13d4ec5f6f34f6bd16e29576a1e5cb0c1dd3dce9
[sfrench/cifs-2.6.git] / drivers / net / usb / usbnet.c
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, see <http://www.gnu.org/licenses/>.
18  */
19
20 /*
21  * This is a generic "USB networking" framework that works with several
22  * kinds of full and high speed networking devices:  host-to-host cables,
23  * smart usb peripherals, and actual Ethernet adapters.
24  *
25  * These devices usually differ in terms of control protocols (if they
26  * even have one!) and sometimes they define new framing to wrap or batch
27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
29  * issues can usefully be addressed by this framework.
30  */
31
32 // #define      DEBUG                   // error path messages, extra info
33 // #define      VERBOSE                 // more; success messages
34
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/netdevice.h>
38 #include <linux/etherdevice.h>
39 #include <linux/ctype.h>
40 #include <linux/ethtool.h>
41 #include <linux/workqueue.h>
42 #include <linux/mii.h>
43 #include <linux/usb.h>
44 #include <linux/usb/usbnet.h>
45 #include <linux/slab.h>
46 #include <linux/kernel.h>
47 #include <linux/pm_runtime.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  * The goal is to let the USB host controller be busy for 5msec or
62  * more before an irq is required, under load.  Jumbograms change
63  * the equation.
64  */
65 #define MAX_QUEUE_MEMORY        (60 * 1518)
66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
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 hub_wq might disconnect()
73  * us (it polls at HZ/4 usually) before we report too many false errors.
74  */
75 #define THROTTLE_JIFFIES        (HZ/8)
76
77 // between wakeups
78 #define UNLINK_TIMEOUT_MS       3
79
80 /*-------------------------------------------------------------------------*/
81
82 // randomly generated ethernet address
83 static u8       node_id [ETH_ALEN];
84
85 static const char driver_name [] = "usbnet";
86
87 /* use ethtool to change the level for any given device */
88 static int msg_level = -1;
89 module_param (msg_level, int, 0);
90 MODULE_PARM_DESC (msg_level, "Override default message level");
91
92 /*-------------------------------------------------------------------------*/
93
94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
96 {
97         int                             tmp;
98         struct usb_host_interface       *alt = NULL;
99         struct usb_host_endpoint        *in = NULL, *out = NULL;
100         struct usb_host_endpoint        *status = NULL;
101
102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
103                 unsigned        ep;
104
105                 in = out = status = NULL;
106                 alt = intf->altsetting + tmp;
107
108                 /* take the first altsetting with in-bulk + out-bulk;
109                  * remember any status endpoint, just in case;
110                  * ignore other endpoints and altsettings.
111                  */
112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
113                         struct usb_host_endpoint        *e;
114                         int                             intr = 0;
115
116                         e = alt->endpoint + ep;
117                         switch (e->desc.bmAttributes) {
118                         case USB_ENDPOINT_XFER_INT:
119                                 if (!usb_endpoint_dir_in(&e->desc))
120                                         continue;
121                                 intr = 1;
122                                 /* FALLTHROUGH */
123                         case USB_ENDPOINT_XFER_BULK:
124                                 break;
125                         default:
126                                 continue;
127                         }
128                         if (usb_endpoint_dir_in(&e->desc)) {
129                                 if (!intr && !in)
130                                         in = e;
131                                 else if (intr && !status)
132                                         status = e;
133                         } else {
134                                 if (!out)
135                                         out = e;
136                         }
137                 }
138                 if (in && out)
139                         break;
140         }
141         if (!alt || !in || !out)
142                 return -EINVAL;
143
144         if (alt->desc.bAlternateSetting != 0 ||
145             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
146                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
147                                 alt->desc.bAlternateSetting);
148                 if (tmp < 0)
149                         return tmp;
150         }
151
152         dev->in = usb_rcvbulkpipe (dev->udev,
153                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
154         dev->out = usb_sndbulkpipe (dev->udev,
155                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
156         dev->status = status;
157         return 0;
158 }
159 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
160
161 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
162 {
163         int             tmp = -1, ret;
164         unsigned char   buf [13];
165
166         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
167         if (ret == 12)
168                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
169         if (tmp < 0) {
170                 dev_dbg(&dev->udev->dev,
171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
172                 if (ret >= 0)
173                         ret = -EINVAL;
174                 return ret;
175         }
176         return 0;
177 }
178 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
179
180 static void intr_complete (struct urb *urb)
181 {
182         struct usbnet   *dev = urb->context;
183         int             status = urb->status;
184
185         switch (status) {
186         /* success */
187         case 0:
188                 dev->driver_info->status(dev, urb);
189                 break;
190
191         /* software-driven interface shutdown */
192         case -ENOENT:           /* urb killed */
193         case -ESHUTDOWN:        /* hardware gone */
194                 netif_dbg(dev, ifdown, dev->net,
195                           "intr shutdown, code %d\n", status);
196                 return;
197
198         /* NOTE:  not throttling like RX/TX, since this endpoint
199          * already polls infrequently
200          */
201         default:
202                 netdev_dbg(dev->net, "intr status %d\n", status);
203                 break;
204         }
205
206         status = usb_submit_urb (urb, GFP_ATOMIC);
207         if (status != 0)
208                 netif_err(dev, timer, dev->net,
209                           "intr resubmit --> %d\n", status);
210 }
211
212 static int init_status (struct usbnet *dev, struct usb_interface *intf)
213 {
214         char            *buf = NULL;
215         unsigned        pipe = 0;
216         unsigned        maxp;
217         unsigned        period;
218
219         if (!dev->driver_info->status)
220                 return 0;
221
222         pipe = usb_rcvintpipe (dev->udev,
223                         dev->status->desc.bEndpointAddress
224                                 & USB_ENDPOINT_NUMBER_MASK);
225         maxp = usb_maxpacket (dev->udev, pipe, 0);
226
227         /* avoid 1 msec chatter:  min 8 msec poll rate */
228         period = max ((int) dev->status->desc.bInterval,
229                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
230
231         buf = kmalloc (maxp, GFP_KERNEL);
232         if (buf) {
233                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
234                 if (!dev->interrupt) {
235                         kfree (buf);
236                         return -ENOMEM;
237                 } else {
238                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
239                                 buf, maxp, intr_complete, dev, period);
240                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
241                         dev_dbg(&intf->dev,
242                                 "status ep%din, %d bytes period %d\n",
243                                 usb_pipeendpoint(pipe), maxp, period);
244                 }
245         }
246         return 0;
247 }
248
249 /* Submit the interrupt URB if not previously submitted, increasing refcount */
250 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
251 {
252         int ret = 0;
253
254         WARN_ON_ONCE(dev->interrupt == NULL);
255         if (dev->interrupt) {
256                 mutex_lock(&dev->interrupt_mutex);
257
258                 if (++dev->interrupt_count == 1)
259                         ret = usb_submit_urb(dev->interrupt, mem_flags);
260
261                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
262                         dev->interrupt_count);
263                 mutex_unlock(&dev->interrupt_mutex);
264         }
265         return ret;
266 }
267 EXPORT_SYMBOL_GPL(usbnet_status_start);
268
269 /* For resume; submit interrupt URB if previously submitted */
270 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
271 {
272         int ret = 0;
273
274         mutex_lock(&dev->interrupt_mutex);
275         if (dev->interrupt_count) {
276                 ret = usb_submit_urb(dev->interrupt, mem_flags);
277                 dev_dbg(&dev->udev->dev,
278                         "submitted interrupt URB for resume\n");
279         }
280         mutex_unlock(&dev->interrupt_mutex);
281         return ret;
282 }
283
284 /* Kill the interrupt URB if all submitters want it killed */
285 void usbnet_status_stop(struct usbnet *dev)
286 {
287         if (dev->interrupt) {
288                 mutex_lock(&dev->interrupt_mutex);
289                 WARN_ON(dev->interrupt_count == 0);
290
291                 if (dev->interrupt_count && --dev->interrupt_count == 0)
292                         usb_kill_urb(dev->interrupt);
293
294                 dev_dbg(&dev->udev->dev,
295                         "decremented interrupt URB count to %d\n",
296                         dev->interrupt_count);
297                 mutex_unlock(&dev->interrupt_mutex);
298         }
299 }
300 EXPORT_SYMBOL_GPL(usbnet_status_stop);
301
302 /* For suspend; always kill interrupt URB */
303 static void __usbnet_status_stop_force(struct usbnet *dev)
304 {
305         if (dev->interrupt) {
306                 mutex_lock(&dev->interrupt_mutex);
307                 usb_kill_urb(dev->interrupt);
308                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
309                 mutex_unlock(&dev->interrupt_mutex);
310         }
311 }
312
313 /* Passes this packet up the stack, updating its accounting.
