_err, dev->net,
1019				  "tx err %d\n", entry->urb->status);
1020			break;
1021		}
1022	}
1023
1024	usb_autopm_put_interface_async(dev->intf);
1025	urb->dev = NULL;
1026	entry->state = tx_done;
1027	defer_bh(dev, skb, &dev->txq);
1028}
1029
1030/*-------------------------------------------------------------------------*/
1031
1032void usbnet_tx_timeout (struct net_device *net)
1033{
1034	struct usbnet		*dev = netdev_priv(net);
1035
1036	unlink_urbs (dev, &dev->txq);
1037	tasklet_schedule (&dev->bh);
1038
1039	// FIXME: device recovery -- reset?
 
 
 
 
1040}
1041EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1042
1043/*-------------------------------------------------------------------------*/
1044
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1045netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1046				     struct net_device *net)
1047{
1048	struct usbnet		*dev = netdev_priv(net);
1049	int			length;
1050	struct urb		*urb = NULL;
1051	struct skb_data		*entry;
1052	struct driver_info	*info = dev->driver_info;
1053	unsigned long		flags;
1054	int retval;
1055
 
 
 
1056	// some devices want funky USB-level framing, for
1057	// win32 driver (usually) and/or hardware quirks
1058	if (info->tx_fixup) {
1059		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1060		if (!skb) {
1061			if (netif_msg_tx_err(dev)) {
1062				netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1063				goto drop;
1064			} else {
1065				/* cdc_ncm collected packet; waits for more */
1066				goto not_drop;
1067			}
 
1068		}
1069	}
1070	length = skb->len;
1071
1072	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1073		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1074		goto drop;
1075	}
1076
1077	entry = (struct skb_data *) skb->cb;
1078	entry->urb = urb;
1079	entry->dev = dev;
1080	entry->state = tx_start;
1081	entry->length = length;
1082
1083	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1084			skb->data, skb->len, tx_complete, skb);
 
 
 
 
 
1085
1086	/* don't assume the hardware handles USB_ZERO_PACKET
1087	 * NOTE:  strictly conforming cdc-ether devices should expect
1088	 * the ZLP here, but ignore the one-byte packet.
1089	 * NOTE2: CDC NCM specification is different from CDC ECM when
1090	 * handling ZLP/short packets, so cdc_ncm driver will make short
1091	 * packet itself if needed.
1092	 */
1093	if (length % dev->maxpacket == 0) {
1094		if (!(info->flags & FLAG_SEND_ZLP)) {
1095			if (!(info->flags & FLAG_MULTI_PACKET)) {
1096				urb->transfer_buffer_length++;
1097				if (skb_tailroom(skb)) {
1098					skb->data[skb->len] = 0;
1099					__skb_put(skb, 1);
1100				}
 
 
1101			}
1102		} else
1103			urb->transfer_flags |= URB_ZERO_PACKET;
1104	}
 
 
 
 
 
 
 
 
 
 
 
 
 
1105
1106	spin_lock_irqsave(&dev->txq.lock, flags);
1107	retval = usb_autopm_get_interface_async(dev->intf);
1108	if (retval < 0) {
1109		spin_unlock_irqrestore(&dev->txq.lock, flags);
1110		goto drop;
1111	}
 
 
 
 
 
1112
1113#ifdef CONFIG_PM
1114	/* if this triggers the device is still a sleep */
1115	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1116		/* transmission will be done in resume */
1117		usb_anchor_urb(urb, &dev->deferred);
1118		/* no use to process more packets */
1119		netif_stop_queue(net);
 
1120		spin_unlock_irqrestore(&dev->txq.lock, flags);
1121		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1122		goto deferred;
1123	}
1124#endif
1125
1126	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1127	case -EPIPE:
1128		netif_stop_queue (net);
1129		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1130		usb_autopm_put_interface_async(dev->intf);
1131		break;
1132	default:
1133		usb_autopm_put_interface_async(dev->intf);
1134		netif_dbg(dev, tx_err, dev->net,
1135			  "tx: submit urb err %d\n", retval);
1136		break;
1137	case 0:
1138		net->trans_start = jiffies;
1139		__skb_queue_tail (&dev->txq, skb);
1140		if (dev->txq.qlen >= TX_QLEN (dev))
1141			netif_stop_queue (net);
1142	}
1143	spin_unlock_irqrestore (&dev->txq.lock, flags);
1144
1145	if (retval) {
1146		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1147drop:
1148		dev->net->stats.tx_dropped++;
1149not_drop:
1150		if (skb)
1151			dev_kfree_skb_any (skb);
1152		usb_free_urb (urb);
 
 
 
1153	} else
1154		netif_dbg(dev, tx_queued, dev->net,
1155			  "> tx, len %d, type 0x%x\n", length, skb->protocol);
1156#ifdef CONFIG_PM
1157deferred:
1158#endif
1159	return NETDEV_TX_OK;
1160}
1161EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1162
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1163/*-------------------------------------------------------------------------*/
1164
1165// tasklet (work deferred from completions, in_irq) or timer
1166
1167static void usbnet_bh (unsigned long param)
1168{
1169	struct usbnet		*dev = (struct usbnet *) param;
1170	struct sk_buff		*skb;
1171	struct skb_data		*entry;
1172
1173	while ((skb = skb_dequeue (&dev->done))) {
1174		entry = (struct skb_data *) skb->cb;
1175		switch (entry->state) {
1176		case rx_done:
1177			entry->state = rx_cleanup;
1178			rx_process (dev, skb);
1179			continue;
1180		case tx_done:
 
 
1181		case rx_cleanup:
1182			usb_free_urb (entry->urb);
1183			dev_kfree_skb (skb);
1184			continue;
1185		default:
1186			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1187		}
1188	}
1189
1190	// waiting for all pending urbs to complete?
1191	if (dev->wait) {
1192		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1193			wake_up (dev->wait);
1194		}
 
 
 
 
1195
1196	// or are we maybe short a few urbs?
1197	} else if (netif_running (dev->net) &&
1198		   netif_device_present (dev->net) &&
1199		   !timer_pending (&dev->delay) &&
1200		   !test_bit (EVENT_RX_HALT, &dev->flags)) {
 
 
1201		int	temp = dev->rxq.qlen;
1202		int	qlen = RX_QLEN (dev);
1203
1204		if (temp < qlen) {
1205			struct urb	*urb;
1206			int		i;
1207
1208			// don't refill the queue all at once
1209			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1210				urb = usb_alloc_urb (0, GFP_ATOMIC);
1211				if (urb != NULL) {
1212					if (rx_submit (dev, urb, GFP_ATOMIC) ==
1213					    -ENOLINK)
1214						return;
1215				}
1216			}
1217			if (temp != dev->rxq.qlen)
1218				netif_dbg(dev, link, dev->net,
1219					  "rxqlen %d --> %d\n",
1220					  temp, dev->rxq.qlen);
1221			if (dev->rxq.qlen < qlen)
1222				tasklet_schedule (&dev->bh);
1223		}
1224		if (dev->txq.qlen < TX_QLEN (dev))
1225			netif_wake_queue (dev->net);
1226	}
1227}
1228
 
 
 
 
 
 
 
1229
1230/*-------------------------------------------------------------------------
1231 *
1232 * USB Device Driver support
1233 *
1234 *-------------------------------------------------------------------------*/
1235
1236// precondition: never called in_interrupt
1237
1238void usbnet_disconnect (struct usb_interface *intf)
1239{
1240	struct usbnet		*dev;
1241	struct usb_device	*xdev;
1242	struct net_device	*net;
 
1243
1244	dev = usb_get_intfdata(intf);
1245	usb_set_intfdata(intf, NULL);
1246	if (!dev)
1247		return;
1248
1249	xdev = interface_to_usbdev (intf);
1250
1251	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1252		   intf->dev.driver->name,
1253		   xdev->bus->bus_name, xdev->devpath,
1254		   dev->driver_info->description);
1255
1256	net = dev->net;
1257	unregister_netdev (net);
1258
1259	cancel_work_sync(&dev->kevent);
 
 
 
 
1260
1261	if (dev->driver_info->unbind)
1262		dev->driver_info->unbind (dev, intf);
1263
1264	usb_kill_urb(dev->interrupt);
1265	usb_free_urb(dev->interrupt);
 
1266
 
1267	free_netdev(net);
1268	usb_put_dev (xdev);
1269}
1270EXPORT_SYMBOL_GPL(usbnet_disconnect);
1271
1272static const struct net_device_ops usbnet_netdev_ops = {
1273	.ndo_open		= usbnet_open,
1274	.ndo_stop		= usbnet_stop,
1275	.ndo_start_xmit		= usbnet_start_xmit,
1276	.ndo_tx_timeout		= usbnet_tx_timeout,
 
1277	.ndo_change_mtu		= usbnet_change_mtu,
 
1278	.ndo_set_mac_address 	= eth_mac_addr,
1279	.ndo_validate_addr	= eth_validate_addr,
1280};
1281
1282/*-------------------------------------------------------------------------*/
1283
1284// precondition: never called in_interrupt
1285
1286static struct device_type wlan_type = {
1287	.name	= "wlan",
1288};
1289
1290static struct device_type wwan_type = {
1291	.name	= "wwan",
1292};
1293
1294int
1295usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1296{
1297	struct usbnet			*dev;
1298	struct net_device		*net;
1299	struct usb_host_interface	*interface;
1300	struct driver_info		*info;
1301	struct usb_device		*xdev;
1302	int				status;
1303	const char			*name;
1304	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1305
1306	/* usbnet already took usb runtime pm, so have to enable the feature
1307	 * for usb interface, otherwise usb_autopm_get_interface may return
1308	 * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1309	 */
1310	if (!driver->supports_autosuspend) {
1311		driver->supports_autosuspend = 1;
1312		pm_runtime_enable(&udev->dev);
1313	}
1314
1315	name = udev->dev.driver->name;
1316	info = (struct driver_info *) prod->driver_info;
1317	if (!info) {
1318		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1319		return -ENODEV;
1320	}
1321	xdev = interface_to_usbdev (udev);
1322	interface = udev->cur_altsetting;
1323
1324	usb_get_dev (xdev);
1325
1326	status = -ENOMEM;
1327
1328	// set up our own records
1329	net = alloc_etherdev(sizeof(*dev));
1330	if (!net) {
1331		dbg ("can't kmalloc dev");
1332		goto out;
1333	}
1334
1335	/* netdev_printk() needs this so do it as early as possible */
1336	SET_NETDEV_DEV(net, &udev->dev);
1337
1338	dev = netdev_priv(net);
1339	dev->udev = xdev;
1340	dev->intf = udev;
1341	dev->driver_info = info;
1342	dev->driver_name = name;
 
 
 
 
 
 
 
1343	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1344				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
 
