xref: /linux/drivers/net/usb/usbnet.c (revision a115bc070b1fc57ab23f3972401425927b5b465c)
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 	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
237 		skb_queue_tail(&dev->rxq_pause, skb);
238 		return;
239 	}
240 
241 	skb->protocol = eth_type_trans (skb, dev->net);
242 	dev->net->stats.rx_packets++;
243 	dev->net->stats.rx_bytes += skb->len;
244 
245 	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
246 		  skb->len + sizeof (struct ethhdr), skb->protocol);
247 	memset (skb->cb, 0, sizeof (struct skb_data));
248 	status = netif_rx (skb);
249 	if (status != NET_RX_SUCCESS)
250 		netif_dbg(dev, rx_err, dev->net,
251 			  "netif_rx status %d\n", status);
252 }
253 EXPORT_SYMBOL_GPL(usbnet_skb_return);
254 
255 
256 /*-------------------------------------------------------------------------
257  *
258  * Network Device Driver (peer link to "Host Device", from USB host)
259  *
260  *-------------------------------------------------------------------------*/
261 
262 int usbnet_change_mtu (struct net_device *net, int new_mtu)
263 {
264 	struct usbnet	*dev = netdev_priv(net);
265 	int		ll_mtu = new_mtu + net->hard_header_len;
266 	int		old_hard_mtu = dev->hard_mtu;
267 	int		old_rx_urb_size = dev->rx_urb_size;
268 
269 	if (new_mtu <= 0)
270 		return -EINVAL;
271 	// no second zero-length packet read wanted after mtu-sized packets
272 	if ((ll_mtu % dev->maxpacket) == 0)
273 		return -EDOM;
274 	net->mtu = new_mtu;
275 
276 	dev->hard_mtu = net->mtu + net->hard_header_len;
277 	if (dev->rx_urb_size == old_hard_mtu) {
278 		dev->rx_urb_size = dev->hard_mtu;
279 		if (dev->rx_urb_size > old_rx_urb_size)
280 			usbnet_unlink_rx_urbs(dev);
281 	}
282 
283 	return 0;
284 }
285 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
286 
287 /*-------------------------------------------------------------------------*/
288 
289 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
290  * completion callbacks.  2.5 should have fixed those bugs...
291  */
292 
293 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
294 {
295 	unsigned long		flags;
296 
297 	spin_lock_irqsave(&list->lock, flags);
298 	__skb_unlink(skb, list);
299 	spin_unlock(&list->lock);
300 	spin_lock(&dev->done.lock);
301 	__skb_queue_tail(&dev->done, skb);
302 	if (dev->done.qlen == 1)
303 		tasklet_schedule(&dev->bh);
304 	spin_unlock_irqrestore(&dev->done.lock, flags);
305 }
306 
307 /* some work can't be done in tasklets, so we use keventd
308  *
309  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
310  * but tasklet_schedule() doesn't.  hope the failure is rare.
311  */
312 void usbnet_defer_kevent (struct usbnet *dev, int work)
313 {
314 	set_bit (work, &dev->flags);
315 	if (!schedule_work (&dev->kevent))
316 		netdev_err(dev->net, "kevent %d may have been dropped\n", work);
317 	else
318 		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
319 }
320 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
321 
322 /*-------------------------------------------------------------------------*/
323 
324 static void rx_complete (struct urb *urb);
325 
326 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
327 {
328 	struct sk_buff		*skb;
329 	struct skb_data		*entry;
330 	int			retval = 0;
331 	unsigned long		lockflags;
332 	size_t			size = dev->rx_urb_size;
333 
334 	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
335 		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
336 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
337 		usb_free_urb (urb);
338 		return;
339 	}
340 	skb_reserve (skb, NET_IP_ALIGN);
341 
342 	entry = (struct skb_data *) skb->cb;
343 	entry->urb = urb;
344 	entry->dev = dev;
345 	entry->state = rx_start;
346 	entry->length = 0;
347 
348 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
349 		skb->data, size, rx_complete, skb);
350 
351 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
352 
353 	if (netif_running (dev->net) &&
354 	    netif_device_present (dev->net) &&
355 	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
356 	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
357 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
358 		case -EPIPE:
359 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
360 			break;
361 		case -ENOMEM:
362 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
363 			break;
364 		case -ENODEV:
365 			netif_dbg(dev, ifdown, dev->net, "device gone\n");
366 			netif_device_detach (dev->net);
367 			break;
368 		default:
369 			netif_dbg(dev, rx_err, dev->net,
370 				  "rx submit, %d\n", retval);
371 			tasklet_schedule (&dev->bh);
372 			break;
373 		case 0:
374 			__skb_queue_tail (&dev->rxq, skb);
375 		}
376 	} else {
377 		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
378 		retval = -ENOLINK;
379 	}
380 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
381 	if (retval) {
382 		dev_kfree_skb_any (skb);
383 		usb_free_urb (urb);
384 	}
385 }
386 
387 
388 /*-------------------------------------------------------------------------*/
389 
390 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
391 {
392 	if (dev->driver_info->rx_fixup &&
393 	    !dev->driver_info->rx_fixup (dev, skb))
394 		goto error;
395 	// else network stack removes extra byte if we forced a short packet
396 
397 	if (skb->len)
398 		usbnet_skb_return (dev, skb);
399 	else {
400 		netif_dbg(dev, rx_err, dev->net, "drop\n");
401 error:
402 		dev->net->stats.rx_errors++;
403 		skb_queue_tail (&dev->done, skb);
404 	}
405 }
406 
407 /*-------------------------------------------------------------------------*/
408 
409 static void rx_complete (struct urb *urb)
410 {
411 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
412 	struct skb_data		*entry = (struct skb_data *) skb->cb;
413 	struct usbnet		*dev = entry->dev;
414 	int			urb_status = urb->status;
415 
416 	skb_put (skb, urb->actual_length);
417 	entry->state = rx_done;
418 	entry->urb = NULL;
419 
420 	switch (urb_status) {
421 	/* success */
422 	case 0:
423 		if (skb->len < dev->net->hard_header_len) {
424 			entry->state = rx_cleanup;
425 			dev->net->stats.rx_errors++;
426 			dev->net->stats.rx_length_errors++;
427 			netif_dbg(dev, rx_err, dev->net,
428 				  "rx length %d\n", skb->len);
429 		}
430 		break;
431 
432 	/* stalls need manual reset. this is rare ... except that
433 	 * when going through USB 2.0 TTs, unplug appears this way.
