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, 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 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63  * let the USB host controller be busy for 5msec or more before an irq
  64  * is required, under load.  Jumbograms change the equation.
  65  */
  66 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72 // reawaken network queue this soon after stopping; else watchdog barks
  73 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  74
  75 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  76 // us (it polls at HZ/4 usually) before we report too many false errors.
  77 #define THROTTLE_JIFFIES        (HZ/8)
  78
  79 // between wakeups
  80 #define UNLINK_TIMEOUT_MS       3
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 // randomly generated ethernet address
  85 static u8       node_id [ETH_ALEN];
  86
  87 static const char driver_name [] = "usbnet";
  88
  89 /* use ethtool to change the level for any given device */
  90 static int msg_level = -1;
  91 module_param (msg_level, int, 0);
  92 MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  97 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98 {
  99         int                             tmp;
 100         struct usb_host_interface       *alt = NULL;
 101         struct usb_host_endpoint        *in = NULL, *out = NULL;
 102         struct usb_host_endpoint        *status = NULL;
 103
 104         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105                 unsigned        ep;
 106
 107                 in = out = status = NULL;
 108                 alt = intf->altsetting + tmp;
 109
 110                 /* take the first altsetting with in-bulk + out-bulk;
 111                  * remember any status endpoint, just in case;
 112                  * ignore other endpoints and altsettings.
 113                  */
 114                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115                         struct usb_host_endpoint        *e;
 116                         int                             intr = 0;
 117
 118                         e = alt->endpoint + ep;
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 /* FALLTHROUGH */
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         int             tmp, i;
 166         unsigned char   buf [13];
 167
 168         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169         if (tmp != 12) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (tmp >= 0)
 173                         tmp = -EINVAL;
 174                 return tmp;
 175         }
 176         for (i = tmp = 0; i < 6; i++, tmp += 2)
 177                 dev->net->dev_addr [i] =
 178                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb)
 184 {
 185         struct usbnet   *dev = urb->context;
 186         int             status = urb->status;
 187
 188         switch (status) {
 189         /* success */
 190         case 0:
 191                 dev->driver_info->status(dev, urb);
 192                 break;
 193
 194         /* software-driven interface shutdown */
 195         case -ENOENT:           /* urb killed */
 196         case -ESHUTDOWN:        /* hardware gone */
 197                 netif_dbg(dev, ifdown, dev->net,
 198                           "intr shutdown, code %d\n", status);
 199                 return;
 200
 201         /* NOTE:  not throttling like RX/TX, since this endpoint
 202          * already polls infrequently
 203          */
 204         default:
 205                 netdev_dbg(dev->net, "intr status %d\n", status);
 206                 break;
 207         }
 208
 209         if (!netif_running (dev->net))
 210                 return;
 211
 212         status = usb_submit_urb (urb, GFP_ATOMIC);
 213         if (status != 0)
 214                 netif_err(dev, timer, dev->net,
 215                           "intr resubmit --> %d\n", status);
 216 }
 217
 218 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 219 {
 220         char            *buf = NULL;
 221         unsigned        pipe = 0;
 222         unsigned        maxp;
 223         unsigned        period;
 224
 225         if (!dev->driver_info->status)
 226                 return 0;
 227
 228         pipe = usb_rcvintpipe (dev->udev,
 229                         dev->status->desc.bEndpointAddress
 230                                 & USB_ENDPOINT_NUMBER_MASK);
 231         maxp = usb_maxpacket (dev->udev, pipe, 0);
 232
 233         /* avoid 1 msec chatter:  min 8 msec poll rate */
 234         period = max ((int) dev->status->desc.bInterval,
 235                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 236
 237         buf = kmalloc (maxp, GFP_KERNEL);
 238         if (buf) {
 239                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 240                 if (!dev->interrupt) {
 241                         kfree (buf);
 242                         return -ENOMEM;
 243                 } else {
 244                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 245                                 buf, maxp, intr_complete, dev, period);
 246                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 247                         dev_dbg(&intf->dev,
 248                                 "status ep%din, %d bytes period %d\n",
 249                                 usb_pipeendpoint(pipe), maxp, period);
 250                 }
 251         }
 252         return 0;
 253 }
 254
 255 /* Passes this packet up the stack, updating its accounting.
 256  * Some link protocols batch packets, so their rx_fixup paths
 257  * can return clones as well as just modify the original skb.
 258  */
 259 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 260 {
 261         int     status;
 262
 263         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 264                 skb_queue_tail(&dev->rxq_pause, skb);
 265                 return;
 266         }
 267
 268         skb->protocol = eth_type_trans (skb, dev->net);
 269         dev->net->stats.rx_packets++;
 270         dev->net->stats.rx_bytes += skb->len;
 271
 272         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 273                   skb->len + sizeof (struct ethhdr), skb->protocol);
 274         memset (skb->cb, 0, sizeof (struct skb_data));
 275
 276         if (skb_defer_rx_timestamp(skb))
 277                 return;
 278
 279         status = netif_rx (skb);
 280         if (status != NET_RX_SUCCESS)
 281                 netif_dbg(dev, rx_err, dev->net,
 282                           "netif_rx status %d\n", status);
 283 }
 284 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 285
 286 \f
 287 /*-------------------------------------------------------------------------
 288  *
 289  * Network Device Driver (peer link to "Host Device", from USB host)
 290  *
 291  *-------------------------------------------------------------------------*/
 292
 293 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 294 {
 295         struct usbnet   *dev = netdev_priv(net);
 296         int             ll_mtu = new_mtu + net->hard_header_len;
 297         int             old_hard_mtu = dev->hard_mtu;
 298         int             old_rx_urb_size = dev->rx_urb_size;
 299
 300         if (new_mtu <= 0)
 301                 return -EINVAL;
 302         // no second zero-length packet read wanted after mtu-sized packets
 303         if ((ll_mtu % dev->maxpacket) == 0)
 304                 return -EDOM;
 305         net->mtu = new_mtu;
 306
 307         dev->hard_mtu = net->mtu + net->hard_header_len;
 308         if (dev->rx_urb_size == old_hard_mtu) {
 309                 dev->rx_urb_size = dev->hard_mtu;
 310                 if (dev->rx_urb_size > old_rx_urb_size)
 311                         usbnet_unlink_rx_urbs(dev);
 312         }
 313
 314         return 0;
 315 }
 316 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 317
 318 /* The caller must hold list->lock */
 319 static void __usbnet_queue_skb(struct sk_buff_head *list,
 320                         struct sk_buff *newsk, enum skb_state state)
 321 {
 322         struct skb_data *entry = (struct skb_data *) newsk->cb;
 323
 324         __skb_queue_tail(list, newsk);
 325         entry->state = state;
 326 }
 327
 328 /*-------------------------------------------------------------------------*/
 329
 330 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 331  * completion callbacks.  2.5 should have fixed those bugs...