1345	skb_queue_head_init (&dev->rxq);
1346	skb_queue_head_init (&dev->txq);
1347	skb_queue_head_init (&dev->done);
1348	skb_queue_head_init(&dev->rxq_pause);
1349	dev->bh.func = usbnet_bh;
1350	dev->bh.data = (unsigned long) dev;
1351	INIT_WORK (&dev->kevent, kevent);
1352	init_usb_anchor(&dev->deferred);
1353	dev->delay.function = usbnet_bh;
1354	dev->delay.data = (unsigned long) dev;
1355	init_timer (&dev->delay);
1356	mutex_init (&dev->phy_mutex);
 
 
1357
1358	dev->net = net;
1359	strcpy (net->name, "usb%d");
1360	memcpy (net->dev_addr, node_id, sizeof node_id);
1361
1362	/* rx and tx sides can use different message sizes;
1363	 * bind() should set rx_urb_size in that case.
1364	 */
1365	dev->hard_mtu = net->mtu + net->hard_header_len;
1366#if 0
1367// dma_supported() is deeply broken on almost all architectures
1368	// possible with some EHCI controllers
1369	if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1370		net->features |= NETIF_F_HIGHDMA;
1371#endif
1372
1373	net->netdev_ops = &usbnet_netdev_ops;
1374	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1375	net->ethtool_ops = &usbnet_ethtool_ops;
1376
1377	// allow device-specific bind/init procedures
1378	// NOTE net->name still not usable ...
1379	if (info->bind) {
1380		status = info->bind (dev, udev);
1381		if (status < 0)
1382			goto out1;
1383
1384		// heuristic:  "usb%d" for links we know are two-host,
1385		// else "eth%d" when there's reasonable doubt.  userspace
1386		// can rename the link if it knows better.
1387		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1388		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1389		     (net->dev_addr [0] & 0x02) == 0))
1390			strcpy (net->name, "eth%d");
1391		/* WLAN devices should always be named "wlan%d" */
1392		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1393			strcpy(net->name, "wlan%d");
1394		/* WWAN devices should always be named "wwan%d" */
1395		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1396			strcpy(net->name, "wwan%d");
 
 
 
 
1397
1398		/* maybe the remote can't receive an Ethernet MTU */
1399		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1400			net->mtu = dev->hard_mtu - net->hard_header_len;
1401	} else if (!info->in || !info->out)
1402		status = usbnet_get_endpoints (dev, udev);
1403	else {
1404		dev->in = usb_rcvbulkpipe (xdev, info->in);
1405		dev->out = usb_sndbulkpipe (xdev, info->out);
1406		if (!(info->flags & FLAG_NO_SETINT))
1407			status = usb_set_interface (xdev,
1408				interface->desc.bInterfaceNumber,
1409				interface->desc.bAlternateSetting);
1410		else
1411			status = 0;
1412
1413	}
1414	if (status >= 0 && dev->status)
1415		status = init_status (dev, udev);
1416	if (status < 0)
1417		goto out3;
1418
1419	if (!dev->rx_urb_size)
1420		dev->rx_urb_size = dev->hard_mtu;
1421	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
 
 
 
 
 
 
 
 
 
1422
1423	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1424		SET_NETDEV_DEVTYPE(net, &wlan_type);
1425	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1426		SET_NETDEV_DEVTYPE(net, &wwan_type);
1427
 
 
 
 
 
 
 
 
 
 
 
 
1428	status = register_netdev (net);
1429	if (status)
1430		goto out3;
1431	netif_info(dev, probe, dev->net,
1432		   "register '%s' at usb-%s-%s, %s, %pM\n",
1433		   udev->dev.driver->name,
1434		   xdev->bus->bus_name, xdev->devpath,
1435		   dev->driver_info->description,
1436		   net->dev_addr);
1437
1438	// ok, it's ready to go.
1439	usb_set_intfdata (udev, dev);
1440
1441	netif_device_attach (net);
1442
1443	if (dev->driver_info->flags & FLAG_LINK_INTR)
1444		netif_carrier_off(net);
1445
1446	return 0;
1447
 
 
 
 
1448out3:
1449	if (info->unbind)
1450		info->unbind (dev, udev);
1451out1:
 
 
 
 
 
 
 
 
 
1452	free_netdev(net);
1453out:
1454	usb_put_dev(xdev);
1455	return status;
1456}
1457EXPORT_SYMBOL_GPL(usbnet_probe);
1458
1459/*-------------------------------------------------------------------------*/
1460
1461/*
1462 * suspend the whole driver as soon as the first interface is suspended
1463 * resume only when the last interface is resumed
1464 */
1465
1466int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1467{
1468	struct usbnet		*dev = usb_get_intfdata(intf);
1469
1470	if (!dev->suspend_count++) {
1471		spin_lock_irq(&dev->txq.lock);
1472		/* don't autosuspend while transmitting */
1473		if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
 
1474			spin_unlock_irq(&dev->txq.lock);
1475			return -EBUSY;
1476		} else {
1477			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1478			spin_unlock_irq(&dev->txq.lock);
1479		}
1480		/*
1481		 * accelerate emptying of the rx and queues, to avoid
1482		 * having everything error out.
1483		 */
1484		netif_device_detach (dev->net);
1485		usbnet_terminate_urbs(dev);
1486		usb_kill_urb(dev->interrupt);
1487
1488		/*
1489		 * reattach so runtime management can use and
1490		 * wake the device
1491		 */
1492		netif_device_attach (dev->net);
1493	}
1494	return 0;
1495}
1496EXPORT_SYMBOL_GPL(usbnet_suspend);
1497
1498int usbnet_resume (struct usb_interface *intf)
1499{
1500	struct usbnet		*dev = usb_get_intfdata(intf);
1501	struct sk_buff          *skb;
1502	struct urb              *res;
1503	int                     retval;
1504
1505	if (!--dev->suspend_count) {
1506		/* resume interrupt URBs */
1507		if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1508			usb_submit_urb(dev->interrupt, GFP_NOIO);
1509
1510		spin_lock_irq(&dev->txq.lock);
1511		while ((res = usb_get_from_anchor(&dev->deferred))) {
1512
1513			skb = (struct sk_buff *)res->context;
1514			retval = usb_submit_urb(res, GFP_ATOMIC);
1515			if (retval < 0) {
1516				dev_kfree_skb_any(skb);
 
1517				usb_free_urb(res);
1518				usb_autopm_put_interface_async(dev->intf);
1519			} else {
1520				dev->net->trans_start = jiffies;
1521				__skb_queue_tail(&dev->txq, skb);
1522			}
1523		}
1524
1525		smp_mb();
1526		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1527		spin_unlock_irq(&dev->txq.lock);
1528
1529		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
 
 
 
 
 
 
 
 
1530			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1531				netif_start_queue(dev->net);
1532			tasklet_schedule (&dev->bh);
1533		}
1534	}
 
 
 
 
1535	return 0;
1536}
1537EXPORT_SYMBOL_GPL(usbnet_resume);
1538
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1539
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1540/*-------------------------------------------------------------------------*/
1541
1542static int __init usbnet_init(void)
1543{
1544	/* Compiler should optimize this out. */
1545	BUILD_BUG_ON(
1546		FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1547
1548	random_ether_addr(node_id);
1549	return 0;
1550}
1551module_init(usbnet_init);
1552
1553static void __exit usbnet_exit(void)
1554{
1555}
1556module_exit(usbnet_exit);
1557
1558MODULE_AUTHOR("David Brownell");
1559MODULE_DESCRIPTION("USB network driver framework");
1560MODULE_LICENSE("GPL");
v6.2
   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#include <linux/module.h>
  21#include <linux/init.h>
  22#include <linux/netdevice.h>
  23#include <linux/etherdevice.h>
  24#include <linux/ctype.h>
  25#include <linux/ethtool.h>
  26#include <linux/workqueue.h>
  27#include <linux/mii.h>
  28#include <linux/usb.h>
  29#include <linux/usb/usbnet.h>
  30#include <linux/slab.h>
  31#include <linux/kernel.h>
  32#include <linux/pm_runtime.h>
  33
 
 
 
  34/*-------------------------------------------------------------------------*/
  35
  36/*
  37 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  38 * Several dozen bytes of IPv4 data can fit in two such transactions.
  39 * One maximum size Ethernet packet takes twenty four of them.
  40 * For high speed, each frame comfortably fits almost 36 max size
  41 * Ethernet packets (so queues should be bigger).
  42 *
  43 * The goal is to let the USB host controller be busy for 5msec or
  44 * more before an irq is required, under load.  Jumbograms change
  45 * the equation.
  46 */
  47#define	MAX_QUEUE_MEMORY	(60 * 1518)
  48#define	RX_QLEN(dev)		((dev)->rx_qlen)
  49#define	TX_QLEN(dev)		((dev)->tx_qlen)
 
 
  50
  51// reawaken network queue this soon after stopping; else watchdog barks
  52#define TX_TIMEOUT_JIFFIES	(5*HZ)
  53
  54/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  55 * us (it polls at HZ/4 usually) before we report too many false errors.
  56 */
  57#define THROTTLE_JIFFIES	(HZ/8)
  58
  59// between wakeups
  60#define UNLINK_TIMEOUT_MS	3
  61
  62/*-------------------------------------------------------------------------*/
  63
  64// randomly generated ethernet address
  65static u8	node_id [ETH_ALEN];
  66
 
