xref: /openbmc/linux/drivers/net/usb/usbnet.c (revision a33e9e7f35ef6dcab528e0327f29188475f60691)
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 
47 #define DRIVER_VERSION		"22-Aug-2005"
48 
49 
50 /*-------------------------------------------------------------------------*/
51 
52 /*
53  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
54  * Several dozen bytes of IPv4 data can fit in two such transactions.
55  * One maximum size Ethernet packet takes twenty four of them.
56  * For high speed, each frame comfortably fits almost 36 max size
57  * Ethernet packets (so queues should be bigger).
58  *
59  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
60  * let the USB host controller be busy for 5msec or more before an irq
61  * is required, under load.  Jumbograms change the equation.
62  */
63 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
64 #define	RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
65 			(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
66 #define	TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
67 			(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
68 
69 // reawaken network queue this soon after stopping; else watchdog barks
70 #define TX_TIMEOUT_JIFFIES	(5*HZ)
71 
72 // throttle rx/tx briefly after some faults, so khubd might disconnect()
73 // us (it polls at HZ/4 usually) before we report too many false errors.
74 #define THROTTLE_JIFFIES	(HZ/8)
75 
76 // between wakeups
77 #define UNLINK_TIMEOUT_MS	3
78 
79 /*-------------------------------------------------------------------------*/
80 
81 // randomly generated ethernet address
82 static u8	node_id [ETH_ALEN];
83 
84 static const char driver_name [] = "usbnet";
85 
86 /* use ethtool to change the level for any given device */
87 static int msg_level = -1;
88 module_param (msg_level, int, 0);
89 MODULE_PARM_DESC (msg_level, "Override default message level");
90 
91 /*-------------------------------------------------------------------------*/
92 
93 /* handles CDC Ethernet and many other network "bulk data" interfaces */
94 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
95 {
96 	int				tmp;
97 	struct usb_host_interface	*alt = NULL;
98 	struct usb_host_endpoint	*in = NULL, *out = NULL;
99 	struct usb_host_endpoint	*status = NULL;
100 
101 	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
102 		unsigned	ep;
103 
104 		in = out = status = NULL;
105 		alt = intf->altsetting + tmp;
106 
107 		/* take the first altsetting with in-bulk + out-bulk;
108 		 * remember any status endpoint, just in case;
109 		 * ignore other endpoints and altsetttings.
110 		 */
111 		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
112 			struct usb_host_endpoint	*e;
113 			int				intr = 0;
114 
115 			e = alt->endpoint + ep;
116 			switch (e->desc.bmAttributes) {
117 			case USB_ENDPOINT_XFER_INT:
118 				if (!usb_endpoint_dir_in(&e->desc))
119 					continue;
120 				intr = 1;
121 				/* FALLTHROUGH */
122 			case USB_ENDPOINT_XFER_BULK:
123 				break;
124 			default:
125 				continue;
126 			}
127 			if (usb_endpoint_dir_in(&e->desc)) {
128 				if (!intr && !in)
129 					in = e;
130 				else if (intr && !status)
131 					status = e;
132 			} else {
133 				if (!out)
134 					out = e;
135 			}
136 		}
137 		if (in && out)
138 			break;
139 	}
140 	if (!alt || !in || !out)
141 		return -EINVAL;
142 
143 	if (alt->desc.bAlternateSetting != 0
144 			|| !(dev->driver_info->flags & FLAG_NO_SETINT)) {
145 		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
146 				alt->desc.bAlternateSetting);
147 		if (tmp < 0)
148 			return tmp;
149 	}
150 
151 	dev->in = usb_rcvbulkpipe (dev->udev,
152 			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
153 	dev->out = usb_sndbulkpipe (dev->udev,
154 			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
155 	dev->status = status;
156 	return 0;
157 }
158 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
159 
160 static u8 nibble(unsigned char c)
161 {
162 	if (likely(isdigit(c)))
163 		return c - '0';
164 	c = toupper(c);
165 	if (likely(isxdigit(c)))
166 		return 10 + c - 'A';
167 	return 0;
168 }
169 
170 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
171 {
172 	int 		tmp, i;
173 	unsigned char	buf [13];
174 
175 	tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
176 	if (tmp != 12) {
177 		dev_dbg(&dev->udev->dev,
178 			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
179 		if (tmp >= 0)
180 			tmp = -EINVAL;
181 		return tmp;
182 	}
183 	for (i = tmp = 0; i < 6; i++, tmp += 2)
184 		dev->net->dev_addr [i] =
185 			(nibble(buf [tmp]) << 4) + nibble(buf [tmp + 1]);
186 	return 0;
187 }
188 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
189 
190 static void intr_complete (struct urb *urb);
191 
192 static int init_status (struct usbnet *dev, struct usb_interface *intf)
193 {
194 	char		*buf = NULL;
195 	unsigned	pipe = 0;
196 	unsigned	maxp;
197 	unsigned	period;
198 
199 	if (!dev->driver_info->status)
200 		return 0;
201 
202 	pipe = usb_rcvintpipe (dev->udev,
203 			dev->status->desc.bEndpointAddress
204 				& USB_ENDPOINT_NUMBER_MASK);
205 	maxp = usb_maxpacket (dev->udev, pipe, 0);
206 
207 	/* avoid 1 msec chatter:  min 8 msec poll rate */
208 	period = max ((int) dev->status->desc.bInterval,
209 		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
210 
211 	buf = kmalloc (maxp, GFP_KERNEL);
212 	if (buf) {
213 		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
214 		if (!dev->interrupt) {
215 			kfree (buf);
216 			return -ENOMEM;
217 		} else {
218 			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
219 				buf, maxp, intr_complete, dev, period);
220 			dev_dbg(&intf->dev,
221 				"status ep%din, %d bytes period %d\n",
222 				usb_pipeendpoint(pipe), maxp, period);
223 		}
224 	}
225 	return 0;
226 }
227 
228 /* Passes this packet up the stack, updating its accounting.
