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                 netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 364         else
 365                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 366 }
 367 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 368
 369 /*-------------------------------------------------------------------------*/
 370
 371 static void rx_complete (struct urb *urb);
 372
 373 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 374 {
 375         struct sk_buff          *skb;
 376         struct skb_data         *entry;
 377         int                     retval = 0;
 378         unsigned long           lockflags;
 379         size_t                  size = dev->rx_urb_size;
 380
 381         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 382         if (!skb) {
 383                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 384                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 385                 usb_free_urb (urb);
 386                 return -ENOMEM;
 387         }
 388
 389         entry = (struct skb_data *) skb->cb;
 390         entry->urb = urb;
 391         entry->dev = dev;
 392         entry->length = 0;
 393
 394         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 395                 skb->data, size, rx_complete, skb);
 396
 397         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 398
 399         if (netif_running (dev->net) &&
 400             netif_device_present (dev->net) &&
 401             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 402             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 403                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 404                 case -EPIPE:
 405                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 406                         break;
 407                 case -ENOMEM:
 408                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 409                         break;
 410                 case -ENODEV:
 411                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 412                         netif_device_detach (dev->net);
 413                         break;
 414                 case -EHOSTUNREACH:
 415                         retval = -ENOLINK;
 416                         break;
 417                 default:
 418                         netif_dbg(dev, rx_err, dev->net,
 419                                   "rx submit, %d\n", retval);
 420                         tasklet_schedule (&dev->bh);
 421                         break;
 422                 case 0:
 423                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 424                 }
 425         } else {
 426                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 427                 retval = -ENOLINK;
 428         }
 429         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 430         if (retval) {
 431                 dev_kfree_skb_any (skb);
 432                 usb_free_urb (urb);
 433         }
 434         return retval;
 435 }
 436
 437
 438 /*-------------------------------------------------------------------------*/
 439
 440 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 441 {
 442         if (dev->driver_info->rx_fixup &&
 443             !dev->driver_info->rx_fixup (dev, skb)) {
 444                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 445                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 446                         dev->net->stats.rx_errors++;
 447                 goto done;
 448         }
 449         // else network stack removes extra byte if we forced a short packet
 450
 451         if (skb->len) {
 452                 /* all data was already cloned from skb inside the driver */
 453                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 454                         dev_kfree_skb_any(skb);
 455                 else
 456                         usbnet_skb_return(dev, skb);
 457                 return;
 458         }
 459
 460         netif_dbg(dev, rx_err, dev->net, "drop\n");
 461         dev->net->stats.rx_errors++;
 462 done:
 463         skb_queue_tail(&dev->done, skb);
 464 }
 465
 466 /*-------------------------------------------------------------------------*/
 467
 468 static void rx_complete (struct urb *urb)
 469 {
 470         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 471         struct skb_data         *entry = (struct skb_data *) skb->cb;
 472         struct usbnet           *dev = entry->dev;
 473         int                     urb_status = urb->status;
 474         enum skb_state          state;
 475
 476         skb_put (skb, urb->actual_length);
 477         state = rx_done;
 478         entry->urb = NULL;
 479
 480         switch (urb_status) {
 481         /* success */
 482         case 0:
 483                 if (skb->len < dev->net->hard_header_len) {
 484                         state = rx_cleanup;
 485                         dev->net->stats.rx_errors++;
 486                         dev->net->stats.rx_length_errors++;
 487                         netif_dbg(dev, rx_err, dev->net,
 488                                   "rx length %d\n", skb->len);
 489                 }
 490                 break;
 491
 492         /* stalls need manual reset. this is rare ... except that
 493          * when going through USB 2.0 TTs, unplug appears this way.
 494          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 495          * storm, recovering as needed.
 496          */
 497         case -EPIPE:
 498                 dev->net->stats.rx_errors++;
 499                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 500                 // FALLTHROUGH
 501
 502         /* software-driven interface shutdown */
 503         case -ECONNRESET:               /* async unlink */
 504         case -ESHUTDOWN:                /* hardware gone */
 505                 netif_dbg(dev, ifdown, dev->net,
 506                           "rx shutdown, code %d\n", urb_status);
 507                 goto block;
 508
 509         /* we get controller i/o faults during khubd disconnect() delays.
 510          * throttle down resubmits, to avoid log floods; just temporarily,
 511          * so we still recover when the fault isn't a khubd delay.