 
  67/* use ethtool to change the level for any given device */
  68static int msg_level = -1;
  69module_param (msg_level, int, 0);
  70MODULE_PARM_DESC (msg_level, "Override default message level");
  71
  72/*-------------------------------------------------------------------------*/
  73
  74static const char * const usbnet_event_names[] = {
  75	[EVENT_TX_HALT]		   = "EVENT_TX_HALT",
  76	[EVENT_RX_HALT]		   = "EVENT_RX_HALT",
  77	[EVENT_RX_MEMORY]	   = "EVENT_RX_MEMORY",
  78	[EVENT_STS_SPLIT]	   = "EVENT_STS_SPLIT",
  79	[EVENT_LINK_RESET]	   = "EVENT_LINK_RESET",
  80	[EVENT_RX_PAUSED]	   = "EVENT_RX_PAUSED",
  81	[EVENT_DEV_ASLEEP]	   = "EVENT_DEV_ASLEEP",
  82	[EVENT_DEV_OPEN]	   = "EVENT_DEV_OPEN",
  83	[EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE",
  84	[EVENT_NO_RUNTIME_PM]	   = "EVENT_NO_RUNTIME_PM",
  85	[EVENT_RX_KILL]		   = "EVENT_RX_KILL",
  86	[EVENT_LINK_CHANGE]	   = "EVENT_LINK_CHANGE",
  87	[EVENT_SET_RX_MODE]	   = "EVENT_SET_RX_MODE",
  88	[EVENT_NO_IP_ALIGN]	   = "EVENT_NO_IP_ALIGN",
  89};
  90
  91/* handles CDC Ethernet and many other network "bulk data" interfaces */
  92int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  93{
  94	int				tmp;
  95	struct usb_host_interface	*alt = NULL;
  96	struct usb_host_endpoint	*in = NULL, *out = NULL;
  97	struct usb_host_endpoint	*status = NULL;
  98
  99	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 100		unsigned	ep;
 101
 102		in = out = status = NULL;
 103		alt = intf->altsetting + tmp;
 104
 105		/* take the first altsetting with in-bulk + out-bulk;
 106		 * remember any status endpoint, just in case;
 107		 * ignore other endpoints and altsettings.
 108		 */
 109		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 110			struct usb_host_endpoint	*e;
 111			int				intr = 0;
 112
 113			e = alt->endpoint + ep;
 114
 115			/* ignore endpoints which cannot transfer data */
 116			if (!usb_endpoint_maxp(&e->desc))
 117				continue;
 118
 119			switch (e->desc.bmAttributes) {
 120			case USB_ENDPOINT_XFER_INT:
 121				if (!usb_endpoint_dir_in(&e->desc))
 122					continue;
 123				intr = 1;
 124				fallthrough;
 125			case USB_ENDPOINT_XFER_BULK:
 126				break;
 127			default:
 128				continue;
 129			}
 130			if (usb_endpoint_dir_in(&e->desc)) {
 131				if (!intr && !in)
 132					in = e;
 133				else if (intr && !status)
 134					status = e;
 135			} else {
 136				if (!out)
 137					out = e;
 138			}
 139		}
 140		if (in && out)
 141			break;
 142	}
 143	if (!alt || !in || !out)
 144		return -EINVAL;
 145
 146	if (alt->desc.bAlternateSetting != 0 ||
 147	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149				alt->desc.bAlternateSetting);
 150		if (tmp < 0)
 151			return tmp;
 152	}
 153
 154	dev->in = usb_rcvbulkpipe (dev->udev,
 155			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156	dev->out = usb_sndbulkpipe (dev->udev,
 157			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158	dev->status = status;
 159	return 0;
 160}
 161EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164{
 165	u8		addr[ETH_ALEN];
 166	int 		tmp = -1, ret;
 167	unsigned char	buf [13];
 168
 169	ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 170	if (ret == 12)
 171		tmp = hex2bin(addr, buf, 6);
 172	if (tmp < 0) {
 173		dev_dbg(&dev->udev->dev,
 174			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 175		if (ret >= 0)
 176			ret = -EINVAL;
 177		return ret;
 178	}
 179	eth_hw_addr_set(dev->net, addr);
 
 
 180	return 0;
 181}
 182EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 183
 184static void intr_complete (struct urb *urb)
 185{
 186	struct usbnet	*dev = urb->context;
 187	int		status = urb->status;
 188
 189	switch (status) {
 190	/* success */
 191	case 0:
 192		dev->driver_info->status(dev, urb);
 193		break;
 194
 195	/* software-driven interface shutdown */
 196	case -ENOENT:		/* urb killed */
 197	case -ESHUTDOWN:	/* hardware gone */
 198		netif_dbg(dev, ifdown, dev->net,
 199			  "intr shutdown, code %d\n", status);
 200		return;
 201
 202	/* NOTE:  not throttling like RX/TX, since this endpoint
 203	 * already polls infrequently
 204	 */
 205	default:
 206		netdev_dbg(dev->net, "intr status %d\n", status);
 207		break;
 208	}
 209
 210	status = usb_submit_urb (urb, GFP_ATOMIC);
 211	if (status != 0)
 212		netif_err(dev, timer, dev->net,
 213			  "intr resubmit --> %d\n", status);
 214}
 215
 216static int init_status (struct usbnet *dev, struct usb_interface *intf)
 217{
 218	char		*buf = NULL;
 219	unsigned	pipe = 0;
 220	unsigned	maxp;
 221	unsigned	period;
 222
 223	if (!dev->driver_info->status)
 224		return 0;
 225
 226	pipe = usb_rcvintpipe (dev->udev,
 227			dev->status->desc.bEndpointAddress
 228				& USB_ENDPOINT_NUMBER_MASK);
 229	maxp = usb_maxpacket(dev->udev, pipe);
 230
 231	/* avoid 1 msec chatter:  min 8 msec poll rate */
 232	period = max ((int) dev->status->desc.bInterval,
 233		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 234
 235	buf = kmalloc (maxp, GFP_KERNEL);
 236	if (buf) {
 237		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 238		if (!dev->interrupt) {
 239			kfree (buf);
 240			return -ENOMEM;
 241		} else {
 242			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 243				buf, maxp, intr_complete, dev, period);
 244			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 245			dev_dbg(&intf->dev,
 246				"status ep%din, %d bytes period %d\n",
 247				usb_pipeendpoint(pipe), maxp, period);
 248		}
 249	}
 250	return 0;
 251}
 252
 253/* Submit the interrupt URB if not previously submitted, increasing refcount */
 254int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 255{
 256	int ret = 0;
 257
 258	WARN_ON_ONCE(dev->interrupt == NULL);
 259	if (dev->interrupt) {
 260		mutex_lock(&dev->interrupt_mutex);
 261
 262		if (++dev->interrupt_count == 1)
 263			ret = usb_submit_urb(dev->interrupt, mem_flags);
 264
 265		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 266			dev->interrupt_count);
 267		mutex_unlock(&dev->interrupt_mutex);
 268	}
 269	return ret;
 270}
 271EXPORT_SYMBOL_GPL(usbnet_status_start);
 272
 273/* For resume; submit interrupt URB if previously submitted */
 274static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 275{
 276	int ret = 0;
 277
 278	mutex_lock(&dev->interrupt_mutex);
 279	if (dev->interrupt_count) {
 280		ret = usb_submit_urb(dev->interrupt, mem_flags);
 281		dev_dbg(&dev->udev->dev,
 282			"submitted interrupt URB for resume\n");
 283	}
 284	mutex_unlock(&dev->interrupt_mutex);
 285	return ret;
 286}
 287
 288/* Kill the interrupt URB if all submitters want it killed */
 289void usbnet_status_stop(struct usbnet *dev)
 290{
 291	if (dev->interrupt) {
 292		mutex_lock(&dev->interrupt_mutex);
 293		WARN_ON(dev->interrupt_count == 0);
 294
 295		if (dev->interrupt_count && --dev->interrupt_count == 0)
 296			usb_kill_urb(dev->interrupt);
 297
 298		dev_dbg(&dev->udev->dev,
 299			"decremented interrupt URB count to %d\n",
 300			dev->interrupt_count);
 301		mutex_unlock(&dev->interrupt_mutex);
 302	}
 303}
 304EXPORT_SYMBOL_GPL(usbnet_status_stop);
 305
 306/* For suspend; always kill interrupt URB */
 307static void __usbnet_status_stop_force(struct usbnet *dev)
 308{
 309	if (dev->interrupt) {
 310		mutex_lock(&dev->interrupt_mutex);
 311		usb_kill_urb(dev->interrupt);
 312		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 313		mutex_unlock(&dev->interrupt_mutex);
 314	}
 315}
 316
 317/* Passes this packet up the stack, updating its accounting.
 318 * Some link protocols batch packets, so their rx_fixup paths
 319 * can return clones as well as just modify the original skb.
 320 */
 321void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 322{
 323	struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 324	unsigned long flags;
 325	int	status;
 326
 327	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 328		skb_queue_tail(&dev->rxq_pause, skb);
 329		return;
 330	}
 331
 332	/* only update if unset to allow minidriver rx_fixup override */
 333	if (skb->protocol == 0)
 334		skb->protocol = eth_type_trans (skb, dev->net);
 335
 336	flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 337	u64_stats_inc(&stats64->rx_packets);
 338	u64_stats_add(&stats64->rx_bytes, skb->len);
 339	u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 340
 341	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 342		  skb->len + sizeof (struct ethhdr), skb->protocol);
 343	memset (skb->cb, 0, sizeof (struct skb_data));
 344
 345	if (skb_defer_rx_timestamp(skb))
 346		return;
 347
 348	status = netif_rx (skb);
 349	if (status != NET_RX_SUCCESS)
 350		netif_dbg(dev, rx_err, dev->net,
 351			  "netif_rx status %d\n", status);
 352}
 353EXPORT_SYMBOL_GPL(usbnet_skb_return);
 354
 355/* must be called if hard_mtu or rx_urb_size changed */
 356void usbnet_update_max_qlen(struct usbnet *dev)
 357{
 358	enum usb_device_speed speed = dev->udev->speed;
 359
 360	if (!dev->rx_urb_size || !dev->hard_mtu)
 361		goto insanity;
 362	switch (speed) {
 363	case USB_SPEED_HIGH:
 364		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 366		break;
 367	case USB_SPEED_SUPER:
 368	case USB_SPEED_SUPER_PLUS:
 369		/*
 370		 * Not take default 5ms qlen for super speed HC to
 371		 * save memory, and iperf tests show 2.5ms qlen can
 372		 * work well
 373		 */
 374		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 375		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 376		break;
 377	default:
 378insanity:
 379		dev->rx_qlen = dev->tx_qlen = 4;
 380	}
 381}
 382EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 383
 384
 385/*-------------------------------------------------------------------------
 386 *
 387 * Network Device Driver (peer link to "Host Device", from USB host)
 388 *
 389 *-------------------------------------------------------------------------*/
 390
 391int usbnet_change_mtu (struct net_device *net, int new_mtu)
 392{
 393	struct usbnet	*dev = netdev_priv(net);
 394	int		ll_mtu = new_mtu + net->hard_header_len;
 395	int		old_hard_mtu = dev->hard_mtu;
 396	int		old_rx_urb_size = dev->rx_urb_size;
 397
 