229  * Some link protocols batch packets, so their rx_fixup paths
230  * can return clones as well as just modify the original skb.
231  */
232 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
233 {
234 	int	status;
235 
236 	skb->protocol = eth_type_trans (skb, dev->net);
237 	dev->net->stats.rx_packets++;
238 	dev->net->stats.rx_bytes += skb->len;
239 
240 	if (netif_msg_rx_status (dev))
241 		devdbg (dev, "< rx, len %zu, type 0x%x",
242 			skb->len + sizeof (struct ethhdr), skb->protocol);
243 	memset (skb->cb, 0, sizeof (struct skb_data));
244 	status = netif_rx (skb);
245 	if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
246 		devdbg (dev, "netif_rx status %d", status);
247 }
248 EXPORT_SYMBOL_GPL(usbnet_skb_return);
249 
250 
251 /*-------------------------------------------------------------------------
252  *
253  * Network Device Driver (peer link to "Host Device", from USB host)
254  *
255  *-------------------------------------------------------------------------*/
256 
257 int usbnet_change_mtu (struct net_device *net, int new_mtu)
258 {
259 	struct usbnet	*dev = netdev_priv(net);
260 	int		ll_mtu = new_mtu + net->hard_header_len;
261 	int		old_hard_mtu = dev->hard_mtu;
262 	int		old_rx_urb_size = dev->rx_urb_size;
263 
264 	if (new_mtu <= 0)
265 		return -EINVAL;
266 	// no second zero-length packet read wanted after mtu-sized packets
267 	if ((ll_mtu % dev->maxpacket) == 0)
268 		return -EDOM;
269 	net->mtu = new_mtu;
270 
271 	dev->hard_mtu = net->mtu + net->hard_header_len;
272 	if (dev->rx_urb_size == old_hard_mtu) {
273 		dev->rx_urb_size = dev->hard_mtu;
274 		if (dev->rx_urb_size > old_rx_urb_size)
275 			usbnet_unlink_rx_urbs(dev);
276 	}
277 
278 	return 0;
279 }
280 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
281 
282 /*-------------------------------------------------------------------------*/
283 
284 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
285  * completion callbacks.  2.5 should have fixed those bugs...
286  */
287 
288 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
289 {
290 	unsigned long		flags;
291 
292 	spin_lock_irqsave(&list->lock, flags);
293 	__skb_unlink(skb, list);
294 	spin_unlock(&list->lock);
295 	spin_lock(&dev->done.lock);
296 	__skb_queue_tail(&dev->done, skb);
297 	if (dev->done.qlen == 1)
298 		tasklet_schedule(&dev->bh);
299 	spin_unlock_irqrestore(&dev->done.lock, flags);
300 }
301 
302 /* some work can't be done in tasklets, so we use keventd
303  *
304  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
305  * but tasklet_schedule() doesn't.  hope the failure is rare.
306  */
307 void usbnet_defer_kevent (struct usbnet *dev, int work)
308 {
309 	set_bit (work, &dev->flags);
310 	if (!schedule_work (&dev->kevent))
311 		deverr (dev, "kevent %d may have been dropped", work);
312 	else
313 		devdbg (dev, "kevent %d scheduled", work);
314 }
315 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
316 
317 /*-------------------------------------------------------------------------*/
318 
319 static void rx_complete (struct urb *urb);
320 
321 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
322 {
323 	struct sk_buff		*skb;
324 	struct skb_data		*entry;
325 	int			retval = 0;
326 	unsigned long		lockflags;
327 	size_t			size = dev->rx_urb_size;
328 
329 	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
330 		if (netif_msg_rx_err (dev))
331 			devdbg (dev, "no rx skb");
332 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
333 		usb_free_urb (urb);
334 		return;
335 	}
336 	skb_reserve (skb, NET_IP_ALIGN);
337 
338 	entry = (struct skb_data *) skb->cb;
339 	entry->urb = urb;
340 	entry->dev = dev;
341 	entry->state = rx_start;
342 	entry->length = 0;
343 
344 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
345 		skb->data, size, rx_complete, skb);
346 
347 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
348 
349 	if (netif_running (dev->net)
350 			&& netif_device_present (dev->net)
351 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
352 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
353 		case -EPIPE:
354 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
355 			break;
356 		case -ENOMEM:
357 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
358 			break;
359 		case -ENODEV:
360 			if (netif_msg_ifdown (dev))
361 				devdbg (dev, "device gone");
362 			netif_device_detach (dev->net);
363 			break;
364 		default:
365 			if (netif_msg_rx_err (dev))
366 				devdbg (dev, "rx submit, %d", retval);
367 			tasklet_schedule (&dev->bh);
368 			break;
369 		case 0:
370 			__skb_queue_tail (&dev->rxq, skb);
371 		}
372 	} else {
373 		if (netif_msg_ifdown (dev))
374 			devdbg (dev, "rx: stopped");
375 		retval = -ENOLINK;
376 	}
377 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
378 	if (retval) {
379 		dev_kfree_skb_any (skb);
380 		usb_free_urb (urb);
381 	}
382 }
383 
384 
385 /*-------------------------------------------------------------------------*/
386 
387 static 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 		goto error;
392 	// else network stack removes extra byte if we forced a short packet
393 
394 	if (skb->len)
395 		usbnet_skb_return (dev, skb);
396 	else {
397 		if (netif_msg_rx_err (dev))
398 			devdbg (dev, "drop");
399 error:
400 		dev->net->stats.rx_errors++;
401 		skb_queue_tail (&dev->done, skb);
402 	}
403 }
404 
405 /*-------------------------------------------------------------------------*/
406 
407 static void rx_complete (struct urb *urb)
408 {
409 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
410 	struct skb_data		*entry = (struct skb_data *) skb->cb;
411 	struct usbnet		*dev = entry->dev;
412 	int			urb_status = urb->status;
413 
414 	skb_put (skb, urb->actual_length);
415 	entry->state = rx_done;
416 	entry->urb = NULL;
417 
418 	switch (urb_status) {
419 	/* success */
420 	case 0:
421 		if (skb->len < dev->net->hard_header_len) {
422 			entry->state = rx_cleanup;
423 			dev->net->stats.rx_errors++;
424 			dev->net->stats.rx_length_errors++;
425 			if (netif_msg_rx_err (dev))
426 				devdbg (dev, "rx length %d", skb->len);
427 		}
428 		break;
429 
430 	/* stalls need manual reset. this is rare ... except that
431 	 * when going through USB 2.0 TTs, unplug appears this way.