 512          */
 513         case -EPROTO:
 514         case -ETIME:
 515         case -EILSEQ:
 516                 dev->net->stats.rx_errors++;
 517                 if (!timer_pending (&dev->delay)) {
 518                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 519                         netif_dbg(dev, link, dev->net,
 520                                   "rx throttle %d\n", urb_status);
 521                 }
 522 block:
 523                 state = rx_cleanup;
 524                 entry->urb = urb;
 525                 urb = NULL;
 526                 break;
 527
 528         /* data overrun ... flush fifo? */
 529         case -EOVERFLOW:
 530                 dev->net->stats.rx_over_errors++;
 531                 // FALLTHROUGH
 532
 533         default:
 534                 state = rx_cleanup;
 535                 dev->net->stats.rx_errors++;
 536                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 537                 break;
 538         }
 539
 540         state = defer_bh(dev, skb, &dev->rxq, state);
 541
 542         if (urb) {
 543                 if (netif_running (dev->net) &&
 544                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 545                     state != unlink_start) {
 546                         rx_submit (dev, urb, GFP_ATOMIC);
 547                         usb_mark_last_busy(dev->udev);
 548                         return;
 549                 }
 550                 usb_free_urb (urb);
 551         }
 552         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 553 }
 554
 555 /*-------------------------------------------------------------------------*/
 556 void usbnet_pause_rx(struct usbnet *dev)
 557 {
 558         set_bit(EVENT_RX_PAUSED, &dev->flags);
 559
 560         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 561 }
 562 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 563
 564 void usbnet_resume_rx(struct usbnet *dev)
 565 {
 566         struct sk_buff *skb;
 567         int num = 0;
 568
 569         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 570
 571         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 572                 usbnet_skb_return(dev, skb);
 573                 num++;
 574         }
 575
 576         tasklet_schedule(&dev->bh);
 577
 578         netif_dbg(dev, rx_status, dev->net,
 579                   "paused rx queue disabled, %d skbs requeued\n", num);
 580 }
 581 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 582
 583 void usbnet_purge_paused_rxq(struct usbnet *dev)
 584 {
 585         skb_queue_purge(&dev->rxq_pause);
 586 }
 587 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 588
 589 /*-------------------------------------------------------------------------*/
 590
 591 // unlink pending rx/tx; completion handlers do all other cleanup
 592
 593 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 594 {
 595         unsigned long           flags;
 596         struct sk_buff          *skb;
 597         int                     count = 0;
 598
 599         spin_lock_irqsave (&q->lock, flags);
 600         while (!skb_queue_empty(q)) {
 601                 struct skb_data         *entry;
 602                 struct urb              *urb;
 603                 int                     retval;
 604
 605                 skb_queue_walk(q, skb) {
 606                         entry = (struct skb_data *) skb->cb;
 607                         if (entry->state != unlink_start)
 608                                 goto found;
 609                 }
 610                 break;
 611 found:
 612                 entry->state = unlink_start;
 613                 urb = entry->urb;
 614
 615                 /*
 616                  * Get reference count of the URB to avoid it to be
 617                  * freed during usb_unlink_urb, which may trigger
 618                  * use-after-free problem inside usb_unlink_urb since
 619                  * usb_unlink_urb is always racing with .complete
 620                  * handler(include defer_bh).
 621                  */
 622                 usb_get_urb(urb);
 623                 spin_unlock_irqrestore(&q->lock, flags);
 624                 // during some PM-driven resume scenarios,
 625                 // these (async) unlinks complete immediately
 626                 retval = usb_unlink_urb (urb);
 627                 if (retval != -EINPROGRESS && retval != 0)
 628                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 629                 else
 630                         count++;
 631                 usb_put_urb(urb);
 632                 spin_lock_irqsave(&q->lock, flags);
 633         }
 634         spin_unlock_irqrestore (&q->lock, flags);
 635         return count;
 636 }
 637
 638 // Flush all pending rx urbs
 639 // minidrivers may need to do this when the MTU changes
 640
 641 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 642 {
 643         if (netif_running(dev->net)) {
 644                 (void) unlink_urbs (dev, &dev->rxq);
 645                 tasklet_schedule(&dev->bh);
 646         }
 647 }
 648 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 649
 650 /*-------------------------------------------------------------------------*/
 651
 652 // precondition: never called in_interrupt
 653 static void usbnet_terminate_urbs(struct usbnet *dev)
 654 {
 655         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 656         DECLARE_WAITQUEUE(wait, current);
 657         int temp;
 658
 659         /* ensure there are no more active urbs */
 660         add_wait_queue(&unlink_wakeup, &wait);
 661         set_current_state(TASK_UNINTERRUPTIBLE);
 662         dev->wait = &unlink_wakeup;
 663         temp = unlink_urbs(dev, &dev->txq) +
 664                 unlink_urbs(dev, &dev->rxq);
 665
 666         /* maybe wait for deletions to finish. */
 667         while (!skb_queue_empty(&dev->rxq)
 668                 && !skb_queue_empty(&dev->txq)
 669                 && !skb_queue_empty(&dev->done)) {
 670                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 671                         set_current_state(TASK_UNINTERRUPTIBLE);
 672                         netif_dbg(dev, ifdown, dev->net,
 673                                   "waited for %d urb completions\n", temp);
 674         }
 675         set_current_state(TASK_RUNNING);
 676         dev->wait = NULL;
 677         remove_wait_queue(&unlink_wakeup, &wait);
 678 }
 679
 680 int usbnet_stop (struct net_device *net)
 681 {
 682         struct usbnet           *dev = netdev_priv(net);
 683         struct driver_info      *info = dev->driver_info;
 684         int                     retval;
 685
 686         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 687         netif_stop_queue (net);
 688
 689         netif_info(dev, ifdown, dev->net,
 690                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 691                    net->stats.rx_packets, net->stats.tx_packets,
 692                    net->stats.rx_errors, net->stats.tx_errors);
 693
 694         /* allow minidriver to stop correctly (wireless devices to turn off
 695          * radio etc) */
 696         if (info->stop) {
 697                 retval = info->stop(dev);
 698                 if (retval < 0)
 699                         netif_info(dev, ifdown, dev->net,
 700                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 701                                    retval,
 702                                    dev->udev->bus->bus_name, dev->udev->devpath,
 703                                    info->description);
 704         }
 705
 706         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 707                 usbnet_terminate_urbs(dev);
 708
 709         usb_kill_urb(dev->interrupt);
 710
 711         usbnet_purge_paused_rxq(dev);
 712
 713         /* deferred work (task, timer, softirq) must also stop.