 
 398	// no second zero-length packet read wanted after mtu-sized packets
 399	if ((ll_mtu % dev->maxpacket) == 0)
 400		return -EDOM;
 401	net->mtu = new_mtu;
 402
 403	dev->hard_mtu = net->mtu + net->hard_header_len;
 404	if (dev->rx_urb_size == old_hard_mtu) {
 405		dev->rx_urb_size = dev->hard_mtu;
 406		if (dev->rx_urb_size > old_rx_urb_size) {
 407			usbnet_pause_rx(dev);
 408			usbnet_unlink_rx_urbs(dev);
 409			usbnet_resume_rx(dev);
 410		}
 411	}
 412
 413	/* max qlen depend on hard_mtu and rx_urb_size */
 414	usbnet_update_max_qlen(dev);
 415
 416	return 0;
 417}
 418EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 419
 420/* The caller must hold list->lock */
 421static void __usbnet_queue_skb(struct sk_buff_head *list,
 422			struct sk_buff *newsk, enum skb_state state)
 423{
 424	struct skb_data *entry = (struct skb_data *) newsk->cb;
 425
 426	__skb_queue_tail(list, newsk);
 427	entry->state = state;
 428}
 429
 430/*-------------------------------------------------------------------------*/
 431
 432/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 433 * completion callbacks.  2.5 should have fixed those bugs...
 434 */
 435
 436static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 437		struct sk_buff_head *list, enum skb_state state)
 438{
 439	unsigned long		flags;
 440	enum skb_state 		old_state;
 441	struct skb_data *entry = (struct skb_data *) skb->cb;
 442
 443	spin_lock_irqsave(&list->lock, flags);
 444	old_state = entry->state;
 445	entry->state = state;
 446	__skb_unlink(skb, list);
 447
 448	/* defer_bh() is never called with list == &dev->done.
 449	 * spin_lock_nested() tells lockdep that it is OK to take
 450	 * dev->done.lock here with list->lock held.
 451	 */
 452	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 453
 454	__skb_queue_tail(&dev->done, skb);
 455	if (dev->done.qlen == 1)
 456		tasklet_schedule(&dev->bh);
 457	spin_unlock(&dev->done.lock);
 458	spin_unlock_irqrestore(&list->lock, flags);
 459	return old_state;
 460}
 461
 462/* some work can't be done in tasklets, so we use keventd
 463 *
 464 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 465 * but tasklet_schedule() doesn't.  hope the failure is rare.
 466 */
 467void usbnet_defer_kevent (struct usbnet *dev, int work)
 468{
 469	set_bit (work, &dev->flags);
 470	if (!schedule_work (&dev->kevent))
 471		netdev_dbg(dev->net, "kevent %s may have been dropped\n", usbnet_event_names[work]);
 472	else
 473		netdev_dbg(dev->net, "kevent %s scheduled\n", usbnet_event_names[work]);
 474}
 475EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 476
 477/*-------------------------------------------------------------------------*/
 478
 479static void rx_complete (struct urb *urb);
 480
 481static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 482{
 483	struct sk_buff		*skb;
 484	struct skb_data		*entry;
 485	int			retval = 0;
 486	unsigned long		lockflags;
 487	size_t			size = dev->rx_urb_size;
 488
 489	/* prevent rx skb allocation when error ratio is high */
 490	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 491		usb_free_urb(urb);
 492		return -ENOLINK;
 493	}
 494
 495	if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 496		skb = __netdev_alloc_skb(dev->net, size, flags);
 497	else
 498		skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 499	if (!skb) {
 500		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 501		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 502		usb_free_urb (urb);
 503		return -ENOMEM;
 504	}
 
 505
 506	entry = (struct skb_data *) skb->cb;
 507	entry->urb = urb;
 508	entry->dev = dev;
 
 509	entry->length = 0;
 510
 511	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 512		skb->data, size, rx_complete, skb);
 513
 514	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 515
 516	if (netif_running (dev->net) &&
 517	    netif_device_present (dev->net) &&
 518	    test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 519	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 520	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 521		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 522		case -EPIPE:
 523			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 524			break;
 525		case -ENOMEM:
 526			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 527			break;
 528		case -ENODEV:
 529			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 530			netif_device_detach (dev->net);
 531			break;
 532		case -EHOSTUNREACH:
 533			retval = -ENOLINK;
 534			break;
 535		default:
 536			netif_dbg(dev, rx_err, dev->net,
 537				  "rx submit, %d\n", retval);
 538			tasklet_schedule (&dev->bh);
 539			break;
 540		case 0:
 541			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
 542		}
 543	} else {
 544		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 545		retval = -ENOLINK;
 546	}
 547	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 548	if (retval) {
 549		dev_kfree_skb_any (skb);
 550		usb_free_urb (urb);
 551	}
 552	return retval;
 553}
 554
 555
 556/*-------------------------------------------------------------------------*/
 557
 558static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 559{
 560	if (dev->driver_info->rx_fixup &&
 561	    !dev->driver_info->rx_fixup (dev, skb)) {
 562		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 563		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 564			dev->net->stats.rx_errors++;
 565		goto done;
 566	}
 567	// else network stack removes extra byte if we forced a short packet
 568
 569	/* all data was already cloned from skb inside the driver */
 570	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 571		goto done;
 572
 573	if (skb->len < ETH_HLEN) {
 574		dev->net->stats.rx_errors++;
 575		dev->net->stats.rx_length_errors++;
 576		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 577	} else {
 578		usbnet_skb_return(dev, skb);
 579		return;
 580	}
 581
 
 
 582done:
 583	skb_queue_tail(&dev->done, skb);
 584}
 585
 586/*-------------------------------------------------------------------------*/
 587
 588static void rx_complete (struct urb *urb)
 589{
 590	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 591	struct skb_data		*entry = (struct skb_data *) skb->cb;
 592	struct usbnet		*dev = entry->dev;
 593	int			urb_status = urb->status;
 594	enum skb_state		state;
 595
 596	skb_put (skb, urb->actual_length);
 597	state = rx_done;
 598	entry->urb = NULL;
 599
 600	switch (urb_status) {
 601	/* success */
 602	case 0:
 
 
 
 
 
 
 
 603		break;
 604
 605	/* stalls need manual reset. this is rare ... except that
 606	 * when going through USB 2.0 TTs, unplug appears this way.
 607	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 608	 * storm, recovering as needed.
 609	 */
 610	case -EPIPE:
 611		dev->net->stats.rx_errors++;
 612		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 613		fallthrough;
 614
 615	/* software-driven interface shutdown */
 616	case -ECONNRESET:		/* async unlink */
 617	case -ESHUTDOWN:		/* hardware gone */
 618		netif_dbg(dev, ifdown, dev->net,
 619			  "rx shutdown, code %d\n", urb_status);
 620		goto block;
 621
 622	/* we get controller i/o faults during hub_wq disconnect() delays.
 623	 * throttle down resubmits, to avoid log floods; just temporarily,
 624	 * so we still recover when the fault isn't a hub_wq delay.
 625	 */
 626	case -EPROTO:
 627	case -ETIME:
 628	case -EILSEQ:
 629		dev->net->stats.rx_errors++;
 630		if (!timer_pending (&dev->delay)) {
 631			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 632			netif_dbg(dev, link, dev->net,
 633				  "rx throttle %d\n", urb_status);
 634		}
 635block:
 636		state = rx_cleanup;
 637		entry->urb = urb;
 638		urb = NULL;
 639		break;
 640
 641	/* data overrun ... flush fifo? */
 642	case -EOVERFLOW:
 643		dev->net->stats.rx_over_errors++;
 644		fallthrough;
 645
 646	default:
 647		state = rx_cleanup;
 648		dev->net->stats.rx_errors++;
 649		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 650		break;
 651	}
 652
 653	/* stop rx if packet error rate is high */
 654	if (++dev->pkt_cnt > 30) {
 655		dev->pkt_cnt = 0;
 656		dev->pkt_err = 0;
 657	} else {
 658		if (state == rx_cleanup)
 659			dev->pkt_err++;
 660		if (dev->pkt_err > 20)
 661			set_bit(EVENT_RX_KILL, &dev->flags);
 662	}
 663
 664	state = defer_bh(dev, skb, &dev->rxq, state);
 665
 666	if (urb) {
 667		if (netif_running (dev->net) &&
 668		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 669		    state != unlink_start) {
 670			rx_submit (dev, urb, GFP_ATOMIC);
 671			usb_mark_last_busy(dev->udev);
 672			return;
 673		}
 674		usb_free_urb (urb);
 675	}
 676	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 677}
 678
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 679/*-------------------------------------------------------------------------*/
 680void usbnet_pause_rx(struct usbnet *dev)
 681{
 682	set_bit(EVENT_RX_PAUSED, &dev->flags);
 683
 684	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 685}
 686EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 687
 688void usbnet_resume_rx(struct usbnet *dev)
 689{
 690	struct sk_buff *skb;
 691	int num = 0;
 692
 693	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 694
 695	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 696		usbnet_skb_return(dev, skb);
 697		num++;
 698	}
 699
 700	tasklet_schedule(&dev->bh);
 701
 702	netif_dbg(dev, rx_status, dev->net,
 703		  "paused rx queue disabled, %d skbs requeued\n", num);
 704}
 705EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 706
 707void usbnet_purge_paused_rxq(struct usbnet *dev)
 708{
 709	skb_queue_purge(&dev->rxq_pause);
 710}
 711EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 712
 713/*-------------------------------------------------------------------------*/
 714
 715// unlink pending rx/tx; completion handlers do all other cleanup
 716
 717static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 718{
 719	unsigned long		flags;
 720	struct sk_buff		*skb;
 721	int			count = 0;
 722
 723	spin_lock_irqsave (&q->lock, flags);
 724	while (!skb_queue_empty(q)) {
 725		struct skb_data		*entry;
 726		struct urb		*urb;
 727		int			retval;
 728
 729		skb_queue_walk(q, skb) {
 730			entry = (struct skb_data *) skb->cb;
 731			if (entry->state != unlink_start)
 732				goto found;
 733		}
 734		break;
 735found:
 736		entry->state = unlink_start;
 737		urb = entry->urb;
 738
 739		/*
 740		 * Get reference count of the URB to avoid it to be
 741		 * freed during usb_unlink_urb, which may trigger
 742		 * use-after-free problem inside usb_unlink_urb since
 743		 * usb_unlink_urb is always racing with .complete
 744		 * handler(include defer_bh).
 745		 */
 746		usb_get_urb(urb);
 747		spin_unlock_irqrestore(&q->lock, flags);
 748		// during some PM-driven resume scenarios,
 749		// these (async) unlinks complete immediately
 750		retval = usb_unlink_urb (urb);
 751		if (retval != -EINPROGRESS && retval != 0)
 752			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 753		else
 754			count++;
 755		usb_put_urb(urb);
 756		spin_lock_irqsave(&q->lock, flags);
 757	}
 758	spin_unlock_irqrestore (&q->lock, flags);
 759	return count;
 760}
 761
 762// Flush all pending rx urbs
 763// minidrivers may need to do this when the MTU changes
 764
 765void usbnet_unlink_rx_urbs(struct usbnet *dev)
 766{
 767	if (netif_running(dev->net)) {
 768		(void) unlink_urbs (dev, &dev->rxq);
 769		tasklet_schedule(&dev->bh);
 770	}
 771}
 772EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 773
 774/*-------------------------------------------------------------------------*/
 775
 776static void wait_skb_queue_empty(struct sk_buff_head *q)
 777{
 778	unsigned long flags;
 779
 780	spin_lock_irqsave(&q->lock, flags);
 781	while (!skb_queue_empty(q)) {
 782		spin_unlock_irqrestore(&q->lock, flags);
 783		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 784		set_current_state(TASK_UNINTERRUPTIBLE);
 785		spin_lock_irqsave(&q->lock, flags);
 786	}
 787	spin_unlock_irqrestore(&q->lock, flags);
 788}
 789
 790// precondition: never called in_interrupt
 791static void usbnet_terminate_urbs(struct usbnet *dev)
 792{
 