314  * Some link protocols batch packets, so their rx_fixup paths
315  * can return clones as well as just modify the original skb.
316  */
317 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
318 {
319         int     status;
320
321         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
322                 skb_queue_tail(&dev->rxq_pause, skb);
323                 return;
324         }
325
326         /* only update if unset to allow minidriver rx_fixup override */
327         if (skb->protocol == 0)
328                 skb->protocol = eth_type_trans (skb, dev->net);
329
330         dev->net->stats.rx_packets++;
331         dev->net->stats.rx_bytes += skb->len;
332
333         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
334                   skb->len + sizeof (struct ethhdr), skb->protocol);
335         memset (skb->cb, 0, sizeof (struct skb_data));
336
337         if (skb_defer_rx_timestamp(skb))
338                 return;
339
340         status = netif_rx (skb);
341         if (status != NET_RX_SUCCESS)
342                 netif_dbg(dev, rx_err, dev->net,
343                           "netif_rx status %d\n", status);
344 }
345 EXPORT_SYMBOL_GPL(usbnet_skb_return);
346
347 /* must be called if hard_mtu or rx_urb_size changed */
348 void usbnet_update_max_qlen(struct usbnet *dev)
349 {
350         enum usb_device_speed speed = dev->udev->speed;
351
352         switch (speed) {
353         case USB_SPEED_HIGH:
354                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
355                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
356                 break;
357         case USB_SPEED_SUPER:
358         case USB_SPEED_SUPER_PLUS:
359                 /*
360                  * Not take default 5ms qlen for super speed HC to
361                  * save memory, and iperf tests show 2.5ms qlen can
362                  * work well
363                  */
364                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
365                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
366                 break;
367         default:
368                 dev->rx_qlen = dev->tx_qlen = 4;
369         }
370 }
371 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
372
373 \f
374 /*-------------------------------------------------------------------------
375  *
376  * Network Device Driver (peer link to "Host Device", from USB host)
377  *
378  *-------------------------------------------------------------------------*/
379
380 int usbnet_change_mtu (struct net_device *net, int new_mtu)
381 {
382         struct usbnet   *dev = netdev_priv(net);
383         int             ll_mtu = new_mtu + net->hard_header_len;
384         int             old_hard_mtu = dev->hard_mtu;
385         int             old_rx_urb_size = dev->rx_urb_size;
386
387         // no second zero-length packet read wanted after mtu-sized packets
388         if ((ll_mtu % dev->maxpacket) == 0)
389                 return -EDOM;
390         net->mtu = new_mtu;
391
392         dev->hard_mtu = net->mtu + net->hard_header_len;
393         if (dev->rx_urb_size == old_hard_mtu) {
394                 dev->rx_urb_size = dev->hard_mtu;
395                 if (dev->rx_urb_size > old_rx_urb_size) {
396                         usbnet_pause_rx(dev);
397                         usbnet_unlink_rx_urbs(dev);
398                         usbnet_resume_rx(dev);
399                 }
400         }
401
402         /* max qlen depend on hard_mtu and rx_urb_size */
403         usbnet_update_max_qlen(dev);
404
405         return 0;
406 }
407 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
408
409 /* The caller must hold list->lock */
410 static void __usbnet_queue_skb(struct sk_buff_head *list,
411                         struct sk_buff *newsk, enum skb_state state)
412 {
413         struct skb_data *entry = (struct skb_data *) newsk->cb;
414
415         __skb_queue_tail(list, newsk);
416         entry->state = state;
417 }
418
419 /*-------------------------------------------------------------------------*/
420
421 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
422  * completion callbacks.  2.5 should have fixed those bugs...
423  */
424
425 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
426                 struct sk_buff_head *list, enum skb_state state)
427 {
428         unsigned long           flags;
429         enum skb_state          old_state;
430         struct skb_data *entry = (struct skb_data *) skb->cb;
431
432         spin_lock_irqsave(&list->lock, flags);
433         old_state = entry->state;
434         entry->state = state;
435         __skb_unlink(skb, list);
436
437         /* defer_bh() is never called with list == &dev->done.
438          * spin_lock_nested() tells lockdep that it is OK to take
439          * dev->done.lock here with list->lock held.
440          */
441         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
442
443         __skb_queue_tail(&dev->done, skb);
444         if (dev->done.qlen == 1)
445                 tasklet_schedule(&dev->bh);
446         spin_unlock(&dev->done.lock);
447         spin_unlock_irqrestore(&list->lock, flags);
448         return old_state;
449 }
450
451 /* some work can't be done in tasklets, so we use keventd
452  *
453  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
454  * but tasklet_schedule() doesn't.  hope the failure is rare.
455  */
456 void usbnet_defer_kevent (struct usbnet *dev, int work)
457 {
458         set_bit (work, &dev->flags);
459         if (!schedule_work (&dev->kevent)) {
460                 if (net_ratelimit())
461                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
462         } else {
463                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
464         }
465 }
466 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
467
468 /*-------------------------------------------------------------------------*/
469
470 static void rx_complete (struct urb *urb);
471
472 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
473 {
474         struct sk_buff          *skb;
475         struct skb_data         *entry;
476         int                     retval = 0;
477         unsigned long           lockflags;
478         size_t                  size = dev->rx_urb_size;
479
480         /* prevent rx skb allocation when error ratio is high */
481         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
482                 usb_free_urb(urb);
483                 return -ENOLINK;
484         }
485
486         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
487         if (!skb) {
488                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
489                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
490                 usb_free_urb (urb);
491                 return -ENOMEM;
492         }
493
494         entry = (struct skb_data *) skb->cb;
495         entry->urb = urb;
496         entry->dev = dev;
497         entry->length = 0;
498
499         usb_fill_bulk_urb (urb, dev->udev, dev->in,
500                 skb->data, size, rx_complete, skb);
501
502         spin_lock_irqsave (&dev->rxq.lock, lockflags);
503
504         if (netif_running (dev->net) &&
505             netif_device_present (dev->net) &&
506             !test_bit (EVENT_RX_HALT, &dev->flags) &&
507             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
508                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
509                 case -EPIPE:
510                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
511                         break;
512                 case -ENOMEM:
513                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
514                         break;
515                 case -ENODEV:
516                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
517                         netif_device_detach (dev->net);
518                         break;
519                 case -EHOSTUNREACH:
520                         retval = -ENOLINK;
521                         break;
522                 default:
523                         netif_dbg(dev, rx_err, dev->net,
524                                   "rx submit, %d\n", retval);
525                         tasklet_schedule (&dev->bh);
526                         break;
527                 case 0:
528                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
529                 }
530         } else {
531                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
532                 retval = -ENOLINK;
533         }
534         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
535         if (retval) {
536                 dev_kfree_skb_any (skb);
537                 usb_free_urb (urb);
538         }
539         return retval;
540 }
541
542
543 /*-------------------------------------------------------------------------*/
544
545 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
546 {
547         if (dev->driver_info->rx_fixup &&
548             !dev->driver_info->rx_fixup (dev, skb)) {
549                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
550                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
551                         dev->net->stats.rx_errors++;
552                 goto done;
553         }
554         // else network stack removes extra byte if we forced a short packet
555
556         /* all data was already cloned from skb inside the driver */
557         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
558                 goto done;
559
560         if (skb->len < ETH_HLEN) {
561                 dev->net->stats.rx_errors++;
562                 dev->net->stats.rx_length_errors++;
563                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
564         } else {
565                 usbnet_skb_return(dev, skb);
566                 return;
567         }
568
569 done:
570         skb_queue_tail(&dev->done, skb);
571 }
572
573 /*-------------------------------------------------------------------------*/
574
575 static void rx_complete (struct urb *urb)
576 {
577         struct sk_buff          *skb = (struct sk_buff *) urb->context;
578         struct skb_data         *entry = (struct skb_data *) skb->cb;
579         struct usbnet           *dev = entry->dev;
580         int                     urb_status = urb->status;
581         enum skb_state          state;
582
583         skb_put (skb, urb->actual_length);
584         state = rx_done;
585         entry->urb = NULL;
586
587         switch (urb_status) {
588         /* success */
589         case 0:
590                 break;
591
592         /* stalls need manual reset. this is rare ... except that
593          * when going through USB 2.0 TTs, unplug appears this way.
