xref: /openbmc/linux/drivers/net/usb/usbnet.c (revision a1e58bbd)
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 static struct net_device_stats *usbnet_get_stats (struct net_device *net)
253 {
254 	struct usbnet	*dev = netdev_priv(net);
255 	return &dev->stats;
256 }
257 
258 /*-------------------------------------------------------------------------*/
259 
260 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
261  * completion callbacks.  2.5 should have fixed those bugs...
262  */
263 
264 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
265 {
266 	unsigned long		flags;
267 
268 	spin_lock_irqsave(&list->lock, flags);
269 	__skb_unlink(skb, list);
270 	spin_unlock(&list->lock);
271 	spin_lock(&dev->done.lock);
272 	__skb_queue_tail(&dev->done, skb);
273 	if (dev->done.qlen == 1)
274 		tasklet_schedule(&dev->bh);
275 	spin_unlock_irqrestore(&dev->done.lock, flags);
276 }
277 
278 /* some work can't be done in tasklets, so we use keventd
279  *
280  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
281  * but tasklet_schedule() doesn't.  hope the failure is rare.
282  */
283 void usbnet_defer_kevent (struct usbnet *dev, int work)
284 {
285 	set_bit (work, &dev->flags);
286 	if (!schedule_work (&dev->kevent))
287 		deverr (dev, "kevent %d may have been dropped", work);
288 	else
289 		devdbg (dev, "kevent %d scheduled", work);
290 }
291 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
292 
293 /*-------------------------------------------------------------------------*/
294 
295 static void rx_complete (struct urb *urb);
296 
297 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
298 {
299 	struct sk_buff		*skb;
300 	struct skb_data		*entry;
301 	int			retval = 0;
302 	unsigned long		lockflags;
303 	size_t			size = dev->rx_urb_size;
304 
305 	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
306 		if (netif_msg_rx_err (dev))
307 			devdbg (dev, "no rx skb");
308 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
309 		usb_free_urb (urb);
310 		return;
311 	}
312 	skb_reserve (skb, NET_IP_ALIGN);
313 
314 	entry = (struct skb_data *) skb->cb;
315 	entry->urb = urb;
316 	entry->dev = dev;
317 	entry->state = rx_start;
318 	entry->length = 0;
319 
320 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
321 		skb->data, size, rx_complete, skb);
322 
323 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
324 
325 	if (netif_running (dev->net)
326 			&& netif_device_present (dev->net)
327 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
328 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
329 		case -EPIPE:
330 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
331 			break;
332 		case -ENOMEM:
333 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
334 			break;
335 		case -ENODEV:
336 			if (netif_msg_ifdown (dev))
337 				devdbg (dev, "device gone");
338 			netif_device_detach (dev->net);
339 			break;
340 		default:
341 			if (netif_msg_rx_err (dev))
342 				devdbg (dev, "rx submit, %d", retval);
343 			tasklet_schedule (&dev->bh);
344 			break;
345 		case 0:
346 			__skb_queue_tail (&dev->rxq, skb);
347 		}
348 	} else {
349 		if (netif_msg_ifdown (dev))
350 			devdbg (dev, "rx: stopped");
351 		retval = -ENOLINK;
352 	}
353 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
354 	if (retval) {
355 		dev_kfree_skb_any (skb);
356 		usb_free_urb (urb);
357 	}
358 }
359 
360 
361 /*-------------------------------------------------------------------------*/
362 
363 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
364 {
365 	if (dev->driver_info->rx_fixup
366 			&& !dev->driver_info->rx_fixup (dev, skb))
367 		goto error;
368 	// else network stack removes extra byte if we forced a short packet
369 
370 	if (skb->len)
371 		usbnet_skb_return (dev, skb);
372 	else {
373 		if (netif_msg_rx_err (dev))
374 			devdbg (dev, "drop");
375 error:
376 		dev->stats.rx_errors++;
377 		skb_queue_tail (&dev->done, skb);
378 	}
379 }
380 
381 /*-------------------------------------------------------------------------*/
382 
383 static void rx_complete (struct urb *urb)
384 {
385 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
386 	struct skb_data		*entry = (struct skb_data *) skb->cb;
387 	struct usbnet		*dev = entry->dev;
388 	int			urb_status = urb->status;
389 
390 	skb_put (skb, urb->actual_length);
391 	entry->state = rx_done;
392 	entry->urb = NULL;
393 
394 	switch (urb_status) {
395 	/* success */
396 	case 0:
397 		if (skb->len < dev->net->hard_header_len) {
398 			entry->state = rx_cleanup;
399 			dev->stats.rx_errors++;
400 			dev->stats.rx_length_errors++;
401 			if (netif_msg_rx_err (dev))
402 				devdbg (dev, "rx length %d", skb->len);
403 		}
404 		break;
405 
406 	/* stalls need manual reset. this is rare ... except that
407 	 * when going through USB 2.0 TTs, unplug appears this way.
