xref: /openbmc/linux/drivers/net/usb/usbnet.c (revision 805aaa29fa3c5afb26cb42f440f40d3f7f5c4bdc)
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/ethtool.h>
41 #include <linux/workqueue.h>
42 #include <linux/mii.h>
43 #include <linux/usb.h>
44 #include <linux/usb/usbnet.h>
45 
46 #define DRIVER_VERSION		"22-Aug-2005"
47 
48 
49 /*-------------------------------------------------------------------------*/
50 
51 /*
52  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
53  * Several dozen bytes of IPv4 data can fit in two such transactions.
54  * One maximum size Ethernet packet takes twenty four of them.
55  * For high speed, each frame comfortably fits almost 36 max size
56  * Ethernet packets (so queues should be bigger).
57  *
58  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
59  * let the USB host controller be busy for 5msec or more before an irq
60  * is required, under load.  Jumbograms change the equation.
61  */
62 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
63 #define	RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
64 			(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
65 #define	TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
66 			(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
67 
68 // reawaken network queue this soon after stopping; else watchdog barks
69 #define TX_TIMEOUT_JIFFIES	(5*HZ)
70 
71 // throttle rx/tx briefly after some faults, so khubd might disconnect()
72 // us (it polls at HZ/4 usually) before we report too many false errors.
73 #define THROTTLE_JIFFIES	(HZ/8)
74 
75 // between wakeups
76 #define UNLINK_TIMEOUT_MS	3
77 
78 /*-------------------------------------------------------------------------*/
79 
80 // randomly generated ethernet address
81 static u8	node_id [ETH_ALEN];
82 
83 static const char driver_name [] = "usbnet";
84 
85 /* use ethtool to change the level for any given device */
86 static int msg_level = -1;
87 module_param (msg_level, int, 0);
88 MODULE_PARM_DESC (msg_level, "Override default message level");
89 
90 /*-------------------------------------------------------------------------*/
91 
92 /* handles CDC Ethernet and many other network "bulk data" interfaces */
93 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
94 {
95 	int				tmp;
96 	struct usb_host_interface	*alt = NULL;
97 	struct usb_host_endpoint	*in = NULL, *out = NULL;
98 	struct usb_host_endpoint	*status = NULL;
99 
100 	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
101 		unsigned	ep;
102 
103 		in = out = status = NULL;
104 		alt = intf->altsetting + tmp;
105 
106 		/* take the first altsetting with in-bulk + out-bulk;
107 		 * remember any status endpoint, just in case;
108 		 * ignore other endpoints and altsetttings.
109 		 */
110 		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
111 			struct usb_host_endpoint	*e;
112 			int				intr = 0;
113 
114 			e = alt->endpoint + ep;
115 			switch (e->desc.bmAttributes) {
116 			case USB_ENDPOINT_XFER_INT:
117 				if (!usb_endpoint_dir_in(&e->desc))
118 					continue;
119 				intr = 1;
120 				/* FALLTHROUGH */
121 			case USB_ENDPOINT_XFER_BULK:
122 				break;
123 			default:
124 				continue;
125 			}
126 			if (usb_endpoint_dir_in(&e->desc)) {
127 				if (!intr && !in)
128 					in = e;
129 				else if (intr && !status)
130 					status = e;
131 			} else {
132 				if (!out)
133 					out = e;
134 			}
135 		}
136 		if (in && out)
137 			break;
138 	}
139 	if (!alt || !in || !out)
140 		return -EINVAL;
141 
142 	if (alt->desc.bAlternateSetting != 0
143 			|| !(dev->driver_info->flags & FLAG_NO_SETINT)) {
144 		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
145 				alt->desc.bAlternateSetting);
146 		if (tmp < 0)
147 			return tmp;
148 	}
149 
150 	dev->in = usb_rcvbulkpipe (dev->udev,
151 			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
152 	dev->out = usb_sndbulkpipe (dev->udev,
153 			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
154 	dev->status = status;
155 	return 0;
156 }
157 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
158 
159 static void intr_complete (struct urb *urb);
160 
161 static int init_status (struct usbnet *dev, struct usb_interface *intf)
162 {
163 	char		*buf = NULL;
164 	unsigned	pipe = 0;
165 	unsigned	maxp;
166 	unsigned	period;
167 
168 	if (!dev->driver_info->status)
169 		return 0;
170 
171 	pipe = usb_rcvintpipe (dev->udev,
172 			dev->status->desc.bEndpointAddress
173 				& USB_ENDPOINT_NUMBER_MASK);
174 	maxp = usb_maxpacket (dev->udev, pipe, 0);
175 
176 	/* avoid 1 msec chatter:  min 8 msec poll rate */
177 	period = max ((int) dev->status->desc.bInterval,
178 		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
179 
180 	buf = kmalloc (maxp, GFP_KERNEL);
181 	if (buf) {
182 		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
183 		if (!dev->interrupt) {
184 			kfree (buf);
185 			return -ENOMEM;
186 		} else {
187 			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
188 				buf, maxp, intr_complete, dev, period);
189 			dev_dbg(&intf->dev,
190 				"status ep%din, %d bytes period %d\n",
191 				usb_pipeendpoint(pipe), maxp, period);
192 		}
193 	}
194 	return 0;
195 }
196 
197 /* Passes this packet up the stack, updating its accounting.