 714          * can't flush_scheduled_work() until we drop rtnl (later),
 715          * else workers could deadlock; so make workers a NOP.
 716          */
 717         dev->flags = 0;
 718         del_timer_sync (&dev->delay);
 719         tasklet_kill (&dev->bh);
 720         if (info->manage_power)
 721                 info->manage_power(dev, 0);
 722         else
 723                 usb_autopm_put_interface(dev->intf);
 724
 725         return 0;
 726 }
 727 EXPORT_SYMBOL_GPL(usbnet_stop);
 728
 729 /*-------------------------------------------------------------------------*/
 730
 731 // posts reads, and enables write queuing
 732
 733 // precondition: never called in_interrupt
 734
 735 int usbnet_open (struct net_device *net)
 736 {
 737         struct usbnet           *dev = netdev_priv(net);
 738         int                     retval;
 739         struct driver_info      *info = dev->driver_info;
 740
 741         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 742                 netif_info(dev, ifup, dev->net,
 743                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 744                            retval,
 745                            dev->udev->bus->bus_name,
 746                            dev->udev->devpath,
 747                            info->description);
 748                 goto done_nopm;
 749         }
 750
 751         // put into "known safe" state
 752         if (info->reset && (retval = info->reset (dev)) < 0) {
 753                 netif_info(dev, ifup, dev->net,
 754                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 755                            retval,
 756                            dev->udev->bus->bus_name,
 757                            dev->udev->devpath,
 758                            info->description);
 759                 goto done;
 760         }
 761
 762         // insist peer be connected
 763         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 764                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 765                 goto done;
 766         }
 767
 768         /* start any status interrupt transfer */
 769         if (dev->interrupt) {
 770                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 771                 if (retval < 0) {
 772                         netif_err(dev, ifup, dev->net,
 773                                   "intr submit %d\n", retval);
 774                         goto done;
 775                 }
 776         }
 777
 778         set_bit(EVENT_DEV_OPEN, &dev->flags);
 779         netif_start_queue (net);
 780         netif_info(dev, ifup, dev->net,
 781                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 782                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 783                    dev->net->mtu,
 784                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 785                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 786                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 787                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 788                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 789                    "simple");
 790
 791         // delay posting reads until we're fully open
 792         tasklet_schedule (&dev->bh);
 793         if (info->manage_power) {
 794                 retval = info->manage_power(dev, 1);
 795                 if (retval < 0)
 796                         goto done_manage_power_error;
 797                 usb_autopm_put_interface(dev->intf);
 798         }
 799         return retval;
 800
 801 done_manage_power_error:
 802         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 803 done:
 804         usb_autopm_put_interface(dev->intf);
 805 done_nopm:
 806         return retval;
 807 }
 808 EXPORT_SYMBOL_GPL(usbnet_open);
 809
 810 /*-------------------------------------------------------------------------*/
 811
 812 /* ethtool methods; minidrivers may need to add some more, but
 813  * they'll probably want to use this base set.