408 	 * we avoid the highspeed version of the ETIMEOUT/EILSEQ
409 	 * storm, recovering as needed.
410 	 */
411 	case -EPIPE:
412 		dev->stats.rx_errors++;
413 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
414 		// FALLTHROUGH
415 
416 	/* software-driven interface shutdown */
417 	case -ECONNRESET:		/* async unlink */
418 	case -ESHUTDOWN:		/* hardware gone */
419 		if (netif_msg_ifdown (dev))
420 			devdbg (dev, "rx shutdown, code %d", urb_status);
421 		goto block;
422 
423 	/* we get controller i/o faults during khubd disconnect() delays.
424 	 * throttle down resubmits, to avoid log floods; just temporarily,
425 	 * so we still recover when the fault isn't a khubd delay.
426 	 */
427 	case -EPROTO:
428 	case -ETIME:
429 	case -EILSEQ:
430 		dev->stats.rx_errors++;
431 		if (!timer_pending (&dev->delay)) {
432 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
433 			if (netif_msg_link (dev))
434 				devdbg (dev, "rx throttle %d", urb_status);
435 		}
436 block:
437 		entry->state = rx_cleanup;
438 		entry->urb = urb;
439 		urb = NULL;
440 		break;
441 
442 	/* data overrun ... flush fifo? */
443 	case -EOVERFLOW:
444 		dev->stats.rx_over_errors++;
445 		// FALLTHROUGH
446 
447 	default:
448 		entry->state = rx_cleanup;
449 		dev->stats.rx_errors++;
450 		if (netif_msg_rx_err (dev))
451 			devdbg (dev, "rx status %d", urb_status);
452 		break;
453 	}
454 
455 	defer_bh(dev, skb, &dev->rxq);
456 
457 	if (urb) {
458 		if (netif_running (dev->net)
459 				&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
460 			rx_submit (dev, urb, GFP_ATOMIC);
461 			return;
462 		}
463 		usb_free_urb (urb);
464 	}
465 	if (netif_msg_rx_err (dev))
466 		devdbg (dev, "no read resubmitted");
467 }
468 
469 static void intr_complete (struct urb *urb)
470 {
471 	struct usbnet	*dev = urb->context;
472 	int		status = urb->status;
473 
474 	switch (status) {
475 	/* success */
476 	case 0:
477 		dev->driver_info->status(dev, urb);
478 		break;
479 
480 	/* software-driven interface shutdown */
481 	case -ENOENT:		/* urb killed */
482 	case -ESHUTDOWN:	/* hardware gone */
483 		if (netif_msg_ifdown (dev))
484 			devdbg (dev, "intr shutdown, code %d", status);
485 		return;
486 
487 	/* NOTE:  not throttling like RX/TX, since this endpoint
488 	 * already polls infrequently
489 	 */
490 	default:
491 		devdbg (dev, "intr status %d", status);
492 		break;
493 	}
494 
495 	if (!netif_running (dev->net))
496 		return;
497 
498 	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
499 	status = usb_submit_urb (urb, GFP_ATOMIC);
500 	if (status != 0 && netif_msg_timer (dev))
501 		deverr(dev, "intr resubmit --> %d", status);
502 }
503 
504 /*-------------------------------------------------------------------------*/
505 
506 // unlink pending rx/tx; completion handlers do all other cleanup
507 
508 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
509 {
510 	unsigned long		flags;
511 	struct sk_buff		*skb, *skbnext;
512 	int			count = 0;
513 
514 	spin_lock_irqsave (&q->lock, flags);
515 	for (skb = q->next; skb != (struct sk_buff *) q; skb = skbnext) {
516 		struct skb_data		*entry;
517 		struct urb		*urb;
518 		int			retval;
519 
520 		entry = (struct skb_data *) skb->cb;
521 		urb = entry->urb;
522 		skbnext = skb->next;
523 
524 		// during some PM-driven resume scenarios,
525 		// these (async) unlinks complete immediately
526 		retval = usb_unlink_urb (urb);
527 		if (retval != -EINPROGRESS && retval != 0)
528 			devdbg (dev, "unlink urb err, %d", retval);
529 		else
530 			count++;
531 	}
532 	spin_unlock_irqrestore (&q->lock, flags);
533 	return count;
534 }
535 
536 // Flush all pending rx urbs
537 // minidrivers may need to do this when the MTU changes
538 
539 void usbnet_unlink_rx_urbs(struct usbnet *dev)
540 {
541 	if (netif_running(dev->net)) {
542 		(void) unlink_urbs (dev, &dev->rxq);
543 		tasklet_schedule(&dev->bh);
544 	}
545 }
546 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
547 
548 /*-------------------------------------------------------------------------*/
549 
550 // precondition: never called in_interrupt
551 
552 static int usbnet_stop (struct net_device *net)
553 {
554 	struct usbnet		*dev = netdev_priv(net);
555 	int			temp;
556 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
557 	DECLARE_WAITQUEUE (wait, current);
558 
559 	netif_stop_queue (net);
560 
561 	if (netif_msg_ifdown (dev))
562 		devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
563 			dev->stats.rx_packets, dev->stats.tx_packets,
564 			dev->stats.rx_errors, dev->stats.tx_errors
565 			);
566 
567 	// ensure there are no more active urbs
568 	add_wait_queue (&unlink_wakeup, &wait);
569 	dev->wait = &unlink_wakeup;
570 	temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
571 
572 	// maybe wait for deletions to finish.
