drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This is a generic "USB networking" framework that works with several
  23  * kinds of full and high speed networking devices:  host-to-host cables,
  24  * smart usb peripherals, and actual Ethernet adapters.
  25  *
  26  * These devices usually differ in terms of control protocols (if they
  27  * even have one!) and sometimes they define new framing to wrap or batch
  28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30  * issues can usefully be addressed by this framework.
  31  */
  32
  33 // #define      DEBUG                   // error path messages, extra info
  34 // #define      VERBOSE                 // more; success messages
  35
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/ctype.h>
  41 #include <linux/ethtool.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/mii.h>
  44 #include <linux/usb.h>
  45 #include <linux/usb/usbnet.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63  * let the USB host controller be busy for 5msec or more before an irq
  64  * is required, under load.  Jumbograms change the equation.
  65  */
  66 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72 // reawaken network queue this soon after stopping; else watchdog barks
  73 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  74
  75 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  76 // us (it polls at HZ/4 usually) before we report too many false errors.
  77 #define THROTTLE_JIFFIES        (HZ/8)
  78
  79 // between wakeups
  80 #define UNLINK_TIMEOUT_MS       3
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 // randomly generated ethernet address
  85 static u8       node_id [ETH_ALEN];
  86
  87 static const char driver_name [] = "usbnet";
  88
  89 /* use ethtool to change the level for any given device */
  90 static int msg_level = -1;
  91 module_param (msg_level, int, 0);
  92 MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  97 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98 {
  99         int                             tmp;
 100         struct usb_host_interface       *alt = NULL;
 101         struct usb_host_endpoint        *in = NULL, *out = NULL;
 102         struct usb_host_endpoint        *status = NULL;
 103
 104         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105                 unsigned        ep;
 106
 107                 in = out = status = NULL;
 108                 alt = intf->altsetting + tmp;
 109
 110                 /* take the first altsetting with in-bulk + out-bulk;
 111                  * remember any status endpoint, just in case;
 112                  * ignore other endpoints and altsettings.
 113                  */
 114                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115                         struct usb_host_endpoint        *e;
 116                         int                             intr = 0;
 117
 118                         e = alt->endpoint + ep;
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 /* FALLTHROUGH */
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         int             tmp, i;
 166         unsigned char   buf [13];
 167
 168         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169         if (tmp != 12) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (tmp >= 0)
 173                         tmp = -EINVAL;
 174                 return tmp;
 175         }
 176         for (i = tmp = 0; i < 6; i++, tmp += 2)
 177                 dev->net->dev_addr [i] =
 178                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb)
 184 {
 185         struct usbnet   *dev = urb->context;
 186         int             status = urb->status;
 187
 188         switch (status) {
 189         /* success */
 190         case 0:
 191                 dev->driver_info->status(dev, urb);
 192                 break;
 193
 194         /* software-driven interface shutdown */
 195         case -ENOENT:           /* urb killed */
 196         case -ESHUTDOWN:        /* hardware gone */
 197                 netif_dbg(dev, ifdown, dev->net,
 198                           "intr shutdown, code %d\n", status);
 199                 return;
 200
 201         /* NOTE:  not throttling like RX/TX, since this endpoint
 202          * already polls infrequently
 203          */
 204         default:
 205                 netdev_dbg(dev->net, "intr status %d\n", status);
 206                 break;
 207         }
 208
 209         if (!netif_running (dev->net))
 210                 return;
 211
 212         status = usb_submit_urb (urb, GFP_ATOMIC);
 213         if (status != 0)
 214                 netif_err(dev, timer, dev->net,
 215                           "intr resubmit --> %d\n", status);
 216 }
 217
 218 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 219 {
 220         char            *buf = NULL;
 221         unsigned        pipe = 0;
 222         unsigned        maxp;
 223         unsigned        period;
 224
 225         if (!dev->driver_info->status)
 226                 return 0;
 227
 228         pipe = usb_rcvintpipe (dev->udev,
 229                         dev->status->desc.bEndpointAddress
 230                                 & USB_ENDPOINT_NUMBER_MASK);
 231         maxp = usb_maxpacket (dev->udev, pipe, 0);
 232
 233         /* avoid 1 msec chatter:  min 8 msec poll rate */
 234         period = max ((int) dev->status->desc.bInterval,
 235                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 236
 237         buf = kmalloc (maxp, GFP_KERNEL);
 238         if (buf) {
 239                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 240                 if (!dev->interrupt) {
 241                         kfree (buf);
 242                         return -ENOMEM;
 243                 } else {
 244                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 245                                 buf, maxp, intr_complete, dev, period);
 246                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 247                         dev_dbg(&intf->dev,
 248                                 "status ep%din, %d bytes period %d\n",
 249                                 usb_pipeendpoint(pipe), maxp, period);
 250                 }
 251         }
 252         return 0;
 253 }
 254
 255 /* Passes this packet up the stack, updating its accounting.