432 	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
433 	 * storm, recovering as needed.
434 	 */
435 	case -EPIPE:
436 		dev->net->stats.rx_errors++;
437 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
438 		// FALLTHROUGH
439 
440 	/* software-driven interface shutdown */
441 	case -ECONNRESET:		/* async unlink */
442 	case -ESHUTDOWN:		/* hardware gone */
443 		if (netif_msg_ifdown (dev))
444 			devdbg (dev, "rx shutdown, code %d", urb_status);
445 		goto block;
446 
447 	/* we get controller i/o faults during khubd disconnect() delays.
448 	 * throttle down resubmits, to avoid log floods; just temporarily,
449 	 * so we still recover when the fault isn't a khubd delay.
450 	 */
451 	case -EPROTO:
452 	case -ETIME:
453 	case -EILSEQ:
454 		dev->net->stats.rx_errors++;
455 		if (!timer_pending (&dev->delay)) {
456 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
457 			if (netif_msg_link (dev))
458 				devdbg (dev, "rx throttle %d", urb_status);
459 		}
460 block:
461 		entry->state = rx_cleanup;
462 		entry->urb = urb;
463 		urb = NULL;
464 		break;
465 
466 	/* data overrun ... flush fifo? */
467 	case -EOVERFLOW:
468 		dev->net->stats.rx_over_errors++;
469 		// FALLTHROUGH
470 
471 	default:
472 		entry->state = rx_cleanup;
473 		dev->net->stats.rx_errors++;
474 		if (netif_msg_rx_err (dev))
475 			devdbg (dev, "rx status %d", urb_status);
476 		break;
477 	}
478 
479 	defer_bh(dev, skb, &dev->rxq);
480 
481 	if (urb) {
482 		if (netif_running (dev->net)
483 				&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
484 			rx_submit (dev, urb, GFP_ATOMIC);
485 			return;
486 		}
487 		usb_free_urb (urb);
488 	}
489 	if (netif_msg_rx_err (dev))
490 		devdbg (dev, "no read resubmitted");
491 }
492 
493 static void intr_complete (struct urb *urb)
494 {
495 	struct usbnet	*dev = urb->context;
496 	int		status = urb->status;
497 
498 	switch (status) {
499 	/* success */
500 	case 0:
501 		dev->driver_info->status(dev, urb);
502 		break;
503 
504 	/* software-driven interface shutdown */
505 	case -ENOENT:		/* urb killed */
506 	case -ESHUTDOWN:	/* hardware gone */
507 		if (netif_msg_ifdown (dev))
508 			devdbg (dev, "intr shutdown, code %d", status);
509 		return;
510 
511 	/* NOTE:  not throttling like RX/TX, since this endpoint
512 	 * already polls infrequently
513 	 */
514 	default:
515 		devdbg (dev, "intr status %d", status);
516 		break;
517 	}
518 
519 	if (!netif_running (dev->net))
520 		return;
521 
522 	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
523 	status = usb_submit_urb (urb, GFP_ATOMIC);
524 	if (status != 0 && netif_msg_timer (dev))
525 		deverr(dev, "intr resubmit --> %d", status);
526 }
527 
528 /*-------------------------------------------------------------------------*/
529 
530 // unlink pending rx/tx; completion handlers do all other cleanup
531 
532 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
533 {
534 	unsigned long		flags;
535 	struct sk_buff		*skb, *skbnext;
536 	int			count = 0;
537 
538 	spin_lock_irqsave (&q->lock, flags);
539 	skb_queue_walk_safe(q, skb, skbnext) {
540 		struct skb_data		*entry;
541 		struct urb		*urb;
542 		int			retval;
543 
544 		entry = (struct skb_data *) skb->cb;
545 		urb = entry->urb;
546 
547 		// during some PM-driven resume scenarios,
548 		// these (async) unlinks complete immediately
549 		retval = usb_unlink_urb (urb);
550 		if (retval != -EINPROGRESS && retval != 0)
551 			devdbg (dev, "unlink urb err, %d", retval);
552 		else
553 			count++;
554 	}
555 	spin_unlock_irqrestore (&q->lock, flags);
556 	return count;
557 }
558 
559 // Flush all pending rx urbs
560 // minidrivers may need to do this when the MTU changes
561 
562 void usbnet_unlink_rx_urbs(struct usbnet *dev)
563 {
564 	if (netif_running(dev->net)) {
565 		(void) unlink_urbs (dev, &dev->rxq);
566 		tasklet_schedule(&dev->bh);
567 	}
568 }
569 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
570 
571 /*-------------------------------------------------------------------------*/
572 
573 // precondition: never called in_interrupt
574 
575 int usbnet_stop (struct net_device *net)
576 {
577 	struct usbnet		*dev = netdev_priv(net);
578 	struct driver_info	*info = dev->driver_info;
579 	int			temp;
580 	int			retval;
581 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
