xref: /linux/drivers/net/usb/usbnet.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  * USB Network driver infrastructure
3  * Copyright (C) 2000-2005 by David Brownell
4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 
21 /*
22  * This is a generic "USB networking" framework that works with several
23  * kinds of full and high speed networking devices:  host-to-host cables,
24  * smart usb peripherals, and actual Ethernet adapters.
25  *
26  * These devices usually differ in terms of control protocols (if they
27  * even have one!) and sometimes they define new framing to wrap or batch
28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
30  * issues can usefully be addressed by this framework.
31  */
32 
33 // #define	DEBUG			// error path messages, extra info
34 // #define	VERBOSE			// more; success messages
35 
36 #include <linux/module.h>
37 #include <linux/init.h>
38 #include <linux/netdevice.h>
39 #include <linux/etherdevice.h>
40 #include <linux/ctype.h>
41 #include <linux/ethtool.h>
42 #include <linux/workqueue.h>
43 #include <linux/mii.h>
44 #include <linux/usb.h>
45 #include <linux/usb/usbnet.h>
46 #include <linux/slab.h>
47 #include <linux/kernel.h>
48 
49 #define DRIVER_VERSION		"22-Aug-2005"
50 
51 
52 /*-------------------------------------------------------------------------*/
53 
54 /*
55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
56  * Several dozen bytes of IPv4 data can fit in two such transactions.
57  * One maximum size Ethernet packet takes twenty four of them.
58  * For high speed, each frame comfortably fits almost 36 max size
59  * Ethernet packets (so queues should be bigger).
60  *
61  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
62  * let the USB host controller be busy for 5msec or more before an irq
63  * is required, under load.  Jumbograms change the equation.
64  */
65 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
66 #define	RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
67 			(RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
68 #define	TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
69 			(RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
70 
71 // reawaken network queue this soon after stopping; else watchdog barks
72 #define TX_TIMEOUT_JIFFIES	(5*HZ)
73 
74 // throttle rx/tx briefly after some faults, so khubd might disconnect()
75 // us (it polls at HZ/4 usually) before we report too many false errors.
76 #define THROTTLE_JIFFIES	(HZ/8)
77 
78 // between wakeups
79 #define UNLINK_TIMEOUT_MS	3
80 
81 /*-------------------------------------------------------------------------*/
82 
83 // randomly generated ethernet address
84 static u8	node_id [ETH_ALEN];
85 
86 static const char driver_name [] = "usbnet";
87 
88 /* use ethtool to change the level for any given device */
89 static int msg_level = -1;
90 module_param (msg_level, int, 0);
91 MODULE_PARM_DESC (msg_level, "Override default message level");
92 
93 /*-------------------------------------------------------------------------*/
94 
95 /* handles CDC Ethernet and many other network "bulk data" interfaces */
96 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
97 {
98 	int				tmp;
99 	struct usb_host_interface	*alt = NULL;
100 	struct usb_host_endpoint	*in = NULL, *out = NULL;
101 	struct usb_host_endpoint	*status = NULL;
102 
103 	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
104 		unsigned	ep;
105 
106 		in = out = status = NULL;
107 		alt = intf->altsetting + tmp;
108 
109 		/* take the first altsetting with in-bulk + out-bulk;
110 		 * remember any status endpoint, just in case;
111 		 * ignore other endpoints and altsetttings.
112 		 */
113 		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
114 			struct usb_host_endpoint	*e;
115 			int				intr = 0;
116 
117 			e = alt->endpoint + ep;
118 			switch (e->desc.bmAttributes) {
119 			case USB_ENDPOINT_XFER_INT:
120 				if (!usb_endpoint_dir_in(&e->desc))
121 					continue;
122 				intr = 1;
123 				/* FALLTHROUGH */
124 			case USB_ENDPOINT_XFER_BULK:
125 				break;
126 			default:
127 				continue;
128 			}
129 			if (usb_endpoint_dir_in(&e->desc)) {
130 				if (!intr && !in)
131 					in = e;
132 				else if (intr && !status)
133 					status = e;
134 			} else {
135 				if (!out)
136 					out = e;
137 			}
138 		}
139 		if (in && out)
140 			break;
141 	}
142 	if (!alt || !in || !out)
143 		return -EINVAL;
144 
145 	if (alt->desc.bAlternateSetting != 0 ||
146 	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
147 		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
148 				alt->desc.bAlternateSetting);
149 		if (tmp < 0)
150 			return tmp;
151 	}
152 
153 	dev->in = usb_rcvbulkpipe (dev->udev,
154 			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
155 	dev->out = usb_sndbulkpipe (dev->udev,
156 			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
157 	dev->status = status;
158 	return 0;
159 }
160 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
161 
162 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
163 {
164 	int 		tmp, i;
165 	unsigned char	buf [13];
166 
167 	tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
168 	if (tmp != 12) {
169 		dev_dbg(&dev->udev->dev,
170 			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
171 		if (tmp >= 0)
172 			tmp = -EINVAL;
173 		return tmp;
174 	}
175 	for (i = tmp = 0; i < 6; i++, tmp += 2)
176 		dev->net->dev_addr [i] =
177 			(hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
178 	return 0;
179 }
180 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
181 
182 static void intr_complete (struct urb *urb);
183 
184 static int init_status (struct usbnet *dev, struct usb_interface *intf)
185 {
186 	char		*buf = NULL;
187 	unsigned	pipe = 0;
188 	unsigned	maxp;
189 	unsigned	period;
190 
191 	if (!dev->driver_info->status)
192 		return 0;
193 
194 	pipe = usb_rcvintpipe (dev->udev,
195 			dev->status->desc.bEndpointAddress
196 				& USB_ENDPOINT_NUMBER_MASK);
197 	maxp = usb_maxpacket (dev->udev, pipe, 0);
198 
199 	/* avoid 1 msec chatter:  min 8 msec poll rate */
200 	period = max ((int) dev->status->desc.bInterval,
201 		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
202 
203 	buf = kmalloc (maxp, GFP_KERNEL);
204 	if (buf) {
205 		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
206 		if (!dev->interrupt) {
207 			kfree (buf);
208 			return -ENOMEM;
209 		} else {
210 			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
211 				buf, maxp, intr_complete, dev, period);
212 			dev_dbg(&intf->dev,
213 				"status ep%din, %d bytes period %d\n",
214 				usb_pipeendpoint(pipe), maxp, period);
215 		}
216 	}
217 	return 0;
218 }
219 
220 /* Passes this packet up the stack, updating its accounting.