 793	DECLARE_WAITQUEUE(wait, current);
 794	int temp;
 795
 796	/* ensure there are no more active urbs */
 797	add_wait_queue(&dev->wait, &wait);
 798	set_current_state(TASK_UNINTERRUPTIBLE);
 
 799	temp = unlink_urbs(dev, &dev->txq) +
 800		unlink_urbs(dev, &dev->rxq);
 801
 802	/* maybe wait for deletions to finish. */
 803	wait_skb_queue_empty(&dev->rxq);
 804	wait_skb_queue_empty(&dev->txq);
 805	wait_skb_queue_empty(&dev->done);
 806	netif_dbg(dev, ifdown, dev->net,
 807		  "waited for %d urb completions\n", temp);
 
 
 
 808	set_current_state(TASK_RUNNING);
 809	remove_wait_queue(&dev->wait, &wait);
 
 810}
 811
 812int usbnet_stop (struct net_device *net)
 813{
 814	struct usbnet		*dev = netdev_priv(net);
 815	const struct driver_info *info = dev->driver_info;
 816	int			retval, pm, mpn;
 817
 818	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 819	netif_stop_queue (net);
 820
 821	netif_info(dev, ifdown, dev->net,
 822		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 823		   net->stats.rx_packets, net->stats.tx_packets,
 824		   net->stats.rx_errors, net->stats.tx_errors);
 825
 826	/* to not race resume */
 827	pm = usb_autopm_get_interface(dev->intf);
 828	/* allow minidriver to stop correctly (wireless devices to turn off
 829	 * radio etc) */
 830	if (info->stop) {
 831		retval = info->stop(dev);
 832		if (retval < 0)
 833			netif_info(dev, ifdown, dev->net,
 834				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 835				   retval,
 836				   dev->udev->bus->bus_name, dev->udev->devpath,
 837				   info->description);
 838	}
 839
 840	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 841		usbnet_terminate_urbs(dev);
 842
 843	usbnet_status_stop(dev);
 844
 845	usbnet_purge_paused_rxq(dev);
 846
 847	mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 848
 849	/* deferred work (timer, softirq, task) must also stop */
 
 850	dev->flags = 0;
 851	del_timer_sync (&dev->delay);
 852	tasklet_kill (&dev->bh);
 853	cancel_work_sync(&dev->kevent);
 854	if (!pm)
 855		usb_autopm_put_interface(dev->intf);
 856
 857	if (info->manage_power && mpn)
 858		info->manage_power(dev, 0);
 859	else
 860		usb_autopm_put_interface(dev->intf);
 861
 862	return 0;
 863}
 864EXPORT_SYMBOL_GPL(usbnet_stop);
 865
 866/*-------------------------------------------------------------------------*/
 867
 868// posts reads, and enables write queuing
 869
 870// precondition: never called in_interrupt
 871
 872int usbnet_open (struct net_device *net)
 873{
 874	struct usbnet		*dev = netdev_priv(net);
 875	int			retval;
 876	const struct driver_info *info = dev->driver_info;
 877
 878	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 879		netif_info(dev, ifup, dev->net,
 880			   "resumption 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_nopm;
 886	}
 887
 888	// put into "known safe" state
 889	if (info->reset && (retval = info->reset (dev)) < 0) {
 890		netif_info(dev, ifup, dev->net,
 891			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 892			   retval,
 893			   dev->udev->bus->bus_name,
 894			   dev->udev->devpath,
 895			   info->description);
 896		goto done;
 897	}
 898
 899	/* hard_mtu or rx_urb_size may change in reset() */
 900	usbnet_update_max_qlen(dev);
 901
 902	// insist peer be connected
 903	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 904		netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 905		goto done;
 906	}
 907
 908	/* start any status interrupt transfer */
 909	if (dev->interrupt) {
 910		retval = usbnet_status_start(dev, GFP_KERNEL);
 911		if (retval < 0) {
 912			netif_err(dev, ifup, dev->net,
 913				  "intr submit %d\n", retval);
 914			goto done;
 915		}
 916	}
 917
 918	set_bit(EVENT_DEV_OPEN, &dev->flags);
 919	netif_start_queue (net);
 920	netif_info(dev, ifup, dev->net,
 921		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 922		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 923		   dev->net->mtu,
 924		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 925		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 926		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 927		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 928		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 929		   "simple");
 930
 931	/* reset rx error state */
 932	dev->pkt_cnt = 0;
 933	dev->pkt_err = 0;
 934	clear_bit(EVENT_RX_KILL, &dev->flags);
 935
 936	// delay posting reads until we're fully open
 937	tasklet_schedule (&dev->bh);
 938	if (info->manage_power) {
 939		retval = info->manage_power(dev, 1);
 940		if (retval < 0) {
 941			retval = 0;
 942			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 943		} else {
 944			usb_autopm_put_interface(dev->intf);
 945		}
 946	}
 947	return retval;
 
 948done:
 949	usb_autopm_put_interface(dev->intf);
 950done_nopm:
 951	return retval;
 952}
 953EXPORT_SYMBOL_GPL(usbnet_open);
 954
 955/*-------------------------------------------------------------------------*/
 956
 957/* ethtool methods; minidrivers may need to add some more, but
 958 * they'll probably want to use this base set.
 959 */
 960
 961/* These methods are written on the assumption that the device
 962 * uses MII
 963 */
 964int usbnet_get_link_ksettings_mii(struct net_device *net,
 965			      struct ethtool_link_ksettings *cmd)
 966{
 967	struct usbnet *dev = netdev_priv(net);
 968
 969	if (!dev->mii.mdio_read)
 970		return -EOPNOTSUPP;
 971
 972	mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 973
 974	return 0;
 975}
 976EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 977
 978int usbnet_get_link_ksettings_internal(struct net_device *net,
 979					struct ethtool_link_ksettings *cmd)
 980{
 981	struct usbnet *dev = netdev_priv(net);
 982
 983	/* the assumption that speed is equal on tx and rx
 984	 * is deeply engrained into the networking layer.
 985	 * For wireless stuff it is not true.
 986	 * We assume that rx_speed matters more.
 987	 */
 988	if (dev->rx_speed != SPEED_UNSET)
 989		cmd->base.speed = dev->rx_speed / 1000000;
 990	else if (dev->tx_speed != SPEED_UNSET)
 991		cmd->base.speed = dev->tx_speed / 1000000;
 992	else
 993		cmd->base.speed = SPEED_UNKNOWN;
 994
 995	return 0;
 996}
 997EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
 998
 999int usbnet_set_link_ksettings_mii(struct net_device *net,
1000			      const struct ethtool_link_ksettings *cmd)
1001{
1002	struct usbnet *dev = netdev_priv(net);
1003	int retval;
1004
1005	if (!dev->mii.mdio_write)
1006		return -EOPNOTSUPP;
1007
1008	retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1009
1010	/* link speed/duplex might have changed */
1011	if (dev->driver_info->link_reset)
1012		dev->driver_info->link_reset(dev);
1013
1014	/* hard_mtu or rx_urb_size may change in link_reset() */
1015	usbnet_update_max_qlen(dev);
1016
1017	return retval;
1018}
1019EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1020
1021u32 usbnet_get_link (struct net_device *net)
1022{
1023	struct usbnet *dev = netdev_priv(net);
1024
1025	/* If a check_connect is defined, return its result */
1026	if (dev->driver_info->check_connect)
1027		return dev->driver_info->check_connect (dev) == 0;
1028
1029	/* if the device has mii operations, use those */
1030	if (dev->mii.mdio_read)
1031		return mii_link_ok(&dev->mii);
1032
1033	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1034	return ethtool_op_get_link(net);
1035}
1036EXPORT_SYMBOL_GPL(usbnet_get_link);
1037
1038int usbnet_nway_reset(struct net_device *net)
1039{
1040	struct usbnet *dev = netdev_priv(net);
1041
1042	if (!dev->mii.mdio_write)
1043		return -EOPNOTSUPP;
1044
1045	return mii_nway_restart(&dev->mii);
1046}
1047EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1048
1049void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1050{
1051	struct usbnet *dev = netdev_priv(net);
1052
1053	strscpy(info->driver, dev->driver_name, sizeof(info->driver));
1054	strscpy(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_mii,
1085	.set_link_ksettings	= usbnet_set_link_ksettings_mii,
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
1114void 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}
1120EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1121
1122static void __handle_set_rx_mode(struct usbnet *dev)
1123{
1124	if (dev->driver_info->set_rx_mode)
1125		(dev->driver_info->set_rx_mode)(dev);
1126
1127	clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1128}
1129
1130/* work that cannot be done in interrupt context uses keventd.
1131 *
1132 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1133 * especially now that control transfers can be queued.
1134 */
1135static void
1136usbnet_deferred_kevent (struct work_struct *work)
1137{
1138	struct usbnet		*dev =
1139		container_of(work, struct usbnet, kevent);
1140	int			status;
1141
1142	/* usb_clear_halt() needs a thread context */
1143	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1144		unlink_urbs (dev, &dev->txq);
1145		status = usb_autopm_get_interface(dev->intf);
1146		if (status < 0)
1147			goto fail_pipe;
1148		status = usb_clear_halt (dev->udev, dev->out);
1149		usb_autopm_put_interface(dev->intf);
1150		if (status < 0 &&
1151		    status != -EPIPE &&
1152		    status != -ESHUTDOWN) {
1153			if (netif_msg_tx_err (dev))
1154fail_pipe:
1155				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1156					   status);
1157		} else {
1158			clear_bit (EVENT_TX_HALT, &dev->flags);
1159			if (status != -ESHUTDOWN)
1160				netif_wake_queue (dev->net);
1161		}
1162	}
1163	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1164		unlink_urbs (dev, &dev->rxq);
1165		status = usb_autopm_get_interface(dev->intf);
1166		if (status < 0)
1167			goto fail_halt;
1168		status = usb_clear_halt (dev->udev, dev->in);
1169		usb_autopm_put_interface(dev->intf);
1170		if (status < 0 &&
1171		    status != -EPIPE &&
1172		    status != -ESHUTDOWN) {
1173			if (netif_msg_rx_err (dev))
1174fail_halt:
1175				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1176					   status);
1177		} else {
1178			clear_bit (EVENT_RX_HALT, &dev->flags);
1179			tasklet_schedule (&dev->bh);
1180		}
1181	}
1182
1183	/* tasklet could resubmit itself forever if memory is tight */
1184	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1185		struct urb	*urb = NULL;
1186		int resched = 1;
1187
1188		if (netif_running (dev->net))
1189			urb = usb_alloc_urb (0, GFP_KERNEL);
1190		else
1191			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1192		if (urb != NULL) {
1193			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1194			status = usb_autopm_get_interface(dev->intf);
1195			if (status < 0) {
1196				usb_free_urb(urb);
1197				goto fail_lowmem;
1198			}
1199			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1200				resched = 0;
1201			usb_autopm_put_interface(dev->intf);
1202fail_lowmem:
1203			if (resched)
1204				tasklet_schedule (&dev->bh);
1205		}
1206	}
1207
1208	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1209		const struct driver_info *info = dev->driver_info;
1210		int			retval = 0;
1211
1212		clear_bit (EVENT_LINK_RESET, &dev->flags);
1213		status = usb_autopm_get_interface(dev->intf);
1214		if (status < 0)
1215			goto skip_reset;
1216		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1217			usb_autopm_put_interface(dev->intf);
1218skip_reset:
1219			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1220				    retval,
1221				    dev->udev->bus->bus_name,
1222				    dev->udev->devpath,
1223				    info->description);
1224		} else {
1225			usb_autopm_put_interface(dev->intf);
1226		}
1227
1228		/* handle link change from link resetting */
1229		__handle_link_change(dev);
1230	}
1231
1232	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1233		__handle_link_change(dev);
1234
1235	if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1236		__handle_set_rx_mode(dev);
1237
1238
1239	if (dev->flags)
1240		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1241}
1242
1243/*-------------------------------------------------------------------------*/
1244
1245static void tx_complete (struct urb *urb)
1246{
1247	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1248	struct skb_data		*entry = (struct skb_data *) skb->cb;
1249	struct usbnet		*dev = entry->dev;
1250
1251	if (urb->status == 0) {
1252		struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1253		unsigned long flags;
1254
1255		flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1256		u64_stats_add(&stats64->tx_packets, entry->packets);
1257		u64_stats_add(&stats64->tx_bytes, entry->length);
1258		u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1259	} else {
1260		dev->net->stats.tx_errors++;
1261
1262		switch (urb->status) {
1263		case -EPIPE:
1264			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1265			break;
1266
1267		/* software-driven interface shutdown */
1268		case -ECONNRESET:		// async unlink
1269		case -ESHUTDOWN:		// hardware gone
1270			break;
1271
1272		/* like rx, tx gets controller i/o faults during hub_wq
1273		 * delays and so it uses the same throttling mechanism.
1274		 */
1275		case -EPROTO:
1276		case -ETIME:
1277		case -EILSEQ:
1278			usb_mark_last_busy(dev->udev);
1279			if (!timer_pending (&dev->delay)) {
1280				mod_timer (&dev->delay,
1281					jiffies + THROTTLE_JIFFIES);
1282				netif_dbg(dev, link, dev->net,
1283					  "tx throttle %d\n", urb->status);
1284			}
1285			netif_stop_queue (dev->net);
1286			break;
1287		default:
1288			netif_dbg(dev, tx_err, dev->net,
1289				  "tx err %d\n", entry->urb->status);
1290			break;
1291		}
1292	}
1293
1294	usb_autopm_put_interface_async(dev->intf);
1295	(void) defer_bh(dev, skb, &dev->txq, tx_done);
 