582 	DECLARE_WAITQUEUE (wait, current);
583 
584 	netif_stop_queue (net);
585 
586 	if (netif_msg_ifdown (dev))
587 		devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
588 			net->stats.rx_packets, net->stats.tx_packets,
589 			net->stats.rx_errors, net->stats.tx_errors
590 			);
591 
592 	/* allow minidriver to stop correctly (wireless devices to turn off
593 	 * radio etc) */
594 	if (info->stop) {
595 		retval = info->stop(dev);
596 		if (retval < 0 && netif_msg_ifdown(dev))
597 			devinfo(dev,
598 				"stop fail (%d) usbnet usb-%s-%s, %s",
599 				retval,
600 				dev->udev->bus->bus_name, dev->udev->devpath,
601 				info->description);
602 	}
603 
604 	// ensure there are no more active urbs
605 	add_wait_queue (&unlink_wakeup, &wait);
606 	dev->wait = &unlink_wakeup;
607 	temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
608 
609 	// maybe wait for deletions to finish.
610 	while (!skb_queue_empty(&dev->rxq)
611 			&& !skb_queue_empty(&dev->txq)
612 			&& !skb_queue_empty(&dev->done)) {
613 		msleep(UNLINK_TIMEOUT_MS);
614 		if (netif_msg_ifdown (dev))
615 			devdbg (dev, "waited for %d urb completions", temp);
616 	}
617 	dev->wait = NULL;
618 	remove_wait_queue (&unlink_wakeup, &wait);
619 
620 	usb_kill_urb(dev->interrupt);
621 
622 	/* deferred work (task, timer, softirq) must also stop.
623 	 * can't flush_scheduled_work() until we drop rtnl (later),
624 	 * else workers could deadlock; so make workers a NOP.
625 	 */
626 	dev->flags = 0;
627 	del_timer_sync (&dev->delay);
628 	tasklet_kill (&dev->bh);
629 	usb_autopm_put_interface(dev->intf);
630 
631 	return 0;
632 }
633 EXPORT_SYMBOL_GPL(usbnet_stop);
634 
635 /*-------------------------------------------------------------------------*/
636 
637 // posts reads, and enables write queuing
638 
639 // precondition: never called in_interrupt
640 
641 int usbnet_open (struct net_device *net)
642 {
643 	struct usbnet		*dev = netdev_priv(net);
644 	int			retval;
645 	struct driver_info	*info = dev->driver_info;
646 
647 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
648 		if (netif_msg_ifup (dev))
649 			devinfo (dev,
650 				"resumption fail (%d) usbnet usb-%s-%s, %s",
651 				retval,
652 				dev->udev->bus->bus_name, dev->udev->devpath,
653 			info->description);
654 		goto done_nopm;
655 	}
656 
657 	// put into "known safe" state
658 	if (info->reset && (retval = info->reset (dev)) < 0) {
659 		if (netif_msg_ifup (dev))
660 			devinfo (dev,
661 				"open reset fail (%d) usbnet usb-%s-%s, %s",
662 				retval,
663 				dev->udev->bus->bus_name, dev->udev->devpath,
664 			info->description);
665 		goto done;
666 	}
667 
668 	// insist peer be connected
669 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
670 		if (netif_msg_ifup (dev))
671 			devdbg (dev, "can't open; %d", retval);
672 		goto done;
673 	}
674 
675 	/* start any status interrupt transfer */
676 	if (dev->interrupt) {
677 		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
678 		if (retval < 0) {
679 			if (netif_msg_ifup (dev))
680 				deverr (dev, "intr submit %d", retval);
681 			goto done;
682 		}
683 	}
684 
685 	netif_start_queue (net);
686 	if (netif_msg_ifup (dev)) {
687 		char	*framing;
688 
689 		if (dev->driver_info->flags & FLAG_FRAMING_NC)
690 			framing = "NetChip";
691 		else if (dev->driver_info->flags & FLAG_FRAMING_GL)
692 			framing = "GeneSys";
693 		else if (dev->driver_info->flags & FLAG_FRAMING_Z)
694 			framing = "Zaurus";
695 		else if (dev->driver_info->flags & FLAG_FRAMING_RN)
696 			framing = "RNDIS";
697 		else if (dev->driver_info->flags & FLAG_FRAMING_AX)
698 			framing = "ASIX";
699 		else
700 			framing = "simple";
701 
702 		devinfo (dev, "open: enable queueing "
703 				"(rx %d, tx %d) mtu %d %s framing",
704 			(int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
705 			framing);
706 	}
707 
708 	// delay posting reads until we're fully open
709 	tasklet_schedule (&dev->bh);
710 	return retval;
711 done:
712 	usb_autopm_put_interface(dev->intf);
713 done_nopm:
714 	return retval;
715 }
716 EXPORT_SYMBOL_GPL(usbnet_open);
717 
718 /*-------------------------------------------------------------------------*/
719 
720 /* ethtool methods; minidrivers may need to add some more, but
721  * they'll probably want to use this base set.