594          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
595          * storm, recovering as needed.
596          */
597         case -EPIPE:
598                 dev->net->stats.rx_errors++;
599                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
600                 // FALLTHROUGH
601
602         /* software-driven interface shutdown */
603         case -ECONNRESET:               /* async unlink */
604         case -ESHUTDOWN:                /* hardware gone */
605                 netif_dbg(dev, ifdown, dev->net,
606                           "rx shutdown, code %d\n", urb_status);
607                 goto block;
608
609         /* we get controller i/o faults during hub_wq disconnect() delays.
610          * throttle down resubmits, to avoid log floods; just temporarily,
611          * so we still recover when the fault isn't a hub_wq delay.
612          */
613         case -EPROTO:
614         case -ETIME:
615         case -EILSEQ:
616                 dev->net->stats.rx_errors++;
617                 if (!timer_pending (&dev->delay)) {
618                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
619                         netif_dbg(dev, link, dev->net,
620                                   "rx throttle %d\n", urb_status);
621                 }
622 block:
623                 state = rx_cleanup;
624                 entry->urb = urb;
625                 urb = NULL;
626                 break;
627
628         /* data overrun ... flush fifo? */
629         case -EOVERFLOW:
630                 dev->net->stats.rx_over_errors++;
631                 // FALLTHROUGH
632
633         default:
634                 state = rx_cleanup;
635                 dev->net->stats.rx_errors++;
636                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
637                 break;
638         }
639
640         /* stop rx if packet error rate is high */
641         if (++dev->pkt_cnt > 30) {
642                 dev->pkt_cnt = 0;
643                 dev->pkt_err = 0;
644         } else {
645                 if (state == rx_cleanup)
646                         dev->pkt_err++;
647                 if (dev->pkt_err > 20)
648                         set_bit(EVENT_RX_KILL, &dev->flags);
649         }
650
651         state = defer_bh(dev, skb, &dev->rxq, state);
652
653         if (urb) {
654                 if (netif_running (dev->net) &&
655                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
656                     state != unlink_start) {
657                         rx_submit (dev, urb, GFP_ATOMIC);
658                         usb_mark_last_busy(dev->udev);
659                         return;
660                 }
661                 usb_free_urb (urb);
662         }
663         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
664 }
665
666 /*-------------------------------------------------------------------------*/
667 void usbnet_pause_rx(struct usbnet *dev)
668 {
669         set_bit(EVENT_RX_PAUSED, &dev->flags);
670
671         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
672 }
673 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
674
675 void usbnet_resume_rx(struct usbnet *dev)
676 {
677         struct sk_buff *skb;
678         int num = 0;
679
680         clear_bit(EVENT_RX_PAUSED, &dev->flags);
681
682         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
683                 usbnet_skb_return(dev, skb);
684                 num++;
685         }
686
687         tasklet_schedule(&dev->bh);
688
689         netif_dbg(dev, rx_status, dev->net,
690                   "paused rx queue disabled, %d skbs requeued\n", num);
691 }
692 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
693
694 void usbnet_purge_paused_rxq(struct usbnet *dev)
695 {
696         skb_queue_purge(&dev->rxq_pause);
697 }
698 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
699
700 /*-------------------------------------------------------------------------*/
701
702 // unlink pending rx/tx; completion handlers do all other cleanup
703
704 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
705 {
706         unsigned long           flags;
707         struct sk_buff          *skb;
708         int                     count = 0;
709
710         spin_lock_irqsave (&q->lock, flags);
711         while (!skb_queue_empty(q)) {
712                 struct skb_data         *entry;
713                 struct urb              *urb;
714                 int                     retval;
715
716                 skb_queue_walk(q, skb) {
717                         entry = (struct skb_data *) skb->cb;
718                         if (entry->state != unlink_start)
719                                 goto found;
720                 }
721                 break;
722 found:
723                 entry->state = unlink_start;
724                 urb = entry->urb;
725
726                 /*
727                  * Get reference count of the URB to avoid it to be
728                  * freed during usb_unlink_urb, which may trigger
729                  * use-after-free problem inside usb_unlink_urb since
730                  * usb_unlink_urb is always racing with .complete
731                  * handler(include defer_bh).
732                  */
733                 usb_get_urb(urb);
734                 spin_unlock_irqrestore(&q->lock, flags);
735                 // during some PM-driven resume scenarios,
736                 // these (async) unlinks complete immediately
737                 retval = usb_unlink_urb (urb);
738                 if (retval != -EINPROGRESS && retval != 0)
739                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
740                 else
741                         count++;
742                 usb_put_urb(urb);
743                 spin_lock_irqsave(&q->lock, flags);
744         }
745         spin_unlock_irqrestore (&q->lock, flags);
746         return count;
747 }
748
749 // Flush all pending rx urbs
750 // minidrivers may need to do this when the MTU changes
751
752 void usbnet_unlink_rx_urbs(struct usbnet *dev)
753 {
754         if (netif_running(dev->net)) {
755                 (void) unlink_urbs (dev, &dev->rxq);
756                 tasklet_schedule(&dev->bh);
757         }
758 }
759 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
760
761 /*-------------------------------------------------------------------------*/
762
763 static void wait_skb_queue_empty(struct sk_buff_head *q)
764 {
765         unsigned long flags;
766
767         spin_lock_irqsave(&q->lock, flags);
768         while (!skb_queue_empty(q)) {
769                 spin_unlock_irqrestore(&q->lock, flags);
770                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
771                 set_current_state(TASK_UNINTERRUPTIBLE);
772                 spin_lock_irqsave(&q->lock, flags);
773         }
774         spin_unlock_irqrestore(&q->lock, flags);
775 }
776
777 // precondition: never called in_interrupt
778 static void usbnet_terminate_urbs(struct usbnet *dev)
779 {
780         DECLARE_WAITQUEUE(wait, current);
781         int temp;
782
783         /* ensure there are no more active urbs */
784         add_wait_queue(&dev->wait, &wait);
785         set_current_state(TASK_UNINTERRUPTIBLE);
786         temp = unlink_urbs(dev, &dev->txq) +
787                 unlink_urbs(dev, &dev->rxq);
788
789         /* maybe wait for deletions to finish. */
790         wait_skb_queue_empty(&dev->rxq);
791         wait_skb_queue_empty(&dev->txq);
792         wait_skb_queue_empty(&dev->done);
793         netif_dbg(dev, ifdown, dev->net,
794                   "waited for %d urb completions\n", temp);
795         set_current_state(TASK_RUNNING);
796         remove_wait_queue(&dev->wait, &wait);
797 }
798
799 int usbnet_stop (struct net_device *net)
800 {
801         struct usbnet           *dev = netdev_priv(net);
802         struct driver_info      *info = dev->driver_info;
803         int                     retval, pm, mpn;
804
805         clear_bit(EVENT_DEV_OPEN, &dev->flags);
806         netif_stop_queue (net);
807
808         netif_info(dev, ifdown, dev->net,
809                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
810                    net->stats.rx_packets, net->stats.tx_packets,
811                    net->stats.rx_errors, net->stats.tx_errors);
812
813         /* to not race resume */
814         pm = usb_autopm_get_interface(dev->intf);
815         /* allow minidriver to stop correctly (wireless devices to turn off
816          * radio etc) */
817         if (info->stop) {
818                 retval = info->stop(dev);
819                 if (retval < 0)
820                         netif_info(dev, ifdown, dev->net,
821                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
822                                    retval,
823                                    dev->udev->bus->bus_name, dev->udev->devpath,
824                                    info->description);
825         }
826
827         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
828                 usbnet_terminate_urbs(dev);
829
830         usbnet_status_stop(dev);
831
832         usbnet_purge_paused_rxq(dev);
833
834         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
835
836         /* deferred work (task, timer, softirq) must also stop.