198  * Some link protocols batch packets, so their rx_fixup paths
199  * can return clones as well as just modify the original skb.
200  */
201 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
202 {
203 	int	status;
204 
205 	skb->protocol = eth_type_trans (skb, dev->net);
206 	dev->stats.rx_packets++;
207 	dev->stats.rx_bytes += skb->len;
208 
209 	if (netif_msg_rx_status (dev))
210 		devdbg (dev, "< rx, len %zu, type 0x%x",
211 			skb->len + sizeof (struct ethhdr), skb->protocol);
212 	memset (skb->cb, 0, sizeof (struct skb_data));
213 	status = netif_rx (skb);
214 	if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
215 		devdbg (dev, "netif_rx status %d", status);
216 }
217 EXPORT_SYMBOL_GPL(usbnet_skb_return);
218 
219 
220 /*-------------------------------------------------------------------------
221  *
222  * Network Device Driver (peer link to "Host Device", from USB host)
223  *
224  *-------------------------------------------------------------------------*/
225 
226 static int usbnet_change_mtu (struct net_device *net, int new_mtu)
227 {
228 	struct usbnet	*dev = netdev_priv(net);
229 	int		ll_mtu = new_mtu + net->hard_header_len;
230 	int		old_hard_mtu = dev->hard_mtu;
231 	int		old_rx_urb_size = dev->rx_urb_size;
232 
233 	if (new_mtu <= 0)
234 		return -EINVAL;
235 	// no second zero-length packet read wanted after mtu-sized packets
236 	if ((ll_mtu % dev->maxpacket) == 0)
237 		return -EDOM;
238 	net->mtu = new_mtu;
239 
240 	dev->hard_mtu = net->mtu + net->hard_header_len;
241 	if (dev->rx_urb_size == old_hard_mtu) {
242 		dev->rx_urb_size = dev->hard_mtu;
243 		if (dev->rx_urb_size > old_rx_urb_size)
244 			usbnet_unlink_rx_urbs(dev);
245 	}
246 
247 	return 0;
248 }
249 
250 /*-------------------------------------------------------------------------*/
251 
252 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
253  * completion callbacks.  2.5 should have fixed those bugs...
254  */
255 
256 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
257 {
258 	unsigned long		flags;
259 
260 	spin_lock_irqsave(&list->lock, flags);
261 	__skb_unlink(skb, list);
262 	spin_unlock(&list->lock);
263 	spin_lock(&dev->done.lock);
264 	__skb_queue_tail(&dev->done, skb);
265 	if (dev->done.qlen == 1)
266 		tasklet_schedule(&dev->bh);
267 	spin_unlock_irqrestore(&dev->done.lock, flags);
268 }
269 
270 /* some work can't be done in tasklets, so we use keventd
271  *
272  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
273  * but tasklet_schedule() doesn't.  hope the failure is rare.
274  */
275 void usbnet_defer_kevent (struct usbnet *dev, int work)
276 {
277 	set_bit (work, &dev->flags);
278 	if (!schedule_work (&dev->kevent))
279 		deverr (dev, "kevent %d may have been dropped", work);
280 	else
281 		devdbg (dev, "kevent %d scheduled", work);
282 }
283 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
284 
285 /*-------------------------------------------------------------------------*/
286 
287 static void rx_complete (struct urb *urb);
288 
289 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
290 {
291 	struct sk_buff		*skb;
292 	struct skb_data		*entry;
293 	int			retval = 0;
294 	unsigned long		lockflags;
295 	size_t			size = dev->rx_urb_size;
296 
297 	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
298 		if (netif_msg_rx_err (dev))
299 			devdbg (dev, "no rx skb");
300 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
301 		usb_free_urb (urb);
302 		return;
303 	}
304 	skb_reserve (skb, NET_IP_ALIGN);
305 
306 	entry = (struct skb_data *) skb->cb;
307 	entry->urb = urb;
308 	entry->dev = dev;
309 	entry->state = rx_start;
310 	entry->length = 0;
311 
312 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
313 		skb->data, size, rx_complete, skb);
314 
315 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
316 
317 	if (netif_running (dev->net)
318 			&& netif_device_present (dev->net)
319 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
320 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
321 		case -EPIPE:
322 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
323 			break;
324 		case -ENOMEM:
325 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
326 			break;
327 		case -ENODEV:
328 			if (netif_msg_ifdown (dev))
329 				devdbg (dev, "device gone");
330 			netif_device_detach (dev->net);
331 			break;
332 		default:
333 			if (netif_msg_rx_err (dev))
334 				devdbg (dev, "rx submit, %d", retval);
335 			tasklet_schedule (&dev->bh);
336 			break;
337 		case 0:
338 			__skb_queue_tail (&dev->rxq, skb);
339 		}
340 	} else {
341 		if (netif_msg_ifdown (dev))
342 			devdbg (dev, "rx: stopped");
343 		retval = -ENOLINK;
344 	}
345 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
346 	if (retval) {
347 		dev_kfree_skb_any (skb);
348 		usb_free_urb (urb);
349 	}
350 }
351 
352 
353 /*-------------------------------------------------------------------------*/
354 
355 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
356 {
357 	if (dev->driver_info->rx_fixup
358 			&& !dev->driver_info->rx_fixup (dev, skb))
359 		goto error;
360 	// else network stack removes extra byte if we forced a short packet
361 
362 	if (skb->len)
363 		usbnet_skb_return (dev, skb);
364 	else {
365 		if (netif_msg_rx_err (dev))
366 			devdbg (dev, "drop");
367 error:
368 		dev->stats.rx_errors++;
369 		skb_queue_tail (&dev->done, skb);
370 	}
371 }
372 
373 /*-------------------------------------------------------------------------*/
374 
375 static void rx_complete (struct urb *urb)
376 {
377 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
378 	struct skb_data		*entry = (struct skb_data *) skb->cb;
379 	struct usbnet		*dev = entry->dev;
380 	int			urb_status = urb->status;
381 
382 	skb_put (skb, urb->actual_length);
383 	entry->state = rx_done;
384 	entry->urb = NULL;
385 
386 	switch (urb_status) {
387 	/* success */
388 	case 0:
389 		if (skb->len < dev->net->hard_header_len) {
390 			entry->state = rx_cleanup;
391 			dev->stats.rx_errors++;
392 			dev->stats.rx_length_errors++;
393 			if (netif_msg_rx_err (dev))
394 				devdbg (dev, "rx length %d", skb->len);
395 		}
396 		break;
397 
398 	/* stalls need manual reset. this is rare ... except that
399 	 * when going through USB 2.0 TTs, unplug appears this way.