221  * Some link protocols batch packets, so their rx_fixup paths
222  * can return clones as well as just modify the original skb.
223  */
224 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
225 {
226 	int	status;
227 
228 	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
229 		skb_queue_tail(&dev->rxq_pause, skb);
230 		return;
231 	}
232 
233 	skb->protocol = eth_type_trans (skb, dev->net);
234 	dev->net->stats.rx_packets++;
235 	dev->net->stats.rx_bytes += skb->len;
236 
237 	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
238 		  skb->len + sizeof (struct ethhdr), skb->protocol);
239 	memset (skb->cb, 0, sizeof (struct skb_data));
240 	status = netif_rx (skb);
241 	if (status != NET_RX_SUCCESS)
242 		netif_dbg(dev, rx_err, dev->net,
243 			  "netif_rx status %d\n", status);
244 }
245 EXPORT_SYMBOL_GPL(usbnet_skb_return);
246 
247 
248 /*-------------------------------------------------------------------------
249  *
250  * Network Device Driver (peer link to "Host Device", from USB host)
251  *
252  *-------------------------------------------------------------------------*/
253 
254 int usbnet_change_mtu (struct net_device *net, int new_mtu)
255 {
256 	struct usbnet	*dev = netdev_priv(net);
257 	int		ll_mtu = new_mtu + net->hard_header_len;
258 	int		old_hard_mtu = dev->hard_mtu;
259 	int		old_rx_urb_size = dev->rx_urb_size;
260 
261 	if (new_mtu <= 0)
262 		return -EINVAL;
263 	// no second zero-length packet read wanted after mtu-sized packets
264 	if ((ll_mtu % dev->maxpacket) == 0)
265 		return -EDOM;
266 	net->mtu = new_mtu;
267 
268 	dev->hard_mtu = net->mtu + net->hard_header_len;
269 	if (dev->rx_urb_size == old_hard_mtu) {
270 		dev->rx_urb_size = dev->hard_mtu;
271 		if (dev->rx_urb_size > old_rx_urb_size)
272 			usbnet_unlink_rx_urbs(dev);
273 	}
274 
275 	return 0;
276 }
277 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
278 
279 /*-------------------------------------------------------------------------*/
280 
281 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
282  * completion callbacks.  2.5 should have fixed those bugs...
283  */
284 
285 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
286 {
287 	unsigned long		flags;
288 
289 	spin_lock_irqsave(&list->lock, flags);
290 	__skb_unlink(skb, list);
291 	spin_unlock(&list->lock);
292 	spin_lock(&dev->done.lock);
293 	__skb_queue_tail(&dev->done, skb);
294 	if (dev->done.qlen == 1)
295 		tasklet_schedule(&dev->bh);
296 	spin_unlock_irqrestore(&dev->done.lock, flags);
297 }
298 
299 /* some work can't be done in tasklets, so we use keventd
300  *
301  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
302  * but tasklet_schedule() doesn't.  hope the failure is rare.
303  */
304 void usbnet_defer_kevent (struct usbnet *dev, int work)
305 {
306 	set_bit (work, &dev->flags);
307 	if (!schedule_work (&dev->kevent))
308 		netdev_err(dev->net, "kevent %d may have been dropped\n", work);
309 	else
310 		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
311 }
312 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
313 
314 /*-------------------------------------------------------------------------*/
315 
316 static void rx_complete (struct urb *urb);
317 
318 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
319 {
320 	struct sk_buff		*skb;
321 	struct skb_data		*entry;
322 	int			retval = 0;
323 	unsigned long		lockflags;
324 	size_t			size = dev->rx_urb_size;
325 
326 	if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
327 		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
328 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
329 		usb_free_urb (urb);
330 		return -ENOMEM;
331 	}
332 	skb_reserve (skb, NET_IP_ALIGN);
333 
334 	entry = (struct skb_data *) skb->cb;
335 	entry->urb = urb;
336 	entry->dev = dev;
337 	entry->state = rx_start;
338 	entry->length = 0;
339 
340 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
341 		skb->data, size, rx_complete, skb);
342 
343 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
344 
345 	if (netif_running (dev->net) &&
346 	    netif_device_present (dev->net) &&
347 	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
348 	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
349 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
350 		case -EPIPE:
351 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
352 			break;
353 		case -ENOMEM:
354 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
355 			break;
356 		case -ENODEV:
357 			netif_dbg(dev, ifdown, dev->net, "device gone\n");
358 			netif_device_detach (dev->net);
359 			break;
360 		case -EHOSTUNREACH:
361 			retval = -ENOLINK;
362 			break;
363 		default:
364 			netif_dbg(dev, rx_err, dev->net,
365 				  "rx submit, %d\n", retval);
366 			tasklet_schedule (&dev->bh);
367 			break;
368 		case 0:
369 			__skb_queue_tail (&dev->rxq, skb);
370 		}
371 	} else {
372 		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
373 		retval = -ENOLINK;
374 	}
375 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
376 	if (retval) {
377 		dev_kfree_skb_any (skb);
378 		usb_free_urb (urb);
379 	}
380 	return retval;
381 }
382 
383 
384 /*-------------------------------------------------------------------------*/
385 
386 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
387 {
388 	if (dev->driver_info->rx_fixup &&
389 	    !dev->driver_info->rx_fixup (dev, skb))
390 		goto error;
391 	// else network stack removes extra byte if we forced a short packet
392 
393 	if (skb->len)
394 		usbnet_skb_return (dev, skb);
395 	else {
396 		netif_dbg(dev, rx_err, dev->net, "drop\n");
397 error:
398 		dev->net->stats.rx_errors++;
399 		skb_queue_tail (&dev->done, skb);
400 	}
401 }
402 
403 /*-------------------------------------------------------------------------*/
404 
405 static void rx_complete (struct urb *urb)
406 {
407 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
408 	struct skb_data		*entry = (struct skb_data *) skb->cb;
409 	struct usbnet		*dev = entry->dev;
410 	int			urb_status = urb->status;
411 
412 	skb_put (skb, urb->actual_length);
413 	entry->state = rx_done;
414 	entry->urb = NULL;
415 
416 	switch (urb_status) {
417 	/* success */
418 	case 0:
419 		if (skb->len < dev->net->hard_header_len) {
420 			entry->state = rx_cleanup;
421 			dev->net->stats.rx_errors++;
422 			dev->net->stats.rx_length_errors++;
423 			netif_dbg(dev, rx_err, dev->net,
424 				  "rx length %d\n", skb->len);
425 		}
426 		break;
427 
428 	/* stalls need manual reset. this is rare ... except that
429 	 * when going through USB 2.0 TTs, unplug appears this way.