837          * can't flush_scheduled_work() until we drop rtnl (later),
838          * else workers could deadlock; so make workers a NOP.
839          */
840         dev->flags = 0;
841         del_timer_sync (&dev->delay);
842         tasklet_kill (&dev->bh);
843         if (!pm)
844                 usb_autopm_put_interface(dev->intf);
845
846         if (info->manage_power && mpn)
847                 info->manage_power(dev, 0);
848         else
849                 usb_autopm_put_interface(dev->intf);
850
851         return 0;
852 }
853 EXPORT_SYMBOL_GPL(usbnet_stop);
854
855 /*-------------------------------------------------------------------------*/
856
857 // posts reads, and enables write queuing
858
859 // precondition: never called in_interrupt
860
861 int usbnet_open (struct net_device *net)
862 {
863         struct usbnet           *dev = netdev_priv(net);
864         int                     retval;
865         struct driver_info      *info = dev->driver_info;
866
867         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
868                 netif_info(dev, ifup, dev->net,
869                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
870                            retval,
871                            dev->udev->bus->bus_name,
872                            dev->udev->devpath,
873                            info->description);
874                 goto done_nopm;
875         }
876
877         // put into "known safe" state
878         if (info->reset && (retval = info->reset (dev)) < 0) {
879                 netif_info(dev, ifup, dev->net,
880                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
881                            retval,
882                            dev->udev->bus->bus_name,
883                            dev->udev->devpath,
884                            info->description);
885                 goto done;
886         }
887
888         /* hard_mtu or rx_urb_size may change in reset() */
889         usbnet_update_max_qlen(dev);
890
891         // insist peer be connected
892         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
893                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
894                 goto done;
895         }
896
897         /* start any status interrupt transfer */
898         if (dev->interrupt) {
899                 retval = usbnet_status_start(dev, GFP_KERNEL);
900                 if (retval < 0) {
901                         netif_err(dev, ifup, dev->net,
902                                   "intr submit %d\n", retval);
903                         goto done;
904                 }
905         }
906
907         set_bit(EVENT_DEV_OPEN, &dev->flags);
908         netif_start_queue (net);
909         netif_info(dev, ifup, dev->net,
910                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
911                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
912                    dev->net->mtu,
913                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
914                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
915                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
916                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
917                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
918                    "simple");
919
920         /* reset rx error state */
921         dev->pkt_cnt = 0;
922         dev->pkt_err = 0;
923         clear_bit(EVENT_RX_KILL, &dev->flags);
924
925         // delay posting reads until we're fully open
926         tasklet_schedule (&dev->bh);
927         if (info->manage_power) {
928                 retval = info->manage_power(dev, 1);
929                 if (retval < 0) {
930                         retval = 0;
931                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
932                 } else {
933                         usb_autopm_put_interface(dev->intf);
934                 }
935         }
936         return retval;
937 done:
938         usb_autopm_put_interface(dev->intf);
939 done_nopm:
940         return retval;
941 }
942 EXPORT_SYMBOL_GPL(usbnet_open);
943
944 /*-------------------------------------------------------------------------*/
945
946 /* ethtool methods; minidrivers may need to add some more, but
947  * they'll probably want to use this base set.
948  */
949
950 int usbnet_get_link_ksettings(struct net_device *net,
951                               struct ethtool_link_ksettings *cmd)
952 {
953         struct usbnet *dev = netdev_priv(net);
954
955         if (!dev->mii.mdio_read)
956                 return -EOPNOTSUPP;
957
958         return mii_ethtool_get_link_ksettings(&dev->mii, cmd);
959 }
960 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
961
962 int usbnet_set_link_ksettings(struct net_device *net,
963                               const struct ethtool_link_ksettings *cmd)
964 {
965         struct usbnet *dev = netdev_priv(net);
966         int retval;
967
968         if (!dev->mii.mdio_write)
969                 return -EOPNOTSUPP;
970
971         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
972
973         /* link speed/duplex might have changed */
974         if (dev->driver_info->link_reset)
975                 dev->driver_info->link_reset(dev);
976
977         /* hard_mtu or rx_urb_size may change in link_reset() */
978         usbnet_update_max_qlen(dev);
979
980         return retval;
981 }
982 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
983
984 u32 usbnet_get_link (struct net_device *net)
985 {
986         struct usbnet *dev = netdev_priv(net);
987
988         /* If a check_connect is defined, return its result */
989         if (dev->driver_info->check_connect)
990                 return dev->driver_info->check_connect (dev) == 0;
991
992         /* if the device has mii operations, use those */
993         if (dev->mii.mdio_read)
994                 return mii_link_ok(&dev->mii);
995
996         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
997         return ethtool_op_get_link(net);
998 }
999 EXPORT_SYMBOL_GPL(usbnet_get_link);
1000
1001 int usbnet_nway_reset(struct net_device *net)
1002 {
1003         struct usbnet *dev = netdev_priv(net);
1004
1005         if (!dev->mii.mdio_write)
1006                 return -EOPNOTSUPP;
1007
1008         return mii_nway_restart(&dev->mii);
1009 }
1010 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1011
1012 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1013 {
1014         struct usbnet *dev = netdev_priv(net);
1015
1016         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1017         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1018         strlcpy (info->fw_version, dev->driver_info->description,
1019                 sizeof info->fw_version);
1020         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1021 }
1022 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1023
1024 u32 usbnet_get_msglevel (struct net_device *net)
1025 {
1026         struct usbnet *dev = netdev_priv(net);
1027
1028         return dev->msg_enable;
1029 }
1030 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1031
1032 void usbnet_set_msglevel (struct net_device *net, u32 level)
1033 {
1034         struct usbnet *dev = netdev_priv(net);
1035
1036         dev->msg_enable = level;
1037 }
1038 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1039
1040 /* drivers may override default ethtool_ops in their bind() routine */
1041 static const struct ethtool_ops usbnet_ethtool_ops = {
1042         .get_link               = usbnet_get_link,
1043         .nway_reset             = usbnet_nway_reset,
1044         .get_drvinfo            = usbnet_get_drvinfo,
1045         .get_msglevel           = usbnet_get_msglevel,
1046         .set_msglevel           = usbnet_set_msglevel,
1047         .get_ts_info            = ethtool_op_get_ts_info,
1048         .get_link_ksettings     = usbnet_get_link_ksettings,
1049         .set_link_ksettings     = usbnet_set_link_ksettings,
1050 };
1051
1052 /*-------------------------------------------------------------------------*/
1053
1054 static void __handle_link_change(struct usbnet *dev)
1055 {
1056         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1057                 return;
1058
1059         if (!netif_carrier_ok(dev->net)) {
1060                 /* kill URBs for reading packets to save bus bandwidth */
1061                 unlink_urbs(dev, &dev->rxq);
1062
1063                 /*
1064                  * tx_timeout will unlink URBs for sending packets and
1065                  * tx queue is stopped by netcore after link becomes off
1066                  */
1067         } else {
1068                 /* submitting URBs for reading packets */
1069                 tasklet_schedule(&dev->bh);
1070         }
1071
1072         /* hard_mtu or rx_urb_size may change during link change */
1073         usbnet_update_max_qlen(dev);
1074
1075         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1076 }
1077
1078 static void usbnet_set_rx_mode(struct net_device *net)
1079 {
1080         struct usbnet           *dev = netdev_priv(net);
1081
1082         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1083 }
1084
1085 static void __handle_set_rx_mode(struct usbnet *dev)
1086 {
1087         if (dev->driver_info->set_rx_mode)
1088                 (dev->driver_info->set_rx_mode)(dev);
1089
1090         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1091 }
1092
1093 /* work that cannot be done in interrupt context uses keventd.
1094  *
1095  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1096  * especially now that control transfers can be queued.
