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 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 186 {
 187         char            *buf = NULL;
 188         unsigned        pipe = 0;
 189         unsigned        maxp;
 190         unsigned        period;
 191
 192         if (!dev->driver_info->status)
 193                 return 0;
 194
 195         pipe = usb_rcvintpipe (dev->udev,
 196                         dev->status->desc.bEndpointAddress
 197                                 & USB_ENDPOINT_NUMBER_MASK);
 198         maxp = usb_maxpacket (dev->udev, pipe, 0);
 199
 200         /* avoid 1 msec chatter:  min 8 msec poll rate */
 201         period = max ((int) dev->status->desc.bInterval,
 202                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 203
 204         buf = kmalloc (maxp, GFP_KERNEL);
 205         if (buf) {
 206                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 207                 if (!dev->interrupt) {
 208                         kfree (buf);
 209                         return -ENOMEM;
 210                 } else {
 211                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 212                                 buf, maxp, intr_complete, dev, period);
 213                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 214                         dev_dbg(&intf->dev,
 215                                 "status ep%din, %d bytes period %d\n",
 216                                 usb_pipeendpoint(pipe), maxp, period);
 217                 }
 218         }
 219         return 0;
 220 }
 221
 222 /* Passes this packet up the stack, updating its accounting.
 223  * Some link protocols batch packets, so their rx_fixup paths
 224  * can return clones as well as just modify the original skb.
 225  */
 226 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 227 {
 228         int     status;
 229
 230         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 231                 skb_queue_tail(&dev->rxq_pause, skb);
 232                 return;
 233         }
 234
 235         skb->protocol = eth_type_trans (skb, dev->net);
 236         dev->net->stats.rx_packets++;
 237         dev->net->stats.rx_bytes += skb->len;
 238
 239         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 240                   skb->len + sizeof (struct ethhdr), skb->protocol);
 241         memset (skb->cb, 0, sizeof (struct skb_data));
 242
 243         if (skb_defer_rx_timestamp(skb))
 244                 return;
 245
 246         status = netif_rx (skb);
 247         if (status != NET_RX_SUCCESS)
 248                 netif_dbg(dev, rx_err, dev->net,
 249                           "netif_rx status %d\n", status);
 250 }
 251 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 252
 253 \f
 254 /*-------------------------------------------------------------------------
 255  *
 256  * Network Device Driver (peer link to "Host Device", from USB host)
 257  *
 258  *-------------------------------------------------------------------------*/
 259
 260 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 261 {
 262         struct usbnet   *dev = netdev_priv(net);
 263         int             ll_mtu = new_mtu + net->hard_header_len;
 264         int             old_hard_mtu = dev->hard_mtu;
 265         int             old_rx_urb_size = dev->rx_urb_size;
 266
 267         if (new_mtu <= 0)
 268                 return -EINVAL;
 269         // no second zero-length packet read wanted after mtu-sized packets
 270         if ((ll_mtu % dev->maxpacket) == 0)
 271                 return -EDOM;
 272         net->mtu = new_mtu;
 273
 274         dev->hard_mtu = net->mtu + net->hard_header_len;
 275         if (dev->rx_urb_size == old_hard_mtu) {
 276                 dev->rx_urb_size = dev->hard_mtu;
 277                 if (dev->rx_urb_size > old_rx_urb_size)
 278                         usbnet_unlink_rx_urbs(dev);
 279         }
 280
 281         return 0;
 282 }
 283 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 284
 285 /*-------------------------------------------------------------------------*/
 286
 287 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 288  * completion callbacks.  2.5 should have fixed those bugs...
 289  */
 290
 291 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
 292 {
 293         unsigned long           flags;
 294
 295         spin_lock_irqsave(&list->lock, flags);
 296         __skb_unlink(skb, list);
 297         spin_unlock(&list->lock);
 298         spin_lock(&dev->done.lock);
 299         __skb_queue_tail(&dev->done, skb);
 300         if (dev->done.qlen == 1)
 301                 tasklet_schedule(&dev->bh);
 302         spin_unlock_irqrestore(&dev->done.lock, flags);
 303 }
 304
 305 /* some work can't be done in tasklets, so we use keventd
 306  *
 307  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 308  * but tasklet_schedule() doesn't.  hope the failure is rare.