434 	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
435 	 * storm, recovering as needed.
436 	 */
437 	case -EPIPE:
438 		dev->net->stats.rx_errors++;
439 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
440 		// FALLTHROUGH
441 
442 	/* software-driven interface shutdown */
443 	case -ECONNRESET:		/* async unlink */
444 	case -ESHUTDOWN:		/* hardware gone */
445 		netif_dbg(dev, ifdown, dev->net,
446 			  "rx shutdown, code %d\n", urb_status);
447 		goto block;
448 
449 	/* we get controller i/o faults during khubd disconnect() delays.
450 	 * throttle down resubmits, to avoid log floods; just temporarily,
451 	 * so we still recover when the fault isn't a khubd delay.
452 	 */
453 	case -EPROTO:
454 	case -ETIME:
455 	case -EILSEQ:
456 		dev->net->stats.rx_errors++;
457 		if (!timer_pending (&dev->delay)) {
458 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
459 			netif_dbg(dev, link, dev->net,
460 				  "rx throttle %d\n", urb_status);
461 		}
462 block:
463 		entry->state = rx_cleanup;
464 		entry->urb = urb;
465 		urb = NULL;
466 		break;
467 
468 	/* data overrun ... flush fifo? */
469 	case -EOVERFLOW:
470 		dev->net->stats.rx_over_errors++;
471 		// FALLTHROUGH
472 
473 	default:
474 		entry->state = rx_cleanup;
475 		dev->net->stats.rx_errors++;
476 		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
477 		break;
478 	}
479 
480 	defer_bh(dev, skb, &dev->rxq);
481 
482 	if (urb) {
483 		if (netif_running (dev->net) &&
484 		    !test_bit (EVENT_RX_HALT, &dev->flags)) {
485 			rx_submit (dev, urb, GFP_ATOMIC);
486 			return;
487 		}
488 		usb_free_urb (urb);
489 	}
490 	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
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 		netif_dbg(dev, ifdown, dev->net,
508 			  "intr shutdown, code %d\n", status);
509 		return;
510 
511 	/* NOTE:  not throttling like RX/TX, since this endpoint
512 	 * already polls infrequently
513 	 */
514 	default:
515 		netdev_dbg(dev->net, "intr status %d\n", 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)
525 		netif_err(dev, timer, dev->net,
526 			  "intr resubmit --> %d\n", status);
527 }
528 
529 /*-------------------------------------------------------------------------*/
530 void usbnet_pause_rx(struct usbnet *dev)
531 {
532 	set_bit(EVENT_RX_PAUSED, &dev->flags);
533 
534 	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
535 }
536 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
537 
538 void usbnet_resume_rx(struct usbnet *dev)
539 {
540 	struct sk_buff *skb;
541 	int num = 0;
542 
543 	clear_bit(EVENT_RX_PAUSED, &dev->flags);
544 
545 	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
546 		usbnet_skb_return(dev, skb);
547 		num++;
548 	}
549 
550 	tasklet_schedule(&dev->bh);
551 
552 	netif_dbg(dev, rx_status, dev->net,
553 		  "paused rx queue disabled, %d skbs requeued\n", num);
554 }
555 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
556 
557 void usbnet_purge_paused_rxq(struct usbnet *dev)
558 {
559 	skb_queue_purge(&dev->rxq_pause);
560 }
561 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
562 
563 /*-------------------------------------------------------------------------*/
564 
565 // unlink pending rx/tx; completion handlers do all other cleanup
566 
567 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
568 {
569 	unsigned long		flags;
570 	struct sk_buff		*skb, *skbnext;
571 	int			count = 0;
572 
573 	spin_lock_irqsave (&q->lock, flags);
574 	skb_queue_walk_safe(q, skb, skbnext) {
575 		struct skb_data		*entry;
576 		struct urb		*urb;
577 		int			retval;
578 
579 		entry = (struct skb_data *) skb->cb;
580 		urb = entry->urb;
581 
582 		// during some PM-driven resume scenarios,
583 		// these (async) unlinks complete immediately
584 		retval = usb_unlink_urb (urb);
585 		if (retval != -EINPROGRESS && retval != 0)
586 			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
587 		else
588 			count++;
589 	}
590 	spin_unlock_irqrestore (&q->lock, flags);
591 	return count;
592 }
593 
594 // Flush all pending rx urbs
595 // minidrivers may need to do this when the MTU changes
596 
597 void usbnet_unlink_rx_urbs(struct usbnet *dev)
598 {
599 	if (netif_running(dev->net)) {
600 		(void) unlink_urbs (dev, &dev->rxq);
601 		tasklet_schedule(&dev->bh);
602 	}
603 }
604 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
605 
606 /*-------------------------------------------------------------------------*/
607 
608 // precondition: never called in_interrupt
609 static void usbnet_terminate_urbs(struct usbnet *dev)
610 {
611 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
612 	DECLARE_WAITQUEUE(wait, current);
613 	int temp;
614 
615 	/* ensure there are no more active urbs */