430 	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
431 	 * storm, recovering as needed.
432 	 */
433 	case -EPIPE:
434 		dev->net->stats.rx_errors++;
435 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
436 		// FALLTHROUGH
437 
438 	/* software-driven interface shutdown */
439 	case -ECONNRESET:		/* async unlink */
440 	case -ESHUTDOWN:		/* hardware gone */
441 		netif_dbg(dev, ifdown, dev->net,
442 			  "rx shutdown, code %d\n", urb_status);
443 		goto block;
444 
445 	/* we get controller i/o faults during khubd disconnect() delays.
446 	 * throttle down resubmits, to avoid log floods; just temporarily,
447 	 * so we still recover when the fault isn't a khubd delay.
448 	 */
449 	case -EPROTO:
450 	case -ETIME:
451 	case -EILSEQ:
452 		dev->net->stats.rx_errors++;
453 		if (!timer_pending (&dev->delay)) {
454 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
455 			netif_dbg(dev, link, dev->net,
456 				  "rx throttle %d\n", urb_status);
457 		}
458 block:
459 		entry->state = rx_cleanup;
460 		entry->urb = urb;
461 		urb = NULL;
462 		break;
463 
464 	/* data overrun ... flush fifo? */
465 	case -EOVERFLOW:
466 		dev->net->stats.rx_over_errors++;
467 		// FALLTHROUGH
468 
469 	default:
470 		entry->state = rx_cleanup;
471 		dev->net->stats.rx_errors++;
472 		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
473 		break;
474 	}
475 
476 	defer_bh(dev, skb, &dev->rxq);
477 
478 	if (urb) {
479 		if (netif_running (dev->net) &&
480 		    !test_bit (EVENT_RX_HALT, &dev->flags)) {
481 			rx_submit (dev, urb, GFP_ATOMIC);
482 			return;
483 		}
484 		usb_free_urb (urb);
485 	}
486 	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
487 }
488 
489 static void intr_complete (struct urb *urb)
490 {
491 	struct usbnet	*dev = urb->context;
492 	int		status = urb->status;
493 
494 	switch (status) {
495 	/* success */
496 	case 0:
497 		dev->driver_info->status(dev, urb);
498 		break;
499 
500 	/* software-driven interface shutdown */
501 	case -ENOENT:		/* urb killed */
502 	case -ESHUTDOWN:	/* hardware gone */
503 		netif_dbg(dev, ifdown, dev->net,
504 			  "intr shutdown, code %d\n", status);
505 		return;
506 
507 	/* NOTE:  not throttling like RX/TX, since this endpoint
508 	 * already polls infrequently
509 	 */
510 	default:
511 		netdev_dbg(dev->net, "intr status %d\n", status);
512 		break;
513 	}
514 
515 	if (!netif_running (dev->net))
516 		return;
517 
518 	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
519 	status = usb_submit_urb (urb, GFP_ATOMIC);
520 	if (status != 0)
521 		netif_err(dev, timer, dev->net,
522 			  "intr resubmit --> %d\n", status);
523 }
524 
525 /*-------------------------------------------------------------------------*/
526 void usbnet_pause_rx(struct usbnet *dev)
527 {
528 	set_bit(EVENT_RX_PAUSED, &dev->flags);
529 
530 	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
531 }
532 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
533 
534 void usbnet_resume_rx(struct usbnet *dev)
535 {
536 	struct sk_buff *skb;
537 	int num = 0;
538 
539 	clear_bit(EVENT_RX_PAUSED, &dev->flags);
540 
541 	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
542 		usbnet_skb_return(dev, skb);
543 		num++;
544 	}
545 
546 	tasklet_schedule(&dev->bh);
547 
548 	netif_dbg(dev, rx_status, dev->net,
549 		  "paused rx queue disabled, %d skbs requeued\n", num);
550 }
551 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
552 
553 void usbnet_purge_paused_rxq(struct usbnet *dev)
554 {
555 	skb_queue_purge(&dev->rxq_pause);
556 }
557 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
558 
559 /*-------------------------------------------------------------------------*/
560 
561 // unlink pending rx/tx; completion handlers do all other cleanup
562 
563 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
564 {
565 	unsigned long		flags;
566 	struct sk_buff		*skb, *skbnext;
567 	int			count = 0;
568 
569 	spin_lock_irqsave (&q->lock, flags);
570 	skb_queue_walk_safe(q, skb, skbnext) {
571 		struct skb_data		*entry;
572 		struct urb		*urb;
573 		int			retval;
574 
575 		entry = (struct skb_data *) skb->cb;
576 		urb = entry->urb;
577 
578 		// during some PM-driven resume scenarios,
579 		// these (async) unlinks complete immediately
580 		retval = usb_unlink_urb (urb);
581 		if (retval != -EINPROGRESS && retval != 0)
582 			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
583 		else
584 			count++;
585 	}
586 	spin_unlock_irqrestore (&q->lock, flags);
587 	return count;
588 }
589 
590 // Flush all pending rx urbs
591 // minidrivers may need to do this when the MTU changes
592 
593 void usbnet_unlink_rx_urbs(struct usbnet *dev)
594 {
595 	if (netif_running(dev->net)) {
596 		(void) unlink_urbs (dev, &dev->rxq);
597 		tasklet_schedule(&dev->bh);
598 	}
599 }
600 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
601 
602 /*-------------------------------------------------------------------------*/
603 
604 // precondition: never called in_interrupt