1097  */
1098 static void
1099 usbnet_deferred_kevent (struct work_struct *work)
1100 {
1101         struct usbnet           *dev =
1102                 container_of(work, struct usbnet, kevent);
1103         int                     status;
1104
1105         /* usb_clear_halt() needs a thread context */
1106         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1107                 unlink_urbs (dev, &dev->txq);
1108                 status = usb_autopm_get_interface(dev->intf);
1109                 if (status < 0)
1110                         goto fail_pipe;
1111                 status = usb_clear_halt (dev->udev, dev->out);
1112                 usb_autopm_put_interface(dev->intf);
1113                 if (status < 0 &&
1114                     status != -EPIPE &&
1115                     status != -ESHUTDOWN) {
1116                         if (netif_msg_tx_err (dev))
1117 fail_pipe:
1118                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1119                                            status);
1120                 } else {
1121                         clear_bit (EVENT_TX_HALT, &dev->flags);
1122                         if (status != -ESHUTDOWN)
1123                                 netif_wake_queue (dev->net);
1124                 }
1125         }
1126         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1127                 unlink_urbs (dev, &dev->rxq);
1128                 status = usb_autopm_get_interface(dev->intf);
1129                 if (status < 0)
1130                         goto fail_halt;
1131                 status = usb_clear_halt (dev->udev, dev->in);
1132                 usb_autopm_put_interface(dev->intf);
1133                 if (status < 0 &&
1134                     status != -EPIPE &&
1135                     status != -ESHUTDOWN) {
1136                         if (netif_msg_rx_err (dev))
1137 fail_halt:
1138                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1139                                            status);
1140                 } else {
1141                         clear_bit (EVENT_RX_HALT, &dev->flags);
1142                         tasklet_schedule (&dev->bh);
1143                 }
1144         }
1145
1146         /* tasklet could resubmit itself forever if memory is tight */
1147         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1148                 struct urb      *urb = NULL;
1149                 int resched = 1;
1150
1151                 if (netif_running (dev->net))
1152                         urb = usb_alloc_urb (0, GFP_KERNEL);
1153                 else
1154                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1155                 if (urb != NULL) {
1156                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1157                         status = usb_autopm_get_interface(dev->intf);
1158                         if (status < 0) {
1159                                 usb_free_urb(urb);
1160                                 goto fail_lowmem;
1161                         }
1162                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1163                                 resched = 0;
1164                         usb_autopm_put_interface(dev->intf);
1165 fail_lowmem:
1166                         if (resched)
1167                                 tasklet_schedule (&dev->bh);
1168                 }
1169         }
1170
1171         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1172                 struct driver_info      *info = dev->driver_info;
1173                 int                     retval = 0;
1174
1175                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1176                 status = usb_autopm_get_interface(dev->intf);
1177                 if (status < 0)
1178                         goto skip_reset;
1179                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1180                         usb_autopm_put_interface(dev->intf);
1181 skip_reset:
1182                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1183                                     retval,
1184                                     dev->udev->bus->bus_name,
1185                                     dev->udev->devpath,
1186                                     info->description);
1187                 } else {
1188                         usb_autopm_put_interface(dev->intf);
1189                 }
1190
1191                 /* handle link change from link resetting */
1192                 __handle_link_change(dev);
1193         }
1194
1195         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1196                 __handle_link_change(dev);
1197
1198         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1199                 __handle_set_rx_mode(dev);
1200
1201
1202         if (dev->flags)
1203                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1204 }
1205
1206 /*-------------------------------------------------------------------------*/
1207
1208 static void tx_complete (struct urb *urb)
1209 {
1210         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1211         struct skb_data         *entry = (struct skb_data *) skb->cb;
1212         struct usbnet           *dev = entry->dev;
1213
1214         if (urb->status == 0) {
1215                 dev->net->stats.tx_packets += entry->packets;
1216                 dev->net->stats.tx_bytes += entry->length;
1217         } else {
1218                 dev->net->stats.tx_errors++;
1219
1220                 switch (urb->status) {
1221                 case -EPIPE:
1222                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1223                         break;
1224
1225                 /* software-driven interface shutdown */
1226                 case -ECONNRESET:               // async unlink
1227                 case -ESHUTDOWN:                // hardware gone
1228                         break;
1229
1230                 /* like rx, tx gets controller i/o faults during hub_wq
1231                  * delays and so it uses the same throttling mechanism.
1232                  */
1233                 case -EPROTO:
1234                 case -ETIME:
1235                 case -EILSEQ:
1236                         usb_mark_last_busy(dev->udev);
1237                         if (!timer_pending (&dev->delay)) {
1238                                 mod_timer (&dev->delay,
1239                                         jiffies + THROTTLE_JIFFIES);
1240                                 netif_dbg(dev, link, dev->net,
1241                                           "tx throttle %d\n", urb->status);
1242                         }
1243                         netif_stop_queue (dev->net);
1244                         break;
1245                 default:
1246                         netif_dbg(dev, tx_err, dev->net,
1247                                   "tx err %d\n", entry->urb->status);
1248                         break;
1249                 }
1250         }
1251
1252         usb_autopm_put_interface_async(dev->intf);
1253         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1254 }
1255
1256 /*-------------------------------------------------------------------------*/
1257
1258 void usbnet_tx_timeout (struct net_device *net)
1259 {
1260         struct usbnet           *dev = netdev_priv(net);
1261
1262         unlink_urbs (dev, &dev->txq);
1263         tasklet_schedule (&dev->bh);
1264         /* this needs to be handled individually because the generic layer
1265          * doesn't know what is sufficient and could not restore private
1266          * information if a remedy of an unconditional reset were used.
1267          */
1268         if (dev->driver_info->recover)
1269                 (dev->driver_info->recover)(dev);
1270 }
1271 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1272
1273 /*-------------------------------------------------------------------------*/
1274
1275 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1276 {
1277         unsigned num_sgs, total_len = 0;
1278         int i, s = 0;
1279
1280         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1281         if (num_sgs == 1)
1282                 return 0;
1283
1284         /* reserve one for zero packet */
1285         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1286                           GFP_ATOMIC);
1287         if (!urb->sg)
1288                 return -ENOMEM;
1289
1290         urb->num_sgs = num_sgs;
1291         sg_init_table(urb->sg, urb->num_sgs + 1);
1292
1293         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1294         total_len += skb_headlen(skb);
1295
1296         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1297                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1298
1299                 total_len += skb_frag_size(f);
1300                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1301                                 f->page_offset);
1302         }
1303         urb->transfer_buffer_length = total_len;
1304
1305         return 1;
1306 }
1307
1308 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1309                                      struct net_device *net)
1310 {
1311         struct usbnet           *dev = netdev_priv(net);
1312         unsigned int                    length;
1313         struct urb              *urb = NULL;
1314         struct skb_data         *entry;
1315         struct driver_info      *info = dev->driver_info;
1316         unsigned long           flags;
1317         int retval;
1318
1319         if (skb)
1320                 skb_tx_timestamp(skb);
1321
1322         // some devices want funky USB-level framing, for
1323         // win32 driver (usually) and/or hardware quirks
1324         if (info->tx_fixup) {
1325                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1326                 if (!skb) {
1327                         /* packet collected; minidriver waiting for more */
1328                         if (info->flags & FLAG_MULTI_PACKET)
1329                                 goto not_drop;
1330                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1331                         goto drop;
1332                 }
1333         }
1334
1335         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1336                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1337                 goto drop;
1338         }
1339
1340         entry = (struct skb_data *) skb->cb;
1341         entry->urb = urb;
1342         entry->dev = dev;
1343
1344         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1345                         skb->data, skb->len, tx_complete, skb);
1346         if (dev->can_dma_sg) {
1347                 if (build_dma_sg(skb, urb) < 0)
1348                         goto drop;
1349         }
1350         length = urb->transfer_buffer_length;
1351
1352         /* don't assume the hardware handles USB_ZERO_PACKET
1353          * NOTE:  strictly conforming cdc-ether devices should expect
1354          * the ZLP here, but ignore the one-byte packet.
1355          * NOTE2: CDC NCM specification is different from CDC ECM when
1356          * handling ZLP/short packets, so cdc_ncm driver will make short
1357          * packet itself if needed.