400 	 * we avoid the highspeed version of the ETIMEOUT/EILSEQ
401 	 * storm, recovering as needed.
402 	 */
403 	case -EPIPE:
404 		dev->stats.rx_errors++;
405 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
406 		// FALLTHROUGH
407 
408 	/* software-driven interface shutdown */
409 	case -ECONNRESET:		/* async unlink */
410 	case -ESHUTDOWN:		/* hardware gone */
411 		if (netif_msg_ifdown (dev))
412 			devdbg (dev, "rx shutdown, code %d", urb_status);
413 		goto block;
414 
415 	/* we get controller i/o faults during khubd disconnect() delays.
416 	 * throttle down resubmits, to avoid log floods; just temporarily,
417 	 * so we still recover when the fault isn't a khubd delay.
418 	 */
419 	case -EPROTO:
420 	case -ETIME:
421 	case -EILSEQ:
422 		dev->stats.rx_errors++;
423 		if (!timer_pending (&dev->delay)) {
424 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
425 			if (netif_msg_link (dev))
426 				devdbg (dev, "rx throttle %d", urb_status);
427 		}
428 block:
429 		entry->state = rx_cleanup;
430 		entry->urb = urb;
431 		urb = NULL;
432 		break;
433 
434 	/* data overrun ... flush fifo? */
435 	case -EOVERFLOW:
436 		dev->stats.rx_over_errors++;
437 		// FALLTHROUGH
438 
439 	default:
440 		entry->state = rx_cleanup;
441 		dev->stats.rx_errors++;
442 		if (netif_msg_rx_err (dev))
443 			devdbg (dev, "rx status %d", urb_status);
444 		break;
445 	}
446 
447 	defer_bh(dev, skb, &dev->rxq);
448 
449 	if (urb) {
450 		if (netif_running (dev->net)
451 				&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
452 			rx_submit (dev, urb, GFP_ATOMIC);
453 			return;
454 		}
455 		usb_free_urb (urb);
456 	}
457 	if (netif_msg_rx_err (dev))
458 		devdbg (dev, "no read resubmitted");
459 }
460 
461 static void intr_complete (struct urb *urb)
462 {
463 	struct usbnet	*dev = urb->context;
464 	int		status = urb->status;
465 
466 	switch (status) {
467 	/* success */
468 	case 0:
469 		dev->driver_info->status(dev, urb);
470 		break;
471 
472 	/* software-driven interface shutdown */
473 	case -ENOENT:		/* urb killed */
474 	case -ESHUTDOWN:	/* hardware gone */
475 		if (netif_msg_ifdown (dev))
476 			devdbg (dev, "intr shutdown, code %d", status);
477 		return;
478 
479 	/* NOTE:  not throttling like RX/TX, since this endpoint
480 	 * already polls infrequently
481 	 */
482 	default:
483 		devdbg (dev, "intr status %d", status);
484 		break;
485 	}
486 
487 	if (!netif_running (dev->net))
488 		return;
489 
490 	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
491 	status = usb_submit_urb (urb, GFP_ATOMIC);
492 	if (status != 0 && netif_msg_timer (dev))
493 		deverr(dev, "intr resubmit --> %d", status);
494 }
495 
496 /*-------------------------------------------------------------------------*/
497 
498 // unlink pending rx/tx; completion handlers do all other cleanup
499 
500 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
501 {
502 	unsigned long		flags;
503 	struct sk_buff		*skb, *skbnext;
504 	int			count = 0;
505 
506 	spin_lock_irqsave (&q->lock, flags);
507 	skb_queue_walk_safe(q, skb, skbnext) {
508 		struct skb_data		*entry;
509 		struct urb		*urb;
510 		int			retval;
511 
512 		entry = (struct skb_data *) skb->cb;
513 		urb = entry->urb;
514 
515 		// during some PM-driven resume scenarios,
516 		// these (async) unlinks complete immediately
517 		retval = usb_unlink_urb (urb);
518 		if (retval != -EINPROGRESS && retval != 0)
519 			devdbg (dev, "unlink urb err, %d", retval);
520 		else
521 			count++;
522 	}
523 	spin_unlock_irqrestore (&q->lock, flags);
524 	return count;
525 }
526 
527 // Flush all pending rx urbs
528 // minidrivers may need to do this when the MTU changes
529 
530 void usbnet_unlink_rx_urbs(struct usbnet *dev)
531 {
532 	if (netif_running(dev->net)) {
533 		(void) unlink_urbs (dev, &dev->rxq);
534 		tasklet_schedule(&dev->bh);
535 	}
536 }
537 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
538 
539 /*-------------------------------------------------------------------------*/
540 
541 // precondition: never called in_interrupt
542 
543 static int usbnet_stop (struct net_device *net)
544 {
545 	struct usbnet		*dev = netdev_priv(net);
546 	int			temp;
547 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
548 	DECLARE_WAITQUEUE (wait, current);
549 
550 	netif_stop_queue (net);
551 
552 	if (netif_msg_ifdown (dev))
553 		devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
554 			dev->stats.rx_packets, dev->stats.tx_packets,
555 			dev->stats.rx_errors, dev->stats.tx_errors
556 			);
557 
558 	// ensure there are no more active urbs
559 	add_wait_queue (&unlink_wakeup, &wait);
560 	dev->wait = &unlink_wakeup;
561 	temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
562 
563 	// maybe wait for deletions to finish.