 309  */
 310 void usbnet_defer_kevent (struct usbnet *dev, int work)
 311 {
 312         set_bit (work, &dev->flags);
 313         if (!schedule_work (&dev->kevent))
 314                 netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 315         else
 316                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 317 }
 318 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 319
 320 /*-------------------------------------------------------------------------*/
 321
 322 static void rx_complete (struct urb *urb);
 323
 324 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 325 {
 326         struct sk_buff          *skb;
 327         struct skb_data         *entry;
 328         int                     retval = 0;
 329         unsigned long           lockflags;
 330         size_t                  size = dev->rx_urb_size;
 331
 332         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 333         if (!skb) {
 334                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 335                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 336                 usb_free_urb (urb);
 337                 return -ENOMEM;
 338         }
 339
 340         entry = (struct skb_data *) skb->cb;
 341         entry->urb = urb;
 342         entry->dev = dev;
 343         entry->state = rx_start;
 344         entry->length = 0;
 345
 346         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 347                 skb->data, size, rx_complete, skb);
 348
 349         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 350
 351         if (netif_running (dev->net) &&
 352             netif_device_present (dev->net) &&
 353             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 354             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 355                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 356                 case -EPIPE:
 357                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 358                         break;
 359                 case -ENOMEM:
 360                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 361                         break;
 362                 case -ENODEV:
 363                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 364                         netif_device_detach (dev->net);
 365                         break;
 366                 case -EHOSTUNREACH:
 367                         retval = -ENOLINK;
 368                         break;
 369                 default:
 370                         netif_dbg(dev, rx_err, dev->net,
 371                                   "rx submit, %d\n", retval);
 372                         tasklet_schedule (&dev->bh);
 373                         break;
 374                 case 0:
 375                         __skb_queue_tail (&dev->rxq, skb);
 376                 }
 377         } else {
 378                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 379                 retval = -ENOLINK;
 380         }
 381         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 382         if (retval) {
 383                 dev_kfree_skb_any (skb);
 384                 usb_free_urb (urb);
 385         }
 386         return retval;
 387 }
 388
 389
 390 /*-------------------------------------------------------------------------*/
 391
 392 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 393 {
 394         if (dev->driver_info->rx_fixup &&
 395             !dev->driver_info->rx_fixup (dev, skb)) {
 396                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 397                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 398                         dev->net->stats.rx_errors++;
 399                 goto done;
 400         }
 401         // else network stack removes extra byte if we forced a short packet
 402
 403         if (skb->len) {
 404                 /* all data was already cloned from skb inside the driver */
 405                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 406                         dev_kfree_skb_any(skb);
 407                 else
 408                         usbnet_skb_return(dev, skb);
 409                 return;
 410         }
 411
 412         netif_dbg(dev, rx_err, dev->net, "drop\n");
 413         dev->net->stats.rx_errors++;
 414 done:
 415         skb_queue_tail(&dev->done, skb);
 416 }
 417
 418 /*-------------------------------------------------------------------------*/
 419
 420 static void rx_complete (struct urb *urb)
 421 {
 422         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 423         struct skb_data         *entry = (struct skb_data *) skb->cb;
 424         struct usbnet           *dev = entry->dev;
 425         int                     urb_status = urb->status;
 426
 427         skb_put (skb, urb->actual_length);
 428         entry->state = rx_done;
 429         entry->urb = NULL;
 430
 431         switch (urb_status) {
 432         /* success */
 433         case 0:
 434                 if (skb->len < dev->net->hard_header_len) {
 435                         entry->state = rx_cleanup;
 436                         dev->net->stats.rx_errors++;
 437                         dev->net->stats.rx_length_errors++;
 438                         netif_dbg(dev, rx_err, dev->net,
 439                                   "rx length %d\n", skb->len);
 440                 }
 441                 break;
 442
 443         /* stalls need manual reset. this is rare ... except that
 444          * when going through USB 2.0 TTs, unplug appears this way.
 445          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 446          * storm, recovering as needed.
 447          */
 448         case -EPIPE:
 449                 dev->net->stats.rx_errors++;
 450                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 451                 // FALLTHROUGH
 452
 453         /* software-driven interface shutdown */
 454         case -ECONNRESET:               /* async unlink */
 455         case -ESHUTDOWN:                /* hardware gone */
 456                 netif_dbg(dev, ifdown, dev->net,
 457                           "rx shutdown, code %d\n", urb_status);
 458                 goto block;
 459
 460         /* we get controller i/o faults during khubd disconnect() delays.
 461          * throttle down resubmits, to avoid log floods; just temporarily,
 462          * so we still recover when the fault isn't a khubd delay.
 463          */
 464         case -EPROTO:
 465         case -ETIME:
 466         case -EILSEQ:
 467                 dev->net->stats.rx_errors++;
 468                 if (!timer_pending (&dev->delay)) {
 469                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 470                         netif_dbg(dev, link, dev->net,
 471                                   "rx throttle %d\n", urb_status);
 472                 }
 473 block:
 474                 entry->state = rx_cleanup;
 475                 entry->urb = urb;
 476                 urb = NULL;
 477                 break;
 478
 479         /* data overrun ... flush fifo? */
 480         case -EOVERFLOW:
 481                 dev->net->stats.rx_over_errors++;
 482                 // FALLTHROUGH
 483
 484         default:
 485                 entry->state = rx_cleanup;
 486                 dev->net->stats.rx_errors++;
 487                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 488                 break;
 489         }
 490
 491         defer_bh(dev, skb, &dev->rxq);
 492
 493         if (urb) {
 494                 if (netif_running (dev->net) &&
 495                     !test_bit (EVENT_RX_HALT, &dev->flags)) {
 496                         rx_submit (dev, urb, GFP_ATOMIC);