 332  */
 333
 334 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 335                 struct sk_buff_head *list, enum skb_state state)
 336 {
 337         unsigned long           flags;
 338         enum skb_state          old_state;
 339         struct skb_data *entry = (struct skb_data *) skb->cb;
 340
 341         spin_lock_irqsave(&list->lock, flags);
 342         old_state = entry->state;
 343         entry->state = state;
 344         __skb_unlink(skb, list);
 345         spin_unlock(&list->lock);
 346         spin_lock(&dev->done.lock);
 347         __skb_queue_tail(&dev->done, skb);
 348         if (dev->done.qlen == 1)
 349                 tasklet_schedule(&dev->bh);
 350         spin_unlock_irqrestore(&dev->done.lock, flags);
 351         return old_state;
 352 }
 353
 354 /* some work can't be done in tasklets, so we use keventd
 355  *
 356  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 357  * but tasklet_schedule() doesn't.  hope the failure is rare.
 358  */
 359 void usbnet_defer_kevent (struct usbnet *dev, int work)
 360 {
 361         set_bit (work, &dev->flags);
 362         if (!schedule_work (&dev->kevent)) {
 363                 if (net_ratelimit())
 364                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 365         } else {
 366                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 367         }
 368 }
 369 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 370
 371 /*-------------------------------------------------------------------------*/
 372
 373 static void rx_complete (struct urb *urb);
 374
 375 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 376 {
 377         struct sk_buff          *skb;
 378         struct skb_data         *entry;
 379         int                     retval = 0;
 380         unsigned long           lockflags;
 381         size_t                  size = dev->rx_urb_size;
 382
 383         /* prevent rx skb allocation when error ratio is high */
 384         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 385                 usb_free_urb(urb);
 386                 return -ENOLINK;
 387         }
 388
 389         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 390         if (!skb) {
 391                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 392                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 393                 usb_free_urb (urb);
 394                 return -ENOMEM;
 395         }
 396
 397         entry = (struct skb_data *) skb->cb;
 398         entry->urb = urb;
 399         entry->dev = dev;
 400         entry->length = 0;
 401
 402         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 403                 skb->data, size, rx_complete, skb);
 404
 405         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 406
 407         if (netif_running (dev->net) &&
 408             netif_device_present (dev->net) &&
 409             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 410             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 411                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 412                 case -EPIPE:
 413                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 414                         break;
 415                 case -ENOMEM:
 416                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 417                         break;
 418                 case -ENODEV:
 419                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 420                         netif_device_detach (dev->net);
 421                         break;
 422                 case -EHOSTUNREACH:
 423                         retval = -ENOLINK;
 424                         break;
 425                 default:
 426                         netif_dbg(dev, rx_err, dev->net,
 427                                   "rx submit, %d\n", retval);
 428                         tasklet_schedule (&dev->bh);
 429                         break;
 430                 case 0:
 431                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 432                 }
 433         } else {
 434                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 435                 retval = -ENOLINK;
 436         }
 437         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 438         if (retval) {
 439                 dev_kfree_skb_any (skb);
 440                 usb_free_urb (urb);
 441         }
 442         return retval;
 443 }
 444
 445
 446 /*-------------------------------------------------------------------------*/
 447
 448 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 449 {
 450         if (dev->driver_info->rx_fixup &&
 451             !dev->driver_info->rx_fixup (dev, skb)) {
 452                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 453                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 454                         dev->net->stats.rx_errors++;
 455                 goto done;
 456         }
 457         // else network stack removes extra byte if we forced a short packet
 458
 459         if (skb->len) {
 460                 /* all data was already cloned from skb inside the driver */
 461                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 462                         dev_kfree_skb_any(skb);
 463                 else
 464                         usbnet_skb_return(dev, skb);
 465                 return;
 466         }
 467
 468         netif_dbg(dev, rx_err, dev->net, "drop\n");
 469         dev->net->stats.rx_errors++;
 470 done:
 471         skb_queue_tail(&dev->done, skb);
 472 }
 473
 474 /*-------------------------------------------------------------------------*/
 475
 476 static void rx_complete (struct urb *urb)
 477 {
 478         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 479         struct skb_data         *entry = (struct skb_data *) skb->cb;
 480         struct usbnet           *dev = entry->dev;
 481         int                     urb_status = urb->status;
 482         enum skb_state          state;
 483
 484         skb_put (skb, urb->actual_length);
 485         state = rx_done;
 486         entry->urb = NULL;
 487
 488         switch (urb_status) {
 489         /* success */
 490         case 0:
 491                 if (skb->len < dev->net->hard_header_len) {
 492                         state = rx_cleanup;
 493                         dev->net->stats.rx_errors++;
 494                         dev->net->stats.rx_length_errors++;
 495                         netif_dbg(dev, rx_err, dev->net,
 496                                   "rx length %d\n", skb->len);
 497                 }
 498                 break;
 499
 500         /* stalls need manual reset. this is rare ... except that
 501          * when going through USB 2.0 TTs, unplug appears this way.
 502          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 503          * storm, recovering as needed.
 504          */
 505         case -EPIPE:
 506                 dev->net->stats.rx_errors++;
 507                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 508                 // FALLTHROUGH
 509
 510         /* software-driven interface shutdown */
 511         case -ECONNRESET:               /* async unlink */
 512         case -ESHUTDOWN:                /* hardware gone */
 513                 netif_dbg(dev, ifdown, dev->net,
 514                           "rx shutdown, code %d\n", urb_status);
 515                 goto block;
 516
 517         /* we get controller i/o faults during khubd disconnect() delays.
 518          * throttle down resubmits, to avoid log floods; just temporarily,
 519          * so we still recover when the fault isn't a khubd delay.