564 	while (!skb_queue_empty(&dev->rxq)
565 			&& !skb_queue_empty(&dev->txq)
566 			&& !skb_queue_empty(&dev->done)) {
567 		msleep(UNLINK_TIMEOUT_MS);
568 		if (netif_msg_ifdown (dev))
569 			devdbg (dev, "waited for %d urb completions", temp);
570 	}
571 	dev->wait = NULL;
572 	remove_wait_queue (&unlink_wakeup, &wait);
573 
574 	usb_kill_urb(dev->interrupt);
575 
576 	/* deferred work (task, timer, softirq) must also stop.
577 	 * can't flush_scheduled_work() until we drop rtnl (later),
578 	 * else workers could deadlock; so make workers a NOP.
579 	 */
580 	dev->flags = 0;
581 	del_timer_sync (&dev->delay);
582 	tasklet_kill (&dev->bh);
583 	usb_autopm_put_interface(dev->intf);
584 
585 	return 0;
586 }
587 
588 /*-------------------------------------------------------------------------*/
589 
590 // posts reads, and enables write queuing
591 
592 // precondition: never called in_interrupt
593 
594 static int usbnet_open (struct net_device *net)
595 {
596 	struct usbnet		*dev = netdev_priv(net);
597 	int			retval;
598 	struct driver_info	*info = dev->driver_info;
599 
600 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
601 		if (netif_msg_ifup (dev))
602 			devinfo (dev,
603 				"resumption fail (%d) usbnet usb-%s-%s, %s",
604 				retval,
605 				dev->udev->bus->bus_name, dev->udev->devpath,
606 			info->description);
607 		goto done_nopm;
608 	}
609 
610 	// put into "known safe" state
611 	if (info->reset && (retval = info->reset (dev)) < 0) {
612 		if (netif_msg_ifup (dev))
613 			devinfo (dev,
614 				"open reset fail (%d) usbnet usb-%s-%s, %s",
615 				retval,
616 				dev->udev->bus->bus_name, dev->udev->devpath,
617 			info->description);
618 		goto done;
619 	}
620 
621 	// insist peer be connected
622 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
623 		if (netif_msg_ifup (dev))
624 			devdbg (dev, "can't open; %d", retval);
625 		goto done;
626 	}
627 
628 	/* start any status interrupt transfer */
629 	if (dev->interrupt) {
630 		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
631 		if (retval < 0) {
632 			if (netif_msg_ifup (dev))
633 				deverr (dev, "intr submit %d", retval);
634 			goto done;
635 		}
636 	}
637 
638 	netif_start_queue (net);
639 	if (netif_msg_ifup (dev)) {
640 		char	*framing;
641 
642 		if (dev->driver_info->flags & FLAG_FRAMING_NC)
643 			framing = "NetChip";
644 		else if (dev->driver_info->flags & FLAG_FRAMING_GL)
645 			framing = "GeneSys";
646 		else if (dev->driver_info->flags & FLAG_FRAMING_Z)
647 			framing = "Zaurus";
648 		else if (dev->driver_info->flags & FLAG_FRAMING_RN)
649 			framing = "RNDIS";
650 		else if (dev->driver_info->flags & FLAG_FRAMING_AX)
651 			framing = "ASIX";
652 		else
653 			framing = "simple";
654 
655 		devinfo (dev, "open: enable queueing "
656 				"(rx %d, tx %d) mtu %d %s framing",
657 			(int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
658 			framing);
659 	}
660 
661 	// delay posting reads until we're fully open
662 	tasklet_schedule (&dev->bh);
663 	return retval;
664 done:
665 	usb_autopm_put_interface(dev->intf);
666 done_nopm:
667 	return retval;
668 }
669 
670 /*-------------------------------------------------------------------------*/
671 
672 /* ethtool methods; minidrivers may need to add some more, but
673  * they'll probably want to use this base set.