616 	add_wait_queue(&unlink_wakeup, &wait);
617 	set_current_state(TASK_UNINTERRUPTIBLE);
618 	dev->wait = &unlink_wakeup;
619 	temp = unlink_urbs(dev, &dev->txq) +
620 		unlink_urbs(dev, &dev->rxq);
621 
622 	/* maybe wait for deletions to finish. */
623 	while (!skb_queue_empty(&dev->rxq)
624 		&& !skb_queue_empty(&dev->txq)
625 		&& !skb_queue_empty(&dev->done)) {
626 			schedule_timeout(UNLINK_TIMEOUT_MS);
627 			set_current_state(TASK_UNINTERRUPTIBLE);
628 			netif_dbg(dev, ifdown, dev->net,
629 				  "waited for %d urb completions\n", temp);
630 	}
631 	set_current_state(TASK_RUNNING);
632 	dev->wait = NULL;
633 	remove_wait_queue(&unlink_wakeup, &wait);
634 }
635 
636 int usbnet_stop (struct net_device *net)
637 {
638 	struct usbnet		*dev = netdev_priv(net);
639 	struct driver_info	*info = dev->driver_info;
640 	int			retval;
641 
642 	netif_stop_queue (net);
643 
644 	netif_info(dev, ifdown, dev->net,
645 		   "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
646 		   net->stats.rx_packets, net->stats.tx_packets,
647 		   net->stats.rx_errors, net->stats.tx_errors);
648 
649 	/* allow minidriver to stop correctly (wireless devices to turn off
650 	 * radio etc) */
651 	if (info->stop) {
652 		retval = info->stop(dev);
653 		if (retval < 0)
654 			netif_info(dev, ifdown, dev->net,
655 				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
656 				   retval,
657 				   dev->udev->bus->bus_name, dev->udev->devpath,
658 				   info->description);
659 	}
660 
661 	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
662 		usbnet_terminate_urbs(dev);
663 
664 	usb_kill_urb(dev->interrupt);
665 
666 	usbnet_purge_paused_rxq(dev);
667 
668 	/* deferred work (task, timer, softirq) must also stop.
669 	 * can't flush_scheduled_work() until we drop rtnl (later),
670 	 * else workers could deadlock; so make workers a NOP.
671 	 */
672 	dev->flags = 0;
673 	del_timer_sync (&dev->delay);
674 	tasklet_kill (&dev->bh);
675 	if (info->manage_power)
676 		info->manage_power(dev, 0);
677 	else
678 		usb_autopm_put_interface(dev->intf);
679 
680 	return 0;
681 }
682 EXPORT_SYMBOL_GPL(usbnet_stop);
683 
684 /*-------------------------------------------------------------------------*/
685 
686 // posts reads, and enables write queuing
687 
688 // precondition: never called in_interrupt
689 
690 int usbnet_open (struct net_device *net)
691 {
692 	struct usbnet		*dev = netdev_priv(net);
693 	int			retval;
694 	struct driver_info	*info = dev->driver_info;
695 
696 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
697 		netif_info(dev, ifup, dev->net,
698 			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
699 			   retval,
700 			   dev->udev->bus->bus_name,
701 			   dev->udev->devpath,
702 			   info->description);
703 		goto done_nopm;
704 	}
705 
706 	// put into "known safe" state
707 	if (info->reset && (retval = info->reset (dev)) < 0) {
708 		netif_info(dev, ifup, dev->net,
709 			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
710 			   retval,
711 			   dev->udev->bus->bus_name,
712 			   dev->udev->devpath,
713 			   info->description);
714 		goto done;
715 	}
716 
717 	// insist peer be connected
718 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
719 		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
720 		goto done;
721 	}
722 
723 	/* start any status interrupt transfer */
724 	if (dev->interrupt) {
725 		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
726 		if (retval < 0) {
727 			netif_err(dev, ifup, dev->net,
728 				  "intr submit %d\n", retval);
729 			goto done;
730 		}
731 	}
732 
733 	netif_start_queue (net);
734 	netif_info(dev, ifup, dev->net,
735 		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
736 		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
737 		   dev->net->mtu,
738 		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
739 		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
740 		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
741 		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
742 		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
743 		   "simple");
744 
745 	// delay posting reads until we're fully open
746 	tasklet_schedule (&dev->bh);
747 	if (info->manage_power) {
748 		retval = info->manage_power(dev, 1);
749 		if (retval < 0)
750 			goto done;
751 		usb_autopm_put_interface(dev->intf);
752 	}
753 	return retval;
754 
755 done:
756 	usb_autopm_put_interface(dev->intf);
757 done_nopm:
758 	return retval;
759 }
760 EXPORT_SYMBOL_GPL(usbnet_open);
761 
762 /*-------------------------------------------------------------------------*/
763 
764 /* ethtool methods; minidrivers may need to add some more, but
765  * they'll probably want to use this base set.