605 static void usbnet_terminate_urbs(struct usbnet *dev)
606 {
607 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
608 	DECLARE_WAITQUEUE(wait, current);
609 	int temp;
610 
611 	/* ensure there are no more active urbs */
612 	add_wait_queue(&unlink_wakeup, &wait);
613 	set_current_state(TASK_UNINTERRUPTIBLE);
614 	dev->wait = &unlink_wakeup;
615 	temp = unlink_urbs(dev, &dev->txq) +
616 		unlink_urbs(dev, &dev->rxq);
617 
618 	/* maybe wait for deletions to finish. */
619 	while (!skb_queue_empty(&dev->rxq)
620 		&& !skb_queue_empty(&dev->txq)
621 		&& !skb_queue_empty(&dev->done)) {
622 			schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
623 			set_current_state(TASK_UNINTERRUPTIBLE);
624 			netif_dbg(dev, ifdown, dev->net,
625 				  "waited for %d urb completions\n", temp);
626 	}
627 	set_current_state(TASK_RUNNING);
628 	dev->wait = NULL;
629 	remove_wait_queue(&unlink_wakeup, &wait);
630 }
631 
632 int usbnet_stop (struct net_device *net)
633 {
634 	struct usbnet		*dev = netdev_priv(net);
635 	struct driver_info	*info = dev->driver_info;
636 	int			retval;
637 
638 	netif_stop_queue (net);
639 
640 	netif_info(dev, ifdown, dev->net,
641 		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
642 		   net->stats.rx_packets, net->stats.tx_packets,
643 		   net->stats.rx_errors, net->stats.tx_errors);
644 
645 	/* allow minidriver to stop correctly (wireless devices to turn off
646 	 * radio etc) */
647 	if (info->stop) {
648 		retval = info->stop(dev);
649 		if (retval < 0)
650 			netif_info(dev, ifdown, dev->net,
651 				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
652 				   retval,
653 				   dev->udev->bus->bus_name, dev->udev->devpath,
654 				   info->description);
655 	}
656 
657 	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
658 		usbnet_terminate_urbs(dev);
659 
660 	usb_kill_urb(dev->interrupt);
661 
662 	usbnet_purge_paused_rxq(dev);
663 
664 	/* deferred work (task, timer, softirq) must also stop.
665 	 * can't flush_scheduled_work() until we drop rtnl (later),
666 	 * else workers could deadlock; so make workers a NOP.
667 	 */
668 	dev->flags = 0;
669 	del_timer_sync (&dev->delay);
670 	tasklet_kill (&dev->bh);
671 	if (info->manage_power)
672 		info->manage_power(dev, 0);
673 	else
674 		usb_autopm_put_interface(dev->intf);
675 
676 	return 0;
677 }
678 EXPORT_SYMBOL_GPL(usbnet_stop);
679 
680 /*-------------------------------------------------------------------------*/
681 
682 // posts reads, and enables write queuing
683 
684 // precondition: never called in_interrupt
685 
686 int usbnet_open (struct net_device *net)
687 {
688 	struct usbnet		*dev = netdev_priv(net);
689 	int			retval;
690 	struct driver_info	*info = dev->driver_info;
691 
692 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
693 		netif_info(dev, ifup, dev->net,
694 			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
695 			   retval,
696 			   dev->udev->bus->bus_name,
697 			   dev->udev->devpath,
698 			   info->description);
699 		goto done_nopm;
700 	}
701 
702 	// put into "known safe" state
703 	if (info->reset && (retval = info->reset (dev)) < 0) {
704 		netif_info(dev, ifup, dev->net,
705 			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
706 			   retval,
707 			   dev->udev->bus->bus_name,
708 			   dev->udev->devpath,
709 			   info->description);
710 		goto done;
711 	}
712 
713 	// insist peer be connected
714 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
715 		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
716 		goto done;
717 	}
718 
719 	/* start any status interrupt transfer */
720 	if (dev->interrupt) {
721 		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
722 		if (retval < 0) {
723 			netif_err(dev, ifup, dev->net,
724 				  "intr submit %d\n", retval);
725 			goto done;
726 		}
727 	}
728 
729 	netif_start_queue (net);
730 	netif_info(dev, ifup, dev->net,
731 		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
732 		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
733 		   dev->net->mtu,
734 		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
735 		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
736 		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
737 		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
738 		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
739 		   "simple");
740 
741 	// delay posting reads until we're fully open
742 	tasklet_schedule (&dev->bh);
743 	if (info->manage_power) {
744 		retval = info->manage_power(dev, 1);
745 		if (retval < 0)
746 			goto done;
747 		usb_autopm_put_interface(dev->intf);
748 	}
749 	return retval;
750 
751 done:
752 	usb_autopm_put_interface(dev->intf);
753 done_nopm:
754 	return retval;
755 }
756 EXPORT_SYMBOL_GPL(usbnet_open);
757 
758 /*-------------------------------------------------------------------------*/
759 
760 /* ethtool methods; minidrivers may need to add some more, but
761  * they'll probably want to use this base set.