674  */
675 
676 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
677 {
678 	struct usbnet *dev = netdev_priv(net);
679 
680 	if (!dev->mii.mdio_read)
681 		return -EOPNOTSUPP;
682 
683 	return mii_ethtool_gset(&dev->mii, cmd);
684 }
685 EXPORT_SYMBOL_GPL(usbnet_get_settings);
686 
687 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
688 {
689 	struct usbnet *dev = netdev_priv(net);
690 	int retval;
691 
692 	if (!dev->mii.mdio_write)
693 		return -EOPNOTSUPP;
694 
695 	retval = mii_ethtool_sset(&dev->mii, cmd);
696 
697 	/* link speed/duplex might have changed */
698 	if (dev->driver_info->link_reset)
699 		dev->driver_info->link_reset(dev);
700 
701 	return retval;
702 
703 }
704 EXPORT_SYMBOL_GPL(usbnet_set_settings);
705 
706 u32 usbnet_get_link (struct net_device *net)
707 {
708 	struct usbnet *dev = netdev_priv(net);
709 
710 	/* If a check_connect is defined, return its result */
711 	if (dev->driver_info->check_connect)
712 		return dev->driver_info->check_connect (dev) == 0;
713 
714 	/* if the device has mii operations, use those */
715 	if (dev->mii.mdio_read)
716 		return mii_link_ok(&dev->mii);
717 
718 	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
719 	return ethtool_op_get_link(net);
720 }
721 EXPORT_SYMBOL_GPL(usbnet_get_link);
722 
723 int usbnet_nway_reset(struct net_device *net)
724 {
725 	struct usbnet *dev = netdev_priv(net);
726 
727 	if (!dev->mii.mdio_write)
728 		return -EOPNOTSUPP;
729 
730 	return mii_nway_restart(&dev->mii);
731 }
732 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
733 
734 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
735 {
736 	struct usbnet *dev = netdev_priv(net);
737 
738 	strncpy (info->driver, dev->driver_name, sizeof info->driver);
739 	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
740 	strncpy (info->fw_version, dev->driver_info->description,
741 		sizeof info->fw_version);
742 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
743 }
744 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
745 
746 u32 usbnet_get_msglevel (struct net_device *net)
747 {
748 	struct usbnet *dev = netdev_priv(net);
749 
750 	return dev->msg_enable;
751 }
752 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
753 
754 void usbnet_set_msglevel (struct net_device *net, u32 level)
755 {
756 	struct usbnet *dev = netdev_priv(net);
757 
758 	dev->msg_enable = level;
759 }
760 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
761 
762 /* drivers may override default ethtool_ops in their bind() routine */
763 static struct ethtool_ops usbnet_ethtool_ops = {
764 	.get_settings		= usbnet_get_settings,
765 	.set_settings		= usbnet_set_settings,
766 	.get_link		= usbnet_get_link,
767 	.nway_reset		= usbnet_nway_reset,
768 	.get_drvinfo		= usbnet_get_drvinfo,
769 	.get_msglevel		= usbnet_get_msglevel,
770 	.set_msglevel		= usbnet_set_msglevel,
771 };
772 
773 /*-------------------------------------------------------------------------*/
774 
775 /* work that cannot be done in interrupt context uses keventd.
776  *
777  * NOTE:  with 2.5 we could do more of this using completion callbacks,
778  * especially now that control transfers can be queued.
779  */
780 static void
781 kevent (struct work_struct *work)
782 {
783 	struct usbnet		*dev =
784 		container_of(work, struct usbnet, kevent);
785 	int			status;
786 
787 	/* usb_clear_halt() needs a thread context */
788 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
789 		unlink_urbs (dev, &dev->txq);
790 		status = usb_clear_halt (dev->udev, dev->out);
791 		if (status < 0
792 				&& status != -EPIPE
793 				&& status != -ESHUTDOWN) {
794 			if (netif_msg_tx_err (dev))
795 				deverr (dev, "can't clear tx halt, status %d",
796 					status);
797 		} else {
798 			clear_bit (EVENT_TX_HALT, &dev->flags);
799 			if (status != -ESHUTDOWN)
800 				netif_wake_queue (dev->net);
801 		}
802 	}
803 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
804 		unlink_urbs (dev, &dev->rxq);
805 		status = usb_clear_halt (dev->udev, dev->in);
806 		if (status < 0
807 				&& status != -EPIPE
808 				&& status != -ESHUTDOWN) {
809 			if (netif_msg_rx_err (dev))
810 				deverr (dev, "can't clear rx halt, status %d",
811 					status);
812 		} else {
813 			clear_bit (EVENT_RX_HALT, &dev->flags);
814 			tasklet_schedule (&dev->bh);
815 		}
816 	}
817 
818 	/* tasklet could resubmit itself forever if memory is tight */
819 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
820 		struct urb	*urb = NULL;
821 
822 		if (netif_running (dev->net))
823 			urb = usb_alloc_urb (0, GFP_KERNEL);
824 		else
825 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
826 		if (urb != NULL) {
827 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
828 			rx_submit (dev, urb, GFP_KERNEL);
829 			tasklet_schedule (&dev->bh);
830 		}
831 	}
832 
833 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
834 		struct driver_info	*info = dev->driver_info;
835 		int			retval = 0;
836 
837 		clear_bit (EVENT_LINK_RESET, &dev->flags);
838 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
839 			devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
840 				retval,
841 				dev->udev->bus->bus_name, dev->udev->devpath,
842 				info->description);
843 		}
844 	}
845 
846 	if (dev->flags)
847 		devdbg (dev, "kevent done, flags = 0x%lx",
848 			dev->flags);
849 }
850 
851 /*-------------------------------------------------------------------------*/
852 
853 static void tx_complete (struct urb *urb)
854 {
855 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
856 	struct skb_data		*entry = (struct skb_data *) skb->cb;
857 	struct usbnet		*dev = entry->dev;
858 
859 	if (urb->status == 0) {
860 		dev->stats.tx_packets++;
861 		dev->stats.tx_bytes += entry->length;
862 	} else {
863 		dev->stats.tx_errors++;
864 
865 		switch (urb->status) {
866 		case -EPIPE:
867 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
868 			break;
869 
870 		/* software-driven interface shutdown */
871 		case -ECONNRESET:		// async unlink
872 		case -ESHUTDOWN:		// hardware gone
873 			break;
874 
875 		// like rx, tx gets controller i/o faults during khubd delays
876 		// and so it uses the same throttling mechanism.