 520          */
 521         case -EPROTO:
 522         case -ETIME:
 523         case -EILSEQ:
 524                 dev->net->stats.rx_errors++;
 525                 if (!timer_pending (&dev->delay)) {
 526                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 527                         netif_dbg(dev, link, dev->net,
 528                                   "rx throttle %d\n", urb_status);
 529                 }
 530 block:
 531                 state = rx_cleanup;
 532                 entry->urb = urb;
 533                 urb = NULL;
 534                 break;
 535
 536         /* data overrun ... flush fifo? */
 537         case -EOVERFLOW:
 538                 dev->net->stats.rx_over_errors++;
 539                 // FALLTHROUGH
 540
 541         default:
 542                 state = rx_cleanup;
 543                 dev->net->stats.rx_errors++;
 544                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 545                 break;
 546         }
 547
 548         /* stop rx if packet error rate is high */
 549         if (++dev->pkt_cnt > 30) {
 550                 dev->pkt_cnt = 0;
 551                 dev->pkt_err = 0;
 552         } else {
 553                 if (state == rx_cleanup)
 554                         dev->pkt_err++;
 555                 if (dev->pkt_err > 20)
 556                         set_bit(EVENT_RX_KILL, &dev->flags);
 557         }
 558
 559         state = defer_bh(dev, skb, &dev->rxq, state);
 560
 561         if (urb) {
 562                 if (netif_running (dev->net) &&
 563                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 564                     state != unlink_start) {
 565                         rx_submit (dev, urb, GFP_ATOMIC);
 566                         usb_mark_last_busy(dev->udev);
 567                         return;
 568                 }
 569                 usb_free_urb (urb);
 570         }
 571         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 572 }
 573
 574 /*-------------------------------------------------------------------------*/
 575 void usbnet_pause_rx(struct usbnet *dev)
 576 {
 577         set_bit(EVENT_RX_PAUSED, &dev->flags);
 578
 579         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 580 }
 581 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 582
 583 void usbnet_resume_rx(struct usbnet *dev)
 584 {
 585         struct sk_buff *skb;
 586         int num = 0;
 587
 588         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 589
 590         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 591                 usbnet_skb_return(dev, skb);
 592                 num++;
 593         }
 594
 595         tasklet_schedule(&dev->bh);
 596
 597         netif_dbg(dev, rx_status, dev->net,
 598                   "paused rx queue disabled, %d skbs requeued\n", num);
 599 }
 600 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 601
 602 void usbnet_purge_paused_rxq(struct usbnet *dev)
 603 {
 604         skb_queue_purge(&dev->rxq_pause);
 605 }
 606 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 607
 608 /*-------------------------------------------------------------------------*/
 609
 610 // unlink pending rx/tx; completion handlers do all other cleanup
 611
 612 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 613 {
 614         unsigned long           flags;
 615         struct sk_buff          *skb;
 616         int                     count = 0;
 617
 618         spin_lock_irqsave (&q->lock, flags);
 619         while (!skb_queue_empty(q)) {
 620                 struct skb_data         *entry;
 621                 struct urb              *urb;
 622                 int                     retval;
 623
 624                 skb_queue_walk(q, skb) {
 625                         entry = (struct skb_data *) skb->cb;
 626                         if (entry->state != unlink_start)
 627                                 goto found;
 628                 }
 629                 break;
 630 found:
 631                 entry->state = unlink_start;
 632                 urb = entry->urb;
 633
 634                 /*
 635                  * Get reference count of the URB to avoid it to be
 636                  * freed during usb_unlink_urb, which may trigger
 637                  * use-after-free problem inside usb_unlink_urb since
 638                  * usb_unlink_urb is always racing with .complete
 639                  * handler(include defer_bh).
 640                  */
 641                 usb_get_urb(urb);
 642                 spin_unlock_irqrestore(&q->lock, flags);
 643                 // during some PM-driven resume scenarios,
 644                 // these (async) unlinks complete immediately
 645                 retval = usb_unlink_urb (urb);
 646                 if (retval != -EINPROGRESS && retval != 0)
 647                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 648                 else
 649                         count++;
 650                 usb_put_urb(urb);
 651                 spin_lock_irqsave(&q->lock, flags);
 652         }
 653         spin_unlock_irqrestore (&q->lock, flags);
 654         return count;
 655 }
 656
 657 // Flush all pending rx urbs
 658 // minidrivers may need to do this when the MTU changes
 659
 660 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 661 {
 662         if (netif_running(dev->net)) {
 663                 (void) unlink_urbs (dev, &dev->rxq);
 664                 tasklet_schedule(&dev->bh);
 665         }
 666 }
 667 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 668
 669 /*-------------------------------------------------------------------------*/
 670
 671 // precondition: never called in_interrupt
 672 static void usbnet_terminate_urbs(struct usbnet *dev)
 673 {
 674         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 675         DECLARE_WAITQUEUE(wait, current);
 676         int temp;
 677
 678         /* ensure there are no more active urbs */
 679         add_wait_queue(&unlink_wakeup, &wait);
 680         set_current_state(TASK_UNINTERRUPTIBLE);
 681         dev->wait = &unlink_wakeup;
 682         temp = unlink_urbs(dev, &dev->txq) +
 683                 unlink_urbs(dev, &dev->rxq);
 684
 685         /* maybe wait for deletions to finish. */
 686         while (!skb_queue_empty(&dev->rxq)
 687                 && !skb_queue_empty(&dev->txq)
 688                 && !skb_queue_empty(&dev->done)) {
 689                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 690                         set_current_state(TASK_UNINTERRUPTIBLE);
 691                         netif_dbg(dev, ifdown, dev->net,
 692                                   "waited for %d urb completions\n", temp);
 693         }
 694         set_current_state(TASK_RUNNING);
 695         dev->wait = NULL;
 696         remove_wait_queue(&unlink_wakeup, &wait);
 697 }
 698
 699 int usbnet_stop (struct net_device *net)
 700 {
 701         struct usbnet           *dev = netdev_priv(net);
 702         struct driver_info      *info = dev->driver_info;
 703         int                     retval;
 704
 705         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 706         netif_stop_queue (net);
 707
 708         netif_info(dev, ifdown, dev->net,
 709                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 710                    net->stats.rx_packets, net->stats.tx_packets,
 711                    net->stats.rx_errors, net->stats.tx_errors);
 712
 713         /* allow minidriver to stop correctly (wireless devices to turn off
 714          * radio etc) */
 715         if (info->stop) {
 716                 retval = info->stop(dev);
 717                 if (retval < 0)
 718                         netif_info(dev, ifdown, dev->net,
 719                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 720                                    retval,
 721                                    dev->udev->bus->bus_name, dev->udev->devpath,
 722                                    info->description);
 723         }
 724
 725         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 726                 usbnet_terminate_urbs(dev);
 727
 728         usb_kill_urb(dev->interrupt);
 729
 730         usbnet_purge_paused_rxq(dev);
 731
 732         /* deferred work (task, timer, softirq) must also stop.
 733          * can't flush_scheduled_work() until we drop rtnl (later),
 734          * else workers could deadlock; so make workers a NOP.