722  */
723 
724 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
725 {
726 	struct usbnet *dev = netdev_priv(net);
727 
728 	if (!dev->mii.mdio_read)
729 		return -EOPNOTSUPP;
730 
731 	return mii_ethtool_gset(&dev->mii, cmd);
732 }
733 EXPORT_SYMBOL_GPL(usbnet_get_settings);
734 
735 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
736 {
737 	struct usbnet *dev = netdev_priv(net);
738 	int retval;
739 
740 	if (!dev->mii.mdio_write)
741 		return -EOPNOTSUPP;
742 
743 	retval = mii_ethtool_sset(&dev->mii, cmd);
744 
745 	/* link speed/duplex might have changed */
746 	if (dev->driver_info->link_reset)
747 		dev->driver_info->link_reset(dev);
748 
749 	return retval;
750 
751 }
752 EXPORT_SYMBOL_GPL(usbnet_set_settings);
753 
754 u32 usbnet_get_link (struct net_device *net)
755 {
756 	struct usbnet *dev = netdev_priv(net);
757 
758 	/* If a check_connect is defined, return its result */
759 	if (dev->driver_info->check_connect)
760 		return dev->driver_info->check_connect (dev) == 0;
761 
762 	/* if the device has mii operations, use those */
763 	if (dev->mii.mdio_read)
764 		return mii_link_ok(&dev->mii);
765 
766 	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
767 	return ethtool_op_get_link(net);
768 }
769 EXPORT_SYMBOL_GPL(usbnet_get_link);
770 
771 int usbnet_nway_reset(struct net_device *net)
772 {
773 	struct usbnet *dev = netdev_priv(net);
774 
775 	if (!dev->mii.mdio_write)
776 		return -EOPNOTSUPP;
777 
778 	return mii_nway_restart(&dev->mii);
779 }
780 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
781 
782 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
783 {
784 	struct usbnet *dev = netdev_priv(net);
785 
786 	strncpy (info->driver, dev->driver_name, sizeof info->driver);
787 	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
788 	strncpy (info->fw_version, dev->driver_info->description,
789 		sizeof info->fw_version);
790 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
791 }
792 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
793 
794 u32 usbnet_get_msglevel (struct net_device *net)
795 {
796 	struct usbnet *dev = netdev_priv(net);
797 
798 	return dev->msg_enable;
799 }
800 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
801 
802 void usbnet_set_msglevel (struct net_device *net, u32 level)
803 {
804 	struct usbnet *dev = netdev_priv(net);
805 
806 	dev->msg_enable = level;
807 }
808 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
809 
810 /* drivers may override default ethtool_ops in their bind() routine */
811 static struct ethtool_ops usbnet_ethtool_ops = {
812 	.get_settings		= usbnet_get_settings,
813 	.set_settings		= usbnet_set_settings,
814 	.get_link		= usbnet_get_link,
815 	.nway_reset		= usbnet_nway_reset,
816 	.get_drvinfo		= usbnet_get_drvinfo,
817 	.get_msglevel		= usbnet_get_msglevel,
818 	.set_msglevel		= usbnet_set_msglevel,
819 };
820 
821 /*-------------------------------------------------------------------------*/
822 
823 /* work that cannot be done in interrupt context uses keventd.
824  *
825  * NOTE:  with 2.5 we could do more of this using completion callbacks,
826  * especially now that control transfers can be queued.
827  */
828 static void
829 kevent (struct work_struct *work)
830 {
831 	struct usbnet		*dev =
832 		container_of(work, struct usbnet, kevent);
833 	int			status;
834 
835 	/* usb_clear_halt() needs a thread context */
836 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
837 		unlink_urbs (dev, &dev->txq);
838 		status = usb_clear_halt (dev->udev, dev->out);
839 		if (status < 0
840 				&& status != -EPIPE
841 				&& status != -ESHUTDOWN) {
842 			if (netif_msg_tx_err (dev))
843 				deverr (dev, "can't clear tx halt, status %d",
844 					status);
845 		} else {
846 			clear_bit (EVENT_TX_HALT, &dev->flags);
847 			if (status != -ESHUTDOWN)
848 				netif_wake_queue (dev->net);
849 		}
850 	}
851 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
852 		unlink_urbs (dev, &dev->rxq);
853 		status = usb_clear_halt (dev->udev, dev->in);
854 		if (status < 0
855 				&& status != -EPIPE
856 				&& status != -ESHUTDOWN) {
857 			if (netif_msg_rx_err (dev))
858 				deverr (dev, "can't clear rx halt, status %d",
859 					status);
860 		} else {
861 			clear_bit (EVENT_RX_HALT, &dev->flags);
862 			tasklet_schedule (&dev->bh);
863 		}
864 	}
865 
866 	/* tasklet could resubmit itself forever if memory is tight */
867 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
868 		struct urb	*urb = NULL;
869 
870 		if (netif_running (dev->net))
871 			urb = usb_alloc_urb (0, GFP_KERNEL);
872 		else
873 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
874 		if (urb != NULL) {
875 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
876 			rx_submit (dev, urb, GFP_KERNEL);
877 			tasklet_schedule (&dev->bh);
878 		}
879 	}
880 
881 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
882 		struct driver_info	*info = dev->driver_info;
883 		int			retval = 0;
884 
885 		clear_bit (EVENT_LINK_RESET, &dev->flags);
886 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
887 			devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
888 				retval,
889 				dev->udev->bus->bus_name, dev->udev->devpath,
890 				info->description);
891 		}
892 	}
893 
894 	if (dev->flags)
895 		devdbg (dev, "kevent done, flags = 0x%lx",
896 			dev->flags);
897 }
898 
899 /*-------------------------------------------------------------------------*/
900 
901 static void tx_complete (struct urb *urb)
902 {
903 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
904 	struct skb_data		*entry = (struct skb_data *) skb->cb;
905 	struct usbnet		*dev = entry->dev;
906 
907 	if (urb->status == 0) {
908 		dev->net->stats.tx_packets++;
909 		dev->net->stats.tx_bytes += entry->length;
910 	} else {
911 		dev->net->stats.tx_errors++;
912 
913 		switch (urb->status) {
914 		case -EPIPE:
915 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
916 			break;
917 
918 		/* software-driven interface shutdown */
919 		case -ECONNRESET:		// async unlink
920 		case -ESHUTDOWN:		// hardware gone
921 			break;
922 
923 		// like rx, tx gets controller i/o faults during khubd delays
924 		// and so it uses the same throttling mechanism.