 814  */
 815
 816 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 817 {
 818         struct usbnet *dev = netdev_priv(net);
 819
 820         if (!dev->mii.mdio_read)
 821                 return -EOPNOTSUPP;
 822
 823         return mii_ethtool_gset(&dev->mii, cmd);
 824 }
 825 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 826
 827 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 828 {
 829         struct usbnet *dev = netdev_priv(net);
 830         int retval;
 831
 832         if (!dev->mii.mdio_write)
 833                 return -EOPNOTSUPP;
 834
 835         retval = mii_ethtool_sset(&dev->mii, cmd);
 836
 837         /* link speed/duplex might have changed */
 838         if (dev->driver_info->link_reset)
 839                 dev->driver_info->link_reset(dev);
 840
 841         return retval;
 842
 843 }
 844 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 845
 846 u32 usbnet_get_link (struct net_device *net)
 847 {
 848         struct usbnet *dev = netdev_priv(net);
 849
 850         /* If a check_connect is defined, return its result */
 851         if (dev->driver_info->check_connect)
 852                 return dev->driver_info->check_connect (dev) == 0;
 853
 854         /* if the device has mii operations, use those */
 855         if (dev->mii.mdio_read)
 856                 return mii_link_ok(&dev->mii);
 857
 858         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 859         return ethtool_op_get_link(net);
 860 }
 861 EXPORT_SYMBOL_GPL(usbnet_get_link);
 862
 863 int usbnet_nway_reset(struct net_device *net)
 864 {
 865         struct usbnet *dev = netdev_priv(net);
 866
 867         if (!dev->mii.mdio_write)
 868                 return -EOPNOTSUPP;
 869
 870         return mii_nway_restart(&dev->mii);
 871 }
 872 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 873
 874 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 875 {
 876         struct usbnet *dev = netdev_priv(net);
 877
 878         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 879         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 880         strlcpy (info->fw_version, dev->driver_info->description,
 881                 sizeof info->fw_version);
 882         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 883 }
 884 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 885
 886 u32 usbnet_get_msglevel (struct net_device *net)
 887 {
 888         struct usbnet *dev = netdev_priv(net);
 889
 890         return dev->msg_enable;
 891 }
 892 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 893
 894 void usbnet_set_msglevel (struct net_device *net, u32 level)
 895 {
 896         struct usbnet *dev = netdev_priv(net);
 897
 898         dev->msg_enable = level;
 899 }
 900 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 901
 902 /* drivers may override default ethtool_ops in their bind() routine */
 903 static const struct ethtool_ops usbnet_ethtool_ops = {
 904         .get_settings           = usbnet_get_settings,
 905         .set_settings           = usbnet_set_settings,
 906         .get_link               = usbnet_get_link,
 907         .nway_reset             = usbnet_nway_reset,
 908         .get_drvinfo            = usbnet_get_drvinfo,
 909         .get_msglevel           = usbnet_get_msglevel,
 910         .set_msglevel           = usbnet_set_msglevel,
 911         .get_ts_info            = ethtool_op_get_ts_info,
 912 };
 913
 914 /*-------------------------------------------------------------------------*/
 915
 916 /* work that cannot be done in interrupt context uses keventd.
 917  *
 918  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 919  * especially now that control transfers can be queued.
 920  */
 921 static void
 922 kevent (struct work_struct *work)
 923 {
 924         struct usbnet           *dev =
 925                 container_of(work, struct usbnet, kevent);
 926         int                     status;
 927
 928         /* usb_clear_halt() needs a thread context */
 929         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 930                 unlink_urbs (dev, &dev->txq);
 931                 status = usb_autopm_get_interface(dev->intf);
 932                 if (status < 0)
 933                         goto fail_pipe;
 934                 status = usb_clear_halt (dev->udev, dev->out);
 935                 usb_autopm_put_interface(dev->intf);
 936                 if (status < 0 &&
 937                     status != -EPIPE &&
 938                     status != -ESHUTDOWN) {
 939                         if (netif_msg_tx_err (dev))
 940 fail_pipe:
 941                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 942                                            status);
 943                 } else {
 944                         clear_bit (EVENT_TX_HALT, &dev->flags);
 945                         if (status != -ESHUTDOWN)
 946                                 netif_wake_queue (dev->net);
 947                 }
 948         }
 949         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 950                 unlink_urbs (dev, &dev->rxq);
 951                 status = usb_autopm_get_interface(dev->intf);
 952                 if (status < 0)
 953                         goto fail_halt;
 954                 status = usb_clear_halt (dev->udev, dev->in);
 955                 usb_autopm_put_interface(dev->intf);
 956                 if (status < 0 &&
 957                     status != -EPIPE &&
 958                     status != -ESHUTDOWN) {
 959                         if (netif_msg_rx_err (dev))
 960 fail_halt:
 961                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 962                                            status);
 963                 } else {
 964                         clear_bit (EVENT_RX_HALT, &dev->flags);
 965                         tasklet_schedule (&dev->bh);
 966                 }
 967         }
 968
 969         /* tasklet could resubmit itself forever if memory is tight */
 970         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 971                 struct urb      *urb = NULL;
 972                 int resched = 1;
 973
 974                 if (netif_running (dev->net))
 975                         urb = usb_alloc_urb (0, GFP_KERNEL);
 976                 else
 977                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 978                 if (urb != NULL) {
 979                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 980                         status = usb_autopm_get_interface(dev->intf);
 981                         if (status < 0) {
 982                                 usb_free_urb(urb);
 983                                 goto fail_lowmem;
 984                         }
 985                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 986                                 resched = 0;
 987                         usb_autopm_put_interface(dev->intf);
 988 fail_lowmem:
 989                         if (resched)
 990                                 tasklet_schedule (&dev->bh);
 991                 }
 992         }
 993
 994         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 995                 struct driver_info      *info = dev->driver_info;
 996                 int                     retval = 0;
 997
 998                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 999                 status = usb_autopm_get_interface(dev->intf);
1000                 if (status < 0)
1001                         goto skip_reset;
1002                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1003                         usb_autopm_put_interface(dev->intf);
1004 skip_reset:
1005                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1006                                     retval,
1007                                     dev->udev->bus->bus_name,
1008                                     dev->udev->devpath,
1009                                     info->description);
1010                 } else {
1011                         usb_autopm_put_interface(dev->intf);
1012                 }
1013         }
1014
1015         if (dev->flags)
1016                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1017 }
1018
1019 /*-------------------------------------------------------------------------*/
1020
1021 static void tx_complete (struct urb *urb)
1022 {
1023         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1024         struct skb_data         *entry = (struct skb_data *) skb->cb;
1025         struct usbnet           *dev = entry->dev;
1026
1027         if (urb->status == 0) {
1028                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1029                         dev->net->stats.tx_packets++;
1030                 dev->net->stats.tx_bytes += entry->length;
1031         } else {
1032                 dev->net->stats.tx_errors++;
1033
1034                 switch (urb->status) {
1035                 case -EPIPE:
1036                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1037                         break;
1038
1039                 /* software-driven interface shutdown */
1040                 case -ECONNRESET:               // async unlink
1041                 case -ESHUTDOWN:                // hardware gone
1042                         break;
1043
1044                 // like rx, tx gets controller i/o faults during khubd delays
1045                 // and so it uses the same throttling mechanism.