 497                         usb_mark_last_busy(dev->udev);
 498                         return;
 499                 }
 500                 usb_free_urb (urb);
 501         }
 502         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 503 }
 504
 505 static void intr_complete (struct urb *urb)
 506 {
 507         struct usbnet   *dev = urb->context;
 508         int             status = urb->status;
 509
 510         switch (status) {
 511         /* success */
 512         case 0:
 513                 dev->driver_info->status(dev, urb);
 514                 break;
 515
 516         /* software-driven interface shutdown */
 517         case -ENOENT:           /* urb killed */
 518         case -ESHUTDOWN:        /* hardware gone */
 519                 netif_dbg(dev, ifdown, dev->net,
 520                           "intr shutdown, code %d\n", status);
 521                 return;
 522
 523         /* NOTE:  not throttling like RX/TX, since this endpoint
 524          * already polls infrequently
 525          */
 526         default:
 527                 netdev_dbg(dev->net, "intr status %d\n", status);
 528                 break;
 529         }
 530
 531         if (!netif_running (dev->net))
 532                 return;
 533
 534         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 535         status = usb_submit_urb (urb, GFP_ATOMIC);
 536         if (status != 0)
 537                 netif_err(dev, timer, dev->net,
 538                           "intr resubmit --> %d\n", status);
 539 }
 540
 541 /*-------------------------------------------------------------------------*/
 542 void usbnet_pause_rx(struct usbnet *dev)
 543 {
 544         set_bit(EVENT_RX_PAUSED, &dev->flags);
 545
 546         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 547 }
 548 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 549
 550 void usbnet_resume_rx(struct usbnet *dev)
 551 {
 552         struct sk_buff *skb;
 553         int num = 0;
 554
 555         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 556
 557         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 558                 usbnet_skb_return(dev, skb);
 559                 num++;
 560         }
 561
 562         tasklet_schedule(&dev->bh);
 563
 564         netif_dbg(dev, rx_status, dev->net,
 565                   "paused rx queue disabled, %d skbs requeued\n", num);
 566 }
 567 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 568
 569 void usbnet_purge_paused_rxq(struct usbnet *dev)
 570 {
 571         skb_queue_purge(&dev->rxq_pause);
 572 }
 573 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 574
 575 /*-------------------------------------------------------------------------*/
 576
 577 // unlink pending rx/tx; completion handlers do all other cleanup
 578
 579 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 580 {
 581         unsigned long           flags;
 582         struct sk_buff          *skb, *skbnext;
 583         int                     count = 0;
 584
 585         spin_lock_irqsave (&q->lock, flags);
 586         skb_queue_walk_safe(q, skb, skbnext) {
 587                 struct skb_data         *entry;
 588                 struct urb              *urb;
 589                 int                     retval;
 590
 591                 entry = (struct skb_data *) skb->cb;
 592                 urb = entry->urb;
 593
 594                 /*
 595                  * Get reference count of the URB to avoid it to be
 596                  * freed during usb_unlink_urb, which may trigger
 597                  * use-after-free problem inside usb_unlink_urb since
 598                  * usb_unlink_urb is always racing with .complete
 599                  * handler(include defer_bh).
 600                  */
 601                 usb_get_urb(urb);
 602                 spin_unlock_irqrestore(&q->lock, flags);
 603                 // during some PM-driven resume scenarios,
 604                 // these (async) unlinks complete immediately
 605                 retval = usb_unlink_urb (urb);
 606                 if (retval != -EINPROGRESS && retval != 0)
 607                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 608                 else
 609                         count++;
 610                 usb_put_urb(urb);
 611                 spin_lock_irqsave(&q->lock, flags);
 612         }
 613         spin_unlock_irqrestore (&q->lock, flags);
 614         return count;
 615 }
 616
 617 // Flush all pending rx urbs
 618 // minidrivers may need to do this when the MTU changes
 619
 620 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 621 {
 622         if (netif_running(dev->net)) {
 623                 (void) unlink_urbs (dev, &dev->rxq);
 624                 tasklet_schedule(&dev->bh);
 625         }
 626 }
 627 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 628
 629 /*-------------------------------------------------------------------------*/
 630
 631 // precondition: never called in_interrupt
 632 static void usbnet_terminate_urbs(struct usbnet *dev)
 633 {
 634         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 635         DECLARE_WAITQUEUE(wait, current);
 636         int temp;
 637
 638         /* ensure there are no more active urbs */
 639         add_wait_queue(&unlink_wakeup, &wait);
 640         set_current_state(TASK_UNINTERRUPTIBLE);
 641         dev->wait = &unlink_wakeup;
 642         temp = unlink_urbs(dev, &dev->txq) +
 643                 unlink_urbs(dev, &dev->rxq);
 644
 645         /* maybe wait for deletions to finish. */
 646         while (!skb_queue_empty(&dev->rxq)
 647                 && !skb_queue_empty(&dev->txq)
 648                 && !skb_queue_empty(&dev->done)) {
 649                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 650                         set_current_state(TASK_UNINTERRUPTIBLE);
 651                         netif_dbg(dev, ifdown, dev->net,
 652                                   "waited for %d urb completions\n", temp);
 653         }
 654         set_current_state(TASK_RUNNING);
 655         dev->wait = NULL;
 656         remove_wait_queue(&unlink_wakeup, &wait);
 657 }
 658
 659 int usbnet_stop (struct net_device *net)
 660 {
 661         struct usbnet           *dev = netdev_priv(net);
 662         struct driver_info      *info = dev->driver_info;
 663         int                     retval;
 664
 665         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 666         netif_stop_queue (net);
 667
 668         netif_info(dev, ifdown, dev->net,
 669                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 670                    net->stats.rx_packets, net->stats.tx_packets,
 671                    net->stats.rx_errors, net->stats.tx_errors);
 672
 673         /* allow minidriver to stop correctly (wireless devices to turn off
 674          * radio etc) */
 675         if (info->stop) {
 676                 retval = info->stop(dev);
 677                 if (retval < 0)
 678                         netif_info(dev, ifdown, dev->net,
 679                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 680                                    retval,
 681                                    dev->udev->bus->bus_name, dev->udev->devpath,
 682                                    info->description);
 683         }
 684
 685         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 686                 usbnet_terminate_urbs(dev);
 687
 688         usb_kill_urb(dev->interrupt);
 689
 690         usbnet_purge_paused_rxq(dev);
 691
 692         /* deferred work (task, timer, softirq) must also stop.
 693          * can't flush_scheduled_work() until we drop rtnl (later),
 694          * else workers could deadlock; so make workers a NOP.