925 		case -EPROTO:
926 		case -ETIME:
927 		case -EILSEQ:
928 			if (!timer_pending (&dev->delay)) {
929 				mod_timer (&dev->delay,
930 					jiffies + THROTTLE_JIFFIES);
931 				if (netif_msg_link (dev))
932 					devdbg (dev, "tx throttle %d",
933 							urb->status);
934 			}
935 			netif_stop_queue (dev->net);
936 			break;
937 		default:
938 			if (netif_msg_tx_err (dev))
939 				devdbg (dev, "tx err %d", entry->urb->status);
940 			break;
941 		}
942 	}
943 
944 	urb->dev = NULL;
945 	entry->state = tx_done;
946 	defer_bh(dev, skb, &dev->txq);
947 }
948 
949 /*-------------------------------------------------------------------------*/
950 
951 void usbnet_tx_timeout (struct net_device *net)
952 {
953 	struct usbnet		*dev = netdev_priv(net);
954 
955 	unlink_urbs (dev, &dev->txq);
956 	tasklet_schedule (&dev->bh);
957 
958 	// FIXME: device recovery -- reset?
959 }
960 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
961 
962 /*-------------------------------------------------------------------------*/
963 
964 int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
965 {
966 	struct usbnet		*dev = netdev_priv(net);
967 	int			length;
968 	int			retval = NET_XMIT_SUCCESS;
969 	struct urb		*urb = NULL;
970 	struct skb_data		*entry;
971 	struct driver_info	*info = dev->driver_info;
972 	unsigned long		flags;
973 
974 	// some devices want funky USB-level framing, for
975 	// win32 driver (usually) and/or hardware quirks
976 	if (info->tx_fixup) {
977 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
978 		if (!skb) {
979 			if (netif_msg_tx_err (dev))
980 				devdbg (dev, "can't tx_fixup skb");
981 			goto drop;
982 		}
983 	}
984 	length = skb->len;
985 
986 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
987 		if (netif_msg_tx_err (dev))
988 			devdbg (dev, "no urb");
989 		goto drop;
990 	}
991 
992 	entry = (struct skb_data *) skb->cb;
993 	entry->urb = urb;
994 	entry->dev = dev;
995 	entry->state = tx_start;
996 	entry->length = length;
997 
998 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
999 			skb->data, skb->len, tx_complete, skb);
1000 
1001 	/* don't assume the hardware handles USB_ZERO_PACKET
1002 	 * NOTE:  strictly conforming cdc-ether devices should expect
1003 	 * the ZLP here, but ignore the one-byte packet.
1004 	 */
1005 	if ((length % dev->maxpacket) == 0) {
1006 		urb->transfer_buffer_length++;
1007 		if (skb_tailroom(skb)) {
1008 			skb->data[skb->len] = 0;
1009 			__skb_put(skb, 1);
1010 		}
1011 	}
1012 
1013 	spin_lock_irqsave (&dev->txq.lock, flags);
1014 
1015 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1016 	case -EPIPE:
1017 		netif_stop_queue (net);
1018 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1019 		break;
1020 	default:
1021 		if (netif_msg_tx_err (dev))
1022 			devdbg (dev, "tx: submit urb err %d", retval);
1023 		break;
1024 	case 0:
1025 		net->trans_start = jiffies;
1026 		__skb_queue_tail (&dev->txq, skb);
1027 		if (dev->txq.qlen >= TX_QLEN (dev))
1028 			netif_stop_queue (net);
1029 	}
1030 	spin_unlock_irqrestore (&dev->txq.lock, flags);
1031 
1032 	if (retval) {
1033 		if (netif_msg_tx_err (dev))
1034 			devdbg (dev, "drop, code %d", retval);
1035 drop:
1036 		retval = NET_XMIT_SUCCESS;
1037 		dev->net->stats.tx_dropped++;
1038 		if (skb)
1039 			dev_kfree_skb_any (skb);
1040 		usb_free_urb (urb);
1041 	} else if (netif_msg_tx_queued (dev)) {
1042 		devdbg (dev, "> tx, len %d, type 0x%x",
1043 			length, skb->protocol);
1044 	}
1045 	return retval;
1046 }
1047 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1048 
1049 /*-------------------------------------------------------------------------*/
1050 
1051 // tasklet (work deferred from completions, in_irq) or timer
1052 
1053 static void usbnet_bh (unsigned long param)
1054 {
1055 	struct usbnet		*dev = (struct usbnet *) param;
1056 	struct sk_buff		*skb;
1057 	struct skb_data		*entry;
1058 
1059 	while ((skb = skb_dequeue (&dev->done))) {
1060 		entry = (struct skb_data *) skb->cb;
1061 		switch (entry->state) {
1062 		case rx_done:
1063 			entry->state = rx_cleanup;
1064 			rx_process (dev, skb);
1065 			continue;
1066 		case tx_done:
1067 		case rx_cleanup:
1068 			usb_free_urb (entry->urb);
1069 			dev_kfree_skb (skb);
1070 			continue;
1071 		default:
1072 			devdbg (dev, "bogus skb state %d", entry->state);
1073 		}
1074 	}
1075 
1076 	// waiting for all pending urbs to complete?