762  */
763 
764 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
765 {
766 	struct usbnet *dev = netdev_priv(net);
767 
768 	if (!dev->mii.mdio_read)
769 		return -EOPNOTSUPP;
770 
771 	return mii_ethtool_gset(&dev->mii, cmd);
772 }
773 EXPORT_SYMBOL_GPL(usbnet_get_settings);
774 
775 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
776 {
777 	struct usbnet *dev = netdev_priv(net);
778 	int retval;
779 
780 	if (!dev->mii.mdio_write)
781 		return -EOPNOTSUPP;
782 
783 	retval = mii_ethtool_sset(&dev->mii, cmd);
784 
785 	/* link speed/duplex might have changed */
786 	if (dev->driver_info->link_reset)
787 		dev->driver_info->link_reset(dev);
788 
789 	return retval;
790 
791 }
792 EXPORT_SYMBOL_GPL(usbnet_set_settings);
793 
794 u32 usbnet_get_link (struct net_device *net)
795 {
796 	struct usbnet *dev = netdev_priv(net);
797 
798 	/* If a check_connect is defined, return its result */
799 	if (dev->driver_info->check_connect)
800 		return dev->driver_info->check_connect (dev) == 0;
801 
802 	/* if the device has mii operations, use those */
803 	if (dev->mii.mdio_read)
804 		return mii_link_ok(&dev->mii);
805 
806 	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
807 	return ethtool_op_get_link(net);
808 }
809 EXPORT_SYMBOL_GPL(usbnet_get_link);
810 
811 int usbnet_nway_reset(struct net_device *net)
812 {
813 	struct usbnet *dev = netdev_priv(net);
814 
815 	if (!dev->mii.mdio_write)
816 		return -EOPNOTSUPP;
817 
818 	return mii_nway_restart(&dev->mii);
819 }
820 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
821 
822 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
823 {
824 	struct usbnet *dev = netdev_priv(net);
825 
826 	strncpy (info->driver, dev->driver_name, sizeof info->driver);
827 	strncpy (info->version, DRIVER_VERSION, sizeof info->version);
828 	strncpy (info->fw_version, dev->driver_info->description,
829 		sizeof info->fw_version);
830 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
831 }
832 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
833 
834 u32 usbnet_get_msglevel (struct net_device *net)
835 {
836 	struct usbnet *dev = netdev_priv(net);
837 
838 	return dev->msg_enable;
839 }
840 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
841 
842 void usbnet_set_msglevel (struct net_device *net, u32 level)
843 {
844 	struct usbnet *dev = netdev_priv(net);
845 
846 	dev->msg_enable = level;
847 }
848 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
849 
850 /* drivers may override default ethtool_ops in their bind() routine */
851 static const struct ethtool_ops usbnet_ethtool_ops = {
852 	.get_settings		= usbnet_get_settings,
853 	.set_settings		= usbnet_set_settings,
854 	.get_link		= usbnet_get_link,
855 	.nway_reset		= usbnet_nway_reset,
856 	.get_drvinfo		= usbnet_get_drvinfo,
857 	.get_msglevel		= usbnet_get_msglevel,
858 	.set_msglevel		= usbnet_set_msglevel,
859 };
860 
861 /*-------------------------------------------------------------------------*/
862 
863 /* work that cannot be done in interrupt context uses keventd.
864  *
865  * NOTE:  with 2.5 we could do more of this using completion callbacks,
866  * especially now that control transfers can be queued.
867  */
868 static void
869 kevent (struct work_struct *work)
870 {
871 	struct usbnet		*dev =
872 		container_of(work, struct usbnet, kevent);
873 	int			status;
874 
875 	/* usb_clear_halt() needs a thread context */
876 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
877 		unlink_urbs (dev, &dev->txq);
878 		status = usb_autopm_get_interface(dev->intf);
879 		if (status < 0)
880 			goto fail_pipe;
881 		status = usb_clear_halt (dev->udev, dev->out);
882 		usb_autopm_put_interface(dev->intf);
883 		if (status < 0 &&
884 		    status != -EPIPE &&
885 		    status != -ESHUTDOWN) {
886 			if (netif_msg_tx_err (dev))
887 fail_pipe:
888 				netdev_err(dev->net, "can't clear tx halt, status %d\n",
889 					   status);
890 		} else {
891 			clear_bit (EVENT_TX_HALT, &dev->flags);
892 			if (status != -ESHUTDOWN)
893 				netif_wake_queue (dev->net);
894 		}
895 	}
896 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
897 		unlink_urbs (dev, &dev->rxq);
898 		status = usb_autopm_get_interface(dev->intf);
899 		if (status < 0)
900 			goto fail_halt;
901 		status = usb_clear_halt (dev->udev, dev->in);
902 		usb_autopm_put_interface(dev->intf);
903 		if (status < 0 &&
904 		    status != -EPIPE &&
905 		    status != -ESHUTDOWN) {
906 			if (netif_msg_rx_err (dev))
907 fail_halt:
908 				netdev_err(dev->net, "can't clear rx halt, status %d\n",
909 					   status);
910 		} else {
911 			clear_bit (EVENT_RX_HALT, &dev->flags);
912 			tasklet_schedule (&dev->bh);
913 		}
914 	}
915 
916 	/* tasklet could resubmit itself forever if memory is tight */
917 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
918 		struct urb	*urb = NULL;
919 		int resched = 1;
920 
921 		if (netif_running (dev->net))
922 			urb = usb_alloc_urb (0, GFP_KERNEL);
923 		else
924 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
925 		if (urb != NULL) {
926 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
927 			status = usb_autopm_get_interface(dev->intf);
928 			if (status < 0)
929 				goto fail_lowmem;
930 			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
931 				resched = 0;
932 			usb_autopm_put_interface(dev->intf);
933 fail_lowmem:
934 			if (resched)
935 				tasklet_schedule (&dev->bh);
936 		}
937 	}
938 
939 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
940 		struct driver_info	*info = dev->driver_info;
941 		int			retval = 0;
942 
943 		clear_bit (EVENT_LINK_RESET, &dev->flags);
944 		status = usb_autopm_get_interface(dev->intf);
945 		if (status < 0)
946 			goto skip_reset;
947 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
948 			usb_autopm_put_interface(dev->intf);
949 skip_reset:
950 			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
951 				    retval,
952 				    dev->udev->bus->bus_name,
953 				    dev->udev->devpath,
954 				    info->description);
955 		} else {
956 			usb_autopm_put_interface(dev->intf);
957 		}
958 	}
959 
960 	if (dev->flags)
961 		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
962 }
963 
964 /*-------------------------------------------------------------------------*/
965 
966 static void tx_complete (struct urb *urb)
967 {
968 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
969 	struct skb_data		*entry = (struct skb_data *) skb->cb;
970 	struct usbnet		*dev = entry->dev;
971 
972 	if (urb->status == 0) {
973 		dev->net->stats.tx_packets++;
974 		dev->net->stats.tx_bytes += entry->length;
975 	} else {
976 		dev->net->stats.tx_errors++;
977 
978 		switch (urb->status) {
979 		case -EPIPE:
980 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
981 			break;
982 
983 		/* software-driven interface shutdown */
984 		case -ECONNRESET:		// async unlink
985 		case -ESHUTDOWN:		// hardware gone
986 			break;
987 
988 		// like rx, tx gets controller i/o faults during khubd delays
989 		// and so it uses the same throttling mechanism.