 
1296}
1297
1298/*-------------------------------------------------------------------------*/
1299
1300void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1301{
1302	struct usbnet		*dev = netdev_priv(net);
1303
1304	unlink_urbs (dev, &dev->txq);
1305	tasklet_schedule (&dev->bh);
1306	/* this needs to be handled individually because the generic layer
1307	 * doesn't know what is sufficient and could not restore private
1308	 * information if a remedy of an unconditional reset were used.
1309	 */
1310	if (dev->driver_info->recover)
1311		(dev->driver_info->recover)(dev);
1312}
1313EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1314
1315/*-------------------------------------------------------------------------*/
1316
1317static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1318{
1319	unsigned num_sgs, total_len = 0;
1320	int i, s = 0;
1321
1322	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1323	if (num_sgs == 1)
1324		return 0;
1325
1326	/* reserve one for zero packet */
1327	urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1328				GFP_ATOMIC);
1329	if (!urb->sg)
1330		return -ENOMEM;
1331
1332	urb->num_sgs = num_sgs;
1333	sg_init_table(urb->sg, urb->num_sgs + 1);
1334
1335	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1336	total_len += skb_headlen(skb);
1337
1338	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1339		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1340
1341		total_len += skb_frag_size(f);
1342		sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1343			    skb_frag_off(f));
1344	}
1345	urb->transfer_buffer_length = total_len;
1346
1347	return 1;
1348}
1349
1350netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1351				     struct net_device *net)
1352{
1353	struct usbnet		*dev = netdev_priv(net);
1354	unsigned int			length;
1355	struct urb		*urb = NULL;
1356	struct skb_data		*entry;
1357	const struct driver_info *info = dev->driver_info;
1358	unsigned long		flags;
1359	int retval;
1360
1361	if (skb)
1362		skb_tx_timestamp(skb);
1363
1364	// some devices want funky USB-level framing, for
1365	// win32 driver (usually) and/or hardware quirks
1366	if (info->tx_fixup) {
1367		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1368		if (!skb) {
1369			/* packet collected; minidriver waiting for more */
1370			if (info->flags & FLAG_MULTI_PACKET)
 
 
 
1371				goto not_drop;
1372			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1373			goto drop;
1374		}
1375	}
 
1376
1377	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1378		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1379		goto drop;
1380	}
1381
1382	entry = (struct skb_data *) skb->cb;
1383	entry->urb = urb;
1384	entry->dev = dev;
 
 
1385
1386	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1387			skb->data, skb->len, tx_complete, skb);
1388	if (dev->can_dma_sg) {
1389		if (build_dma_sg(skb, urb) < 0)
1390			goto drop;
1391	}
1392	length = urb->transfer_buffer_length;
1393
1394	/* don't assume the hardware handles USB_ZERO_PACKET
1395	 * NOTE:  strictly conforming cdc-ether devices should expect
1396	 * the ZLP here, but ignore the one-byte packet.
1397	 * NOTE2: CDC NCM specification is different from CDC ECM when
1398	 * handling ZLP/short packets, so cdc_ncm driver will make short
1399	 * packet itself if needed.
1400	 */
1401	if (length % dev->maxpacket == 0) {
1402		if (!(info->flags & FLAG_SEND_ZLP)) {
1403			if (!(info->flags & FLAG_MULTI_PACKET)) {
1404				length++;
1405				if (skb_tailroom(skb) && !urb->num_sgs) {
1406					skb->data[skb->len] = 0;
1407					__skb_put(skb, 1);
1408				} else if (urb->num_sgs)
1409					sg_set_buf(&urb->sg[urb->num_sgs++],
1410							dev->padding_pkt, 1);
1411			}
1412		} else
1413			urb->transfer_flags |= URB_ZERO_PACKET;
1414	}
1415	urb->transfer_buffer_length = length;
1416
1417	if (info->flags & FLAG_MULTI_PACKET) {
1418		/* Driver has set number of packets and a length delta.
1419		 * Calculate the complete length and ensure that it's
1420		 * positive.
1421		 */
1422		entry->length += length;
1423		if (WARN_ON_ONCE(entry->length <= 0))
1424			entry->length = length;
1425	} else {
1426		usbnet_set_skb_tx_stats(skb, 1, length);
1427	}
1428
1429	spin_lock_irqsave(&dev->txq.lock, flags);
1430	retval = usb_autopm_get_interface_async(dev->intf);
1431	if (retval < 0) {
1432		spin_unlock_irqrestore(&dev->txq.lock, flags);
1433		goto drop;
1434	}
1435	if (netif_queue_stopped(net)) {
1436		usb_autopm_put_interface_async(dev->intf);
1437		spin_unlock_irqrestore(&dev->txq.lock, flags);
1438		goto drop;
1439	}
1440
1441#ifdef CONFIG_PM
1442	/* if this triggers the device is still a sleep */
1443	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1444		/* transmission will be done in resume */
1445		usb_anchor_urb(urb, &dev->deferred);
1446		/* no use to process more packets */
1447		netif_stop_queue(net);
1448		usb_put_urb(urb);
1449		spin_unlock_irqrestore(&dev->txq.lock, flags);
1450		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1451		goto deferred;
1452	}
1453#endif
1454
1455	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1456	case -EPIPE:
1457		netif_stop_queue (net);
1458		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1459		usb_autopm_put_interface_async(dev->intf);
1460		break;
1461	default:
1462		usb_autopm_put_interface_async(dev->intf);
1463		netif_dbg(dev, tx_err, dev->net,
1464			  "tx: submit urb err %d\n", retval);
1465		break;
1466	case 0:
1467		netif_trans_update(net);
1468		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1469		if (dev->txq.qlen >= TX_QLEN (dev))
1470			netif_stop_queue (net);
1471	}
1472	spin_unlock_irqrestore (&dev->txq.lock, flags);
1473
1474	if (retval) {
1475		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1476drop:
1477		dev->net->stats.tx_dropped++;
1478not_drop:
1479		if (skb)
1480			dev_kfree_skb_any (skb);
1481		if (urb) {
1482			kfree(urb->sg);
1483			usb_free_urb(urb);
1484		}
1485	} else
1486		netif_dbg(dev, tx_queued, dev->net,
1487			  "> tx, len %u, type 0x%x\n", length, skb->protocol);
1488#ifdef CONFIG_PM
1489deferred:
1490#endif
1491	return NETDEV_TX_OK;
1492}
1493EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1494
1495static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1496{
1497	struct urb	*urb;
1498	int		i;
1499	int		ret = 0;
1500
1501	/* don't refill the queue all at once */
1502	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1503		urb = usb_alloc_urb(0, flags);
1504		if (urb != NULL) {
1505			ret = rx_submit(dev, urb, flags);
1506			if (ret)
1507				goto err;
1508		} else {
1509			ret = -ENOMEM;
1510			goto err;
1511		}
1512	}
1513err:
1514	return ret;
1515}
1516
1517/*-------------------------------------------------------------------------*/
1518
1519// tasklet (work deferred from completions, in_irq) or timer
1520
1521static void usbnet_bh (struct timer_list *t)
1522{
1523	struct usbnet		*dev = from_timer(dev, t, delay);
1524	struct sk_buff		*skb;
1525	struct skb_data		*entry;
1526
1527	while ((skb = skb_dequeue (&dev->done))) {
1528		entry = (struct skb_data *) skb->cb;
1529		switch (entry->state) {
1530		case rx_done:
1531			entry->state = rx_cleanup;
1532			rx_process (dev, skb);
1533			continue;
1534		case tx_done:
1535			kfree(entry->urb->sg);
1536			fallthrough;
1537		case rx_cleanup:
1538			usb_free_urb (entry->urb);
1539			dev_kfree_skb (skb);
1540			continue;
1541		default:
1542			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1543		}
1544	}
1545
1546	/* restart RX again after disabling due to high error rate */
1547	clear_bit(EVENT_RX_KILL, &dev->flags);
1548
1549	/* waiting for all pending urbs to complete?
1550	 * only then can we forgo submitting anew
1551	 */
1552	if (waitqueue_active(&dev->wait)) {
1553		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1554			wake_up_all(&dev->wait);
1555
1556	// or are we maybe short a few urbs?
1557	} else if (netif_running (dev->net) &&
1558		   netif_device_present (dev->net) &&
1559		   netif_carrier_ok(dev->net) &&
1560		   !timer_pending(&dev->delay) &&
1561		   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1562		   !test_bit(EVENT_RX_HALT, &dev->flags)) {
1563		int	temp = dev->rxq.qlen;
 