573 	while (!skb_queue_empty(&dev->rxq)
574 			&& !skb_queue_empty(&dev->txq)
575 			&& !skb_queue_empty(&dev->done)) {
576 		msleep(UNLINK_TIMEOUT_MS);
577 		if (netif_msg_ifdown (dev))
578 			devdbg (dev, "waited for %d urb completions", temp);
579 	}
580 	dev->wait = NULL;
581 	remove_wait_queue (&unlink_wakeup, &wait);
582 
583 	usb_kill_urb(dev->interrupt);
584 
585 	/* deferred work (task, timer, softirq) must also stop.
586 	 * can't flush_scheduled_work() until we drop rtnl (later),
587 	 * else workers could deadlock; so make workers a NOP.
588 	 */
589 	dev->flags = 0;
590 	del_timer_sync (&dev->delay);
591 	tasklet_kill (&dev->bh);
592 	usb_autopm_put_interface(dev->intf);
593 
594 	return 0;
595 }
596 
597 /*-------------------------------------------------------------------------*/
598 
599 // posts reads, and enables write queuing
600 
601 // precondition: never called in_interrupt
602 
603 static int usbnet_open (struct net_device *net)
604 {
605 	struct usbnet		*dev = netdev_priv(net);
606 	int			retval;
607 	struct driver_info	*info = dev->driver_info;
608 
609 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
610 		if (netif_msg_ifup (dev))
611 			devinfo (dev,
612 				"resumption fail (%d) usbnet usb-%s-%s, %s",
613 				retval,
614 				dev->udev->bus->bus_name, dev->udev->devpath,
615 			info->description);
616 		goto done_nopm;
617 	}
618 
619 	// put into "known safe" state
620 	if (info->reset && (retval = info->reset (dev)) < 0) {
621 		if (netif_msg_ifup (dev))
622 			devinfo (dev,
623 				"open reset fail (%d) usbnet usb-%s-%s, %s",
624 				retval,
625 				dev->udev->bus->bus_name, dev->udev->devpath,
626 			info->description);
627 		goto done;
628 	}
629 
630 	// insist peer be connected
631 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
632 		if (netif_msg_ifup (dev))
633 			devdbg (dev, "can't open; %d", retval);
634 		goto done;
635 	}
636 
637 	/* start any status interrupt transfer */
638 	if (dev->interrupt) {
639 		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
640 		if (retval < 0) {
641 			if (netif_msg_ifup (dev))
642 				deverr (dev, "intr submit %d", retval);
643 			goto done;
644 		}
645 	}
646 
647 	netif_start_queue (net);
648 	if (netif_msg_ifup (dev)) {
649 		char	*framing;
650 
651 		if (dev->driver_info->flags & FLAG_FRAMING_NC)
652 			framing = "NetChip";
653 		else if (dev->driver_info->flags & FLAG_FRAMING_GL)
654 			framing = "GeneSys";
655 		else if (dev->driver_info->flags & FLAG_FRAMING_Z)
656 			framing = "Zaurus";
657 		else if (dev->driver_info->flags & FLAG_FRAMING_RN)
658 			framing = "RNDIS";
659 		else if (dev->driver_info->flags & FLAG_FRAMING_AX)
660 			framing = "ASIX";
661 		else
662 			framing = "simple";
663 
664 		devinfo (dev, "open: enable queueing "
665 				"(rx %d, tx %d) mtu %d %s framing",
666 			(int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
667 			framing);
668 	}
669 
670 	// delay posting reads until we're fully open
671 	tasklet_schedule (&dev->bh);
672 	return retval;
673 done:
674 	usb_autopm_put_interface(dev->intf);
675 done_nopm:
676 	return retval;
677 }
678 
679 /*-------------------------------------------------------------------------*/
680 
681 /* ethtool methods; minidrivers may need to add some more, but
682  * they'll probably want to use this base set.