766  */
767 
768 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
769 {
770 	struct usbnet *dev = netdev_priv(net);
771 
772 	if (!dev->mii.mdio_read)
773 		return -EOPNOTSUPP;
774 
775 	return mii_ethtool_gset(&dev->mii, cmd);
776 }
777 EXPORT_SYMBOL_GPL(usbnet_get_settings);
778 
779 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
780 {
781 	struct usbnet *dev = netdev_priv(net);
782 	int retval;
783 
784 	if (!dev->mii.mdio_write)
785 		return -EOPNOTSUPP;
786 
787 	retval = mii_ethtool_sset(&dev->mii, cmd);
788 
789 	/* link speed/duplex might have changed */
790 	if (dev->driver_info->link_reset)
791 		dev->driver_info->link_reset(dev);
792 
793 	return retval;
794 
795 }
796 EXPORT_SYMBOL_GPL(usbnet_set_settings);
797 
798 u32 usbnet_get_link (struct net_device *net)
799 {
800 	struct usbnet *dev = netdev_priv(net);
801 
802 	/* If a check_connect is defined, return its result */
803 	if (dev->driver_info->check_connect)
804 		return dev->driver_info->check_connect (dev) == 0;
805 
806 	/* if the device has mii operations, use those */
807 	if (dev->mii.mdio_read)
808 		return mii_link_ok(&dev->mii);
809 
810 	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
811 	return ethtool_op_get_link(net);
812 }
813 EXPORT_SYMBOL_GPL(usbnet_get_link);
814 
815 int usbnet_nway_reset(struct net_device *net)
816 {
817 	struct usbnet *dev = netdev_priv(net);
818 
819 	if (!dev->mii.mdio_write)
820 		return -EOPNOTSUPP;
821 
822 	return mii_nway_restart(&dev->mii);
823 }
824 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
825 
826 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
827 {
828 	struct usbnet *dev = netdev_priv(net);
829 
830 	strncpy (info->driver, dev->driver_name, sizeof info->driver);
831 	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
832 	strncpy (info->fw_version, dev->driver_info->description,
833 		sizeof info->fw_version);
834 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
835 }
836 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
837 
838 u32 usbnet_get_msglevel (struct net_device *net)
839 {
840 	struct usbnet *dev = netdev_priv(net);
841 
842 	return dev->msg_enable;
843 }
844 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
845 
846 void usbnet_set_msglevel (struct net_device *net, u32 level)
847 {
848 	struct usbnet *dev = netdev_priv(net);
849 
850 	dev->msg_enable = level;
851 }
852 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
853 
854 /* drivers may override default ethtool_ops in their bind() routine */
855 static const struct ethtool_ops usbnet_ethtool_ops = {
856 	.get_settings		= usbnet_get_settings,
857 	.set_settings		= usbnet_set_settings,
858 	.get_link		= usbnet_get_link,
859 	.nway_reset		= usbnet_nway_reset,
860 	.get_drvinfo		= usbnet_get_drvinfo,
861 	.get_msglevel		= usbnet_get_msglevel,
862 	.set_msglevel		= usbnet_set_msglevel,
863 };
864 
865 /*-------------------------------------------------------------------------*/
866 
867 /* work that cannot be done in interrupt context uses keventd.
868  *
869  * NOTE:  with 2.5 we could do more of this using completion callbacks,
870  * especially now that control transfers can be queued.