877 		case -EPROTO:
878 		case -ETIME:
879 		case -EILSEQ:
880 			if (!timer_pending (&dev->delay)) {
881 				mod_timer (&dev->delay,
882 					jiffies + THROTTLE_JIFFIES);
883 				if (netif_msg_link (dev))
884 					devdbg (dev, "tx throttle %d",
885 							urb->status);
886 			}
887 			netif_stop_queue (dev->net);
888 			break;
889 		default:
890 			if (netif_msg_tx_err (dev))
891 				devdbg (dev, "tx err %d", entry->urb->status);
892 			break;
893 		}
894 	}
895 
896 	urb->dev = NULL;
897 	entry->state = tx_done;
898 	defer_bh(dev, skb, &dev->txq);
899 }
900 
901 /*-------------------------------------------------------------------------*/
902 
903 static void usbnet_tx_timeout (struct net_device *net)
904 {
905 	struct usbnet		*dev = netdev_priv(net);
906 
907 	unlink_urbs (dev, &dev->txq);
908 	tasklet_schedule (&dev->bh);
909 
910 	// FIXME: device recovery -- reset?
911 }
912 
913 /*-------------------------------------------------------------------------*/
914 
915 static int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
916 {
917 	struct usbnet		*dev = netdev_priv(net);
918 	int			length;
919 	int			retval = NET_XMIT_SUCCESS;
920 	struct urb		*urb = NULL;
921 	struct skb_data		*entry;
922 	struct driver_info	*info = dev->driver_info;
923 	unsigned long		flags;
924 
925 	// some devices want funky USB-level framing, for
926 	// win32 driver (usually) and/or hardware quirks
927 	if (info->tx_fixup) {
928 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
929 		if (!skb) {
930 			if (netif_msg_tx_err (dev))
931 				devdbg (dev, "can't tx_fixup skb");
932 			goto drop;
933 		}
934 	}
935 	length = skb->len;
936 
937 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
938 		if (netif_msg_tx_err (dev))
939 			devdbg (dev, "no urb");
940 		goto drop;
941 	}
942 
943 	entry = (struct skb_data *) skb->cb;
944 	entry->urb = urb;
945 	entry->dev = dev;
946 	entry->state = tx_start;
947 	entry->length = length;
948 
949 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
950 			skb->data, skb->len, tx_complete, skb);
951 
952 	/* don't assume the hardware handles USB_ZERO_PACKET
953 	 * NOTE:  strictly conforming cdc-ether devices should expect
954 	 * the ZLP here, but ignore the one-byte packet.
955 	 */
956 	if ((length % dev->maxpacket) == 0) {
957 		urb->transfer_buffer_length++;
958 		if (skb_tailroom(skb)) {
959 			skb->data[skb->len] = 0;
960 			__skb_put(skb, 1);
961 		}
962 	}
963 
964 	spin_lock_irqsave (&dev->txq.lock, flags);
965 
966 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
967 	case -EPIPE:
968 		netif_stop_queue (net);
969 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
970 		break;
971 	default:
972 		if (netif_msg_tx_err (dev))
973 			devdbg (dev, "tx: submit urb err %d", retval);
974 		break;
975 	case 0:
976 		net->trans_start = jiffies;
977 		__skb_queue_tail (&dev->txq, skb);
978 		if (dev->txq.qlen >= TX_QLEN (dev))
979 			netif_stop_queue (net);
980 	}
981 	spin_unlock_irqrestore (&dev->txq.lock, flags);
982 
983 	if (retval) {
984 		if (netif_msg_tx_err (dev))
985 			devdbg (dev, "drop, code %d", retval);
986 drop:
987 		retval = NET_XMIT_SUCCESS;
988 		dev->stats.tx_dropped++;
989 		if (skb)
990 			dev_kfree_skb_any (skb);
991 		usb_free_urb (urb);
992 	} else if (netif_msg_tx_queued (dev)) {
993 		devdbg (dev, "> tx, len %d, type 0x%x",
994 			length, skb->protocol);
995 	}
996 	return retval;
997 }
998 
999 
1000 /*-------------------------------------------------------------------------*/
1001 
1002 // tasklet (work deferred from completions, in_irq) or timer
1003 
1004 static void usbnet_bh (unsigned long param)
1005 {
1006 	struct usbnet		*dev = (struct usbnet *) param;
1007 	struct sk_buff		*skb;
1008 	struct skb_data		*entry;
1009 
1010 	while ((skb = skb_dequeue (&dev->done))) {
1011 		entry = (struct skb_data *) skb->cb;
1012 		switch (entry->state) {
1013 		case rx_done:
1014 			entry->state = rx_cleanup;
1015 			rx_process (dev, skb);
1016 			continue;
1017 		case tx_done:
1018 		case rx_cleanup:
1019 			usb_free_urb (entry->urb);
1020 			dev_kfree_skb (skb);
1021 			continue;
1022 		default:
1023 			devdbg (dev, "bogus skb state %d", entry->state);
1024 		}
1025 	}
1026 
1027 	// waiting for all pending urbs to complete?