683  */
684 
685 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
686 {
687 	struct usbnet *dev = netdev_priv(net);
688 
689 	if (!dev->mii.mdio_read)
690 		return -EOPNOTSUPP;
691 
692 	return mii_ethtool_gset(&dev->mii, cmd);
693 }
694 EXPORT_SYMBOL_GPL(usbnet_get_settings);
695 
696 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
697 {
698 	struct usbnet *dev = netdev_priv(net);
699 	int retval;
700 
701 	if (!dev->mii.mdio_write)
702 		return -EOPNOTSUPP;
703 
704 	retval = mii_ethtool_sset(&dev->mii, cmd);
705 
706 	/* link speed/duplex might have changed */
707 	if (dev->driver_info->link_reset)
708 		dev->driver_info->link_reset(dev);
709 
710 	return retval;
711 
712 }
713 EXPORT_SYMBOL_GPL(usbnet_set_settings);
714 
715 u32 usbnet_get_link (struct net_device *net)
716 {
717 	struct usbnet *dev = netdev_priv(net);
718 
719 	/* If a check_connect is defined, return its result */
720 	if (dev->driver_info->check_connect)
721 		return dev->driver_info->check_connect (dev) == 0;
722 
723 	/* if the device has mii operations, use those */
724 	if (dev->mii.mdio_read)
725 		return mii_link_ok(&dev->mii);
726 
727 	/* Otherwise, say we're up (to avoid breaking scripts) */
728 	return 1;
729 }
730 EXPORT_SYMBOL_GPL(usbnet_get_link);
731 
732 int usbnet_nway_reset(struct net_device *net)
733 {
734 	struct usbnet *dev = netdev_priv(net);
735 
736 	if (!dev->mii.mdio_write)
737 		return -EOPNOTSUPP;
738 
739 	return mii_nway_restart(&dev->mii);
740 }
741 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
742 
743 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
744 {
745 	struct usbnet *dev = netdev_priv(net);
746 
747 	strncpy (info->driver, dev->driver_name, sizeof info->driver);
748 	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
749 	strncpy (info->fw_version, dev->driver_info->description,
750 		sizeof info->fw_version);
751 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
752 }
753 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
754 
755 u32 usbnet_get_msglevel (struct net_device *net)
756 {
757 	struct usbnet *dev = netdev_priv(net);
758 
759 	return dev->msg_enable;
760 }
761 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
762 
763 void usbnet_set_msglevel (struct net_device *net, u32 level)
764 {
765 	struct usbnet *dev = netdev_priv(net);
766 
767 	dev->msg_enable = level;
768 }
769 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
770 
771 /* drivers may override default ethtool_ops in their bind() routine */
772 static struct ethtool_ops usbnet_ethtool_ops = {
773 	.get_settings		= usbnet_get_settings,
774 	.set_settings		= usbnet_set_settings,
775 	.get_link		= usbnet_get_link,
776 	.nway_reset		= usbnet_nway_reset,
777 	.get_drvinfo		= usbnet_get_drvinfo,
778 	.get_msglevel		= usbnet_get_msglevel,
779 	.set_msglevel		= usbnet_set_msglevel,
780 };
781 
782 /*-------------------------------------------------------------------------*/
783 
784 /* work that cannot be done in interrupt context uses keventd.
785  *
786  * NOTE:  with 2.5 we could do more of this using completion callbacks,
787  * especially now that control transfers can be queued.