1046                 case -EPROTO:
1047                 case -ETIME:
1048                 case -EILSEQ:
1049                         usb_mark_last_busy(dev->udev);
1050                         if (!timer_pending (&dev->delay)) {
1051                                 mod_timer (&dev->delay,
1052                                         jiffies + THROTTLE_JIFFIES);
1053                                 netif_dbg(dev, link, dev->net,
1054                                           "tx throttle %d\n", urb->status);
1055                         }
1056                         netif_stop_queue (dev->net);
1057                         break;
1058                 default:
1059                         netif_dbg(dev, tx_err, dev->net,
1060                                   "tx err %d\n", entry->urb->status);
1061                         break;
1062                 }
1063         }
1064
1065         usb_autopm_put_interface_async(dev->intf);
1066         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1067 }
1068
1069 /*-------------------------------------------------------------------------*/
1070
1071 void usbnet_tx_timeout (struct net_device *net)
1072 {
1073         struct usbnet           *dev = netdev_priv(net);
1074
1075         unlink_urbs (dev, &dev->txq);
1076         tasklet_schedule (&dev->bh);
1077
1078         // FIXME: device recovery -- reset?
1079 }
1080 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1081
1082 /*-------------------------------------------------------------------------*/
1083
1084 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1085                                      struct net_device *net)
1086 {
1087         struct usbnet           *dev = netdev_priv(net);
1088         int                     length;
1089         struct urb              *urb = NULL;
1090         struct skb_data         *entry;
1091         struct driver_info      *info = dev->driver_info;
1092         unsigned long           flags;
1093         int retval;
1094
1095         if (skb)
1096                 skb_tx_timestamp(skb);
1097
1098         // some devices want funky USB-level framing, for
1099         // win32 driver (usually) and/or hardware quirks
1100         if (info->tx_fixup) {
1101                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1102                 if (!skb) {
1103                         if (netif_msg_tx_err(dev)) {
1104                                 netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1105                                 goto drop;
1106                         } else {
1107                                 /* cdc_ncm collected packet; waits for more */
1108                                 goto not_drop;
1109                         }
1110                 }
1111         }
1112         length = skb->len;
1113
1114         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1115                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1116                 goto drop;
1117         }
1118
1119         entry = (struct skb_data *) skb->cb;
1120         entry->urb = urb;
1121         entry->dev = dev;
1122         entry->length = length;
1123
1124         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1125                         skb->data, skb->len, tx_complete, skb);
1126
1127         /* don't assume the hardware handles USB_ZERO_PACKET
1128          * NOTE:  strictly conforming cdc-ether devices should expect
1129          * the ZLP here, but ignore the one-byte packet.
1130          * NOTE2: CDC NCM specification is different from CDC ECM when
1131          * handling ZLP/short packets, so cdc_ncm driver will make short
1132          * packet itself if needed.