 695          */
 696         dev->flags = 0;
 697         del_timer_sync (&dev->delay);
 698         tasklet_kill (&dev->bh);
 699         if (info->manage_power)
 700                 info->manage_power(dev, 0);
 701         else
 702                 usb_autopm_put_interface(dev->intf);
 703
 704         return 0;
 705 }
 706 EXPORT_SYMBOL_GPL(usbnet_stop);
 707
 708 /*-------------------------------------------------------------------------*/
 709
 710 // posts reads, and enables write queuing
 711
 712 // precondition: never called in_interrupt
 713
 714 int usbnet_open (struct net_device *net)
 715 {
 716         struct usbnet           *dev = netdev_priv(net);
 717         int                     retval;
 718         struct driver_info      *info = dev->driver_info;
 719
 720         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 721                 netif_info(dev, ifup, dev->net,
 722                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 723                            retval,
 724                            dev->udev->bus->bus_name,
 725                            dev->udev->devpath,
 726                            info->description);
 727                 goto done_nopm;
 728         }
 729
 730         // put into "known safe" state
 731         if (info->reset && (retval = info->reset (dev)) < 0) {
 732                 netif_info(dev, ifup, dev->net,
 733                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 734                            retval,
 735                            dev->udev->bus->bus_name,
 736                            dev->udev->devpath,
 737                            info->description);
 738                 goto done;
 739         }
 740
 741         // insist peer be connected
 742         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 743                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 744                 goto done;
 745         }
 746
 747         /* start any status interrupt transfer */
 748         if (dev->interrupt) {
 749                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 750                 if (retval < 0) {
 751                         netif_err(dev, ifup, dev->net,
 752                                   "intr submit %d\n", retval);
 753                         goto done;
 754                 }
 755         }
 756
 757         set_bit(EVENT_DEV_OPEN, &dev->flags);
 758         netif_start_queue (net);
 759         netif_info(dev, ifup, dev->net,
 760                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 761                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 762                    dev->net->mtu,
 763                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 764                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 765                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 766                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 767                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 768                    "simple");
 769
 770         // delay posting reads until we're fully open
 771         tasklet_schedule (&dev->bh);
 772         if (info->manage_power) {
 773                 retval = info->manage_power(dev, 1);
 774                 if (retval < 0)
 775                         goto done;
 776                 usb_autopm_put_interface(dev->intf);
 777         }
 778         return retval;
 779
 780 done:
 781         usb_autopm_put_interface(dev->intf);
 782 done_nopm:
 783         return retval;
 784 }
 785 EXPORT_SYMBOL_GPL(usbnet_open);
 786
 787 /*-------------------------------------------------------------------------*/
 788
 789 /* ethtool methods; minidrivers may need to add some more, but
 790  * they'll probably want to use this base set.
 791  */
 792
 793 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 794 {
 795         struct usbnet *dev = netdev_priv(net);
 796
 797         if (!dev->mii.mdio_read)
 798                 return -EOPNOTSUPP;
 799
 800         return mii_ethtool_gset(&dev->mii, cmd);
 801 }
 802 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 803
 804 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 805 {
 806         struct usbnet *dev = netdev_priv(net);
 807         int retval;
 808
 809         if (!dev->mii.mdio_write)
 810                 return -EOPNOTSUPP;
 811
 812         retval = mii_ethtool_sset(&dev->mii, cmd);
 813
 814         /* link speed/duplex might have changed */
 815         if (dev->driver_info->link_reset)
 816                 dev->driver_info->link_reset(dev);
 817
 818         return retval;
 819
 820 }
 821 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 822
 823 u32 usbnet_get_link (struct net_device *net)
 824 {
 825         struct usbnet *dev = netdev_priv(net);
 826
 827         /* If a check_connect is defined, return its result */
 828         if (dev->driver_info->check_connect)
 829                 return dev->driver_info->check_connect (dev) == 0;
 830
 831         /* if the device has mii operations, use those */
 832         if (dev->mii.mdio_read)
 833                 return mii_link_ok(&dev->mii);
 834
 835         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 836         return ethtool_op_get_link(net);
 837 }
 838 EXPORT_SYMBOL_GPL(usbnet_get_link);
 839
 840 int usbnet_nway_reset(struct net_device *net)
 841 {
 842         struct usbnet *dev = netdev_priv(net);
 843
 844         if (!dev->mii.mdio_write)
 845                 return -EOPNOTSUPP;
 846
 847         return mii_nway_restart(&dev->mii);
 848 }
 849 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 850
 851 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 852 {
 853         struct usbnet *dev = netdev_priv(net);
 854
 855         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 856         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 857         strncpy (info->fw_version, dev->driver_info->description,
 858                 sizeof info->fw_version);
 859         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 860 }
 861 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 862
 863 u32 usbnet_get_msglevel (struct net_device *net)
 864 {
 865         struct usbnet *dev = netdev_priv(net);
 866
 867         return dev->msg_enable;
 868 }
 869 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 870
 871 void usbnet_set_msglevel (struct net_device *net, u32 level)
 872 {
 873         struct usbnet *dev = netdev_priv(net);
 874
 875         dev->msg_enable = level;
 876 }
 877 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 878
 879 /* drivers may override default ethtool_ops in their bind() routine */
 880 static const struct ethtool_ops usbnet_ethtool_ops = {
 881         .get_settings           = usbnet_get_settings,
 882         .set_settings           = usbnet_set_settings,
 883         .get_link               = usbnet_get_link,
 884         .nway_reset             = usbnet_nway_reset,
 885         .get_drvinfo            = usbnet_get_drvinfo,
 886         .get_msglevel           = usbnet_get_msglevel,
 887         .set_msglevel           = usbnet_set_msglevel,
 888 };
 889
 890 /*-------------------------------------------------------------------------*/
 891
 892 /* work that cannot be done in interrupt context uses keventd.
 893  *
 894  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 895  * especially now that control transfers can be queued.