990 		case -EPROTO:
991 		case -ETIME:
992 		case -EILSEQ:
993 			usb_mark_last_busy(dev->udev);
994 			if (!timer_pending (&dev->delay)) {
995 				mod_timer (&dev->delay,
996 					jiffies + THROTTLE_JIFFIES);
997 				netif_dbg(dev, link, dev->net,
998 					  "tx throttle %d\n", urb->status);
999 			}
1000 			netif_stop_queue (dev->net);
1001 			break;
1002 		default:
1003 			netif_dbg(dev, tx_err, dev->net,
1004 				  "tx err %d\n", entry->urb->status);
1005 			break;
1006 		}
1007 	}
1008 
1009 	usb_autopm_put_interface_async(dev->intf);
1010 	urb->dev = NULL;
1011 	entry->state = tx_done;
1012 	defer_bh(dev, skb, &dev->txq);
1013 }
1014 
1015 /*-------------------------------------------------------------------------*/
1016 
1017 void usbnet_tx_timeout (struct net_device *net)
1018 {
1019 	struct usbnet		*dev = netdev_priv(net);
1020 
1021 	unlink_urbs (dev, &dev->txq);
1022 	tasklet_schedule (&dev->bh);
1023 
1024 	// FIXME: device recovery -- reset?
1025 }
1026 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1027 
1028 /*-------------------------------------------------------------------------*/
1029 
1030 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1031 				     struct net_device *net)
1032 {
1033 	struct usbnet		*dev = netdev_priv(net);
1034 	int			length;
1035 	struct urb		*urb = NULL;
1036 	struct skb_data		*entry;
1037 	struct driver_info	*info = dev->driver_info;
1038 	unsigned long		flags;
1039 	int retval;
1040 
1041 	// some devices want funky USB-level framing, for
1042 	// win32 driver (usually) and/or hardware quirks
1043 	if (info->tx_fixup) {
1044 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1045 		if (!skb) {
1046 			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1047 			goto drop;
1048 		}
1049 	}
1050 	length = skb->len;
1051 
1052 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1053 		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1054 		goto drop;
1055 	}
1056 
1057 	entry = (struct skb_data *) skb->cb;
1058 	entry->urb = urb;
1059 	entry->dev = dev;
1060 	entry->state = tx_start;
1061 	entry->length = length;
1062 
1063 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1064 			skb->data, skb->len, tx_complete, skb);
1065 
1066 	/* don't assume the hardware handles USB_ZERO_PACKET
1067 	 * NOTE:  strictly conforming cdc-ether devices should expect
1068 	 * the ZLP here, but ignore the one-byte packet.
1069 	 */
1070 	if (length % dev->maxpacket == 0) {
1071 		if (!(info->flags & FLAG_SEND_ZLP)) {
1072 			urb->transfer_buffer_length++;
1073 			if (skb_tailroom(skb)) {
1074 				skb->data[skb->len] = 0;
1075 				__skb_put(skb, 1);
1076 			}
1077 		} else
1078 			urb->transfer_flags |= URB_ZERO_PACKET;
1079 	}
1080 
1081 	spin_lock_irqsave(&dev->txq.lock, flags);
1082 	retval = usb_autopm_get_interface_async(dev->intf);
1083 	if (retval < 0) {
1084 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1085 		goto drop;
1086 	}
1087 
1088 #ifdef CONFIG_PM
1089 	/* if this triggers the device is still a sleep */
1090 	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1091 		/* transmission will be done in resume */
1092 		usb_anchor_urb(urb, &dev->deferred);
1093 		/* no use to process more packets */
1094 		netif_stop_queue(net);
1095 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1096 		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1097 		goto deferred;
1098 	}
1099 #endif
1100 
1101 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1102 	case -EPIPE:
1103 		netif_stop_queue (net);
1104 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1105 		usb_autopm_put_interface_async(dev->intf);
1106 		break;
1107 	default:
1108 		usb_autopm_put_interface_async(dev->intf);
1109 		netif_dbg(dev, tx_err, dev->net,
1110 			  "tx: submit urb err %d\n", retval);
1111 		break;
1112 	case 0:
1113 		net->trans_start = jiffies;
1114 		__skb_queue_tail (&dev->txq, skb);
1115 		if (dev->txq.qlen >= TX_QLEN (dev))
1116 			netif_stop_queue (net);
1117 	}
1118 	spin_unlock_irqrestore (&dev->txq.lock, flags);
1119 
1120 	if (retval) {
1121 		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1122 drop:
1123 		dev->net->stats.tx_dropped++;
1124 		if (skb)
1125 			dev_kfree_skb_any (skb);
1126 		usb_free_urb (urb);
1127 	} else
1128 		netif_dbg(dev, tx_queued, dev->net,
1129 			  "> tx, len %d, type 0x%x\n", length, skb->protocol);
1130 #ifdef CONFIG_PM
1131 deferred:
1132 #endif
1133 	return NETDEV_TX_OK;
1134 }
1135 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1136 
1137 /*-------------------------------------------------------------------------*/
1138 
1139 // tasklet (work deferred from completions, in_irq) or timer
1140 
1141 static void usbnet_bh (unsigned long param)
1142 {
1143 	struct usbnet		*dev = (struct usbnet *) param;
1144 	struct sk_buff		*skb;
1145 	struct skb_data		*entry;
1146 
1147 	while ((skb = skb_dequeue (&dev->done))) {
1148 		entry = (struct skb_data *) skb->cb;
1149 		switch (entry->state) {
1150 		case rx_done:
1151 			entry->state = rx_cleanup;
1152 			rx_process (dev, skb);
1153 			continue;
1154 		case tx_done:
1155 		case rx_cleanup:
1156 			usb_free_urb (entry->urb);
1157 			dev_kfree_skb (skb);
1158 			continue;
1159 		default:
1160 			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1161 		}
1162 	}
1163 
1164 	// waiting for all pending urbs to complete?
1165 	if (dev->wait) {
1166 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1167 			wake_up (dev->wait);
1168 		}
1169 
1170 	// or are we maybe short a few urbs?