788  */
789 static void
790 kevent (struct work_struct *work)
791 {
792 	struct usbnet		*dev =
793 		container_of(work, struct usbnet, kevent);
794 	int			status;
795 
796 	/* usb_clear_halt() needs a thread context */
797 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
798 		unlink_urbs (dev, &dev->txq);
799 		status = usb_clear_halt (dev->udev, dev->out);
800 		if (status < 0
801 				&& status != -EPIPE
802 				&& status != -ESHUTDOWN) {
803 			if (netif_msg_tx_err (dev))
804 				deverr (dev, "can't clear tx halt, status %d",
805 					status);
806 		} else {
807 			clear_bit (EVENT_TX_HALT, &dev->flags);
808 			if (status != -ESHUTDOWN)
809 				netif_wake_queue (dev->net);
810 		}
811 	}
812 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
813 		unlink_urbs (dev, &dev->rxq);
814 		status = usb_clear_halt (dev->udev, dev->in);
815 		if (status < 0
816 				&& status != -EPIPE
817 				&& status != -ESHUTDOWN) {
818 			if (netif_msg_rx_err (dev))
819 				deverr (dev, "can't clear rx halt, status %d",
820 					status);
821 		} else {
822 			clear_bit (EVENT_RX_HALT, &dev->flags);
823 			tasklet_schedule (&dev->bh);
824 		}
825 	}
826 
827 	/* tasklet could resubmit itself forever if memory is tight */
828 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
829 		struct urb	*urb = NULL;
830 
831 		if (netif_running (dev->net))
832 			urb = usb_alloc_urb (0, GFP_KERNEL);
833 		else
834 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
835 		if (urb != NULL) {
836 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
837 			rx_submit (dev, urb, GFP_KERNEL);
838 			tasklet_schedule (&dev->bh);
839 		}
840 	}
841 
842 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
843 		struct driver_info	*info = dev->driver_info;
844 		int			retval = 0;
845 
846 		clear_bit (EVENT_LINK_RESET, &dev->flags);
847 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
848 			devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
849 				retval,
850 				dev->udev->bus->bus_name, dev->udev->devpath,
851 				info->description);
852 		}
853 	}
854 
855 	if (dev->flags)
856 		devdbg (dev, "kevent done, flags = 0x%lx",
857 			dev->flags);
858 }
859 
860 /*-------------------------------------------------------------------------*/
861 
862 static void tx_complete (struct urb *urb)
863 {
864 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
865 	struct skb_data		*entry = (struct skb_data *) skb->cb;
866 	struct usbnet		*dev = entry->dev;
867 
868 	if (urb->status == 0) {
869 		dev->stats.tx_packets++;
870 		dev->stats.tx_bytes += entry->length;
871 	} else {
872 		dev->stats.tx_errors++;
873 
874 		switch (urb->status) {
875 		case -EPIPE:
876 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
877 			break;
878 
879 		/* software-driven interface shutdown */
880 		case -ECONNRESET:		// async unlink
881 		case -ESHUTDOWN:		// hardware gone
882 			break;
883 
884 		// like rx, tx gets controller i/o faults during khubd delays
885 		// and so it uses the same throttling mechanism.
886 		case -EPROTO:
887 		case -ETIME:
888 		case -EILSEQ:
889 			if (!timer_pending (&dev->delay)) {
890 				mod_timer (&dev->delay,
891 					jiffies + THROTTLE_JIFFIES);
892 				if (netif_msg_link (dev))
893 					devdbg (dev, "tx throttle %d",
894 							urb->status);
895 			}
896 			netif_stop_queue (dev->net);
897 			break;
898 		default:
899 			if (netif_msg_tx_err (dev))
900 				devdbg (dev, "tx err %d", entry->urb->status);
901 			break;
902 		}
903 	}
904 
905 	urb->dev = NULL;
906 	entry->state = tx_done;
907 	defer_bh(dev, skb, &dev->txq);
908 }
909 
910 /*-------------------------------------------------------------------------*/
911 
912 static void usbnet_tx_timeout (struct net_device *net)
913 {
914 	struct usbnet		*dev = netdev_priv(net);
915 
916 	unlink_urbs (dev, &dev->txq);
917 	tasklet_schedule (&dev->bh);
918 
919 	// FIXME: device recovery -- reset?