871  */
872 static void
873 kevent (struct work_struct *work)
874 {
875 	struct usbnet		*dev =
876 		container_of(work, struct usbnet, kevent);
877 	int			status;
878 
879 	/* usb_clear_halt() needs a thread context */
880 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
881 		unlink_urbs (dev, &dev->txq);
882 		status = usb_autopm_get_interface(dev->intf);
883 		if (status < 0)
884 			goto fail_pipe;
885 		status = usb_clear_halt (dev->udev, dev->out);
886 		usb_autopm_put_interface(dev->intf);
887 		if (status < 0 &&
888 		    status != -EPIPE &&
889 		    status != -ESHUTDOWN) {
890 			if (netif_msg_tx_err (dev))
891 fail_pipe:
892 				netdev_err(dev->net, "can't clear tx halt, status %d\n",
893 					   status);
894 		} else {
895 			clear_bit (EVENT_TX_HALT, &dev->flags);
896 			if (status != -ESHUTDOWN)
897 				netif_wake_queue (dev->net);
898 		}
899 	}
900 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
901 		unlink_urbs (dev, &dev->rxq);
902 		status = usb_autopm_get_interface(dev->intf);
903 		if (status < 0)
904 			goto fail_halt;
905 		status = usb_clear_halt (dev->udev, dev->in);
906 		usb_autopm_put_interface(dev->intf);
907 		if (status < 0 &&
908 		    status != -EPIPE &&
909 		    status != -ESHUTDOWN) {
910 			if (netif_msg_rx_err (dev))
911 fail_halt:
912 				netdev_err(dev->net, "can't clear rx halt, status %d\n",
913 					   status);
914 		} else {
915 			clear_bit (EVENT_RX_HALT, &dev->flags);
916 			tasklet_schedule (&dev->bh);
917 		}
918 	}
919 
920 	/* tasklet could resubmit itself forever if memory is tight */
921 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
922 		struct urb	*urb = NULL;
923 
924 		if (netif_running (dev->net))
925 			urb = usb_alloc_urb (0, GFP_KERNEL);
926 		else
927 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
928 		if (urb != NULL) {
929 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
930 			status = usb_autopm_get_interface(dev->intf);
931 			if (status < 0)
932 				goto fail_lowmem;
933 			rx_submit (dev, urb, GFP_KERNEL);
934 			usb_autopm_put_interface(dev->intf);
935 fail_lowmem:
936 			tasklet_schedule (&dev->bh);
937 		}
938 	}
939 
940 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
941 		struct driver_info	*info = dev->driver_info;
942 		int			retval = 0;
943 
944 		clear_bit (EVENT_LINK_RESET, &dev->flags);
945 		status = usb_autopm_get_interface(dev->intf);
946 		if (status < 0)
947 			goto skip_reset;
948 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
949 			usb_autopm_put_interface(dev->intf);
950 skip_reset:
951 			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
952 				    retval,
953 				    dev->udev->bus->bus_name,
954 				    dev->udev->devpath,
955 				    info->description);
956 		} else {
957 			usb_autopm_put_interface(dev->intf);
958 		}
959 	}
960 
961 	if (dev->flags)
962 		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
963 }
964 
965 /*-------------------------------------------------------------------------*/
966 
967 static void tx_complete (struct urb *urb)
968 {
969 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
970 	struct skb_data		*entry = (struct skb_data *) skb->cb;
971 	struct usbnet		*dev = entry->dev;
972 
973 	if (urb->status == 0) {
974 		dev->net->stats.tx_packets++;
975 		dev->net->stats.tx_bytes += entry->length;
976 	} else {
977 		dev->net->stats.tx_errors++;
978 
979 		switch (urb->status) {
980 		case -EPIPE:
981 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
982 			break;
983 
984 		/* software-driven interface shutdown */
985 		case -ECONNRESET:		// async unlink
986 		case -ESHUTDOWN:		// hardware gone
987 			break;
988 
989 		// like rx, tx gets controller i/o faults during khubd delays
990 		// and so it uses the same throttling mechanism.
991 		case -EPROTO:
992 		case -ETIME:
993 		case -EILSEQ:
994 			usb_mark_last_busy(dev->udev);
995 			if (!timer_pending (&dev->delay)) {
996 				mod_timer (&dev->delay,
997 					jiffies + THROTTLE_JIFFIES);
998 				netif_dbg(dev, link, dev->net,
999 					  "tx throttle %d\n", urb->status);
1000 			}
1001 			netif_stop_queue (dev->net);
1002 			break;
1003 		default:
1004 			netif_dbg(dev, tx_err, dev->net,
1005 				  "tx err %d\n", entry->urb->status);
1006 			break;
1007 		}
1008 	}
1009 
1010 	usb_autopm_put_interface_async(dev->intf);
1011 	urb->dev = NULL;
1012 	entry->state = tx_done;
1013 	defer_bh(dev, skb, &dev->txq);
1014 }
1015 
1016 /*-------------------------------------------------------------------------*/
1017 
1018 void usbnet_tx_timeout (struct net_device *net)
1019 {
1020 	struct usbnet		*dev = netdev_priv(net);
1021 
1022 	unlink_urbs (dev, &dev->txq);
1023 	tasklet_schedule (&dev->bh);
1024 
1025 	// FIXME: device recovery -- reset?
1026 }
1027 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1028 
1029 /*-------------------------------------------------------------------------*/
1030 
1031 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1032 				     struct net_device *net)
1033 {
1034 	struct usbnet		*dev = netdev_priv(net);
1035 	int			length;
1036 	struct urb		*urb = NULL;
1037 	struct skb_data		*entry;
1038 	struct driver_info	*info = dev->driver_info;
1039 	unsigned long		flags;
1040 	int retval;
1041 
1042 	// some devices want funky USB-level framing, for
1043 	// win32 driver (usually) and/or hardware quirks
1044 	if (info->tx_fixup) {
1045 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1046 		if (!skb) {
1047 			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1048 			goto drop;
1049 		}
1050 	}
1051 	length = skb->len;
1052 
1053 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1054 		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1055 		goto drop;
1056 	}
1057 
1058 	entry = (struct skb_data *) skb->cb;
1059 	entry->urb = urb;
1060 	entry->dev = dev;
1061 	entry->state = tx_start;
1062 	entry->length = length;
1063 
1064 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1065 			skb->data, skb->len, tx_complete, skb);
1066 
1067 	/* don't assume the hardware handles USB_ZERO_PACKET
1068 	 * NOTE:  strictly conforming cdc-ether devices should expect
1069 	 * the ZLP here, but ignore the one-byte packet.