1077 	if (dev->wait) {
1078 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1079 			wake_up (dev->wait);
1080 		}
1081 
1082 	// or are we maybe short a few urbs?
1083 	} else if (netif_running (dev->net)
1084 			&& netif_device_present (dev->net)
1085 			&& !timer_pending (&dev->delay)
1086 			&& !test_bit (EVENT_RX_HALT, &dev->flags)) {
1087 		int	temp = dev->rxq.qlen;
1088 		int	qlen = RX_QLEN (dev);
1089 
1090 		if (temp < qlen) {
1091 			struct urb	*urb;
1092 			int		i;
1093 
1094 			// don't refill the queue all at once
1095 			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1096 				urb = usb_alloc_urb (0, GFP_ATOMIC);
1097 				if (urb != NULL)
1098 					rx_submit (dev, urb, GFP_ATOMIC);
1099 			}
1100 			if (temp != dev->rxq.qlen && netif_msg_link (dev))
1101 				devdbg (dev, "rxqlen %d --> %d",
1102 						temp, dev->rxq.qlen);
1103 			if (dev->rxq.qlen < qlen)
1104 				tasklet_schedule (&dev->bh);
1105 		}
1106 		if (dev->txq.qlen < TX_QLEN (dev))
1107 			netif_wake_queue (dev->net);
1108 	}
1109 }
1110 
1111 
1112 
1113 /*-------------------------------------------------------------------------
1114  *
1115  * USB Device Driver support
1116  *
1117  *-------------------------------------------------------------------------*/
1118 
1119 // precondition: never called in_interrupt
1120 
1121 void usbnet_disconnect (struct usb_interface *intf)
1122 {
1123 	struct usbnet		*dev;
1124 	struct usb_device	*xdev;
1125 	struct net_device	*net;
1126 
1127 	dev = usb_get_intfdata(intf);
1128 	usb_set_intfdata(intf, NULL);
1129 	if (!dev)
1130 		return;
1131 
1132 	xdev = interface_to_usbdev (intf);
1133 
1134 	if (netif_msg_probe (dev))
1135 		devinfo (dev, "unregister '%s' usb-%s-%s, %s",
1136 			intf->dev.driver->name,
1137 			xdev->bus->bus_name, xdev->devpath,
1138 			dev->driver_info->description);
1139 
1140 	net = dev->net;
1141 	unregister_netdev (net);
1142 
1143 	/* we don't hold rtnl here ... */
1144 	flush_scheduled_work ();
1145 
1146 	if (dev->driver_info->unbind)
1147 		dev->driver_info->unbind (dev, intf);
1148 
1149 	free_netdev(net);
1150 	usb_put_dev (xdev);
1151 }
1152 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1153 
1154 static const struct net_device_ops usbnet_netdev_ops = {
1155 	.ndo_open		= usbnet_open,
1156 	.ndo_stop		= usbnet_stop,
1157 	.ndo_start_xmit		= usbnet_start_xmit,
1158 	.ndo_tx_timeout		= usbnet_tx_timeout,
1159 	.ndo_change_mtu		= usbnet_change_mtu,
1160 	.ndo_set_mac_address 	= eth_mac_addr,
1161 	.ndo_validate_addr	= eth_validate_addr,
1162 };
1163 
1164 /*-------------------------------------------------------------------------*/
1165 
1166 // precondition: never called in_interrupt
1167 
1168 int
1169 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1170 {
1171 	struct usbnet			*dev;
1172 	struct net_device		*net;
1173 	struct usb_host_interface	*interface;
1174 	struct driver_info		*info;
1175 	struct usb_device		*xdev;
1176 	int				status;
1177 	const char			*name;
1178 
1179 	name = udev->dev.driver->name;
1180 	info = (struct driver_info *) prod->driver_info;
1181 	if (!info) {
1182 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1183 		return -ENODEV;
1184 	}
1185 	xdev = interface_to_usbdev (udev);
1186 	interface = udev->cur_altsetting;
1187 
1188 	usb_get_dev (xdev);
1189 
1190 	status = -ENOMEM;
1191 
1192 	// set up our own records
1193 	net = alloc_etherdev(sizeof(*dev));
1194 	if (!net) {
1195 		dbg ("can't kmalloc dev");
1196 		goto out;
1197 	}
1198 
1199 	dev = netdev_priv(net);
1200 	dev->udev = xdev;
1201 	dev->intf = udev;
1202 	dev->driver_info = info;
1203 	dev->driver_name = name;
1204 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1205 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1206 	skb_queue_head_init (&dev->rxq);
1207 	skb_queue_head_init (&dev->txq);
1208 	skb_queue_head_init (&dev->done);
1209 	dev->bh.func = usbnet_bh;
1210 	dev->bh.data = (unsigned long) dev;
1211 	INIT_WORK (&dev->kevent, kevent);
1212 	dev->delay.function = usbnet_bh;
1213 	dev->delay.data = (unsigned long) dev;
1214 	init_timer (&dev->delay);
1215 	mutex_init (&dev->phy_mutex);
1216 
1217 	dev->net = net;
1218 	strcpy (net->name, "usb%d");
1219 	memcpy (net->dev_addr, node_id, sizeof node_id);
1220 
1221 	/* rx and tx sides can use different message sizes;
1222 	 * bind() should set rx_urb_size in that case.