1358          */
1359         if (length % dev->maxpacket == 0) {
1360                 if (!(info->flags & FLAG_SEND_ZLP)) {
1361                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1362                                 length++;
1363                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1364                                         skb->data[skb->len] = 0;
1365                                         __skb_put(skb, 1);
1366                                 } else if (urb->num_sgs)
1367                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1368                                                         dev->padding_pkt, 1);
1369                         }
1370                 } else
1371                         urb->transfer_flags |= URB_ZERO_PACKET;
1372         }
1373         urb->transfer_buffer_length = length;
1374
1375         if (info->flags & FLAG_MULTI_PACKET) {
1376                 /* Driver has set number of packets and a length delta.
1377                  * Calculate the complete length and ensure that it's
1378                  * positive.
1379                  */
1380                 entry->length += length;
1381                 if (WARN_ON_ONCE(entry->length <= 0))
1382                         entry->length = length;
1383         } else {
1384                 usbnet_set_skb_tx_stats(skb, 1, length);
1385         }
1386
1387         spin_lock_irqsave(&dev->txq.lock, flags);
1388         retval = usb_autopm_get_interface_async(dev->intf);
1389         if (retval < 0) {
1390                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1391                 goto drop;
1392         }
1393
1394 #ifdef CONFIG_PM
1395         /* if this triggers the device is still a sleep */
1396         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1397                 /* transmission will be done in resume */
1398                 usb_anchor_urb(urb, &dev->deferred);
1399                 /* no use to process more packets */
1400                 netif_stop_queue(net);
1401                 usb_put_urb(urb);
1402                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1403                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1404                 goto deferred;
1405         }
1406 #endif
1407
1408         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1409         case -EPIPE:
1410                 netif_stop_queue (net);
1411                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1412                 usb_autopm_put_interface_async(dev->intf);
1413                 break;
1414         default:
1415                 usb_autopm_put_interface_async(dev->intf);
1416                 netif_dbg(dev, tx_err, dev->net,
1417                           "tx: submit urb err %d\n", retval);
1418                 break;
1419         case 0:
1420                 netif_trans_update(net);
1421                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1422                 if (dev->txq.qlen >= TX_QLEN (dev))
1423                         netif_stop_queue (net);
1424         }
1425         spin_unlock_irqrestore (&dev->txq.lock, flags);
1426
1427         if (retval) {
1428                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1429 drop:
1430                 dev->net->stats.tx_dropped++;
1431 not_drop:
1432                 if (skb)
1433                         dev_kfree_skb_any (skb);
1434                 if (urb) {
1435                         kfree(urb->sg);
1436                         usb_free_urb(urb);
1437                 }
1438         } else
1439                 netif_dbg(dev, tx_queued, dev->net,
1440                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1441 #ifdef CONFIG_PM
1442 deferred:
1443 #endif
1444         return NETDEV_TX_OK;
1445 }
1446 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1447
1448 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1449 {
1450         struct urb      *urb;
1451         int             i;
1452         int             ret = 0;
1453
1454         /* don't refill the queue all at once */
1455         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1456                 urb = usb_alloc_urb(0, flags);
1457                 if (urb != NULL) {
1458                         ret = rx_submit(dev, urb, flags);
1459                         if (ret)
1460                                 goto err;
1461                 } else {
1462                         ret = -ENOMEM;
1463                         goto err;
1464                 }
1465         }
1466 err:
1467         return ret;
1468 }
1469
1470 /*-------------------------------------------------------------------------*/
1471
1472 // tasklet (work deferred from completions, in_irq) or timer
1473
1474 static void usbnet_bh (unsigned long param)
1475 {
1476         struct usbnet           *dev = (struct usbnet *) param;
1477         struct sk_buff          *skb;
1478         struct skb_data         *entry;
1479
1480         while ((skb = skb_dequeue (&dev->done))) {
1481                 entry = (struct skb_data *) skb->cb;
1482                 switch (entry->state) {
1483                 case rx_done:
1484                         entry->state = rx_cleanup;
1485                         rx_process (dev, skb);
1486                         continue;
1487                 case tx_done:
1488                         kfree(entry->urb->sg);
1489                 case rx_cleanup:
1490                         usb_free_urb (entry->urb);
1491                         dev_kfree_skb (skb);
1492                         continue;
1493                 default:
1494                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1495                 }
1496         }
1497
1498         /* restart RX again after disabling due to high error rate */
1499         clear_bit(EVENT_RX_KILL, &dev->flags);
1500
1501         /* waiting for all pending urbs to complete?
1502          * only then can we forgo submitting anew
1503          */
1504         if (waitqueue_active(&dev->wait)) {
1505                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1506                         wake_up_all(&dev->wait);
1507
1508         // or are we maybe short a few urbs?
1509         } else if (netif_running (dev->net) &&
1510                    netif_device_present (dev->net) &&
1511                    netif_carrier_ok(dev->net) &&
1512                    !timer_pending(&dev->delay) &&
1513                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1514                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1515                 int     temp = dev->rxq.qlen;
1516
1517                 if (temp < RX_QLEN(dev)) {
1518                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1519                                 return;
1520                         if (temp != dev->rxq.qlen)
1521                                 netif_dbg(dev, link, dev->net,
1522                                           "rxqlen %d --> %d\n",
1523                                           temp, dev->rxq.qlen);
1524                         if (dev->rxq.qlen < RX_QLEN(dev))
1525                                 tasklet_schedule (&dev->bh);
1526                 }
1527                 if (dev->txq.qlen < TX_QLEN (dev))
1528                         netif_wake_queue (dev->net);
1529         }
1530 }
1531
1532
1533 /*-------------------------------------------------------------------------
1534  *
1535  * USB Device Driver support
1536  *
1537  *-------------------------------------------------------------------------*/
1538
1539 // precondition: never called in_interrupt
1540
1541 void usbnet_disconnect (struct usb_interface *intf)
1542 {
1543         struct usbnet           *dev;
1544         struct usb_device       *xdev;
1545         struct net_device       *net;
1546
1547         dev = usb_get_intfdata(intf);
1548         usb_set_intfdata(intf, NULL);
1549         if (!dev)
1550                 return;
1551
1552         xdev = interface_to_usbdev (intf);
1553
1554         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1555                    intf->dev.driver->name,
1556                    xdev->bus->bus_name, xdev->devpath,
1557                    dev->driver_info->description);
1558
1559         net = dev->net;
1560         unregister_netdev (net);
1561
1562         cancel_work_sync(&dev->kevent);
1563
1564         usb_scuttle_anchored_urbs(&dev->deferred);
1565
1566         if (dev->driver_info->unbind)
1567                 dev->driver_info->unbind (dev, intf);
1568
1569         usb_kill_urb(dev->interrupt);
1570         usb_free_urb(dev->interrupt);
1571         kfree(dev->padding_pkt);
1572
1573         free_netdev(net);
1574 }
1575 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1576
1577 static const struct net_device_ops usbnet_netdev_ops = {
1578         .ndo_open               = usbnet_open,
1579         .ndo_stop               = usbnet_stop,
1580         .ndo_start_xmit         = usbnet_start_xmit,
1581         .ndo_tx_timeout         = usbnet_tx_timeout,
1582         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1583         .ndo_change_mtu         = usbnet_change_mtu,
1584         .ndo_set_mac_address    = eth_mac_addr,
1585         .ndo_validate_addr      = eth_validate_addr,
1586 };
1587
1588 /*-------------------------------------------------------------------------*/
1589
1590 // precondition: never called in_interrupt
1591
1592 static struct device_type wlan_type = {
1593         .name   = "wlan",
1594 };
1595
1596 static struct device_type wwan_type = {
1597         .name   = "wwan",
1598 };
1599
1600 int
1601 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1602 {
1603         struct usbnet                   *dev;
1604         struct net_device               *net;
1605         struct usb_host_interface       *interface;
1606         struct driver_info              *info;
1607         struct usb_device               *xdev;
1608         int                             status;
1609         const char                      *name;
1610         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1611
1612         /* usbnet already took usb runtime pm, so have to enable the feature
1613          * for usb interface, otherwise usb_autopm_get_interface may return
1614          * failure if RUNTIME_PM is enabled.