1171 	} else if (netif_running (dev->net) &&
1172 		   netif_device_present (dev->net) &&
1173 		   !timer_pending (&dev->delay) &&
1174 		   !test_bit (EVENT_RX_HALT, &dev->flags)) {
1175 		int	temp = dev->rxq.qlen;
1176 		int	qlen = RX_QLEN (dev);
1177 
1178 		if (temp < qlen) {
1179 			struct urb	*urb;
1180 			int		i;
1181 
1182 			// don't refill the queue all at once
1183 			for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1184 				urb = usb_alloc_urb (0, GFP_ATOMIC);
1185 				if (urb != NULL) {
1186 					if (rx_submit (dev, urb, GFP_ATOMIC) ==
1187 					    -ENOLINK)
1188 						return;
1189 				}
1190 			}
1191 			if (temp != dev->rxq.qlen)
1192 				netif_dbg(dev, link, dev->net,
1193 					  "rxqlen %d --> %d\n",
1194 					  temp, dev->rxq.qlen);
1195 			if (dev->rxq.qlen < qlen)
1196 				tasklet_schedule (&dev->bh);
1197 		}
1198 		if (dev->txq.qlen < TX_QLEN (dev))
1199 			netif_wake_queue (dev->net);
1200 	}
1201 }
1202 
1203 
1204 /*-------------------------------------------------------------------------
1205  *
1206  * USB Device Driver support
1207  *
1208  *-------------------------------------------------------------------------*/
1209 
1210 // precondition: never called in_interrupt
1211 
1212 void usbnet_disconnect (struct usb_interface *intf)
1213 {
1214 	struct usbnet		*dev;
1215 	struct usb_device	*xdev;
1216 	struct net_device	*net;
1217 
1218 	dev = usb_get_intfdata(intf);
1219 	usb_set_intfdata(intf, NULL);
1220 	if (!dev)
1221 		return;
1222 
1223 	xdev = interface_to_usbdev (intf);
1224 
1225 	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1226 		   intf->dev.driver->name,
1227 		   xdev->bus->bus_name, xdev->devpath,
1228 		   dev->driver_info->description);
1229 
1230 	net = dev->net;
1231 	unregister_netdev (net);
1232 
1233 	/* we don't hold rtnl here ... */
1234 	flush_scheduled_work ();
1235 
1236 	if (dev->driver_info->unbind)
1237 		dev->driver_info->unbind (dev, intf);
1238 
1239 	free_netdev(net);
1240 	usb_put_dev (xdev);
1241 }
1242 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1243 
1244 static const struct net_device_ops usbnet_netdev_ops = {
1245 	.ndo_open		= usbnet_open,
1246 	.ndo_stop		= usbnet_stop,
1247 	.ndo_start_xmit		= usbnet_start_xmit,
1248 	.ndo_tx_timeout		= usbnet_tx_timeout,
1249 	.ndo_change_mtu		= usbnet_change_mtu,
1250 	.ndo_set_mac_address 	= eth_mac_addr,
1251 	.ndo_validate_addr	= eth_validate_addr,
1252 };
1253 
1254 /*-------------------------------------------------------------------------*/
1255 
1256 // precondition: never called in_interrupt
1257 
1258 static struct device_type wlan_type = {
1259 	.name	= "wlan",
1260 };
1261 
1262 static struct device_type wwan_type = {
1263 	.name	= "wwan",
1264 };
1265 
1266 int
1267 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1268 {
1269 	struct usbnet			*dev;
1270 	struct net_device		*net;
1271 	struct usb_host_interface	*interface;
1272 	struct driver_info		*info;
1273 	struct usb_device		*xdev;
1274 	int				status;
1275 	const char			*name;
1276 
1277 	name = udev->dev.driver->name;
1278 	info = (struct driver_info *) prod->driver_info;
1279 	if (!info) {
1280 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1281 		return -ENODEV;
1282 	}
1283 	xdev = interface_to_usbdev (udev);
1284 	interface = udev->cur_altsetting;
1285 
1286 	usb_get_dev (xdev);
1287 
1288 	status = -ENOMEM;
1289 
1290 	// set up our own records
1291 	net = alloc_etherdev(sizeof(*dev));
1292 	if (!net) {
1293 		dbg ("can't kmalloc dev");
1294 		goto out;
1295 	}
1296 
1297 	/* netdev_printk() needs this so do it as early as possible */
1298 	SET_NETDEV_DEV(net, &udev->dev);
1299 
1300 	dev = netdev_priv(net);
1301 	dev->udev = xdev;
1302 	dev->intf = udev;
1303 	dev->driver_info = info;
1304 	dev->driver_name = name;
1305 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1306 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1307 	skb_queue_head_init (&dev->rxq);
1308 	skb_queue_head_init (&dev->txq);
1309 	skb_queue_head_init (&dev->done);
1310 	skb_queue_head_init(&dev->rxq_pause);
1311 	dev->bh.func = usbnet_bh;
1312 	dev->bh.data = (unsigned long) dev;
1313 	INIT_WORK (&dev->kevent, kevent);
1314 	init_usb_anchor(&dev->deferred);
1315 	dev->delay.function = usbnet_bh;
1316 	dev->delay.data = (unsigned long) dev;
1317 	init_timer (&dev->delay);
1318 	mutex_init (&dev->phy_mutex);
1319 
1320 	dev->net = net;
1321 	strcpy (net->name, "usb%d");
1322 	memcpy (net->dev_addr, node_id, sizeof node_id);
1323 
1324 	/* rx and tx sides can use different message sizes;
1325 	 * bind() should set rx_urb_size in that case.
1326 	 */
1327 	dev->hard_mtu = net->mtu + net->hard_header_len;
1328 #if 0
1329 // dma_supported() is deeply broken on almost all architectures
1330 	// possible with some EHCI controllers
1331 	if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1332 		net->features |= NETIF_F_HIGHDMA;
1333 #endif
1334 
1335 	net->netdev_ops = &usbnet_netdev_ops;
1336 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1337 	net->ethtool_ops = &usbnet_ethtool_ops;
1338 
1339 	// allow device-specific bind/init procedures
1340 	// NOTE net->name still not usable ...