 735          */
 736         dev->flags = 0;
 737         del_timer_sync (&dev->delay);
 738         tasklet_kill (&dev->bh);
 739         if (info->manage_power &&
 740             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 741                 info->manage_power(dev, 0);
 742         else
 743                 usb_autopm_put_interface(dev->intf);
 744
 745         return 0;
 746 }
 747 EXPORT_SYMBOL_GPL(usbnet_stop);
 748
 749 /*-------------------------------------------------------------------------*/
 750
 751 // posts reads, and enables write queuing
 752
 753 // precondition: never called in_interrupt
 754
 755 int usbnet_open (struct net_device *net)
 756 {
 757         struct usbnet           *dev = netdev_priv(net);
 758         int                     retval;
 759         struct driver_info      *info = dev->driver_info;
 760
 761         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 762                 netif_info(dev, ifup, dev->net,
 763                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 764                            retval,
 765                            dev->udev->bus->bus_name,
 766                            dev->udev->devpath,
 767                            info->description);
 768                 goto done_nopm;
 769         }
 770
 771         // put into "known safe" state
 772         if (info->reset && (retval = info->reset (dev)) < 0) {
 773                 netif_info(dev, ifup, dev->net,
 774                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 775                            retval,
 776                            dev->udev->bus->bus_name,
 777                            dev->udev->devpath,
 778                            info->description);
 779                 goto done;
 780         }
 781
 782         // insist peer be connected
 783         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 784                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 785                 goto done;
 786         }
 787
 788         /* start any status interrupt transfer */
 789         if (dev->interrupt) {
 790                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 791                 if (retval < 0) {
 792                         netif_err(dev, ifup, dev->net,
 793                                   "intr submit %d\n", retval);
 794                         goto done;
 795                 }
 796         }
 797
 798         set_bit(EVENT_DEV_OPEN, &dev->flags);
 799         netif_start_queue (net);
 800         netif_info(dev, ifup, dev->net,
 801                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 802                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 803                    dev->net->mtu,
 804                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 805                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 806                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 807                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 808                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 809                    "simple");
 810
 811         /* reset rx error state */
 812         dev->pkt_cnt = 0;
 813         dev->pkt_err = 0;
 814         clear_bit(EVENT_RX_KILL, &dev->flags);
 815
 816         // delay posting reads until we're fully open
 817         tasklet_schedule (&dev->bh);
 818         if (info->manage_power) {
 819                 retval = info->manage_power(dev, 1);
 820                 if (retval < 0) {
 821                         retval = 0;
 822                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 823                 } else {
 824                         usb_autopm_put_interface(dev->intf);
 825                 }
 826         }
 827         return retval;
 828 done:
 829         usb_autopm_put_interface(dev->intf);
 830 done_nopm:
 831         return retval;
 832 }
 833 EXPORT_SYMBOL_GPL(usbnet_open);
 834
 835 /*-------------------------------------------------------------------------*/
 836
 837 /* ethtool methods; minidrivers may need to add some more, but
 838  * they'll probably want to use this base set.
 839  */
 840
 841 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 842 {
 843         struct usbnet *dev = netdev_priv(net);
 844
 845         if (!dev->mii.mdio_read)
 846                 return -EOPNOTSUPP;
 847
 848         return mii_ethtool_gset(&dev->mii, cmd);
 849 }
 850 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 851
 852 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 853 {
 854         struct usbnet *dev = netdev_priv(net);
 855         int retval;
 856
 857         if (!dev->mii.mdio_write)
 858                 return -EOPNOTSUPP;
 859
 860         retval = mii_ethtool_sset(&dev->mii, cmd);
 861
 862         /* link speed/duplex might have changed */
 863         if (dev->driver_info->link_reset)
 864                 dev->driver_info->link_reset(dev);
 865
 866         return retval;
 867
 868 }
 869 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 870
 871 u32 usbnet_get_link (struct net_device *net)
 872 {
 873         struct usbnet *dev = netdev_priv(net);
 874
 875         /* If a check_connect is defined, return its result */
 876         if (dev->driver_info->check_connect)
 877                 return dev->driver_info->check_connect (dev) == 0;
 878
 879         /* if the device has mii operations, use those */
 880         if (dev->mii.mdio_read)
 881                 return mii_link_ok(&dev->mii);
 882
 883         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 884         return ethtool_op_get_link(net);
 885 }
 886 EXPORT_SYMBOL_GPL(usbnet_get_link);
 887
 888 int usbnet_nway_reset(struct net_device *net)
 889 {
 890         struct usbnet *dev = netdev_priv(net);
 891
 892         if (!dev->mii.mdio_write)
 893                 return -EOPNOTSUPP;
 894
 895         return mii_nway_restart(&dev->mii);
 896 }
 897 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 898
 899 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 900 {
 901         struct usbnet *dev = netdev_priv(net);
 902
 903         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 904         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 905         strlcpy (info->fw_version, dev->driver_info->description,
 906                 sizeof info->fw_version);
 907         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 908 }
 909 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 910
 911 u32 usbnet_get_msglevel (struct net_device *net)
 912 {
 913         struct usbnet *dev = netdev_priv(net);
 914
 915         return dev->msg_enable;
 916 }
 917 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 918
 919 void usbnet_set_msglevel (struct net_device *net, u32 level)
 920 {
 921         struct usbnet *dev = netdev_priv(net);
 922
 923         dev->msg_enable = level;
 924 }
 925 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 926
 927 /* drivers may override default ethtool_ops in their bind() routine */
 928 static const struct ethtool_ops usbnet_ethtool_ops = {
 929         .get_settings           = usbnet_get_settings,
 930         .set_settings           = usbnet_set_settings,
 931         .get_link               = usbnet_get_link,
 932         .nway_reset             = usbnet_nway_reset,
 933         .get_drvinfo            = usbnet_get_drvinfo,
 934         .get_msglevel           = usbnet_get_msglevel,
 935         .set_msglevel           = usbnet_set_msglevel,
 936         .get_ts_info            = ethtool_op_get_ts_info,
 937 };
 938
 939 /*-------------------------------------------------------------------------*/
 940
 941 /* work that cannot be done in interrupt context uses keventd.
 942  *
 943  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 944  * especially now that control transfers can be queued.