1564
1565		if (temp < RX_QLEN(dev)) {
1566			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1567				return;
 
 
 
 
 
 
 
 
 
 
1568			if (temp != dev->rxq.qlen)
1569				netif_dbg(dev, link, dev->net,
1570					  "rxqlen %d --> %d\n",
1571					  temp, dev->rxq.qlen);
1572			if (dev->rxq.qlen < RX_QLEN(dev))
1573				tasklet_schedule (&dev->bh);
1574		}
1575		if (dev->txq.qlen < TX_QLEN (dev))
1576			netif_wake_queue (dev->net);
1577	}
1578}
1579
1580static void usbnet_bh_tasklet(struct tasklet_struct *t)
1581{
1582	struct usbnet *dev = from_tasklet(dev, t, bh);
1583
1584	usbnet_bh(&dev->delay);
1585}
1586
1587
1588/*-------------------------------------------------------------------------
1589 *
1590 * USB Device Driver support
1591 *
1592 *-------------------------------------------------------------------------*/
1593
1594// precondition: never called in_interrupt
1595
1596void usbnet_disconnect (struct usb_interface *intf)
1597{
1598	struct usbnet		*dev;
1599	struct usb_device	*xdev;
1600	struct net_device	*net;
1601	struct urb		*urb;
1602
1603	dev = usb_get_intfdata(intf);
1604	usb_set_intfdata(intf, NULL);
1605	if (!dev)
1606		return;
1607
1608	xdev = interface_to_usbdev (intf);
1609
1610	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1611		   intf->dev.driver->name,
1612		   xdev->bus->bus_name, xdev->devpath,
1613		   dev->driver_info->description);
1614
1615	net = dev->net;
1616	unregister_netdev (net);
1617
1618	while ((urb = usb_get_from_anchor(&dev->deferred))) {
1619		dev_kfree_skb(urb->context);
1620		kfree(urb->sg);
1621		usb_free_urb(urb);
1622	}
1623
1624	if (dev->driver_info->unbind)
1625		dev->driver_info->unbind(dev, intf);
1626
1627	usb_kill_urb(dev->interrupt);
1628	usb_free_urb(dev->interrupt);
1629	kfree(dev->padding_pkt);
1630
1631	free_percpu(net->tstats);
1632	free_netdev(net);
 
1633}
1634EXPORT_SYMBOL_GPL(usbnet_disconnect);
1635
1636static const struct net_device_ops usbnet_netdev_ops = {
1637	.ndo_open		= usbnet_open,
1638	.ndo_stop		= usbnet_stop,
1639	.ndo_start_xmit		= usbnet_start_xmit,
1640	.ndo_tx_timeout		= usbnet_tx_timeout,
1641	.ndo_set_rx_mode	= usbnet_set_rx_mode,
1642	.ndo_change_mtu		= usbnet_change_mtu,
1643	.ndo_get_stats64	= dev_get_tstats64,
1644	.ndo_set_mac_address 	= eth_mac_addr,
1645	.ndo_validate_addr	= eth_validate_addr,
1646};
1647
1648/*-------------------------------------------------------------------------*/
1649
1650// precondition: never called in_interrupt
1651
1652static struct device_type wlan_type = {
1653	.name	= "wlan",
1654};
1655
1656static struct device_type wwan_type = {
1657	.name	= "wwan",
1658};
1659
1660int
1661usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1662{
1663	struct usbnet			*dev;
1664	struct net_device		*net;
1665	struct usb_host_interface	*interface;
1666	const struct driver_info	*info;
1667	struct usb_device		*xdev;
1668	int				status;
1669	const char			*name;
1670	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1671
1672	/* usbnet already took usb runtime pm, so have to enable the feature
1673	 * for usb interface, otherwise usb_autopm_get_interface may return
1674	 * failure if RUNTIME_PM is enabled.
1675	 */
1676	if (!driver->supports_autosuspend) {
1677		driver->supports_autosuspend = 1;
1678		pm_runtime_enable(&udev->dev);
1679	}
1680
1681	name = udev->dev.driver->name;
1682	info = (const struct driver_info *) prod->driver_info;
1683	if (!info) {
1684		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1685		return -ENODEV;
1686	}
1687	xdev = interface_to_usbdev (udev);
1688	interface = udev->cur_altsetting;
1689
 
 
1690	status = -ENOMEM;
1691
1692	// set up our own records
1693	net = alloc_etherdev(sizeof(*dev));
1694	if (!net)
 
1695		goto out;
 
1696
1697	/* netdev_printk() needs this so do it as early as possible */
1698	SET_NETDEV_DEV(net, &udev->dev);
1699
1700	dev = netdev_priv(net);
1701	dev->udev = xdev;
1702	dev->intf = udev;
1703	dev->driver_info = info;
1704	dev->driver_name = name;
1705	dev->rx_speed = SPEED_UNSET;
1706	dev->tx_speed = SPEED_UNSET;
1707
1708	net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1709	if (!net->tstats)
1710		goto out0;
1711
1712	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1713				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1714	init_waitqueue_head(&dev->wait);
1715	skb_queue_head_init (&dev->rxq);
1716	skb_queue_head_init (&dev->txq);
1717	skb_queue_head_init (&dev->done);
1718	skb_queue_head_init(&dev->rxq_pause);
1719	tasklet_setup(&dev->bh, usbnet_bh_tasklet);
1720	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
 
1721	init_usb_anchor(&dev->deferred);
1722	timer_setup(&dev->delay, usbnet_bh, 0);
 
 
1723	mutex_init (&dev->phy_mutex);
1724	mutex_init(&dev->interrupt_mutex);
1725	dev->interrupt_count = 0;
1726
1727	dev->net = net;
1728	strscpy(net->name, "usb%d", sizeof(net->name));
1729	eth_hw_addr_set(net, node_id);
1730
1731	/* rx and tx sides can use different message sizes;
1732	 * bind() should set rx_urb_size in that case.
1733	 */
1734	dev->hard_mtu = net->mtu + net->hard_header_len;
1735	net->min_mtu = 0;
1736	net->max_mtu = ETH_MAX_MTU;
 
 
 
 
1737
1738	net->netdev_ops = &usbnet_netdev_ops;
1739	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1740	net->ethtool_ops = &usbnet_ethtool_ops;
1741
1742	// allow device-specific bind/init procedures
1743	// NOTE net->name still not usable ...
1744	if (info->bind) {
1745		status = info->bind (dev, udev);
1746		if (status < 0)
1747			goto out1;
1748
1749		// heuristic:  "usb%d" for links we know are two-host,
1750		// else "eth%d" when there's reasonable doubt.  userspace
1751		// can rename the link if it knows better.
1752		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1753		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1754		     (net->dev_addr [0] & 0x02) == 0))
1755			strscpy(net->name, "eth%d", sizeof(net->name));
1756		/* WLAN devices should always be named "wlan%d" */
1757		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1758			strscpy(net->name, "wlan%d", sizeof(net->name));
1759		/* WWAN devices should always be named "wwan%d" */
1760		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1761			strscpy(net->name, "wwan%d", sizeof(net->name));
1762
1763		/* devices that cannot do ARP */
1764		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1765			net->flags |= IFF_NOARP;
1766
1767		/* maybe the remote can't receive an Ethernet MTU */
1768		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1769			net->mtu = dev->hard_mtu - net->hard_header_len;
1770	} else if (!info->in || !info->out)
1771		status = usbnet_get_endpoints (dev, udev);
1772	else {
1773		dev->in = usb_rcvbulkpipe (xdev, info->in);
1774		dev->out = usb_sndbulkpipe (xdev, info->out);
1775		if (!(info->flags & FLAG_NO_SETINT))
1776			status = usb_set_interface (xdev,
1777				interface->desc.bInterfaceNumber,
1778				interface->desc.bAlternateSetting);
1779		else
1780			status = 0;
1781
1782	}
1783	if (status >= 0 && dev->status)
1784		status = init_status (dev, udev);
1785	if (status < 0)
1786		goto out3;
1787
1788	if (!dev->rx_urb_size)
1789		dev->rx_urb_size = dev->hard_mtu;
1790	dev->maxpacket = usb_maxpacket(dev->udev, dev->out);
1791	if (dev->maxpacket == 0) {
1792		/* that is a broken device */
1793		status = -ENODEV;
1794		goto out4;
1795	}
1796
1797	/* let userspace know we have a random address */
1798	if (ether_addr_equal(net->dev_addr, node_id))
1799		net->addr_assign_type = NET_ADDR_RANDOM;
1800
1801	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1802		SET_NETDEV_DEVTYPE(net, &wlan_type);
1803	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1804		SET_NETDEV_DEVTYPE(net, &wwan_type);
1805
1806	/* initialize max rx_qlen and tx_qlen */
1807	usbnet_update_max_qlen(dev);
1808
1809	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1810		!(info->flags & FLAG_MULTI_PACKET)) {
1811		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1812		if (!dev->padding_pkt) {
1813			status = -ENOMEM;
1814			goto out4;
1815		}
1816	}
1817
1818	status = register_netdev (net);
1819	if (status)
1820		goto out5;
1821	netif_info(dev, probe, dev->net,
1822		   "register '%s' at usb-%s-%s, %s, %pM\n",
1823		   udev->dev.driver->name,
1824		   xdev->bus->bus_name, xdev->devpath,
1825		   dev->driver_info->description,
1826		   net->dev_addr);
1827
1828	// ok, it's ready to go.
1829	usb_set_intfdata (udev, dev);
1830
1831	netif_device_attach (net);
1832
1833	if (dev->driver_info->flags & FLAG_LINK_INTR)
1834		usbnet_link_change(dev, 0, 0);
1835
1836	return 0;
1837
1838out5:
1839	kfree(dev->padding_pkt);
1840out4:
1841	usb_free_urb(dev->interrupt);
1842out3:
1843	if (info->unbind)
1844		info->unbind (dev, udev);
1845out1:
1846	/* subdrivers must undo all they did in bind() if they
1847	 * fail it, but we may fail later and a deferred kevent
1848	 * may trigger an error resubmitting itself and, worse,
1849	 * schedule a timer. So we kill it all just in case.
1850	 */
1851	cancel_work_sync(&dev->kevent);
1852	del_timer_sync(&dev->delay);
1853	free_percpu(net->tstats);
1854out0:
1855	free_netdev(net);
1856out:
 