 896  */
 897 static void
 898 kevent (struct work_struct *work)
 899 {
 900         struct usbnet           *dev =
 901                 container_of(work, struct usbnet, kevent);
 902         int                     status;
 903
 904         /* usb_clear_halt() needs a thread context */
 905         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 906                 unlink_urbs (dev, &dev->txq);
 907                 status = usb_autopm_get_interface(dev->intf);
 908                 if (status < 0)
 909                         goto fail_pipe;
 910                 status = usb_clear_halt (dev->udev, dev->out);
 911                 usb_autopm_put_interface(dev->intf);
 912                 if (status < 0 &&
 913                     status != -EPIPE &&
 914                     status != -ESHUTDOWN) {
 915                         if (netif_msg_tx_err (dev))
 916 fail_pipe:
 917                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 918                                            status);
 919                 } else {
 920                         clear_bit (EVENT_TX_HALT, &dev->flags);
 921                         if (status != -ESHUTDOWN)
 922                                 netif_wake_queue (dev->net);
 923                 }
 924         }
 925         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 926                 unlink_urbs (dev, &dev->rxq);
 927                 status = usb_autopm_get_interface(dev->intf);
 928                 if (status < 0)
 929                         goto fail_halt;
 930                 status = usb_clear_halt (dev->udev, dev->in);
 931                 usb_autopm_put_interface(dev->intf);
 932                 if (status < 0 &&
 933                     status != -EPIPE &&
 934                     status != -ESHUTDOWN) {
 935                         if (netif_msg_rx_err (dev))
 936 fail_halt:
 937                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 938                                            status);
 939                 } else {
 940                         clear_bit (EVENT_RX_HALT, &dev->flags);
 941                         tasklet_schedule (&dev->bh);
 942                 }
 943         }
 944
 945         /* tasklet could resubmit itself forever if memory is tight */
 946         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 947                 struct urb      *urb = NULL;
 948                 int resched = 1;
 949
 950                 if (netif_running (dev->net))
 951                         urb = usb_alloc_urb (0, GFP_KERNEL);
 952                 else
 953                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 954                 if (urb != NULL) {
 955                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 956                         status = usb_autopm_get_interface(dev->intf);
 957                         if (status < 0) {
 958                                 usb_free_urb(urb);
 959                                 goto fail_lowmem;
 960                         }
 961                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 962                                 resched = 0;
 963                         usb_autopm_put_interface(dev->intf);
 964 fail_lowmem:
 965                         if (resched)
 966                                 tasklet_schedule (&dev->bh);
 967                 }
 968         }
 969
 970         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 971                 struct driver_info      *info = dev->driver_info;
 972                 int                     retval = 0;
 973
 974                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 975                 status = usb_autopm_get_interface(dev->intf);
 976                 if (status < 0)
 977                         goto skip_reset;
 978                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 979                         usb_autopm_put_interface(dev->intf);
 980 skip_reset:
 981                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
 982                                     retval,
 983                                     dev->udev->bus->bus_name,
 984                                     dev->udev->devpath,
 985                                     info->description);
 986                 } else {
 987                         usb_autopm_put_interface(dev->intf);
 988                 }
 989         }
 990
 991         if (dev->flags)
 992                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
 993 }
 994
 995 /*-------------------------------------------------------------------------*/
 996
 997 static void tx_complete (struct urb *urb)
 998 {
 999         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1000         struct skb_data         *entry = (struct skb_data *) skb->cb;
1001         struct usbnet           *dev = entry->dev;
1002
1003         if (urb->status == 0) {
1004                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1005                         dev->net->stats.tx_packets++;
1006                 dev->net->stats.tx_bytes += entry->length;
1007         } else {
1008                 dev->net->stats.tx_errors++;
1009
1010                 switch (urb->status) {
1011                 case -EPIPE:
1012                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1013                         break;
1014
1015                 /* software-driven interface shutdown */
1016                 case -ECONNRESET:               // async unlink
1017                 case -ESHUTDOWN:                // hardware gone
1018                         break;
1019
1020                 // like rx, tx gets controller i/o faults during khubd delays
1021                 // and so it uses the same throttling mechanism.
1022                 case -EPROTO:
1023                 case -ETIME:
1024                 case -EILSEQ:
1025                         usb_mark_last_busy(dev->udev);
1026                         if (!timer_pending (&dev->delay)) {
1027                                 mod_timer (&dev->delay,
1028                                         jiffies + THROTTLE_JIFFIES);
1029                                 netif_dbg(dev, link, dev->net,
1030                                           "tx throttle %d\n", urb->status);
1031                         }
1032                         netif_stop_queue (dev->net);
1033                         break;
1034                 default:
1035                         netif_dbg(dev, tx_err, dev->net,
1036                                   "tx err %d\n", entry->urb->status);
1037                         break;
1038                 }
1039         }
1040
1041         usb_autopm_put_interface_async(dev->intf);
1042         entry->state = tx_done;
1043         defer_bh(dev, skb, &dev->txq);
1044 }
1045
1046 /*-------------------------------------------------------------------------*/
1047
1048 void usbnet_tx_timeout (struct net_device *net)
1049 {
1050         struct usbnet           *dev = netdev_priv(net);
1051
1052         unlink_urbs (dev, &dev->txq);
1053         tasklet_schedule (&dev->bh);
1054
1055         // FIXME: device recovery -- reset?