 945  */
 946 static void
 947 kevent (struct work_struct *work)
 948 {
 949         struct usbnet           *dev =
 950                 container_of(work, struct usbnet, kevent);
 951         int                     status;
 952
 953         /* usb_clear_halt() needs a thread context */
 954         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 955                 unlink_urbs (dev, &dev->txq);
 956                 status = usb_autopm_get_interface(dev->intf);
 957                 if (status < 0)
 958                         goto fail_pipe;
 959                 status = usb_clear_halt (dev->udev, dev->out);
 960                 usb_autopm_put_interface(dev->intf);
 961                 if (status < 0 &&
 962                     status != -EPIPE &&
 963                     status != -ESHUTDOWN) {
 964                         if (netif_msg_tx_err (dev))
 965 fail_pipe:
 966                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 967                                            status);
 968                 } else {
 969                         clear_bit (EVENT_TX_HALT, &dev->flags);
 970                         if (status != -ESHUTDOWN)
 971                                 netif_wake_queue (dev->net);
 972                 }
 973         }
 974         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 975                 unlink_urbs (dev, &dev->rxq);
 976                 status = usb_autopm_get_interface(dev->intf);
 977                 if (status < 0)
 978                         goto fail_halt;
 979                 status = usb_clear_halt (dev->udev, dev->in);
 980                 usb_autopm_put_interface(dev->intf);
 981                 if (status < 0 &&
 982                     status != -EPIPE &&
 983                     status != -ESHUTDOWN) {
 984                         if (netif_msg_rx_err (dev))
 985 fail_halt:
 986                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 987                                            status);
 988                 } else {
 989                         clear_bit (EVENT_RX_HALT, &dev->flags);
 990                         tasklet_schedule (&dev->bh);
 991                 }
 992         }
 993
 994         /* tasklet could resubmit itself forever if memory is tight */
 995         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 996                 struct urb      *urb = NULL;
 997                 int resched = 1;
 998
 999                 if (netif_running (dev->net))
1000                         urb = usb_alloc_urb (0, GFP_KERNEL);
1001                 else
1002                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1003                 if (urb != NULL) {
1004                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1005                         status = usb_autopm_get_interface(dev->intf);
1006                         if (status < 0) {
1007                                 usb_free_urb(urb);
1008                                 goto fail_lowmem;
1009                         }
1010                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1011                                 resched = 0;
1012                         usb_autopm_put_interface(dev->intf);
1013 fail_lowmem:
1014                         if (resched)
1015                                 tasklet_schedule (&dev->bh);
1016                 }
1017         }
1018
1019         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1020                 struct driver_info      *info = dev->driver_info;
1021                 int                     retval = 0;
1022
1023                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1024                 status = usb_autopm_get_interface(dev->intf);
1025                 if (status < 0)
1026                         goto skip_reset;
1027                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1028                         usb_autopm_put_interface(dev->intf);
1029 skip_reset:
1030                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1031                                     retval,
1032                                     dev->udev->bus->bus_name,
1033                                     dev->udev->devpath,
1034                                     info->description);
1035                 } else {
1036                         usb_autopm_put_interface(dev->intf);
1037                 }
1038         }
1039
1040         if (dev->flags)
1041                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1042 }
1043
1044 /*-------------------------------------------------------------------------*/
1045
1046 static void tx_complete (struct urb *urb)
1047 {
1048         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1049         struct skb_data         *entry = (struct skb_data *) skb->cb;
1050         struct usbnet           *dev = entry->dev;
1051
1052         if (urb->status == 0) {
1053                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1054                         dev->net->stats.tx_packets++;
1055                 dev->net->stats.tx_bytes += entry->length;
1056         } else {
1057                 dev->net->stats.tx_errors++;
1058
1059                 switch (urb->status) {
1060                 case -EPIPE:
1061                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1062                         break;
1063
1064                 /* software-driven interface shutdown */
1065                 case -ECONNRESET:               // async unlink
1066                 case -ESHUTDOWN:                // hardware gone
1067                         break;
1068
1069                 // like rx, tx gets controller i/o faults during khubd delays
1070                 // and so it uses the same throttling mechanism.
1071                 case -EPROTO:
1072                 case -ETIME:
1073                 case -EILSEQ:
1074                         usb_mark_last_busy(dev->udev);
1075                         if (!timer_pending (&dev->delay)) {
1076                                 mod_timer (&dev->delay,
1077                                         jiffies + THROTTLE_JIFFIES);
1078                                 netif_dbg(dev, link, dev->net,
1079                                           "tx throttle %d\n", urb->status);
1080                         }
1081                         netif_stop_queue (dev->net);
1082                         break;
1083                 default:
1084                         netif_dbg(dev, tx_err, dev->net,
1085                                   "tx err %d\n", entry->urb->status);
1086                         break;
1087                 }
1088         }
1089
1090         usb_autopm_put_interface_async(dev->intf);
1091         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1092 }
1093
1094 /*-------------------------------------------------------------------------*/
1095
1096 void usbnet_tx_timeout (struct net_device *net)
1097 {
1098         struct usbnet           *dev = netdev_priv(net);
1099
1100         unlink_urbs (dev, &dev->txq);
1101         tasklet_schedule (&dev->bh);
1102
1103         // FIXME: device recovery -- reset?
1104 }
1105 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1106
1107 /*-------------------------------------------------------------------------*/
1108
1109 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1110                                      struct net_device *net)
1111 {
1112         struct usbnet           *dev = netdev_priv(net);
1113         int                     length;
1114         struct urb              *urb = NULL;
1115         struct skb_data         *entry;
1116         struct driver_info      *info = dev->driver_info;
1117         unsigned long           flags;
1118         int retval;
1119
1120         if (skb)
1121                 skb_tx_timestamp(skb);
1122
1123         // some devices want funky USB-level framing, for
1124         // win32 driver (usually) and/or hardware quirks
1125         if (info->tx_fixup) {
1126                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1127                 if (!skb) {
1128                         /* packet collected; minidriver waiting for more */
1129                         if (info->flags & FLAG_MULTI_PACKET)
1130                                 goto not_drop;
1131                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1132                         goto drop;
1133                 }
1134         }
1135         length = skb->len;
1136
1137         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1138                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1139                 goto drop;
1140         }
1141
1142         entry = (struct skb_data *) skb->cb;
1143         entry->urb = urb;
1144         entry->dev = dev;
1145         entry->length = length;
1146
1147         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1148                         skb->data, skb->len, tx_complete, skb);
1149
1150         /* don't assume the hardware handles USB_ZERO_PACKET
1151          * NOTE:  strictly conforming cdc-ether devices should expect
1152          * the ZLP here, but ignore the one-byte packet.
1153          * NOTE2: CDC NCM specification is different from CDC ECM when
1154          * handling ZLP/short packets, so cdc_ncm driver will make short
1155          * packet itself if needed.