920 }
921 
922 /*-------------------------------------------------------------------------*/
923 
924 static int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
925 {
926 	struct usbnet		*dev = netdev_priv(net);
927 	int			length;
928 	int			retval = NET_XMIT_SUCCESS;
929 	struct urb		*urb = NULL;
930 	struct skb_data		*entry;
931 	struct driver_info	*info = dev->driver_info;
932 	unsigned long		flags;
933 
934 	// some devices want funky USB-level framing, for
935 	// win32 driver (usually) and/or hardware quirks
936 	if (info->tx_fixup) {
937 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
938 		if (!skb) {
939 			if (netif_msg_tx_err (dev))
940 				devdbg (dev, "can't tx_fixup skb");
941 			goto drop;
942 		}
943 	}
944 	length = skb->len;
945 
946 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
947 		if (netif_msg_tx_err (dev))
948 			devdbg (dev, "no urb");
949 		goto drop;
950 	}
951 
952 	entry = (struct skb_data *) skb->cb;
953 	entry->urb = urb;
954 	entry->dev = dev;
955 	entry->state = tx_start;
956 	entry->length = length;
957 
958 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
959 			skb->data, skb->len, tx_complete, skb);
960 
961 	/* don't assume the hardware handles USB_ZERO_PACKET
962 	 * NOTE:  strictly conforming cdc-ether devices should expect
963 	 * the ZLP here, but ignore the one-byte packet.
964 	 */
965 	if ((length % dev->maxpacket) == 0) {
966 		urb->transfer_buffer_length++;
967 		if (skb_tailroom(skb)) {
968 			skb->data[skb->len] = 0;
969 			__skb_put(skb, 1);
970 		}
971 	}
972 
973 	spin_lock_irqsave (&dev->txq.lock, flags);
974 
975 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
976 	case -EPIPE:
977 		netif_stop_queue (net);
978 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
979 		break;
980 	default:
981 		if (netif_msg_tx_err (dev))
982 			devdbg (dev, "tx: submit urb err %d", retval);
983 		break;
984 	case 0:
985 		net->trans_start = jiffies;
986 		__skb_queue_tail (&dev->txq, skb);
987 		if (dev->txq.qlen >= TX_QLEN (dev))
988 			netif_stop_queue (net);
989 	}
990 	spin_unlock_irqrestore (&dev->txq.lock, flags);
991 
992 	if (retval) {
993 		if (netif_msg_tx_err (dev))
994 			devdbg (dev, "drop, code %d", retval);
995 drop:
996 		retval = NET_XMIT_SUCCESS;
997 		dev->stats.tx_dropped++;
998 		if (skb)
999 			dev_kfree_skb_any (skb);
1000 		usb_free_urb (urb);
1001 	} else if (netif_msg_tx_queued (dev)) {
1002 		devdbg (dev, "> tx, len %d, type 0x%x",
1003 			length, skb->protocol);
1004 	}
1005 	return retval;
1006 }
1007 
1008 
1009 /*-------------------------------------------------------------------------*/
1010 
1011 // tasklet (work deferred from completions, in_irq) or timer
1012 
1013 static void usbnet_bh (unsigned long param)
1014 {
1015 	struct usbnet		*dev = (struct usbnet *) param;
1016 	struct sk_buff		*skb;
1017 	struct skb_data		*entry;
1018 
1019 	while ((skb = skb_dequeue (&dev->done))) {
1020 		entry = (struct skb_data *) skb->cb;
1021 		switch (entry->state) {
1022 		case rx_done:
1023 			entry->state = rx_cleanup;
1024 			rx_process (dev, skb);
1025 			continue;
1026 		case tx_done:
1027 		case rx_cleanup:
1028 			usb_free_urb (entry->urb);
1029 			dev_kfree_skb (skb);
1030 			continue;
1031 		default:
1032 			devdbg (dev, "bogus skb state %d", entry->state);
1033 		}
1034 	}
1035 
1036 	// waiting for all pending urbs to complete?
1037 	if (dev->wait) {
1038 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1039 			wake_up (dev->wait);
1040 		}
1041 
1042 	// or are we maybe short a few urbs?