1028 	if (dev->wait) {
1029 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1030 			wake_up (dev->wait);
1031 		}
1032 
1033 	// or are we maybe short a few urbs?
1034 	} else if (netif_running (dev->net)
1035 			&& netif_device_present (dev->net)
1036 			&& !timer_pending (&dev->delay)
1037 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
1038 		int	temp = dev->rxq.qlen;
1039 		int	qlen = RX_QLEN (dev);
1040 
1041 		if (temp < qlen) {
1042 			struct urb	*urb;
1043 			int		i;
1044 
1045 			// don't refill the queue all at once
1046 			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1047 				urb = usb_alloc_urb (0, GFP_ATOMIC);
1048 				if (urb != NULL)
1049 					rx_submit (dev, urb, GFP_ATOMIC);
1050 			}
1051 			if (temp != dev->rxq.qlen && netif_msg_link (dev))
1052 				devdbg (dev, "rxqlen %d --> %d",
1053 						temp, dev->rxq.qlen);
1054 			if (dev->rxq.qlen < qlen)
1055 				tasklet_schedule (&dev->bh);
1056 		}
1057 		if (dev->txq.qlen < TX_QLEN (dev))
1058 			netif_wake_queue (dev->net);
1059 	}
1060 }
1061 
1062 
1063 
1064 /*-------------------------------------------------------------------------
1065  *
1066  * USB Device Driver support
1067  *
1068  *-------------------------------------------------------------------------*/
1069 
1070 // precondition: never called in_interrupt
1071 
1072 void usbnet_disconnect (struct usb_interface *intf)
1073 {
1074 	struct usbnet		*dev;
1075 	struct usb_device	*xdev;
1076 	struct net_device	*net;
1077 
1078 	dev = usb_get_intfdata(intf);
1079 	usb_set_intfdata(intf, NULL);
1080 	if (!dev)
1081 		return;
1082 
1083 	xdev = interface_to_usbdev (intf);
1084 
1085 	if (netif_msg_probe (dev))
1086 		devinfo (dev, "unregister '%s' usb-%s-%s, %s",
1087 			intf->dev.driver->name,
1088 			xdev->bus->bus_name, xdev->devpath,
1089 			dev->driver_info->description);
1090 
1091 	net = dev->net;
1092 	unregister_netdev (net);
1093 
1094 	/* we don't hold rtnl here ... */
1095 	flush_scheduled_work ();
1096 
1097 	if (dev->driver_info->unbind)
1098 		dev->driver_info->unbind (dev, intf);
1099 
1100 	free_netdev(net);
1101 	usb_put_dev (xdev);
1102 }
1103 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1104 
1105 
1106 /*-------------------------------------------------------------------------*/
1107 
1108 // precondition: never called in_interrupt
1109 
1110 int
1111 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1112 {
1113 	struct usbnet			*dev;
1114 	struct net_device		*net;
1115 	struct usb_host_interface	*interface;
1116 	struct driver_info		*info;
1117 	struct usb_device		*xdev;
1118 	int				status;
1119 	const char			*name;
1120 
1121 	name = udev->dev.driver->name;
1122 	info = (struct driver_info *) prod->driver_info;
1123 	if (!info) {
1124 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1125 		return -ENODEV;
1126 	}
1127 	xdev = interface_to_usbdev (udev);
1128 	interface = udev->cur_altsetting;
1129 
1130 	usb_get_dev (xdev);
1131 
1132 	status = -ENOMEM;
1133 
1134 	// set up our own records
1135 	net = alloc_etherdev(sizeof(*dev));
1136 	if (!net) {
1137 		dbg ("can't kmalloc dev");
1138 		goto out;
1139 	}
1140 
1141 	dev = netdev_priv(net);
1142 	dev->udev = xdev;
1143 	dev->intf = udev;
1144 	dev->driver_info = info;
1145 	dev->driver_name = name;
1146 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1147 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1148 	skb_queue_head_init (&dev->rxq);
1149 	skb_queue_head_init (&dev->txq);
1150 	skb_queue_head_init (&dev->done);
1151 	dev->bh.func = usbnet_bh;
1152 	dev->bh.data = (unsigned long) dev;
1153 	INIT_WORK (&dev->kevent, kevent);
1154 	dev->delay.function = usbnet_bh;
1155 	dev->delay.data = (unsigned long) dev;
1156 	init_timer (&dev->delay);
1157 	mutex_init (&dev->phy_mutex);
1158 
1159 	dev->net = net;
1160 	strcpy (net->name, "usb%d");
1161 	memcpy (net->dev_addr, node_id, sizeof node_id);
1162 
1163 	/* rx and tx sides can use different message sizes;
1164 	 * bind() should set rx_urb_size in that case.