1156          */
1157         if (length % dev->maxpacket == 0) {
1158                 if (!(info->flags & FLAG_SEND_ZLP)) {
1159                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1160                                 urb->transfer_buffer_length++;
1161                                 if (skb_tailroom(skb)) {
1162                                         skb->data[skb->len] = 0;
1163                                         __skb_put(skb, 1);
1164                                 }
1165                         }
1166                 } else
1167                         urb->transfer_flags |= URB_ZERO_PACKET;
1168         }
1169
1170         spin_lock_irqsave(&dev->txq.lock, flags);
1171         retval = usb_autopm_get_interface_async(dev->intf);
1172         if (retval < 0) {
1173                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1174                 goto drop;
1175         }
1176
1177 #ifdef CONFIG_PM
1178         /* if this triggers the device is still a sleep */
1179         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1180                 /* transmission will be done in resume */
1181                 usb_anchor_urb(urb, &dev->deferred);
1182                 /* no use to process more packets */
1183                 netif_stop_queue(net);
1184                 usb_put_urb(urb);
1185                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1186                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1187                 goto deferred;
1188         }
1189 #endif
1190
1191         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1192         case -EPIPE:
1193                 netif_stop_queue (net);
1194                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1195                 usb_autopm_put_interface_async(dev->intf);
1196                 break;
1197         default:
1198                 usb_autopm_put_interface_async(dev->intf);
1199                 netif_dbg(dev, tx_err, dev->net,
1200                           "tx: submit urb err %d\n", retval);
1201                 break;
1202         case 0:
1203                 net->trans_start = jiffies;
1204                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1205                 if (dev->txq.qlen >= TX_QLEN (dev))
1206                         netif_stop_queue (net);
1207         }
1208         spin_unlock_irqrestore (&dev->txq.lock, flags);
1209
1210         if (retval) {
1211                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1212 drop:
1213                 dev->net->stats.tx_dropped++;
1214 not_drop:
1215                 if (skb)
1216                         dev_kfree_skb_any (skb);
1217                 usb_free_urb (urb);
1218         } else
1219                 netif_dbg(dev, tx_queued, dev->net,
1220                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1221 #ifdef CONFIG_PM
1222 deferred:
1223 #endif
1224         return NETDEV_TX_OK;
1225 }
1226 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1227
1228 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1229 {
1230         struct urb      *urb;
1231         int             i;
1232         int             ret = 0;
1233
1234         /* don't refill the queue all at once */
1235         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1236                 urb = usb_alloc_urb(0, flags);
1237                 if (urb != NULL) {
1238                         ret = rx_submit(dev, urb, flags);
1239                         if (ret)
1240                                 goto err;
1241                 } else {
1242                         ret = -ENOMEM;
1243                         goto err;
1244                 }
1245         }
1246 err:
1247         return ret;
1248 }
1249
1250 /*-------------------------------------------------------------------------*/
1251
1252 // tasklet (work deferred from completions, in_irq) or timer
1253
1254 static void usbnet_bh (unsigned long param)
1255 {
1256         struct usbnet           *dev = (struct usbnet *) param;
1257         struct sk_buff          *skb;
1258         struct skb_data         *entry;
1259
1260         while ((skb = skb_dequeue (&dev->done))) {
1261                 entry = (struct skb_data *) skb->cb;
1262                 switch (entry->state) {
1263                 case rx_done:
1264                         entry->state = rx_cleanup;
1265                         rx_process (dev, skb);
1266                         continue;
1267                 case tx_done:
1268                 case rx_cleanup:
1269                         usb_free_urb (entry->urb);
1270                         dev_kfree_skb (skb);
1271                         continue;
1272                 default:
1273                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1274                 }
1275         }
1276
1277         /* restart RX again after disabling due to high error rate */
1278         clear_bit(EVENT_RX_KILL, &dev->flags);
1279
1280         // waiting for all pending urbs to complete?
1281         if (dev->wait) {
1282                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1283                         wake_up (dev->wait);
1284                 }
1285
1286         // or are we maybe short a few urbs?
1287         } else if (netif_running (dev->net) &&
1288                    netif_device_present (dev->net) &&
1289                    !timer_pending (&dev->delay) &&
1290                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1291                 int     temp = dev->rxq.qlen;
1292
1293                 if (temp < RX_QLEN(dev)) {
1294                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1295                                 return;
1296                         if (temp != dev->rxq.qlen)
1297                                 netif_dbg(dev, link, dev->net,
1298                                           "rxqlen %d --> %d\n",
1299                                           temp, dev->rxq.qlen);
1300                         if (dev->rxq.qlen < RX_QLEN(dev))
1301                                 tasklet_schedule (&dev->bh);
1302                 }
1303                 if (dev->txq.qlen < TX_QLEN (dev))
1304                         netif_wake_queue (dev->net);
1305         }
1306 }
1307
1308
1309 /*-------------------------------------------------------------------------
1310  *
1311  * USB Device Driver support
1312  *
1313  *-------------------------------------------------------------------------*/
1314
1315 // precondition: never called in_interrupt
1316
1317 void usbnet_disconnect (struct usb_interface *intf)
1318 {
1319         struct usbnet           *dev;
1320         struct usb_device       *xdev;
1321         struct net_device       *net;
1322
1323         dev = usb_get_intfdata(intf);
1324         usb_set_intfdata(intf, NULL);
1325         if (!dev)
1326                 return;
1327
1328         xdev = interface_to_usbdev (intf);
1329
1330         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1331                    intf->dev.driver->name,
1332                    xdev->bus->bus_name, xdev->devpath,
1333                    dev->driver_info->description);
1334
1335         net = dev->net;
1336         unregister_netdev (net);
1337
1338         cancel_work_sync(&dev->kevent);
1339
1340         usb_scuttle_anchored_urbs(&dev->deferred);
1341
1342         if (dev->driver_info->unbind)
1343                 dev->driver_info->unbind (dev, intf);
1344
1345         usb_kill_urb(dev->interrupt);
1346         usb_free_urb(dev->interrupt);
1347
1348         free_netdev(net);
1349 }
1350 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1351
1352 static const struct net_device_ops usbnet_netdev_ops = {
1353         .ndo_open               = usbnet_open,
1354         .ndo_stop               = usbnet_stop,
1355         .ndo_start_xmit         = usbnet_start_xmit,
1356         .ndo_tx_timeout         = usbnet_tx_timeout,
1357         .ndo_change_mtu         = usbnet_change_mtu,
1358         .ndo_set_mac_address    = eth_mac_addr,
1359         .ndo_validate_addr      = eth_validate_addr,
1360 };
1361
1362 /*-------------------------------------------------------------------------*/
1363
1364 // precondition: never called in_interrupt
1365
1366 static struct device_type wlan_type = {
1367         .name   = "wlan",
1368 };
1369
1370 static struct device_type wwan_type = {
1371         .name   = "wwan",
1372 };
1373
1374 int
1375 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1376 {
1377         struct usbnet                   *dev;
1378         struct net_device               *net;
1379         struct usb_host_interface       *interface;
1380         struct driver_info              *info;
1381         struct usb_device               *xdev;
1382         int                             status;
1383         const char                      *name;
1384         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1385
1386         /* usbnet already took usb runtime pm, so have to enable the feature
1387          * for usb interface, otherwise usb_autopm_get_interface may return
1388          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1389          */
1390         if (!driver->supports_autosuspend) {
1391                 driver->supports_autosuspend = 1;
1392                 pm_runtime_enable(&udev->dev);
1393         }
1394
1395         name = udev->dev.driver->name;
1396         info = (struct driver_info *) prod->driver_info;
1397         if (!info) {
1398                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1399                 return -ENODEV;
1400         }
1401         xdev = interface_to_usbdev (udev);
1402         interface = udev->cur_altsetting;
1403
1404         status = -ENOMEM;
1405
1406         // set up our own records
1407         net = alloc_etherdev(sizeof(*dev));
1408         if (!net)
1409                 goto out;
1410
1411         /* netdev_printk() needs this so do it as early as possible */
1412         SET_NETDEV_DEV(net, &udev->dev);
1413
1414         dev = netdev_priv(net);
1415         dev->udev = xdev;
1416         dev->intf = udev;
1417         dev->driver_info = info;
1418         dev->driver_name = name;
1419         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1420                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1421         skb_queue_head_init (&dev->rxq);
1422         skb_queue_head_init (&dev->txq);
1423         skb_queue_head_init (&dev->done);
1424         skb_queue_head_init(&dev->rxq_pause);
1425         dev->bh.func = usbnet_bh;
1426         dev->bh.data = (unsigned long) dev;
1427         INIT_WORK (&dev->kevent, kevent);
1428         init_usb_anchor(&dev->deferred);
1429         dev->delay.function = usbnet_bh;
1430         dev->delay.data = (unsigned long) dev;
1431         init_timer (&dev->delay);
1432         mutex_init (&dev->phy_mutex);
1433
1434         dev->net = net;
1435         strcpy (net->name, "usb%d");
1436         memcpy (net->dev_addr, node_id, sizeof node_id);
1437
1438         /* rx and tx sides can use different message sizes;
1439          * bind() should set rx_urb_size in that case.