1043 	} else if (netif_running (dev->net)
1044 			&& netif_device_present (dev->net)
1045 			&& !timer_pending (&dev->delay)
1046 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
1047 		int	temp = dev->rxq.qlen;
1048 		int	qlen = RX_QLEN (dev);
1049 
1050 		if (temp < qlen) {
1051 			struct urb	*urb;
1052 			int		i;
1053 
1054 			// don't refill the queue all at once
1055 			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1056 				urb = usb_alloc_urb (0, GFP_ATOMIC);
1057 				if (urb != NULL)
1058 					rx_submit (dev, urb, GFP_ATOMIC);
1059 			}
1060 			if (temp != dev->rxq.qlen && netif_msg_link (dev))
1061 				devdbg (dev, "rxqlen %d --> %d",
1062 						temp, dev->rxq.qlen);
1063 			if (dev->rxq.qlen < qlen)
1064 				tasklet_schedule (&dev->bh);
1065 		}
1066 		if (dev->txq.qlen < TX_QLEN (dev))
1067 			netif_wake_queue (dev->net);
1068 	}
1069 }
1070 
1071 
1072 
1073 /*-------------------------------------------------------------------------
1074  *
1075  * USB Device Driver support
1076  *
1077  *-------------------------------------------------------------------------*/
1078 
1079 // precondition: never called in_interrupt
1080 
1081 void usbnet_disconnect (struct usb_interface *intf)
1082 {
1083 	struct usbnet		*dev;
1084 	struct usb_device	*xdev;
1085 	struct net_device	*net;
1086 
1087 	dev = usb_get_intfdata(intf);
1088 	usb_set_intfdata(intf, NULL);
1089 	if (!dev)
1090 		return;
1091 
1092 	xdev = interface_to_usbdev (intf);
1093 
1094 	if (netif_msg_probe (dev))
1095 		devinfo (dev, "unregister '%s' usb-%s-%s, %s",
1096 			intf->dev.driver->name,
1097 			xdev->bus->bus_name, xdev->devpath,
1098 			dev->driver_info->description);
1099 
1100 	net = dev->net;
1101 	unregister_netdev (net);
1102 
1103 	/* we don't hold rtnl here ... */
1104 	flush_scheduled_work ();
1105 
1106 	if (dev->driver_info->unbind)
1107 		dev->driver_info->unbind (dev, intf);
1108 
1109 	free_netdev(net);
1110 	usb_put_dev (xdev);
1111 }
1112 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1113 
1114 
1115 /*-------------------------------------------------------------------------*/
1116 
1117 // precondition: never called in_interrupt
1118 
1119 int
1120 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1121 {
1122 	struct usbnet			*dev;
1123 	struct net_device		*net;
1124 	struct usb_host_interface	*interface;
1125 	struct driver_info		*info;
1126 	struct usb_device		*xdev;
1127 	int				status;
1128 	const char			*name;
1129 	DECLARE_MAC_BUF(mac);
1130 
1131 	name = udev->dev.driver->name;
1132 	info = (struct driver_info *) prod->driver_info;
1133 	if (!info) {
1134 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1135 		return -ENODEV;
1136 	}
1137 	xdev = interface_to_usbdev (udev);
1138 	interface = udev->cur_altsetting;
1139 
1140 	usb_get_dev (xdev);
1141 
1142 	status = -ENOMEM;
1143 
1144 	// set up our own records
1145 	net = alloc_etherdev(sizeof(*dev));
1146 	if (!net) {
1147 		dbg ("can't kmalloc dev");
1148 		goto out;
1149 	}
1150 
1151 	dev = netdev_priv(net);
1152 	dev->udev = xdev;
1153 	dev->intf = udev;
1154 	dev->driver_info = info;
1155 	dev->driver_name = name;
1156 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1157 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1158 	skb_queue_head_init (&dev->rxq);
1159 	skb_queue_head_init (&dev->txq);
1160 	skb_queue_head_init (&dev->done);
1161 	dev->bh.func = usbnet_bh;
1162 	dev->bh.data = (unsigned long) dev;
1163 	INIT_WORK (&dev->kevent, kevent);
1164 	dev->delay.function = usbnet_bh;
1165 	dev->delay.data = (unsigned long) dev;
1166 	init_timer (&dev->delay);
1167 	mutex_init (&dev->phy_mutex);
1168 
1169 	dev->net = net;
1170 	strcpy (net->name, "usb%d");
1171 	memcpy (net->dev_addr, node_id, sizeof node_id);
1172 
1173 	/* rx and tx sides can use different message sizes;
1174 	 * bind() should set rx_urb_size in that case.
1175 	 */
1176 	dev->hard_mtu = net->mtu + net->hard_header_len;
1177 #if 0
1178 // dma_supported() is deeply broken on almost all architectures
1179 	// possible with some EHCI controllers
1180 	if (dma_supported (&udev->dev, DMA_64BIT_MASK))
1181 		net->features |= NETIF_F_HIGHDMA;
1182 #endif
1183 
1184 	net->change_mtu = usbnet_change_mtu;
1185 	net->get_stats = usbnet_get_stats;
1186 	net->hard_start_xmit = usbnet_start_xmit;
1187 	net->open = usbnet_open;
1188 	net->stop = usbnet_stop;
1189 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1190 	net->tx_timeout = usbnet_tx_timeout;
1191 	net->ethtool_ops = &usbnet_ethtool_ops;
1192 
1193 	// allow device-specific bind/init procedures
1194 	// NOTE net->name still not usable ...