1070 	 */
1071 	if (!(info->flags & FLAG_SEND_ZLP) && (length % dev->maxpacket) == 0) {
1072 		urb->transfer_buffer_length++;
1073 		if (skb_tailroom(skb)) {
1074 			skb->data[skb->len] = 0;
1075 			__skb_put(skb, 1);
1076 		}
1077 	}
1078 
1079 	spin_lock_irqsave(&dev->txq.lock, flags);
1080 	retval = usb_autopm_get_interface_async(dev->intf);
1081 	if (retval < 0) {
1082 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1083 		goto drop;
1084 	}
1085 
1086 #ifdef CONFIG_PM
1087 	/* if this triggers the device is still a sleep */
1088 	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1089 		/* transmission will be done in resume */
1090 		usb_anchor_urb(urb, &dev->deferred);
1091 		/* no use to process more packets */
1092 		netif_stop_queue(net);
1093 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1094 		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1095 		goto deferred;
1096 	}
1097 #endif
1098 
1099 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1100 	case -EPIPE:
1101 		netif_stop_queue (net);
1102 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1103 		usb_autopm_put_interface_async(dev->intf);
1104 		break;
1105 	default:
1106 		usb_autopm_put_interface_async(dev->intf);
1107 		netif_dbg(dev, tx_err, dev->net,
1108 			  "tx: submit urb err %d\n", retval);
1109 		break;
1110 	case 0:
1111 		net->trans_start = jiffies;
1112 		__skb_queue_tail (&dev->txq, skb);
1113 		if (dev->txq.qlen >= TX_QLEN (dev))
1114 			netif_stop_queue (net);
1115 	}
1116 	spin_unlock_irqrestore (&dev->txq.lock, flags);
1117 
1118 	if (retval) {
1119 		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1120 drop:
1121 		dev->net->stats.tx_dropped++;
1122 		if (skb)
1123 			dev_kfree_skb_any (skb);
1124 		usb_free_urb (urb);
1125 	} else
1126 		netif_dbg(dev, tx_queued, dev->net,
1127 			  "> tx, len %d, type 0x%x\n", length, skb->protocol);
1128 #ifdef CONFIG_PM
1129 deferred:
1130 #endif
1131 	return NETDEV_TX_OK;
1132 }
1133 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1134 
1135 /*-------------------------------------------------------------------------*/
1136 
1137 // tasklet (work deferred from completions, in_irq) or timer
1138 
1139 static void usbnet_bh (unsigned long param)
1140 {
1141 	struct usbnet		*dev = (struct usbnet *) param;
1142 	struct sk_buff		*skb;
1143 	struct skb_data		*entry;
1144 
1145 	while ((skb = skb_dequeue (&dev->done))) {
1146 		entry = (struct skb_data *) skb->cb;
1147 		switch (entry->state) {
1148 		case rx_done:
1149 			entry->state = rx_cleanup;
1150 			rx_process (dev, skb);
1151 			continue;
1152 		case tx_done:
1153 		case rx_cleanup:
1154 			usb_free_urb (entry->urb);
1155 			dev_kfree_skb (skb);
1156 			continue;
1157 		default:
1158 			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1159 		}
1160 	}
1161 
1162 	// waiting for all pending urbs to complete?
1163 	if (dev->wait) {
1164 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1165 			wake_up (dev->wait);
1166 		}
1167 
1168 	// or are we maybe short a few urbs?
1169 	} else if (netif_running (dev->net) &&
1170 		   netif_device_present (dev->net) &&
1171 		   !timer_pending (&dev->delay) &&
1172 		   !test_bit (EVENT_RX_HALT, &dev->flags)) {
1173 		int	temp = dev->rxq.qlen;
1174 		int	qlen = RX_QLEN (dev);
1175 
1176 		if (temp < qlen) {
1177 			struct urb	*urb;
1178 			int		i;
1179 
1180 			// don't refill the queue all at once
1181 			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1182 				urb = usb_alloc_urb (0, GFP_ATOMIC);
1183 				if (urb != NULL)
1184 					rx_submit (dev, urb, GFP_ATOMIC);
1185 			}
1186 			if (temp != dev->rxq.qlen)
1187 				netif_dbg(dev, link, dev->net,
1188 					  "rxqlen %d --> %d\n",
1189 					  temp, dev->rxq.qlen);
1190 			if (dev->rxq.qlen < qlen)
1191 				tasklet_schedule (&dev->bh);
1192 		}
1193 		if (dev->txq.qlen < TX_QLEN (dev))
1194 			netif_wake_queue (dev->net);
1195 	}
1196 }
1197 
1198 
1199 /*-------------------------------------------------------------------------
1200  *
1201  * USB Device Driver support
1202  *
1203  *-------------------------------------------------------------------------*/
1204 