1056 }
1057 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1058
1059 /*-------------------------------------------------------------------------*/
1060
1061 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1062                                      struct net_device *net)
1063 {
1064         struct usbnet           *dev = netdev_priv(net);
1065         int                     length;
1066         struct urb              *urb = NULL;
1067         struct skb_data         *entry;
1068         struct driver_info      *info = dev->driver_info;
1069         unsigned long           flags;
1070         int retval;
1071
1072         if (skb)
1073                 skb_tx_timestamp(skb);
1074
1075         // some devices want funky USB-level framing, for
1076         // win32 driver (usually) and/or hardware quirks
1077         if (info->tx_fixup) {
1078                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1079                 if (!skb) {
1080                         if (netif_msg_tx_err(dev)) {
1081                                 netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1082                                 goto drop;
1083                         } else {
1084                                 /* cdc_ncm collected packet; waits for more */
1085                                 goto not_drop;
1086                         }
1087                 }
1088         }
1089         length = skb->len;
1090
1091         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1092                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1093                 goto drop;
1094         }
1095
1096         entry = (struct skb_data *) skb->cb;
1097         entry->urb = urb;
1098         entry->dev = dev;
1099         entry->state = tx_start;
1100         entry->length = length;
1101
1102         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1103                         skb->data, skb->len, tx_complete, skb);
1104
1105         /* don't assume the hardware handles USB_ZERO_PACKET
1106          * NOTE:  strictly conforming cdc-ether devices should expect
1107          * the ZLP here, but ignore the one-byte packet.
1108          * NOTE2: CDC NCM specification is different from CDC ECM when
1109          * handling ZLP/short packets, so cdc_ncm driver will make short
1110          * packet itself if needed.
1111          */
1112         if (length % dev->maxpacket == 0) {
1113                 if (!(info->flags & FLAG_SEND_ZLP)) {
1114                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1115                                 urb->transfer_buffer_length++;
1116                                 if (skb_tailroom(skb)) {
1117                                         skb->data[skb->len] = 0;
1118                                         __skb_put(skb, 1);
1119                                 }
1120                         }
1121                 } else
1122                         urb->transfer_flags |= URB_ZERO_PACKET;
1123         }
1124
1125         spin_lock_irqsave(&dev->txq.lock, flags);
1126         retval = usb_autopm_get_interface_async(dev->intf);
1127         if (retval < 0) {
1128                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1129                 goto drop;
1130         }
1131
1132 #ifdef CONFIG_PM
1133         /* if this triggers the device is still a sleep */
1134         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1135                 /* transmission will be done in resume */
1136                 usb_anchor_urb(urb, &dev->deferred);
1137                 /* no use to process more packets */
1138                 netif_stop_queue(net);
1139                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1140                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1141                 goto deferred;
1142         }
1143 #endif
1144
1145         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1146         case -EPIPE:
1147                 netif_stop_queue (net);
1148                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1149                 usb_autopm_put_interface_async(dev->intf);
1150                 break;
1151         default:
1152                 usb_autopm_put_interface_async(dev->intf);
1153                 netif_dbg(dev, tx_err, dev->net,
1154                           "tx: submit urb err %d\n", retval);
1155                 break;
1156         case 0:
1157                 net->trans_start = jiffies;
1158                 __skb_queue_tail (&dev->txq, skb);
1159                 if (dev->txq.qlen >= TX_QLEN (dev))
1160                         netif_stop_queue (net);
1161         }
1162         spin_unlock_irqrestore (&dev->txq.lock, flags);
1163
1164         if (retval) {
1165                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1166 drop:
1167                 dev->net->stats.tx_dropped++;
1168 not_drop:
1169                 if (skb)
1170                         dev_kfree_skb_any (skb);
1171                 usb_free_urb (urb);
1172         } else
1173                 netif_dbg(dev, tx_queued, dev->net,
1174                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1175 #ifdef CONFIG_PM
1176 deferred:
1177 #endif
1178         return NETDEV_TX_OK;
1179 }
1180 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1181
1182 /*-------------------------------------------------------------------------*/
1183
1184 // tasklet (work deferred from completions, in_irq) or timer
1185
1186 static void usbnet_bh (unsigned long param)
1187 {
1188         struct usbnet           *dev = (struct usbnet *) param;
1189         struct sk_buff          *skb;
1190         struct skb_data         *entry;
1191
1192         while ((skb = skb_dequeue (&dev->done))) {
1193                 entry = (struct skb_data *) skb->cb;
1194                 switch (entry->state) {
1195                 case rx_done:
1196                         entry->state = rx_cleanup;
1197                         rx_process (dev, skb);
1198                         continue;
1199                 case tx_done:
1200                 case rx_cleanup:
1201                         usb_free_urb (entry->urb);
1202                         dev_kfree_skb (skb);
1203                         continue;
1204                 default:
1205                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1206                 }
1207         }
1208
1209         // waiting for all pending urbs to complete?
1210         if (dev->wait) {
1211                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1212                         wake_up (dev->wait);
1213                 }
1214
1215         // or are we maybe short a few urbs?