1195 	if (info->bind) {
1196 		status = info->bind (dev, udev);
1197 		if (status < 0)
1198 			goto out1;
1199 
1200 		// heuristic:  "usb%d" for links we know are two-host,
1201 		// else "eth%d" when there's reasonable doubt.  userspace
1202 		// can rename the link if it knows better.
1203 		if ((dev->driver_info->flags & FLAG_ETHER) != 0
1204 				&& (net->dev_addr [0] & 0x02) == 0)
1205 			strcpy (net->name, "eth%d");
1206 		/* WLAN devices should always be named "wlan%d" */
1207 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1208 			strcpy(net->name, "wlan%d");
1209 
1210 		/* maybe the remote can't receive an Ethernet MTU */
1211 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1212 			net->mtu = dev->hard_mtu - net->hard_header_len;
1213 	} else if (!info->in || !info->out)
1214 		status = usbnet_get_endpoints (dev, udev);
1215 	else {
1216 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1217 		dev->out = usb_sndbulkpipe (xdev, info->out);
1218 		if (!(info->flags & FLAG_NO_SETINT))
1219 			status = usb_set_interface (xdev,
1220 				interface->desc.bInterfaceNumber,
1221 				interface->desc.bAlternateSetting);
1222 		else
1223 			status = 0;
1224 
1225 	}
1226 	if (status >= 0 && dev->status)
1227 		status = init_status (dev, udev);
1228 	if (status < 0)
1229 		goto out3;
1230 
1231 	if (!dev->rx_urb_size)
1232 		dev->rx_urb_size = dev->hard_mtu;
1233 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1234 
1235 	SET_NETDEV_DEV(net, &udev->dev);
1236 	status = register_netdev (net);
1237 	if (status)
1238 		goto out3;
1239 	if (netif_msg_probe (dev))
1240 		devinfo (dev, "register '%s' at usb-%s-%s, %s, %s",
1241 			udev->dev.driver->name,
1242 			xdev->bus->bus_name, xdev->devpath,
1243 			dev->driver_info->description,
1244 			print_mac(mac, net->dev_addr));
1245 
1246 	// ok, it's ready to go.
1247 	usb_set_intfdata (udev, dev);
1248 
1249 	// start as if the link is up
1250 	netif_device_attach (net);
1251 
1252 	return 0;
1253 
1254 out3:
1255 	if (info->unbind)
1256 		info->unbind (dev, udev);
1257 out1:
1258 	free_netdev(net);
1259 out:
1260 	usb_put_dev(xdev);
1261 	return status;
1262 }
1263 EXPORT_SYMBOL_GPL(usbnet_probe);
1264 
1265 /*-------------------------------------------------------------------------*/
1266 
1267 /*
1268  * suspend the whole driver as soon as the first interface is suspended
1269  * resume only when the last interface is resumed
1270  */
1271 
1272 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1273 {
1274 	struct usbnet		*dev = usb_get_intfdata(intf);
1275 
1276 	if (!dev->suspend_count++) {
1277 		/*
1278 		 * accelerate emptying of the rx and queues, to avoid
1279 		 * having everything error out.
1280 		 */
1281 		netif_device_detach (dev->net);
1282 		(void) unlink_urbs (dev, &dev->rxq);
1283 		(void) unlink_urbs (dev, &dev->txq);
1284 		/*
1285 		 * reattach so runtime management can use and
1286 		 * wake the device
1287 		 */
1288 		netif_device_attach (dev->net);
1289 	}
1290 	return 0;
1291 }
1292 EXPORT_SYMBOL_GPL(usbnet_suspend);
1293 
1294 int usbnet_resume (struct usb_interface *intf)
1295 {
1296 	struct usbnet		*dev = usb_get_intfdata(intf);
1297 
1298 	if (!--dev->suspend_count)
1299 		tasklet_schedule (&dev->bh);
1300 
1301 	return 0;
1302 }
1303 EXPORT_SYMBOL_GPL(usbnet_resume);
1304 
1305 
1306 /*-------------------------------------------------------------------------*/
1307 
1308 static int __init usbnet_init(void)
1309 {
1310 	/* compiler should optimize this out */
1311 	BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1312 			< sizeof (struct skb_data));
1313 
1314 	random_ether_addr(node_id);
1315 	return 0;
1316 }
1317 module_init(usbnet_init);
1318 
1319 static void __exit usbnet_exit(void)
1320 {
1321 }
1322 module_exit(usbnet_exit);
1323 
1324 MODULE_AUTHOR("David Brownell");
1325 MODULE_DESCRIPTION("USB network driver framework");
1326 MODULE_LICENSE("GPL");
1327