1615          */
1616         if (!driver->supports_autosuspend) {
1617                 driver->supports_autosuspend = 1;
1618                 pm_runtime_enable(&udev->dev);
1619         }
1620
1621         name = udev->dev.driver->name;
1622         info = (struct driver_info *) prod->driver_info;
1623         if (!info) {
1624                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1625                 return -ENODEV;
1626         }
1627         xdev = interface_to_usbdev (udev);
1628         interface = udev->cur_altsetting;
1629
1630         status = -ENOMEM;
1631
1632         // set up our own records
1633         net = alloc_etherdev(sizeof(*dev));
1634         if (!net)
1635                 goto out;
1636
1637         /* netdev_printk() needs this so do it as early as possible */
1638         SET_NETDEV_DEV(net, &udev->dev);
1639
1640         dev = netdev_priv(net);
1641         dev->udev = xdev;
1642         dev->intf = udev;
1643         dev->driver_info = info;
1644         dev->driver_name = name;
1645         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1646                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1647         init_waitqueue_head(&dev->wait);
1648         skb_queue_head_init (&dev->rxq);
1649         skb_queue_head_init (&dev->txq);
1650         skb_queue_head_init (&dev->done);
1651         skb_queue_head_init(&dev->rxq_pause);
1652         dev->bh.func = usbnet_bh;
1653         dev->bh.data = (unsigned long) dev;
1654         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1655         init_usb_anchor(&dev->deferred);
1656         dev->delay.function = usbnet_bh;
1657         dev->delay.data = (unsigned long) dev;
1658         init_timer (&dev->delay);
1659         mutex_init (&dev->phy_mutex);
1660         mutex_init(&dev->interrupt_mutex);
1661         dev->interrupt_count = 0;
1662
1663         dev->net = net;
1664         strcpy (net->name, "usb%d");
1665         memcpy (net->dev_addr, node_id, sizeof node_id);
1666
1667         /* rx and tx sides can use different message sizes;
1668          * bind() should set rx_urb_size in that case.
1669          */
1670         dev->hard_mtu = net->mtu + net->hard_header_len;
1671         net->min_mtu = 0;
1672         net->max_mtu = ETH_MAX_MTU;
1673
1674         net->netdev_ops = &usbnet_netdev_ops;
1675         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1676         net->ethtool_ops = &usbnet_ethtool_ops;
1677
1678         // allow device-specific bind/init procedures
1679         // NOTE net->name still not usable ...
1680         if (info->bind) {
1681                 status = info->bind (dev, udev);
1682                 if (status < 0)
1683                         goto out1;
1684
1685                 // heuristic:  "usb%d" for links we know are two-host,
1686                 // else "eth%d" when there's reasonable doubt.  userspace
1687                 // can rename the link if it knows better.
1688                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1689                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1690                      (net->dev_addr [0] & 0x02) == 0))
1691                         strcpy (net->name, "eth%d");
1692                 /* WLAN devices should always be named "wlan%d" */
1693                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1694                         strcpy(net->name, "wlan%d");
1695                 /* WWAN devices should always be named "wwan%d" */
1696                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1697                         strcpy(net->name, "wwan%d");
1698
1699                 /* devices that cannot do ARP */
1700                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1701                         net->flags |= IFF_NOARP;
1702
1703                 /* maybe the remote can't receive an Ethernet MTU */
1704                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1705                         net->mtu = dev->hard_mtu - net->hard_header_len;
1706         } else if (!info->in || !info->out)
1707                 status = usbnet_get_endpoints (dev, udev);
1708         else {
1709                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1710                 dev->out = usb_sndbulkpipe (xdev, info->out);
1711                 if (!(info->flags & FLAG_NO_SETINT))
1712                         status = usb_set_interface (xdev,
1713                                 interface->desc.bInterfaceNumber,
1714                                 interface->desc.bAlternateSetting);
1715                 else
1716                         status = 0;
1717
1718         }
1719         if (status >= 0 && dev->status)
1720                 status = init_status (dev, udev);
1721         if (status < 0)
1722                 goto out3;
1723
1724         if (!dev->rx_urb_size)
1725                 dev->rx_urb_size = dev->hard_mtu;
1726         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1727
1728         /* let userspace know we have a random address */
1729         if (ether_addr_equal(net->dev_addr, node_id))
1730                 net->addr_assign_type = NET_ADDR_RANDOM;
1731
1732         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1733                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1734         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1735                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1736
1737         /* initialize max rx_qlen and tx_qlen */
1738         usbnet_update_max_qlen(dev);
1739
1740         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1741                 !(info->flags & FLAG_MULTI_PACKET)) {
1742                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1743                 if (!dev->padding_pkt) {
1744                         status = -ENOMEM;
1745                         goto out4;
1746                 }
1747         }
1748
1749         status = register_netdev (net);
1750         if (status)
1751                 goto out5;
1752         netif_info(dev, probe, dev->net,
1753                    "register '%s' at usb-%s-%s, %s, %pM\n",
1754                    udev->dev.driver->name,
1755                    xdev->bus->bus_name, xdev->devpath,
1756                    dev->driver_info->description,
1757                    net->dev_addr);
1758
1759         // ok, it's ready to go.
1760         usb_set_intfdata (udev, dev);
1761
1762         netif_device_attach (net);
1763
1764         if (dev->driver_info->flags & FLAG_LINK_INTR)
1765                 usbnet_link_change(dev, 0, 0);
1766
1767         return 0;
1768
1769 out5:
1770         kfree(dev->padding_pkt);
1771 out4:
1772         usb_free_urb(dev->interrupt);
1773 out3:
1774         if (info->unbind)
1775                 info->unbind (dev, udev);
1776 out1:
1777         /* subdrivers must undo all they did in bind() if they
1778          * fail it, but we may fail later and a deferred kevent
1779          * may trigger an error resubmitting itself and, worse,
1780          * schedule a timer. So we kill it all just in case.
1781          */
1782         cancel_work_sync(&dev->kevent);
1783         del_timer_sync(&dev->delay);
1784         free_netdev(net);
1785 out:
1786         return status;
1787 }
1788 EXPORT_SYMBOL_GPL(usbnet_probe);
1789
1790 /*-------------------------------------------------------------------------*/
1791
1792 /*
1793  * suspend the whole driver as soon as the first interface is suspended
1794  * resume only when the last interface is resumed
1795  */
1796
1797 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1798 {
1799         struct usbnet           *dev = usb_get_intfdata(intf);
1800
1801         if (!dev->suspend_count++) {
1802                 spin_lock_irq(&dev->txq.lock);
1803                 /* don't autosuspend while transmitting */
1804                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1805                         dev->suspend_count--;
1806                         spin_unlock_irq(&dev->txq.lock);
1807                         return -EBUSY;
1808                 } else {
1809                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1810                         spin_unlock_irq(&dev->txq.lock);
1811                 }
1812                 /*
1813                  * accelerate emptying of the rx and queues, to avoid
1814                  * having everything error out.