1133          */
1134         if (length % dev->maxpacket == 0) {
1135                 if (!(info->flags & FLAG_SEND_ZLP)) {
1136                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1137                                 urb->transfer_buffer_length++;
1138                                 if (skb_tailroom(skb)) {
1139                                         skb->data[skb->len] = 0;
1140                                         __skb_put(skb, 1);
1141                                 }
1142                         }
1143                 } else
1144                         urb->transfer_flags |= URB_ZERO_PACKET;
1145         }
1146
1147         spin_lock_irqsave(&dev->txq.lock, flags);
1148         retval = usb_autopm_get_interface_async(dev->intf);
1149         if (retval < 0) {
1150                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1151                 goto drop;
1152         }
1153
1154 #ifdef CONFIG_PM
1155         /* if this triggers the device is still a sleep */
1156         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1157                 /* transmission will be done in resume */
1158                 usb_anchor_urb(urb, &dev->deferred);
1159                 /* no use to process more packets */
1160                 netif_stop_queue(net);
1161                 usb_put_urb(urb);
1162                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1163                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1164                 goto deferred;
1165         }
1166 #endif
1167
1168         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1169         case -EPIPE:
1170                 netif_stop_queue (net);
1171                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1172                 usb_autopm_put_interface_async(dev->intf);
1173                 break;
1174         default:
1175                 usb_autopm_put_interface_async(dev->intf);
1176                 netif_dbg(dev, tx_err, dev->net,
1177                           "tx: submit urb err %d\n", retval);
1178                 break;
1179         case 0:
1180                 net->trans_start = jiffies;
1181                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1182                 if (dev->txq.qlen >= TX_QLEN (dev))
1183                         netif_stop_queue (net);
1184         }
1185         spin_unlock_irqrestore (&dev->txq.lock, flags);
1186
1187         if (retval) {
1188                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1189 drop:
1190                 dev->net->stats.tx_dropped++;
1191 not_drop:
1192                 if (skb)
1193                         dev_kfree_skb_any (skb);
1194                 usb_free_urb (urb);
1195         } else
1196                 netif_dbg(dev, tx_queued, dev->net,
1197                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1198 #ifdef CONFIG_PM
1199 deferred:
1200 #endif
1201         return NETDEV_TX_OK;
1202 }
1203 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1204
1205 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1206 {
1207         struct urb      *urb;
1208         int             i;
1209         int             ret = 0;
1210
1211         /* don't refill the queue all at once */
1212         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1213                 urb = usb_alloc_urb(0, flags);
1214                 if (urb != NULL) {
1215                         ret = rx_submit(dev, urb, flags);
1216                         if (ret)
1217                                 goto err;
1218                 } else {
1219                         ret = -ENOMEM;
1220                         goto err;
1221                 }
1222         }
1223 err:
1224         return ret;
1225 }
1226
1227 /*-------------------------------------------------------------------------*/
1228
1229 // tasklet (work deferred from completions, in_irq) or timer
1230
1231 static void usbnet_bh (unsigned long param)
1232 {
1233         struct usbnet           *dev = (struct usbnet *) param;
1234         struct sk_buff          *skb;
1235         struct skb_data         *entry;
1236
1237         while ((skb = skb_dequeue (&dev->done))) {
1238                 entry = (struct skb_data *) skb->cb;
1239                 switch (entry->state) {
1240                 case rx_done:
1241                         entry->state = rx_cleanup;
1242                         rx_process (dev, skb);
1243                         continue;
1244                 case tx_done:
1245                 case rx_cleanup:
1246                         usb_free_urb (entry->urb);
1247                         dev_kfree_skb (skb);
1248                         continue;
1249                 default:
1250                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1251                 }
1252         }
1253
1254         // waiting for all pending urbs to complete?
1255         if (dev->wait) {
1256                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1257                         wake_up (dev->wait);
1258                 }
1259
1260         // or are we maybe short a few urbs?
1261         } else if (netif_running (dev->net) &&
1262                    netif_device_present (dev->net) &&
1263                    !timer_pending (&dev->delay) &&
1264                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1265                 int     temp = dev->rxq.qlen;
1266
1267                 if (temp < RX_QLEN(dev)) {
1268                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1269                                 return;
1270                         if (temp != dev->rxq.qlen)
1271                                 netif_dbg(dev, link, dev->net,
1272                                           "rxqlen %d --> %d\n",
1273                                           temp, dev->rxq.qlen);
1274                         if (dev->rxq.qlen < RX_QLEN(dev))
1275                                 tasklet_schedule (&dev->bh);
1276                 }
1277                 if (dev->txq.qlen < TX_QLEN (dev))
1278                         netif_wake_queue (dev->net);
1279         }
1280 }
1281
1282
1283 /*-------------------------------------------------------------------------
1284  *
1285  * USB Device Driver support
1286  *
1287  *-------------------------------------------------------------------------*/
1288
1289 // precondition: never called in_interrupt
1290
1291 void usbnet_disconnect (struct usb_interface *intf)
1292 {
1293         struct usbnet           *dev;
1294         struct usb_device       *xdev;
1295         struct net_device       *net;
1296
1297         dev = usb_get_intfdata(intf);
1298         usb_set_intfdata(intf, NULL);
1299         if (!dev)
1300                 return;
1301
1302         xdev = interface_to_usbdev (intf);
1303
1304         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1305                    intf->dev.driver->name,
1306                    xdev->bus->bus_name, xdev->devpath,
1307                    dev->driver_info->description);
1308
1309         net = dev->net;
1310         unregister_netdev (net);
1311
1312         cancel_work_sync(&dev->kevent);
1313
1314         usb_scuttle_anchored_urbs(&dev->deferred);
1315
1316         if (dev->driver_info->unbind)
1317                 dev->driver_info->unbind (dev, intf);