1216         } else if (netif_running (dev->net) &&
1217                    netif_device_present (dev->net) &&
1218                    !timer_pending (&dev->delay) &&
1219                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1220                 int     temp = dev->rxq.qlen;
1221                 int     qlen = RX_QLEN (dev);
1222
1223                 if (temp < qlen) {
1224                         struct urb      *urb;
1225                         int             i;
1226
1227                         // don't refill the queue all at once
1228                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1229                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1230                                 if (urb != NULL) {
1231                                         if (rx_submit (dev, urb, GFP_ATOMIC) ==
1232                                             -ENOLINK)
1233                                                 return;
1234                                 }
1235                         }
1236                         if (temp != dev->rxq.qlen)
1237                                 netif_dbg(dev, link, dev->net,
1238                                           "rxqlen %d --> %d\n",
1239                                           temp, dev->rxq.qlen);
1240                         if (dev->rxq.qlen < qlen)
1241                                 tasklet_schedule (&dev->bh);
1242                 }
1243                 if (dev->txq.qlen < TX_QLEN (dev))
1244                         netif_wake_queue (dev->net);
1245         }
1246 }
1247
1248
1249 /*-------------------------------------------------------------------------
1250  *
1251  * USB Device Driver support
1252  *
1253  *-------------------------------------------------------------------------*/
1254
1255 // precondition: never called in_interrupt
1256
1257 void usbnet_disconnect (struct usb_interface *intf)
1258 {
1259         struct usbnet           *dev;
1260         struct usb_device       *xdev;
1261         struct net_device       *net;
1262
1263         dev = usb_get_intfdata(intf);
1264         usb_set_intfdata(intf, NULL);
1265         if (!dev)
1266                 return;
1267
1268         xdev = interface_to_usbdev (intf);
1269
1270         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1271                    intf->dev.driver->name,
1272                    xdev->bus->bus_name, xdev->devpath,
1273                    dev->driver_info->description);
1274
1275         net = dev->net;
1276         unregister_netdev (net);
1277
1278         cancel_work_sync(&dev->kevent);
1279
1280         if (dev->driver_info->unbind)
1281                 dev->driver_info->unbind (dev, intf);
1282
1283         usb_kill_urb(dev->interrupt);
1284         usb_free_urb(dev->interrupt);
1285
1286         free_netdev(net);
1287         usb_put_dev (xdev);
1288 }
1289 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1290
1291 static const struct net_device_ops usbnet_netdev_ops = {
1292         .ndo_open               = usbnet_open,
1293         .ndo_stop               = usbnet_stop,
1294         .ndo_start_xmit         = usbnet_start_xmit,
1295         .ndo_tx_timeout         = usbnet_tx_timeout,
1296         .ndo_change_mtu         = usbnet_change_mtu,
1297         .ndo_set_mac_address    = eth_mac_addr,
1298         .ndo_validate_addr      = eth_validate_addr,
1299 };
1300
1301 /*-------------------------------------------------------------------------*/
1302
1303 // precondition: never called in_interrupt
1304
1305 static struct device_type wlan_type = {
1306         .name   = "wlan",
1307 };
1308
1309 static struct device_type wwan_type = {
1310         .name   = "wwan",
1311 };
1312
1313 int
1314 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1315 {
1316         struct usbnet                   *dev;
1317         struct net_device               *net;
1318         struct usb_host_interface       *interface;
1319         struct driver_info              *info;
1320         struct usb_device               *xdev;
1321         int                             status;
1322         const char                      *name;
1323         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1324
1325         /* usbnet already took usb runtime pm, so have to enable the feature
1326          * for usb interface, otherwise usb_autopm_get_interface may return
1327          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1328          */
1329         if (!driver->supports_autosuspend) {
1330                 driver->supports_autosuspend = 1;
1331                 pm_runtime_enable(&udev->dev);
1332         }
1333
1334         name = udev->dev.driver->name;
1335         info = (struct driver_info *) prod->driver_info;
1336         if (!info) {
1337                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1338                 return -ENODEV;
1339         }
1340         xdev = interface_to_usbdev (udev);
1341         interface = udev->cur_altsetting;
1342
1343         usb_get_dev (xdev);
1344
1345         status = -ENOMEM;
1346
1347         // set up our own records
1348         net = alloc_etherdev(sizeof(*dev));
1349         if (!net)
1350                 goto out;
1351
1352         /* netdev_printk() needs this so do it as early as possible */
1353         SET_NETDEV_DEV(net, &udev->dev);
1354
1355         dev = netdev_priv(net);
1356         dev->udev = xdev;
1357         dev->intf = udev;
1358         dev->driver_info = info;
1359         dev->driver_name = name;
1360         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1361                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1362         skb_queue_head_init (&dev->rxq);
1363         skb_queue_head_init (&dev->txq);
1364         skb_queue_head_init (&dev->done);
1365         skb_queue_head_init(&dev->rxq_pause);
1366         dev->bh.func = usbnet_bh;
1367         dev->bh.data = (unsigned long) dev;
1368         INIT_WORK (&dev->kevent, kevent);
1369         init_usb_anchor(&dev->deferred);
1370         dev->delay.function = usbnet_bh;
1371         dev->delay.data = (unsigned long) dev;
1372         init_timer (&dev->delay);
1373         mutex_init (&dev->phy_mutex);
1374
1375         dev->net = net;
1376         strcpy (net->name, "usb%d");
1377         memcpy (net->dev_addr, node_id, sizeof node_id);
1378
1379         /* rx and tx sides can use different message sizes;
1380          * bind() should set rx_urb_size in that case.
1381          */
1382         dev->hard_mtu = net->mtu + net->hard_header_len;
1383 #if 0
1384 // dma_supported() is deeply broken on almost all architectures
1385         // possible with some EHCI controllers
1386         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1387                 net->features |= NETIF_F_HIGHDMA;
1388 #endif
1389
1390         net->netdev_ops = &usbnet_netdev_ops;
1391         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1392         net->ethtool_ops = &usbnet_ethtool_ops;
1393
1394         // allow device-specific bind/init procedures
1395         // NOTE net->name still not usable ...
1396         if (info->bind) {
1397                 status = info->bind (dev, udev);
1398                 if (status < 0)
1399                         goto out1;
1400
1401                 // heuristic:  "usb%d" for links we know are two-host,
1402                 // else "eth%d" when there's reasonable doubt.  userspace
1403                 // can rename the link if it knows better.