1205 // precondition: never called in_interrupt
1206 
1207 void usbnet_disconnect (struct usb_interface *intf)
1208 {
1209 	struct usbnet		*dev;
1210 	struct usb_device	*xdev;
1211 	struct net_device	*net;
1212 
1213 	dev = usb_get_intfdata(intf);
1214 	usb_set_intfdata(intf, NULL);
1215 	if (!dev)
1216 		return;
1217 
1218 	xdev = interface_to_usbdev (intf);
1219 
1220 	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1221 		   intf->dev.driver->name,
1222 		   xdev->bus->bus_name, xdev->devpath,
1223 		   dev->driver_info->description);
1224 
1225 	net = dev->net;
1226 	unregister_netdev (net);
1227 
1228 	/* we don't hold rtnl here ... */
1229 	flush_scheduled_work ();
1230 
1231 	if (dev->driver_info->unbind)
1232 		dev->driver_info->unbind (dev, intf);
1233 
1234 	free_netdev(net);
1235 	usb_put_dev (xdev);
1236 }
1237 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1238 
1239 static const struct net_device_ops usbnet_netdev_ops = {
1240 	.ndo_open		= usbnet_open,
1241 	.ndo_stop		= usbnet_stop,
1242 	.ndo_start_xmit		= usbnet_start_xmit,
1243 	.ndo_tx_timeout		= usbnet_tx_timeout,
1244 	.ndo_change_mtu		= usbnet_change_mtu,
1245 	.ndo_set_mac_address 	= eth_mac_addr,
1246 	.ndo_validate_addr	= eth_validate_addr,
1247 };
1248 
1249 /*-------------------------------------------------------------------------*/
1250 
1251 // precondition: never called in_interrupt
1252 
1253 static struct device_type wlan_type = {
1254 	.name	= "wlan",
1255 };
1256 
1257 static struct device_type wwan_type = {
1258 	.name	= "wwan",
1259 };
1260 
1261 int
1262 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1263 {
1264 	struct usbnet			*dev;
1265 	struct net_device		*net;
1266 	struct usb_host_interface	*interface;
1267 	struct driver_info		*info;
1268 	struct usb_device		*xdev;
1269 	int				status;
1270 	const char			*name;
1271 
1272 	name = udev->dev.driver->name;
1273 	info = (struct driver_info *) prod->driver_info;
1274 	if (!info) {
1275 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1276 		return -ENODEV;
1277 	}
1278 	xdev = interface_to_usbdev (udev);
1279 	interface = udev->cur_altsetting;
1280 
1281 	usb_get_dev (xdev);
1282 
1283 	status = -ENOMEM;
1284 
1285 	// set up our own records
1286 	net = alloc_etherdev(sizeof(*dev));
1287 	if (!net) {
1288 		dbg ("can't kmalloc dev");
1289 		goto out;
1290 	}
1291 
1292 	dev = netdev_priv(net);
1293 	dev->udev = xdev;
1294 	dev->intf = udev;
1295 	dev->driver_info = info;
1296 	dev->driver_name = name;
1297 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1298 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1299 	skb_queue_head_init (&dev->rxq);
1300 	skb_queue_head_init (&dev->txq);
1301 	skb_queue_head_init (&dev->done);
1302 	skb_queue_head_init(&dev->rxq_pause);
1303 	dev->bh.func = usbnet_bh;
1304 	dev->bh.data = (unsigned long) dev;
1305 	INIT_WORK (&dev->kevent, kevent);
1306 	init_usb_anchor(&dev->deferred);
1307 	dev->delay.function = usbnet_bh;
1308 	dev->delay.data = (unsigned long) dev;
1309 	init_timer (&dev->delay);
1310 	mutex_init (&dev->phy_mutex);
1311 
1312 	dev->net = net;
1313 	strcpy (net->name, "usb%d");
1314 	memcpy (net->dev_addr, node_id, sizeof node_id);
1315 
1316 	/* rx and tx sides can use different message sizes;
1317 	 * bind() should set rx_urb_size in that case.
1318 	 */
1319 	dev->hard_mtu = net->mtu + net->hard_header_len;
1320 #if 0
1321 // dma_supported() is deeply broken on almost all architectures
1322 	// possible with some EHCI controllers
1323 	if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1324 		net->features |= NETIF_F_HIGHDMA;
1325 #endif
1326 
1327 	net->netdev_ops = &usbnet_netdev_ops;
1328 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1329 	net->ethtool_ops = &usbnet_ethtool_ops;
1330 
1331 	// allow device-specific bind/init procedures
1332 	// NOTE net->name still not usable ...
1333 	if (info->bind) {
1334 		status = info->bind (dev, udev);
1335 		if (status < 0)
1336 			goto out1;
1337 
1338 		// heuristic:  "usb%d" for links we know are two-host,
1339 		// else "eth%d" when there's reasonable doubt.  userspace
1340 		// can rename the link if it knows better.