1318
1319         usb_kill_urb(dev->interrupt);
1320         usb_free_urb(dev->interrupt);
1321
1322         free_netdev(net);
1323 }
1324 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1325
1326 static const struct net_device_ops usbnet_netdev_ops = {
1327         .ndo_open               = usbnet_open,
1328         .ndo_stop               = usbnet_stop,
1329         .ndo_start_xmit         = usbnet_start_xmit,
1330         .ndo_tx_timeout         = usbnet_tx_timeout,
1331         .ndo_change_mtu         = usbnet_change_mtu,
1332         .ndo_set_mac_address    = eth_mac_addr,
1333         .ndo_validate_addr      = eth_validate_addr,
1334 };
1335
1336 /*-------------------------------------------------------------------------*/
1337
1338 // precondition: never called in_interrupt
1339
1340 static struct device_type wlan_type = {
1341         .name   = "wlan",
1342 };
1343
1344 static struct device_type wwan_type = {
1345         .name   = "wwan",
1346 };
1347
1348 int
1349 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1350 {
1351         struct usbnet                   *dev;
1352         struct net_device               *net;
1353         struct usb_host_interface       *interface;
1354         struct driver_info              *info;
1355         struct usb_device               *xdev;
1356         int                             status;
1357         const char                      *name;
1358         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1359
1360         /* usbnet already took usb runtime pm, so have to enable the feature
1361          * for usb interface, otherwise usb_autopm_get_interface may return
1362          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1363          */
1364         if (!driver->supports_autosuspend) {
1365                 driver->supports_autosuspend = 1;
1366                 pm_runtime_enable(&udev->dev);
1367         }
1368
1369         name = udev->dev.driver->name;
1370         info = (struct driver_info *) prod->driver_info;
1371         if (!info) {
1372                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1373                 return -ENODEV;
1374         }
1375         xdev = interface_to_usbdev (udev);
1376         interface = udev->cur_altsetting;
1377
1378         status = -ENOMEM;
1379
1380         // set up our own records
1381         net = alloc_etherdev(sizeof(*dev));
1382         if (!net)
1383                 goto out;
1384
1385         /* netdev_printk() needs this so do it as early as possible */
1386         SET_NETDEV_DEV(net, &udev->dev);
1387
1388         dev = netdev_priv(net);
1389         dev->udev = xdev;
1390         dev->intf = udev;
1391         dev->driver_info = info;
1392         dev->driver_name = name;
1393         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1394                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1395         skb_queue_head_init (&dev->rxq);
1396         skb_queue_head_init (&dev->txq);
1397         skb_queue_head_init (&dev->done);
1398         skb_queue_head_init(&dev->rxq_pause);
1399         dev->bh.func = usbnet_bh;
1400         dev->bh.data = (unsigned long) dev;
1401         INIT_WORK (&dev->kevent, kevent);
1402         init_usb_anchor(&dev->deferred);
1403         dev->delay.function = usbnet_bh;
1404         dev->delay.data = (unsigned long) dev;
1405         init_timer (&dev->delay);
1406         mutex_init (&dev->phy_mutex);
1407
1408         dev->net = net;
1409         strcpy (net->name, "usb%d");
1410         memcpy (net->dev_addr, node_id, sizeof node_id);
1411
1412         /* rx and tx sides can use different message sizes;
1413          * bind() should set rx_urb_size in that case.
1414          */
1415         dev->hard_mtu = net->mtu + net->hard_header_len;
1416 #if 0
1417 // dma_supported() is deeply broken on almost all architectures
1418         // possible with some EHCI controllers
1419         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1420                 net->features |= NETIF_F_HIGHDMA;
1421 #endif
1422
1423         net->netdev_ops = &usbnet_netdev_ops;
1424         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1425         net->ethtool_ops = &usbnet_ethtool_ops;
1426
1427         // allow device-specific bind/init procedures
1428         // NOTE net->name still not usable ...
1429         if (info->bind) {
1430                 status = info->bind (dev, udev);
1431                 if (status < 0)
1432                         goto out1;
1433
1434                 // heuristic:  "usb%d" for links we know are two-host,
1435                 // else "eth%d" when there's reasonable doubt.  userspace
1436                 // can rename the link if it knows better.
1437                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1438                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1439                      (net->dev_addr [0] & 0x02) == 0))
1440                         strcpy (net->name, "eth%d");
1441                 /* WLAN devices should always be named "wlan%d" */
1442                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1443                         strcpy(net->name, "wlan%d");
1444                 /* WWAN devices should always be named "wwan%d" */
1445                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1446                         strcpy(net->name, "wwan%d");
1447
1448                 /* maybe the remote can't receive an Ethernet MTU */
1449                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1450                         net->mtu = dev->hard_mtu - net->hard_header_len;
1451         } else if (!info->in || !info->out)
1452                 status = usbnet_get_endpoints (dev, udev);
1453         else {
1454                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1455                 dev->out = usb_sndbulkpipe (xdev, info->out);
1456                 if (!(info->flags & FLAG_NO_SETINT))
1457                         status = usb_set_interface (xdev,
1458                                 interface->desc.bInterfaceNumber,
1459                                 interface->desc.bAlternateSetting);
1460                 else
1461                         status = 0;
1462
1463         }
1464         if (status >= 0 && dev->status)
1465                 status = init_status (dev, udev);
1466         if (status < 0)
1467                 goto out3;
1468
1469         if (!dev->rx_urb_size)
1470                 dev->rx_urb_size = dev->hard_mtu;
1471         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1472
1473         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1474                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1475         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1476                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1477
1478         status = register_netdev (net);
1479         if (status)
1480                 goto out4;
1481         netif_info(dev, probe, dev->net,
1482                    "register '%s' at usb-%s-%s, %s, %pM\n",
1483                    udev->dev.driver->name,
1484                    xdev->bus->bus_name, xdev->devpath,
1485                    dev->driver_info->description,
1486                    net->dev_addr);
1487
1488         // ok, it's ready to go.