1341 	if (info->bind) {
1342 		status = info->bind (dev, udev);
1343 		if (status < 0)
1344 			goto out1;
1345 
1346 		// heuristic:  "usb%d" for links we know are two-host,
1347 		// else "eth%d" when there's reasonable doubt.  userspace
1348 		// can rename the link if it knows better.
1349 		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1350 		    (net->dev_addr [0] & 0x02) == 0)
1351 			strcpy (net->name, "eth%d");
1352 		/* WLAN devices should always be named "wlan%d" */
1353 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1354 			strcpy(net->name, "wlan%d");
1355 		/* WWAN devices should always be named "wwan%d" */
1356 		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1357 			strcpy(net->name, "wwan%d");
1358 
1359 		/* maybe the remote can't receive an Ethernet MTU */
1360 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1361 			net->mtu = dev->hard_mtu - net->hard_header_len;
1362 	} else if (!info->in || !info->out)
1363 		status = usbnet_get_endpoints (dev, udev);
1364 	else {
1365 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1366 		dev->out = usb_sndbulkpipe (xdev, info->out);
1367 		if (!(info->flags & FLAG_NO_SETINT))
1368 			status = usb_set_interface (xdev,
1369 				interface->desc.bInterfaceNumber,
1370 				interface->desc.bAlternateSetting);
1371 		else
1372 			status = 0;
1373 
1374 	}
1375 	if (status >= 0 && dev->status)
1376 		status = init_status (dev, udev);
1377 	if (status < 0)
1378 		goto out3;
1379 
1380 	if (!dev->rx_urb_size)
1381 		dev->rx_urb_size = dev->hard_mtu;
1382 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1383 
1384 	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1385 		SET_NETDEV_DEVTYPE(net, &wlan_type);
1386 	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1387 		SET_NETDEV_DEVTYPE(net, &wwan_type);
1388 
1389 	status = register_netdev (net);
1390 	if (status)
1391 		goto out3;
1392 	netif_info(dev, probe, dev->net,
1393 		   "register '%s' at usb-%s-%s, %s, %pM\n",
1394 		   udev->dev.driver->name,
1395 		   xdev->bus->bus_name, xdev->devpath,
1396 		   dev->driver_info->description,
1397 		   net->dev_addr);
1398 
1399 	// ok, it's ready to go.
1400 	usb_set_intfdata (udev, dev);
1401 
1402 	netif_device_attach (net);
1403 
1404 	if (dev->driver_info->flags & FLAG_LINK_INTR)
1405 		netif_carrier_off(net);
1406 
1407 	return 0;
1408 
1409 out3:
1410 	if (info->unbind)
1411 		info->unbind (dev, udev);
1412 out1:
1413 	free_netdev(net);
1414 out:
1415 	usb_put_dev(xdev);
1416 	return status;
1417 }
1418 EXPORT_SYMBOL_GPL(usbnet_probe);
1419 
1420 /*-------------------------------------------------------------------------*/
1421 
1422 /*
1423  * suspend the whole driver as soon as the first interface is suspended
1424  * resume only when the last interface is resumed
1425  */
1426 
1427 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1428 {
1429 	struct usbnet		*dev = usb_get_intfdata(intf);
1430 
1431 	if (!dev->suspend_count++) {
1432 		spin_lock_irq(&dev->txq.lock);
1433 		/* don't autosuspend while transmitting */
1434 		if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
1435 			spin_unlock_irq(&dev->txq.lock);
1436 			return -EBUSY;
1437 		} else {
1438 			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1439 			spin_unlock_irq(&dev->txq.lock);
1440 		}
1441 		/*
1442 		 * accelerate emptying of the rx and queues, to avoid
1443 		 * having everything error out.
1444 		 */
1445 		netif_device_detach (dev->net);
1446 		usbnet_terminate_urbs(dev);
1447 		usb_kill_urb(dev->interrupt);
1448 
1449 		/*
1450 		 * reattach so runtime management can use and
1451 		 * wake the device
1452 		 */
1453 		netif_device_attach (dev->net);
1454 	}
1455 	return 0;
1456 }
1457 EXPORT_SYMBOL_GPL(usbnet_suspend);
1458 
1459 int usbnet_resume (struct usb_interface *intf)
1460 {
1461 	struct usbnet		*dev = usb_get_intfdata(intf);
1462 	struct sk_buff          *skb;
1463 	struct urb              *res;
1464 	int                     retval;
1465 
1466 	if (!--dev->suspend_count) {
1467 		spin_lock_irq(&dev->txq.lock);
1468 		while ((res = usb_get_from_anchor(&dev->deferred))) {
1469 
1470 			skb = (struct sk_buff *)res->context;
1471 			retval = usb_submit_urb(res, GFP_ATOMIC);
1472 			if (retval < 0) {
1473 				dev_kfree_skb_any(skb);
1474 				usb_free_urb(res);
1475 				usb_autopm_put_interface_async(dev->intf);
1476 			} else {
1477 				dev->net->trans_start = jiffies;
1478 				__skb_queue_tail(&dev->txq, skb);
1479 			}
1480 		}
1481 
1482 		smp_mb();
1483 		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1484 		spin_unlock_irq(&dev->txq.lock);
1485 		if (!(dev->txq.qlen >= TX_QLEN(dev)))
1486 			netif_start_queue(dev->net);
1487 		tasklet_schedule (&dev->bh);
1488 	}
1489 	return 0;
1490 }
1491 EXPORT_SYMBOL_GPL(usbnet_resume);
1492 
1493 
1494 /*-------------------------------------------------------------------------*/
1495 
1496 static int __init usbnet_init(void)
1497 {
1498 	/* compiler should optimize this out */
1499 	BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1500 			< sizeof (struct skb_data));
1501 
1502 	random_ether_addr(node_id);
1503 	return 0;
1504 }
1505 module_init(usbnet_init);
1506 
1507 static void __exit usbnet_exit(void)
1508 {
1509 }
1510 module_exit(usbnet_exit);
1511 
1512 MODULE_AUTHOR("David Brownell");
1513 MODULE_DESCRIPTION("USB network driver framework");
1514 MODULE_LICENSE("GPL");
1515