1223 	 */
1224 	dev->hard_mtu = net->mtu + net->hard_header_len;
1225 #if 0
1226 // dma_supported() is deeply broken on almost all architectures
1227 	// possible with some EHCI controllers
1228 	if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1229 		net->features |= NETIF_F_HIGHDMA;
1230 #endif
1231 
1232 	net->netdev_ops = &usbnet_netdev_ops;
1233 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1234 	net->ethtool_ops = &usbnet_ethtool_ops;
1235 
1236 	// allow device-specific bind/init procedures
1237 	// NOTE net->name still not usable ...
1238 	if (info->bind) {
1239 		status = info->bind (dev, udev);
1240 		if (status < 0)
1241 			goto out1;
1242 
1243 		// heuristic:  "usb%d" for links we know are two-host,
1244 		// else "eth%d" when there's reasonable doubt.  userspace
1245 		// can rename the link if it knows better.
1246 		if ((dev->driver_info->flags & FLAG_ETHER) != 0
1247 				&& (net->dev_addr [0] & 0x02) == 0)
1248 			strcpy (net->name, "eth%d");
1249 		/* WLAN devices should always be named "wlan%d" */
1250 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1251 			strcpy(net->name, "wlan%d");
1252 
1253 		/* maybe the remote can't receive an Ethernet MTU */
1254 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1255 			net->mtu = dev->hard_mtu - net->hard_header_len;
1256 	} else if (!info->in || !info->out)
1257 		status = usbnet_get_endpoints (dev, udev);
1258 	else {
1259 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1260 		dev->out = usb_sndbulkpipe (xdev, info->out);
1261 		if (!(info->flags & FLAG_NO_SETINT))
1262 			status = usb_set_interface (xdev,
1263 				interface->desc.bInterfaceNumber,
1264 				interface->desc.bAlternateSetting);
1265 		else
1266 			status = 0;
1267 
1268 	}
1269 	if (status >= 0 && dev->status)
1270 		status = init_status (dev, udev);
1271 	if (status < 0)
1272 		goto out3;
1273 
1274 	if (!dev->rx_urb_size)
1275 		dev->rx_urb_size = dev->hard_mtu;
1276 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1277 
1278 	SET_NETDEV_DEV(net, &udev->dev);
1279 	status = register_netdev (net);
1280 	if (status)
1281 		goto out3;
1282 	if (netif_msg_probe (dev))
1283 		devinfo (dev, "register '%s' at usb-%s-%s, %s, %pM",
1284 			udev->dev.driver->name,
1285 			xdev->bus->bus_name, xdev->devpath,
1286 			dev->driver_info->description,
1287 			net->dev_addr);
1288 
1289 	// ok, it's ready to go.
1290 	usb_set_intfdata (udev, dev);
1291 
1292 	// start as if the link is up
1293 	netif_device_attach (net);
1294 
1295 	return 0;
1296 
1297 out3:
1298 	if (info->unbind)
1299 		info->unbind (dev, udev);
1300 out1:
1301 	free_netdev(net);
1302 out:
1303 	usb_put_dev(xdev);
1304 	return status;
1305 }
1306 EXPORT_SYMBOL_GPL(usbnet_probe);
1307 
1308 /*-------------------------------------------------------------------------*/
1309 
1310 /*
1311  * suspend the whole driver as soon as the first interface is suspended
1312  * resume only when the last interface is resumed
1313  */
1314 
1315 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1316 {
1317 	struct usbnet		*dev = usb_get_intfdata(intf);
1318 
1319 	if (!dev->suspend_count++) {
1320 		/*
1321 		 * accelerate emptying of the rx and queues, to avoid
1322 		 * having everything error out.
1323 		 */
1324 		netif_device_detach (dev->net);
1325 		(void) unlink_urbs (dev, &dev->rxq);
1326 		(void) unlink_urbs (dev, &dev->txq);
1327 		/*
1328 		 * reattach so runtime management can use and
1329 		 * wake the device
1330 		 */
1331 		netif_device_attach (dev->net);
1332 	}
1333 	return 0;
1334 }
1335 EXPORT_SYMBOL_GPL(usbnet_suspend);
1336 
1337 int usbnet_resume (struct usb_interface *intf)
1338 {
1339 	struct usbnet		*dev = usb_get_intfdata(intf);
1340 
1341 	if (!--dev->suspend_count)
1342 		tasklet_schedule (&dev->bh);
1343 
1344 	return 0;
1345 }
1346 EXPORT_SYMBOL_GPL(usbnet_resume);
1347 
1348 
1349 /*-------------------------------------------------------------------------*/
1350 
1351 static int __init usbnet_init(void)
1352 {
1353 	/* compiler should optimize this out */
1354 	BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1355 			< sizeof (struct skb_data));
1356 
1357 	random_ether_addr(node_id);
1358 	return 0;
1359 }
1360 module_init(usbnet_init);
1361 
1362 static void __exit usbnet_exit(void)
1363 {
1364 }
1365 module_exit(usbnet_exit);
1366 
1367 MODULE_AUTHOR("David Brownell");
1368 MODULE_DESCRIPTION("USB network driver framework");
1369 MODULE_LICENSE("GPL");
1370