1489         usb_set_intfdata (udev, dev);
1490
1491         netif_device_attach (net);
1492
1493         if (dev->driver_info->flags & FLAG_LINK_INTR)
1494                 netif_carrier_off(net);
1495
1496         return 0;
1497
1498 out4:
1499         usb_free_urb(dev->interrupt);
1500 out3:
1501         if (info->unbind)
1502                 info->unbind (dev, udev);
1503 out1:
1504         free_netdev(net);
1505 out:
1506         return status;
1507 }
1508 EXPORT_SYMBOL_GPL(usbnet_probe);
1509
1510 /*-------------------------------------------------------------------------*/
1511
1512 /*
1513  * suspend the whole driver as soon as the first interface is suspended
1514  * resume only when the last interface is resumed
1515  */
1516
1517 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1518 {
1519         struct usbnet           *dev = usb_get_intfdata(intf);
1520
1521         if (!dev->suspend_count++) {
1522                 spin_lock_irq(&dev->txq.lock);
1523                 /* don't autosuspend while transmitting */
1524                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1525                         dev->suspend_count--;
1526                         spin_unlock_irq(&dev->txq.lock);
1527                         return -EBUSY;
1528                 } else {
1529                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1530                         spin_unlock_irq(&dev->txq.lock);
1531                 }
1532                 /*
1533                  * accelerate emptying of the rx and queues, to avoid
1534                  * having everything error out.
1535                  */
1536                 netif_device_detach (dev->net);
1537                 usbnet_terminate_urbs(dev);
1538                 usb_kill_urb(dev->interrupt);
1539
1540                 /*
1541                  * reattach so runtime management can use and
1542                  * wake the device
1543                  */
1544                 netif_device_attach (dev->net);
1545         }
1546         return 0;
1547 }
1548 EXPORT_SYMBOL_GPL(usbnet_suspend);
1549
1550 int usbnet_resume (struct usb_interface *intf)
1551 {
1552         struct usbnet           *dev = usb_get_intfdata(intf);
1553         struct sk_buff          *skb;
1554         struct urb              *res;
1555         int                     retval;
1556
1557         if (!--dev->suspend_count) {
1558                 /* resume interrupt URBs */
1559                 if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1560                         usb_submit_urb(dev->interrupt, GFP_NOIO);
1561
1562                 spin_lock_irq(&dev->txq.lock);
1563                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1564
1565                         skb = (struct sk_buff *)res->context;
1566                         retval = usb_submit_urb(res, GFP_ATOMIC);
1567                         if (retval < 0) {
1568                                 dev_kfree_skb_any(skb);
1569                                 usb_free_urb(res);
1570                                 usb_autopm_put_interface_async(dev->intf);
1571                         } else {
1572                                 dev->net->trans_start = jiffies;
1573                                 __skb_queue_tail(&dev->txq, skb);
1574                         }
1575                 }
1576
1577                 smp_mb();
1578                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1579                 spin_unlock_irq(&dev->txq.lock);
1580
1581                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1582                         /* handle remote wakeup ASAP */
1583                         if (!dev->wait &&
1584                                 netif_device_present(dev->net) &&
1585                                 !timer_pending(&dev->delay) &&
1586                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1587                                         rx_alloc_submit(dev, GFP_NOIO);
1588
1589                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1590                                 netif_tx_wake_all_queues(dev->net);
1591                         tasklet_schedule (&dev->bh);
1592                 }
1593         }
1594
1595         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1596                 usb_autopm_get_interface_no_resume(intf);
1597
1598         return 0;
1599 }
1600 EXPORT_SYMBOL_GPL(usbnet_resume);
1601
1602 /*
1603  * Either a subdriver implements manage_power, then it is assumed to always
1604  * be ready to be suspended or it reports the readiness to be suspended
1605  * explicitly
1606  */
1607 void usbnet_device_suggests_idle(struct usbnet *dev)
1608 {
1609         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1610                 dev->intf->needs_remote_wakeup = 1;
1611                 usb_autopm_put_interface_async(dev->intf);
1612         }
1613 }
1614 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1615
1616 /*-------------------------------------------------------------------------*/
1617
1618 static int __init usbnet_init(void)
1619 {
1620         /* Compiler should optimize this out. */
1621         BUILD_BUG_ON(
1622                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1623
1624         eth_random_addr(node_id);
1625         return 0;
1626 }
1627 module_init(usbnet_init);
1628
1629 static void __exit usbnet_exit(void)
1630 {
1631 }
1632 module_exit(usbnet_exit);
1633
1634 MODULE_AUTHOR("David Brownell");
1635 MODULE_DESCRIPTION("USB network driver framework");
1636 MODULE_LICENSE("GPL");