1341 		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1342 		    (net->dev_addr [0] & 0x02) == 0)
1343 			strcpy (net->name, "eth%d");
1344 		/* WLAN devices should always be named "wlan%d" */
1345 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1346 			strcpy(net->name, "wlan%d");
1347 		/* WWAN devices should always be named "wwan%d" */
1348 		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1349 			strcpy(net->name, "wwan%d");
1350 
1351 		/* maybe the remote can't receive an Ethernet MTU */
1352 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1353 			net->mtu = dev->hard_mtu - net->hard_header_len;
1354 	} else if (!info->in || !info->out)
1355 		status = usbnet_get_endpoints (dev, udev);
1356 	else {
1357 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1358 		dev->out = usb_sndbulkpipe (xdev, info->out);
1359 		if (!(info->flags & FLAG_NO_SETINT))
1360 			status = usb_set_interface (xdev,
1361 				interface->desc.bInterfaceNumber,
1362 				interface->desc.bAlternateSetting);
1363 		else
1364 			status = 0;
1365 
1366 	}
1367 	if (status >= 0 && dev->status)
1368 		status = init_status (dev, udev);
1369 	if (status < 0)
1370 		goto out3;
1371 
1372 	if (!dev->rx_urb_size)
1373 		dev->rx_urb_size = dev->hard_mtu;
1374 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1375 
1376 	SET_NETDEV_DEV(net, &udev->dev);
1377 
1378 	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1379 		SET_NETDEV_DEVTYPE(net, &wlan_type);
1380 	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1381 		SET_NETDEV_DEVTYPE(net, &wwan_type);
1382 
1383 	status = register_netdev (net);
1384 	if (status)
1385 		goto out3;
1386 	netif_info(dev, probe, dev->net,
1387 		   "register '%s' at usb-%s-%s, %s, %pM\n",
1388 		   udev->dev.driver->name,
1389 		   xdev->bus->bus_name, xdev->devpath,
1390 		   dev->driver_info->description,
1391 		   net->dev_addr);
1392 
1393 	// ok, it's ready to go.
1394 	usb_set_intfdata (udev, dev);
1395 
1396 	netif_device_attach (net);
1397 
1398 	if (dev->driver_info->flags & FLAG_LINK_INTR)
1399 		netif_carrier_off(net);
1400 
1401 	return 0;
1402 
1403 out3:
1404 	if (info->unbind)
1405 		info->unbind (dev, udev);
1406 out1:
1407 	free_netdev(net);
1408 out:
1409 	usb_put_dev(xdev);
1410 	return status;
1411 }
1412 EXPORT_SYMBOL_GPL(usbnet_probe);
1413 
1414 /*-------------------------------------------------------------------------*/
1415 
1416 /*
1417  * suspend the whole driver as soon as the first interface is suspended
1418  * resume only when the last interface is resumed
1419  */
1420 
1421 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1422 {
1423 	struct usbnet		*dev = usb_get_intfdata(intf);
1424 
1425 	if (!dev->suspend_count++) {
1426 		spin_lock_irq(&dev->txq.lock);
1427 		/* don't autosuspend while transmitting */
1428 		if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
1429 			spin_unlock_irq(&dev->txq.lock);
1430 			return -EBUSY;
1431 		} else {
1432 			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1433 			spin_unlock_irq(&dev->txq.lock);
1434 		}
1435 		/*
1436 		 * accelerate emptying of the rx and queues, to avoid
1437 		 * having everything error out.
1438 		 */
1439 		netif_device_detach (dev->net);
1440 		usbnet_terminate_urbs(dev);
1441 		usb_kill_urb(dev->interrupt);
1442 
1443 		/*
1444 		 * reattach so runtime management can use and
1445 		 * wake the device
1446 		 */
1447 		netif_device_attach (dev->net);
1448 	}
1449 	return 0;
1450 }
1451 EXPORT_SYMBOL_GPL(usbnet_suspend);
1452 
1453 int usbnet_resume (struct usb_interface *intf)
1454 {
1455 	struct usbnet		*dev = usb_get_intfdata(intf);
1456 	struct sk_buff          *skb;
1457 	struct urb              *res;
1458 	int                     retval;
1459 
1460 	if (!--dev->suspend_count) {
1461 		spin_lock_irq(&dev->txq.lock);
1462 		while ((res = usb_get_from_anchor(&dev->deferred))) {
1463 
1464 			printk(KERN_INFO"%s has delayed data\n", __func__);
1465 			skb = (struct sk_buff *)res->context;
1466 			retval = usb_submit_urb(res, GFP_ATOMIC);
1467 			if (retval < 0) {
1468 				dev_kfree_skb_any(skb);
1469 				usb_free_urb(res);
1470 				usb_autopm_put_interface_async(dev->intf);
1471 			} else {
1472 				dev->net->trans_start = jiffies;
1473 				__skb_queue_tail(&dev->txq, skb);
1474 			}
1475 		}
1476 
1477 		smp_mb();
1478 		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1479 		spin_unlock_irq(&dev->txq.lock);
1480 		if (!(dev->txq.qlen >= TX_QLEN(dev)))
1481 			netif_start_queue(dev->net);
1482 		tasklet_schedule (&dev->bh);
1483 	}
1484 	return 0;
1485 }
1486 EXPORT_SYMBOL_GPL(usbnet_resume);
1487 
1488 
1489 /*-------------------------------------------------------------------------*/
1490 
1491 static int __init usbnet_init(void)
1492 {
1493 	/* compiler should optimize this out */
1494 	BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1495 			< sizeof (struct skb_data));
1496 
1497 	random_ether_addr(node_id);
1498 	return 0;
1499 }
1500 module_init(usbnet_init);
1501 
1502 static void __exit usbnet_exit(void)
1503 {
1504 }
1505 module_exit(usbnet_exit);
1506 
1507 MODULE_AUTHOR("David Brownell");
1508 MODULE_DESCRIPTION("USB network driver framework");
1509 MODULE_LICENSE("GPL");
1510