1440          */
1441         dev->hard_mtu = net->mtu + net->hard_header_len;
1442 #if 0
1443 // dma_supported() is deeply broken on almost all architectures
1444         // possible with some EHCI controllers
1445         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1446                 net->features |= NETIF_F_HIGHDMA;
1447 #endif
1448
1449         net->netdev_ops = &usbnet_netdev_ops;
1450         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1451         net->ethtool_ops = &usbnet_ethtool_ops;
1452
1453         // allow device-specific bind/init procedures
1454         // NOTE net->name still not usable ...
1455         if (info->bind) {
1456                 status = info->bind (dev, udev);
1457                 if (status < 0)
1458                         goto out1;
1459
1460                 // heuristic:  "usb%d" for links we know are two-host,
1461                 // else "eth%d" when there's reasonable doubt.  userspace
1462                 // can rename the link if it knows better.
1463                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1464                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1465                      (net->dev_addr [0] & 0x02) == 0))
1466                         strcpy (net->name, "eth%d");
1467                 /* WLAN devices should always be named "wlan%d" */
1468                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1469                         strcpy(net->name, "wlan%d");
1470                 /* WWAN devices should always be named "wwan%d" */
1471                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1472                         strcpy(net->name, "wwan%d");
1473
1474                 /* devices that cannot do ARP */
1475                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1476                         net->flags |= IFF_NOARP;
1477
1478                 /* maybe the remote can't receive an Ethernet MTU */
1479                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1480                         net->mtu = dev->hard_mtu - net->hard_header_len;
1481         } else if (!info->in || !info->out)
1482                 status = usbnet_get_endpoints (dev, udev);
1483         else {
1484                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1485                 dev->out = usb_sndbulkpipe (xdev, info->out);
1486                 if (!(info->flags & FLAG_NO_SETINT))
1487                         status = usb_set_interface (xdev,
1488                                 interface->desc.bInterfaceNumber,
1489                                 interface->desc.bAlternateSetting);
1490                 else
1491                         status = 0;
1492
1493         }
1494         if (status >= 0 && dev->status)
1495                 status = init_status (dev, udev);
1496         if (status < 0)
1497                 goto out3;
1498
1499         if (!dev->rx_urb_size)
1500                 dev->rx_urb_size = dev->hard_mtu;
1501         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1502
1503         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1504                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1505         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1506                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1507
1508         status = register_netdev (net);
1509         if (status)
1510                 goto out4;
1511         netif_info(dev, probe, dev->net,
1512                    "register '%s' at usb-%s-%s, %s, %pM\n",
1513                    udev->dev.driver->name,
1514                    xdev->bus->bus_name, xdev->devpath,
1515                    dev->driver_info->description,
1516                    net->dev_addr);
1517
1518         // ok, it's ready to go.
1519         usb_set_intfdata (udev, dev);
1520
1521         netif_device_attach (net);
1522
1523         if (dev->driver_info->flags & FLAG_LINK_INTR)
1524                 netif_carrier_off(net);
1525
1526         return 0;
1527
1528 out4:
1529         usb_free_urb(dev->interrupt);
1530 out3:
1531         if (info->unbind)
1532                 info->unbind (dev, udev);
1533 out1:
1534         free_netdev(net);
1535 out:
1536         return status;
1537 }
1538 EXPORT_SYMBOL_GPL(usbnet_probe);
1539
1540 /*-------------------------------------------------------------------------*/
1541
1542 /*
1543  * suspend the whole driver as soon as the first interface is suspended
1544  * resume only when the last interface is resumed
1545  */
1546
1547 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1548 {
1549         struct usbnet           *dev = usb_get_intfdata(intf);
1550
1551         if (!dev->suspend_count++) {
1552                 spin_lock_irq(&dev->txq.lock);
1553                 /* don't autosuspend while transmitting */
1554                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1555                         dev->suspend_count--;
1556                         spin_unlock_irq(&dev->txq.lock);
1557                         return -EBUSY;
1558                 } else {
1559                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1560                         spin_unlock_irq(&dev->txq.lock);
1561                 }
1562                 /*
1563                  * accelerate emptying of the rx and queues, to avoid
1564                  * having everything error out.
1565                  */
1566                 netif_device_detach (dev->net);
1567                 usbnet_terminate_urbs(dev);
1568                 usb_kill_urb(dev->interrupt);
1569
1570                 /*
1571                  * reattach so runtime management can use and
1572                  * wake the device
1573                  */
1574                 netif_device_attach (dev->net);
1575         }
1576         return 0;
1577 }
1578 EXPORT_SYMBOL_GPL(usbnet_suspend);
1579
1580 int usbnet_resume (struct usb_interface *intf)
1581 {
1582         struct usbnet           *dev = usb_get_intfdata(intf);
1583         struct sk_buff          *skb;
1584         struct urb              *res;
1585         int                     retval;
1586
1587         if (!--dev->suspend_count) {
1588                 /* resume interrupt URBs */
1589                 if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1590                         usb_submit_urb(dev->interrupt, GFP_NOIO);
1591
1592                 spin_lock_irq(&dev->txq.lock);
1593                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1594
1595                         skb = (struct sk_buff *)res->context;
1596                         retval = usb_submit_urb(res, GFP_ATOMIC);
1597                         if (retval < 0) {
1598                                 dev_kfree_skb_any(skb);
1599                                 usb_free_urb(res);
1600                                 usb_autopm_put_interface_async(dev->intf);
1601                         } else {
1602                                 dev->net->trans_start = jiffies;
1603                                 __skb_queue_tail(&dev->txq, skb);
1604                         }
1605                 }
1606
1607                 smp_mb();
1608                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1609                 spin_unlock_irq(&dev->txq.lock);
1610
1611                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1612                         /* handle remote wakeup ASAP */
1613                         if (!dev->wait &&
1614                                 netif_device_present(dev->net) &&
1615                                 !timer_pending(&dev->delay) &&
1616                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1617                                         rx_alloc_submit(dev, GFP_NOIO);
1618
1619                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1620                                 netif_tx_wake_all_queues(dev->net);
1621                         tasklet_schedule (&dev->bh);
1622                 }
1623         }
1624
1625         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1626                 usb_autopm_get_interface_no_resume(intf);
1627
1628         return 0;
1629 }
1630 EXPORT_SYMBOL_GPL(usbnet_resume);
1631
1632 /*
1633  * Either a subdriver implements manage_power, then it is assumed to always
1634  * be ready to be suspended or it reports the readiness to be suspended