1165 	 */
1166 	dev->hard_mtu = net->mtu + net->hard_header_len;
1167 #if 0
1168 // dma_supported() is deeply broken on almost all architectures
1169 	// possible with some EHCI controllers
1170 	if (dma_supported (&udev->dev, DMA_64BIT_MASK))
1171 		net->features |= NETIF_F_HIGHDMA;
1172 #endif
1173 
1174 	net->change_mtu = usbnet_change_mtu;
1175 	net->hard_start_xmit = usbnet_start_xmit;
1176 	net->open = usbnet_open;
1177 	net->stop = usbnet_stop;
1178 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1179 	net->tx_timeout = usbnet_tx_timeout;
1180 	net->ethtool_ops = &usbnet_ethtool_ops;
1181 
1182 	// allow device-specific bind/init procedures
1183 	// NOTE net->name still not usable ...
1184 	if (info->bind) {
1185 		status = info->bind (dev, udev);
1186 		if (status < 0)
1187 			goto out1;
1188 
1189 		// heuristic:  "usb%d" for links we know are two-host,
1190 		// else "eth%d" when there's reasonable doubt.  userspace
1191 		// can rename the link if it knows better.
1192 		if ((dev->driver_info->flags & FLAG_ETHER) != 0
1193 				&& (net->dev_addr [0] & 0x02) == 0)
1194 			strcpy (net->name, "eth%d");
1195 		/* WLAN devices should always be named "wlan%d" */
1196 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1197 			strcpy(net->name, "wlan%d");
1198 
1199 		/* maybe the remote can't receive an Ethernet MTU */
1200 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1201 			net->mtu = dev->hard_mtu - net->hard_header_len;
1202 	} else if (!info->in || !info->out)
1203 		status = usbnet_get_endpoints (dev, udev);
1204 	else {
1205 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1206 		dev->out = usb_sndbulkpipe (xdev, info->out);
1207 		if (!(info->flags & FLAG_NO_SETINT))
1208 			status = usb_set_interface (xdev,
1209 				interface->desc.bInterfaceNumber,
1210 				interface->desc.bAlternateSetting);
1211 		else
1212 			status = 0;
1213 
1214 	}
1215 	if (status >= 0 && dev->status)
1216 		status = init_status (dev, udev);
1217 	if (status < 0)
1218 		goto out3;
1219 
1220 	if (!dev->rx_urb_size)
1221 		dev->rx_urb_size = dev->hard_mtu;
1222 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1223 
1224 	SET_NETDEV_DEV(net, &udev->dev);
1225 	status = register_netdev (net);
1226 	if (status)
1227 		goto out3;
1228 	if (netif_msg_probe (dev))
1229 		devinfo (dev, "register '%s' at usb-%s-%s, %s, %pM",
1230 			udev->dev.driver->name,
1231 			xdev->bus->bus_name, xdev->devpath,
1232 			dev->driver_info->description,
1233 			net->dev_addr);
1234 
1235 	// ok, it's ready to go.
1236 	usb_set_intfdata (udev, dev);
1237 
1238 	// start as if the link is up
1239 	netif_device_attach (net);
1240 
1241 	return 0;
1242 
1243 out3:
1244 	if (info->unbind)
1245 		info->unbind (dev, udev);
1246 out1:
1247 	free_netdev(net);
1248 out:
1249 	usb_put_dev(xdev);
1250 	return status;
1251 }
1252 EXPORT_SYMBOL_GPL(usbnet_probe);
1253 
1254 /*-------------------------------------------------------------------------*/
1255 
1256 /*
1257  * suspend the whole driver as soon as the first interface is suspended
1258  * resume only when the last interface is resumed
1259  */
1260 
1261 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1262 {
1263 	struct usbnet		*dev = usb_get_intfdata(intf);
1264 
1265 	if (!dev->suspend_count++) {
1266 		/*
1267 		 * accelerate emptying of the rx and queues, to avoid
1268 		 * having everything error out.
1269 		 */
1270 		netif_device_detach (dev->net);
1271 		(void) unlink_urbs (dev, &dev->rxq);
1272 		(void) unlink_urbs (dev, &dev->txq);
1273 		/*
1274 		 * reattach so runtime management can use and
1275 		 * wake the device
1276 		 */
1277 		netif_device_attach (dev->net);
1278 	}
1279 	return 0;
1280 }
1281 EXPORT_SYMBOL_GPL(usbnet_suspend);
1282 
1283 int usbnet_resume (struct usb_interface *intf)
1284 {
1285 	struct usbnet		*dev = usb_get_intfdata(intf);
1286 
1287 	if (!--dev->suspend_count)
1288 		tasklet_schedule (&dev->bh);
1289 
1290 	return 0;
1291 }
1292 EXPORT_SYMBOL_GPL(usbnet_resume);
1293 
1294 
1295 /*-------------------------------------------------------------------------*/
1296 
1297 static int __init usbnet_init(void)
1298 {
1299 	/* compiler should optimize this out */
1300 	BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1301 			< sizeof (struct skb_data));
1302 
1303 	random_ether_addr(node_id);
1304 	return 0;
1305 }
1306 module_init(usbnet_init);
1307 
1308 static void __exit usbnet_exit(void)
1309 {
1310 }
1311 module_exit(usbnet_exit);
1312 
1313 MODULE_AUTHOR("David Brownell");
1314 MODULE_DESCRIPTION("USB network driver framework");
1315 MODULE_LICENSE("GPL");
1316