1404                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1405                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1406                      (net->dev_addr [0] & 0x02) == 0))
1407                         strcpy (net->name, "eth%d");
1408                 /* WLAN devices should always be named "wlan%d" */
1409                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1410                         strcpy(net->name, "wlan%d");
1411                 /* WWAN devices should always be named "wwan%d" */
1412                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1413                         strcpy(net->name, "wwan%d");
1414
1415                 /* maybe the remote can't receive an Ethernet MTU */
1416                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1417                         net->mtu = dev->hard_mtu - net->hard_header_len;
1418         } else if (!info->in || !info->out)
1419                 status = usbnet_get_endpoints (dev, udev);
1420         else {
1421                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1422                 dev->out = usb_sndbulkpipe (xdev, info->out);
1423                 if (!(info->flags & FLAG_NO_SETINT))
1424                         status = usb_set_interface (xdev,
1425                                 interface->desc.bInterfaceNumber,
1426                                 interface->desc.bAlternateSetting);
1427                 else
1428                         status = 0;
1429
1430         }
1431         if (status >= 0 && dev->status)
1432                 status = init_status (dev, udev);
1433         if (status < 0)
1434                 goto out3;
1435
1436         if (!dev->rx_urb_size)
1437                 dev->rx_urb_size = dev->hard_mtu;
1438         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1439
1440         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1441                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1442         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1443                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1444
1445         status = register_netdev (net);
1446         if (status)
1447                 goto out4;
1448         netif_info(dev, probe, dev->net,
1449                    "register '%s' at usb-%s-%s, %s, %pM\n",
1450                    udev->dev.driver->name,
1451                    xdev->bus->bus_name, xdev->devpath,
1452                    dev->driver_info->description,
1453                    net->dev_addr);
1454
1455         // ok, it's ready to go.
1456         usb_set_intfdata (udev, dev);
1457
1458         netif_device_attach (net);
1459
1460         if (dev->driver_info->flags & FLAG_LINK_INTR)
1461                 netif_carrier_off(net);
1462
1463         return 0;
1464
1465 out4:
1466         usb_free_urb(dev->interrupt);
1467 out3:
1468         if (info->unbind)
1469                 info->unbind (dev, udev);
1470 out1:
1471         free_netdev(net);
1472 out:
1473         usb_put_dev(xdev);
1474         return status;
1475 }
1476 EXPORT_SYMBOL_GPL(usbnet_probe);
1477
1478 /*-------------------------------------------------------------------------*/
1479
1480 /*
1481  * suspend the whole driver as soon as the first interface is suspended
1482  * resume only when the last interface is resumed
1483  */
1484
1485 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1486 {
1487         struct usbnet           *dev = usb_get_intfdata(intf);
1488
1489         if (!dev->suspend_count++) {
1490                 spin_lock_irq(&dev->txq.lock);
1491                 /* don't autosuspend while transmitting */
1492                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1493                         spin_unlock_irq(&dev->txq.lock);
1494                         return -EBUSY;
1495                 } else {
1496                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1497                         spin_unlock_irq(&dev->txq.lock);
1498                 }
1499                 /*
1500                  * accelerate emptying of the rx and queues, to avoid
1501                  * having everything error out.
1502                  */
1503                 netif_device_detach (dev->net);
1504                 usbnet_terminate_urbs(dev);
1505                 usb_kill_urb(dev->interrupt);
1506
1507                 /*
1508                  * reattach so runtime management can use and
1509                  * wake the device
1510                  */
1511                 netif_device_attach (dev->net);
1512         }
1513         return 0;
1514 }
1515 EXPORT_SYMBOL_GPL(usbnet_suspend);
1516
1517 int usbnet_resume (struct usb_interface *intf)
1518 {
1519         struct usbnet           *dev = usb_get_intfdata(intf);
1520         struct sk_buff          *skb;
1521         struct urb              *res;
1522         int                     retval;
1523
1524         if (!--dev->suspend_count) {
1525                 /* resume interrupt URBs */
1526                 if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1527                         usb_submit_urb(dev->interrupt, GFP_NOIO);
1528
1529                 spin_lock_irq(&dev->txq.lock);
1530                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1531
1532                         skb = (struct sk_buff *)res->context;
1533                         retval = usb_submit_urb(res, GFP_ATOMIC);
1534                         if (retval < 0) {
1535                                 dev_kfree_skb_any(skb);
1536                                 usb_free_urb(res);
1537                                 usb_autopm_put_interface_async(dev->intf);
1538                         } else {
1539                                 dev->net->trans_start = jiffies;
1540                                 __skb_queue_tail(&dev->txq, skb);
1541                         }
1542                 }
1543
1544                 smp_mb();
1545                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1546                 spin_unlock_irq(&dev->txq.lock);
1547
1548                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1549                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1550                                 netif_tx_wake_all_queues(dev->net);
1551                         tasklet_schedule (&dev->bh);
1552                 }
1553         }
1554         return 0;
1555 }
1556 EXPORT_SYMBOL_GPL(usbnet_resume);
1557
1558
1559 /*-------------------------------------------------------------------------*/
1560
1561 static int __init usbnet_init(void)
1562 {
1563         /* Compiler should optimize this out. */
1564         BUILD_BUG_ON(
1565                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1566
1567         random_ether_addr(node_id);
1568         return 0;
1569 }
1570 module_init(usbnet_init);
1571
1572 static void __exit usbnet_exit(void)
1573 {
1574 }
1575 module_exit(usbnet_exit);
1576
1577 MODULE_AUTHOR("David Brownell");
1578 MODULE_DESCRIPTION("USB network driver framework");
1579 MODULE_LICENSE("GPL");