1635  * explicitly
1636  */
1637 void usbnet_device_suggests_idle(struct usbnet *dev)
1638 {
1639         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1640                 dev->intf->needs_remote_wakeup = 1;
1641                 usb_autopm_put_interface_async(dev->intf);
1642         }
1643 }
1644 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1645
1646 /*
1647  * For devices that can do without special commands
1648  */
1649 int usbnet_manage_power(struct usbnet *dev, int on)
1650 {
1651         dev->intf->needs_remote_wakeup = on;
1652         return 0;
1653 }
1654 EXPORT_SYMBOL(usbnet_manage_power);
1655
1656 /*-------------------------------------------------------------------------*/
1657 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1658                              u16 value, u16 index, void *data, u16 size)
1659 {
1660         void *buf = NULL;
1661         int err = -ENOMEM;
1662
1663         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1664                    " value=0x%04x index=0x%04x size=%d\n",
1665                    cmd, reqtype, value, index, size);
1666
1667         if (data) {
1668                 buf = kmalloc(size, GFP_KERNEL);
1669                 if (!buf)
1670                         goto out;
1671         }
1672
1673         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1674                               cmd, reqtype, value, index, buf, size,
1675                               USB_CTRL_GET_TIMEOUT);
1676         if (err > 0 && err <= size)
1677                 memcpy(data, buf, err);
1678         kfree(buf);
1679 out:
1680         return err;
1681 }
1682
1683 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1684                               u16 value, u16 index, const void *data,
1685                               u16 size)
1686 {
1687         void *buf = NULL;
1688         int err = -ENOMEM;
1689
1690         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1691                    " value=0x%04x index=0x%04x size=%d\n",
1692                    cmd, reqtype, value, index, size);
1693
1694         if (data) {
1695                 buf = kmemdup(data, size, GFP_KERNEL);
1696                 if (!buf)
1697                         goto out;
1698         }
1699
1700         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1701                               cmd, reqtype, value, index, buf, size,
1702                               USB_CTRL_SET_TIMEOUT);
1703         kfree(buf);
1704
1705 out:
1706         return err;
1707 }
1708
1709 /*
1710  * The function can't be called inside suspend/resume callback,
1711  * otherwise deadlock will be caused.
1712  */
1713 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1714                     u16 value, u16 index, void *data, u16 size)
1715 {
1716         int ret;
1717
1718         if (usb_autopm_get_interface(dev->intf) < 0)
1719                 return -ENODEV;
1720         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1721                                 data, size);
1722         usb_autopm_put_interface(dev->intf);
1723         return ret;
1724 }
1725 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1726
1727 /*
1728  * The function can't be called inside suspend/resume callback,
1729  * otherwise deadlock will be caused.
1730  */
1731 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1732                      u16 value, u16 index, const void *data, u16 size)
1733 {
1734         int ret;
1735
1736         if (usb_autopm_get_interface(dev->intf) < 0)
1737                 return -ENODEV;
1738         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1739                                  data, size);
1740         usb_autopm_put_interface(dev->intf);
1741         return ret;
1742 }
1743 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1744
1745 /*
1746  * The function can be called inside suspend/resume callback safely
1747  * and should only be called by suspend/resume callback generally.
1748  */
1749 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1750                           u16 value, u16 index, void *data, u16 size)
1751 {
1752         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1753                                  data, size);
1754 }
1755 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1756
1757 /*
1758  * The function can be called inside suspend/resume callback safely
1759  * and should only be called by suspend/resume callback generally.
1760  */
1761 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1762                           u16 value, u16 index, const void *data,
1763                           u16 size)
1764 {
1765         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1766                                   data, size);
1767 }
1768 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1769
1770 static void usbnet_async_cmd_cb(struct urb *urb)
1771 {
1772         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1773         int status = urb->status;
1774
1775         if (status < 0)
1776                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1777                         __func__, status);
1778
1779         kfree(req);
1780         usb_free_urb(urb);
1781 }
1782
1783 /*
1784  * The caller must make sure that device can't be put into suspend
1785  * state until the control URB completes.
1786  */
1787 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1788                            u16 value, u16 index, const void *data, u16 size)
1789 {
1790         struct usb_ctrlrequest *req = NULL;
1791         struct urb *urb;
1792         int err = -ENOMEM;
1793         void *buf = NULL;
1794
1795         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1796                    " value=0x%04x index=0x%04x size=%d\n",
1797                    cmd, reqtype, value, index, size);
1798
1799         urb = usb_alloc_urb(0, GFP_ATOMIC);
1800         if (!urb) {
1801                 netdev_err(dev->net, "Error allocating URB in"
1802                            " %s!\n", __func__);
1803                 goto fail;
1804         }
1805
1806         if (data) {
1807                 buf = kmemdup(data, size, GFP_ATOMIC);
1808                 if (!buf) {
1809                         netdev_err(dev->net, "Error allocating buffer"
1810                                    " in %s!\n", __func__);
1811                         goto fail_free;
1812                 }
1813         }
1814
1815         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
1816         if (!req) {
1817                 netdev_err(dev->net, "Failed to allocate memory for %s\n",
1818                            __func__);
1819                 goto fail_free_buf;
1820         }
1821
1822         req->bRequestType = reqtype;
1823         req->bRequest = cmd;
1824         req->wValue = cpu_to_le16(value);
1825         req->wIndex = cpu_to_le16(index);
1826         req->wLength = cpu_to_le16(size);
1827
1828         usb_fill_control_urb(urb, dev->udev,
1829                              usb_sndctrlpipe(dev->udev, 0),
1830                              (void *)req, buf, size,
1831                              usbnet_async_cmd_cb, req);
1832         urb->transfer_flags |= URB_FREE_BUFFER;
1833
1834         err = usb_submit_urb(urb, GFP_ATOMIC);
1835         if (err < 0) {
1836                 netdev_err(dev->net, "Error submitting the control"
1837                            " message: status=%d\n", err);
1838                 goto fail_free;
1839         }
1840         return 0;
1841
1842 fail_free_buf:
1843         kfree(buf);
1844 fail_free:
1845         kfree(req);
1846         usb_free_urb(urb);
1847 fail:
1848         return err;
1849
1850 }
1851 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
1852 /*-------------------------------------------------------------------------*/
1853
1854 static int __init usbnet_init(void)
1855 {
1856         /* Compiler should optimize this out. */
1857         BUILD_BUG_ON(
1858                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1859
1860         eth_random_addr(node_id);
1861         return 0;
1862 }
1863 module_init(usbnet_init);
1864
1865 static void __exit usbnet_exit(void)
1866 {
1867 }
1868 module_exit(usbnet_exit);
1869
1870 MODULE_AUTHOR("David Brownell");
1871 MODULE_DESCRIPTION("USB network driver framework");
1872 MODULE_LICENSE("GPL");