1815                  */
1816                 netif_device_detach (dev->net);
1817                 usbnet_terminate_urbs(dev);
1818                 __usbnet_status_stop_force(dev);
1819
1820                 /*
1821                  * reattach so runtime management can use and
1822                  * wake the device
1823                  */
1824                 netif_device_attach (dev->net);
1825         }
1826         return 0;
1827 }
1828 EXPORT_SYMBOL_GPL(usbnet_suspend);
1829
1830 int usbnet_resume (struct usb_interface *intf)
1831 {
1832         struct usbnet           *dev = usb_get_intfdata(intf);
1833         struct sk_buff          *skb;
1834         struct urb              *res;
1835         int                     retval;
1836
1837         if (!--dev->suspend_count) {
1838                 /* resume interrupt URB if it was previously submitted */
1839                 __usbnet_status_start_force(dev, GFP_NOIO);
1840
1841                 spin_lock_irq(&dev->txq.lock);
1842                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1843
1844                         skb = (struct sk_buff *)res->context;
1845                         retval = usb_submit_urb(res, GFP_ATOMIC);
1846                         if (retval < 0) {
1847                                 dev_kfree_skb_any(skb);
1848                                 kfree(res->sg);
1849                                 usb_free_urb(res);
1850                                 usb_autopm_put_interface_async(dev->intf);
1851                         } else {
1852                                 netif_trans_update(dev->net);
1853                                 __skb_queue_tail(&dev->txq, skb);
1854                         }
1855                 }
1856
1857                 smp_mb();
1858                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1859                 spin_unlock_irq(&dev->txq.lock);
1860
1861                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1862                         /* handle remote wakeup ASAP
1863                          * we cannot race against stop
1864                          */
1865                         if (netif_device_present(dev->net) &&
1866                                 !timer_pending(&dev->delay) &&
1867                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1868                                         rx_alloc_submit(dev, GFP_NOIO);
1869
1870                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1871                                 netif_tx_wake_all_queues(dev->net);
1872                         tasklet_schedule (&dev->bh);
1873                 }
1874         }
1875
1876         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1877                 usb_autopm_get_interface_no_resume(intf);
1878
1879         return 0;
1880 }
1881 EXPORT_SYMBOL_GPL(usbnet_resume);
1882
1883 /*
1884  * Either a subdriver implements manage_power, then it is assumed to always
1885  * be ready to be suspended or it reports the readiness to be suspended
1886  * explicitly
1887  */
1888 void usbnet_device_suggests_idle(struct usbnet *dev)
1889 {
1890         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1891                 dev->intf->needs_remote_wakeup = 1;
1892                 usb_autopm_put_interface_async(dev->intf);
1893         }
1894 }
1895 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1896
1897 /*
1898  * For devices that can do without special commands
1899  */
1900 int usbnet_manage_power(struct usbnet *dev, int on)
1901 {
1902         dev->intf->needs_remote_wakeup = on;
1903         return 0;
1904 }
1905 EXPORT_SYMBOL(usbnet_manage_power);
1906
1907 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1908 {
1909         /* update link after link is reseted */
1910         if (link && !need_reset)
1911                 netif_carrier_on(dev->net);
1912         else
1913                 netif_carrier_off(dev->net);
1914
1915         if (need_reset && link)
1916                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1917         else
1918                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1919 }
1920 EXPORT_SYMBOL(usbnet_link_change);
1921
1922 /*-------------------------------------------------------------------------*/
1923 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1924                              u16 value, u16 index, void *data, u16 size)
1925 {
1926         void *buf = NULL;
1927         int err = -ENOMEM;
1928
1929         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1930                    " value=0x%04x index=0x%04x size=%d\n",
1931                    cmd, reqtype, value, index, size);
1932
1933         if (data) {
1934                 buf = kmalloc(size, GFP_KERNEL);
1935                 if (!buf)
1936                         goto out;
1937         }
1938
1939         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1940                               cmd, reqtype, value, index, buf, size,
1941                               USB_CTRL_GET_TIMEOUT);
1942         if (err > 0 && err <= size)
1943                 memcpy(data, buf, err);
1944         kfree(buf);
1945 out:
1946         return err;
1947 }
1948
1949 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1950                               u16 value, u16 index, const void *data,
1951                               u16 size)
1952 {
1953         void *buf = NULL;
1954         int err = -ENOMEM;
1955
1956         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1957                    " value=0x%04x index=0x%04x size=%d\n",
1958                    cmd, reqtype, value, index, size);
1959
1960         if (data) {
1961                 buf = kmemdup(data, size, GFP_KERNEL);
1962                 if (!buf)
1963                         goto out;
1964         }
1965
1966         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1967                               cmd, reqtype, value, index, buf, size,
1968                               USB_CTRL_SET_TIMEOUT);
1969         kfree(buf);
1970
1971 out:
1972         return err;
1973 }
1974
1975 /*
1976  * The function can't be called inside suspend/resume callback,
1977  * otherwise deadlock will be caused.
1978  */
1979 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1980                     u16 value, u16 index, void *data, u16 size)
1981 {
1982         int ret;
1983
1984         if (usb_autopm_get_interface(dev->intf) < 0)
1985                 return -ENODEV;
1986         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1987                                 data, size);
1988         usb_autopm_put_interface(dev->intf);
1989         return ret;
1990 }
1991 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1992
1993 /*
1994  * The function can't be called inside suspend/resume callback,
1995  * otherwise deadlock will be caused.
1996  */
1997 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1998                      u16 value, u16 index, const void *data, u16 size)
1999 {
2000         int ret;
2001
2002         if (usb_autopm_get_interface(dev->intf) < 0)
2003                 return -ENODEV;
2004         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2005                                  data, size);
2006         usb_autopm_put_interface(dev->intf);
2007         return ret;
2008 }
2009 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2010
2011 /*
2012  * The function can be called inside suspend/resume callback safely
2013  * and should only be called by suspend/resume callback generally.
2014  */
2015 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2016                           u16 value, u16 index, void *data, u16 size)
2017 {
2018         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2019                                  data, size);
2020 }
2021 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2022
2023 /*
2024  * The function can be called inside suspend/resume callback safely
2025  * and should only be called by suspend/resume callback generally.
2026  */
2027 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2028                           u16 value, u16 index, const void *data,
2029                           u16 size)
2030 {
2031         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2032                                   data, size);
2033 }
2034 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2035
2036 static void usbnet_async_cmd_cb(struct urb *urb)
2037 {
2038         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2039         int status = urb->status;
2040
2041         if (status < 0)
2042                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2043                         __func__, status);
2044
2045         kfree(req);
2046         usb_free_urb(urb);
2047 }
2048
2049 /*
2050  * The caller must make sure that device can't be put into suspend
2051  * state until the control URB completes.
2052  */
2053 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2054                            u16 value, u16 index, const void *data, u16 size)
2055 {
2056         struct usb_ctrlrequest *req = NULL;
2057         struct urb *urb;
2058         int err = -ENOMEM;
2059         void *buf = NULL;
2060
2061         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2062                    " value=0x%04x index=0x%04x size=%d\n",
2063                    cmd, reqtype, value, index, size);
2064
2065         urb = usb_alloc_urb(0, GFP_ATOMIC);
2066         if (!urb)
2067                 goto fail;
2068
2069         if (data) {
2070                 buf = kmemdup(data, size, GFP_ATOMIC);
2071                 if (!buf) {
2072                         netdev_err(dev->net, "Error allocating buffer"
2073                                    " in %s!\n", __func__);
2074                         goto fail_free;
2075                 }
2076         }
2077
2078         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2079         if (!req)
2080                 goto fail_free_buf;
2081
2082         req->bRequestType = reqtype;
2083         req->bRequest = cmd;
2084         req->wValue = cpu_to_le16(value);
2085         req->wIndex = cpu_to_le16(index);
2086         req->wLength = cpu_to_le16(size);
2087
2088         usb_fill_control_urb(urb, dev->udev,
2089                              usb_sndctrlpipe(dev->udev, 0),
2090                              (void *)req, buf, size,
2091                              usbnet_async_cmd_cb, req);
2092         urb->transfer_flags |= URB_FREE_BUFFER;
2093
2094         err = usb_submit_urb(urb, GFP_ATOMIC);
2095         if (err < 0) {
2096                 netdev_err(dev->net, "Error submitting the control"
2097                            " message: status=%d\n", err);
2098                 goto fail_free;
2099         }
2100         return 0;
2101
2102 fail_free_buf:
2103         kfree(buf);
2104 fail_free:
2105         kfree(req);
2106         usb_free_urb(urb);
2107 fail:
2108         return err;
2109
2110 }
2111 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2112 /*-------------------------------------------------------------------------*/
2113
2114 static int __init usbnet_init(void)
2115 {
2116         /* Compiler should optimize this out. */
2117         BUILD_BUG_ON(
2118                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2119
2120         eth_random_addr(node_id);
2121         return 0;
2122 }
2123 module_init(usbnet_init);
2124
2125 static void __exit usbnet_exit(void)
2126 {
2127 }
2128 module_exit(usbnet_exit);
2129
2130 MODULE_AUTHOR("David Brownell");
2131 MODULE_DESCRIPTION("USB network driver framework");
2132 MODULE_LICENSE("GPL");