1857	return status;
1858}
1859EXPORT_SYMBOL_GPL(usbnet_probe);
1860
1861/*-------------------------------------------------------------------------*/
1862
1863/*
1864 * suspend the whole driver as soon as the first interface is suspended
1865 * resume only when the last interface is resumed
1866 */
1867
1868int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1869{
1870	struct usbnet		*dev = usb_get_intfdata(intf);
1871
1872	if (!dev->suspend_count++) {
1873		spin_lock_irq(&dev->txq.lock);
1874		/* don't autosuspend while transmitting */
1875		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1876			dev->suspend_count--;
1877			spin_unlock_irq(&dev->txq.lock);
1878			return -EBUSY;
1879		} else {
1880			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1881			spin_unlock_irq(&dev->txq.lock);
1882		}
1883		/*
1884		 * accelerate emptying of the rx and queues, to avoid
1885		 * having everything error out.
1886		 */
1887		netif_device_detach (dev->net);
1888		usbnet_terminate_urbs(dev);
1889		__usbnet_status_stop_force(dev);
1890
1891		/*
1892		 * reattach so runtime management can use and
1893		 * wake the device
1894		 */
1895		netif_device_attach (dev->net);
1896	}
1897	return 0;
1898}
1899EXPORT_SYMBOL_GPL(usbnet_suspend);
1900
1901int usbnet_resume (struct usb_interface *intf)
1902{
1903	struct usbnet		*dev = usb_get_intfdata(intf);
1904	struct sk_buff          *skb;
1905	struct urb              *res;
1906	int                     retval;
1907
1908	if (!--dev->suspend_count) {
1909		/* resume interrupt URB if it was previously submitted */
1910		__usbnet_status_start_force(dev, GFP_NOIO);
 
1911
1912		spin_lock_irq(&dev->txq.lock);
1913		while ((res = usb_get_from_anchor(&dev->deferred))) {
1914
1915			skb = (struct sk_buff *)res->context;
1916			retval = usb_submit_urb(res, GFP_ATOMIC);
1917			if (retval < 0) {
1918				dev_kfree_skb_any(skb);
1919				kfree(res->sg);
1920				usb_free_urb(res);
1921				usb_autopm_put_interface_async(dev->intf);
1922			} else {
1923				netif_trans_update(dev->net);
1924				__skb_queue_tail(&dev->txq, skb);
1925			}
1926		}
1927
1928		smp_mb();
1929		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1930		spin_unlock_irq(&dev->txq.lock);
1931
1932		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1933			/* handle remote wakeup ASAP
1934			 * we cannot race against stop
1935			 */
1936			if (netif_device_present(dev->net) &&
1937				!timer_pending(&dev->delay) &&
1938				!test_bit(EVENT_RX_HALT, &dev->flags))
1939					rx_alloc_submit(dev, GFP_NOIO);
1940
1941			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1942				netif_tx_wake_all_queues(dev->net);
1943			tasklet_schedule (&dev->bh);
1944		}
1945	}
1946
1947	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1948		usb_autopm_get_interface_no_resume(intf);
1949
1950	return 0;
1951}
1952EXPORT_SYMBOL_GPL(usbnet_resume);
1953
1954/*
1955 * Either a subdriver implements manage_power, then it is assumed to always
1956 * be ready to be suspended or it reports the readiness to be suspended
1957 * explicitly
1958 */
1959void usbnet_device_suggests_idle(struct usbnet *dev)
1960{
1961	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1962		dev->intf->needs_remote_wakeup = 1;
1963		usb_autopm_put_interface_async(dev->intf);
1964	}
1965}
1966EXPORT_SYMBOL(usbnet_device_suggests_idle);
1967
1968/*
1969 * For devices that can do without special commands
1970 */
1971int usbnet_manage_power(struct usbnet *dev, int on)
1972{
1973	dev->intf->needs_remote_wakeup = on;
1974	return 0;
1975}
1976EXPORT_SYMBOL(usbnet_manage_power);
1977
1978void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1979{
1980	/* update link after link is reseted */
1981	if (link && !need_reset)
1982		netif_carrier_on(dev->net);
1983	else
1984		netif_carrier_off(dev->net);
1985
1986	if (need_reset && link)
1987		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1988	else
1989		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1990}
1991EXPORT_SYMBOL(usbnet_link_change);
1992
1993/*-------------------------------------------------------------------------*/
1994static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1995			     u16 value, u16 index, void *data, u16 size)
1996{
1997	void *buf = NULL;
1998	int err = -ENOMEM;
1999
2000	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
2001		   " value=0x%04x index=0x%04x size=%d\n",
2002		   cmd, reqtype, value, index, size);
2003
2004	if (size) {
2005		buf = kmalloc(size, GFP_NOIO);
2006		if (!buf)
2007			goto out;
2008	}
2009
2010	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2011			      cmd, reqtype, value, index, buf, size,
2012			      USB_CTRL_GET_TIMEOUT);
2013	if (err > 0 && err <= size) {
2014		if (data)
2015			memcpy(data, buf, err);
2016		else
2017			netdev_dbg(dev->net,
2018				   "Huh? Data requested but thrown away.\n");
2019	}
2020	kfree(buf);
2021out:
2022	return err;
2023}
2024
2025static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2026			      u16 value, u16 index, const void *data,
2027			      u16 size)
2028{
2029	void *buf = NULL;
2030	int err = -ENOMEM;
2031
2032	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2033		   " value=0x%04x index=0x%04x size=%d\n",
2034		   cmd, reqtype, value, index, size);
2035
2036	if (data) {
2037		buf = kmemdup(data, size, GFP_NOIO);
2038		if (!buf)
2039			goto out;
2040	} else {
2041        if (size) {
2042            WARN_ON_ONCE(1);
2043            err = -EINVAL;
2044            goto out;
2045        }
2046    }
2047
2048	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2049			      cmd, reqtype, value, index, buf, size,
2050			      USB_CTRL_SET_TIMEOUT);
2051	kfree(buf);
2052
2053out:
2054	return err;
2055}
2056
2057/*
2058 * The function can't be called inside suspend/resume callback,
2059 * otherwise deadlock will be caused.
2060 */
2061int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2062		    u16 value, u16 index, void *data, u16 size)
2063{
2064	int ret;
2065
2066	if (usb_autopm_get_interface(dev->intf) < 0)
2067		return -ENODEV;
2068	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2069				data, size);
2070	usb_autopm_put_interface(dev->intf);
2071	return ret;
2072}
2073EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2074
2075/*
2076 * The function can't be called inside suspend/resume callback,
2077 * otherwise deadlock will be caused.
2078 */
2079int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2080		     u16 value, u16 index, const void *data, u16 size)
2081{
2082	int ret;
2083
2084	if (usb_autopm_get_interface(dev->intf) < 0)
2085		return -ENODEV;
2086	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2087				 data, size);
2088	usb_autopm_put_interface(dev->intf);
2089	return ret;
2090}
2091EXPORT_SYMBOL_GPL(usbnet_write_cmd);
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_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2098			  u16 value, u16 index, void *data, u16 size)
2099{
2100	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2101				 data, size);
2102}
2103EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2104
2105/*
2106 * The function can be called inside suspend/resume callback safely
2107 * and should only be called by suspend/resume callback generally.
2108 */
2109int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2110			  u16 value, u16 index, const void *data,
2111			  u16 size)
2112{
2113	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2114				  data, size);
2115}
2116EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2117
2118static void usbnet_async_cmd_cb(struct urb *urb)
2119{
2120	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2121	int status = urb->status;
2122
2123	if (status < 0)
2124		dev_dbg(&urb->dev->dev, "%s failed with %d",
2125			__func__, status);
2126
2127	kfree(req);
2128	usb_free_urb(urb);
2129}
2130
2131/*
2132 * The caller must make sure that device can't be put into suspend
2133 * state until the control URB completes.
2134 */
2135int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2136			   u16 value, u16 index, const void *data, u16 size)
2137{
2138	struct usb_ctrlrequest *req;
2139	struct urb *urb;
2140	int err = -ENOMEM;
2141	void *buf = NULL;
2142
2143	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2144		   " value=0x%04x index=0x%04x size=%d\n",
2145		   cmd, reqtype, value, index, size);
2146
2147	urb = usb_alloc_urb(0, GFP_ATOMIC);
2148	if (!urb)
2149		goto fail;
2150
2151	if (data) {
2152		buf = kmemdup(data, size, GFP_ATOMIC);
2153		if (!buf) {
2154			netdev_err(dev->net, "Error allocating buffer"
2155				   " in %s!\n", __func__);
2156			goto fail_free_urb;
2157		}
2158	}
2159
2160	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2161	if (!req)
2162		goto fail_free_buf;
2163
2164	req->bRequestType = reqtype;
2165	req->bRequest = cmd;
2166	req->wValue = cpu_to_le16(value);
2167	req->wIndex = cpu_to_le16(index);
2168	req->wLength = cpu_to_le16(size);
2169
2170	usb_fill_control_urb(urb, dev->udev,
2171			     usb_sndctrlpipe(dev->udev, 0),
2172			     (void *)req, buf, size,
2173			     usbnet_async_cmd_cb, req);
2174	urb->transfer_flags |= URB_FREE_BUFFER;
2175
2176	err = usb_submit_urb(urb, GFP_ATOMIC);
2177	if (err < 0) {
2178		netdev_err(dev->net, "Error submitting the control"
2179			   " message: status=%d\n", err);
2180		goto fail_free_all;
2181	}
2182	return 0;
2183
2184fail_free_all:
2185	kfree(req);
2186fail_free_buf:
2187	kfree(buf);
2188	/*
2189	 * avoid a double free
2190	 * needed because the flag can be set only
2191	 * after filling the URB
2192	 */
2193	urb->transfer_flags = 0;
2194fail_free_urb:
2195	usb_free_urb(urb);
2196fail:
2197	return err;
2198
2199}
2200EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2201/*-------------------------------------------------------------------------*/
2202
2203static int __init usbnet_init(void)
2204{
2205	/* Compiler should optimize this out. */
2206	BUILD_BUG_ON(
2207		sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2208
2209	eth_random_addr(node_id);
2210	return 0;
2211}
2212module_init(usbnet_init);
2213
2214static void __exit usbnet_exit(void)
2215{
2216}
2217module_exit(usbnet_exit);
2218
2219MODULE_AUTHOR("David Brownell");
2220MODULE_DESCRIPTION("USB network driver framework");
2221MODULE_LICENSE("GPL");