 256  * Some link protocols batch packets, so their rx_fixup paths
 257  * can return clones as well as just modify the original skb.
 258  */
 259 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 260 {
 261         int     status;
 262
 263         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 264                 skb_queue_tail(&dev->rxq_pause, skb);
 265                 return;
 266         }
 267
 268         skb->protocol = eth_type_trans (skb, dev->net);
 269         dev->net->stats.rx_packets++;
 270         dev->net->stats.rx_bytes += skb->len;
 271
 272         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 273                   skb->len + sizeof (struct ethhdr), skb->protocol);
 274         memset (skb->cb, 0, sizeof (struct skb_data));
 275
 276         if (skb_defer_rx_timestamp(skb))
 277                 return;
 278
 279         status = netif_rx (skb);
 280         if (status != NET_RX_SUCCESS)
 281                 netif_dbg(dev, rx_err, dev->net,
 282                           "netif_rx status %d\n", status);
 283 }
 284 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 285
 286 \f
 287 /*-------------------------------------------------------------------------
 288  *
 289  * Network Device Driver (peer link to "Host Device", from USB host)
 290  *
 291  *-------------------------------------------------------------------------*/
 292
 293 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 294 {
 295         struct usbnet   *dev = netdev_priv(net);
 296         int             ll_mtu = new_mtu + net->hard_header_len;
 297         int             old_hard_mtu = dev->hard_mtu;
 298         int             old_rx_urb_size = dev->rx_urb_size;
 299
 300         if (new_mtu <= 0)
 301                 return -EINVAL;
 302         // no second zero-length packet read wanted after mtu-sized packets
 303         if ((ll_mtu % dev->maxpacket) == 0)
 304                 return -EDOM;
 305         net->mtu = new_mtu;
 306
 307         dev->hard_mtu = net->mtu + net->hard_header_len;
 308         if (dev->rx_urb_size == old_hard_mtu) {
 309                 dev->rx_urb_size = dev->hard_mtu;
 310                 if (dev->rx_urb_size > old_rx_urb_size)
 311                         usbnet_unlink_rx_urbs(dev);
 312         }
 313
 314         return 0;
 315 }
 316 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 317
 318 /* The caller must hold list->lock */
 319 static void __usbnet_queue_skb(struct sk_buff_head *list,
 320                         struct sk_buff *newsk, enum skb_state state)
 321 {
 322         struct skb_data *entry = (struct skb_data *) newsk->cb;
 323
 324         __skb_queue_tail(list, newsk);
 325         entry->state = state;
 326 }
 327
 328 /*-------------------------------------------------------------------------*/
 329
 330 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 331  * completion callbacks.  2.5 should have fixed those bugs...
 332  */
 333
 334 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 335                 struct sk_buff_head *list, enum skb_state state)
 336 {
 337         unsigned long           flags;
 338         enum skb_state          old_state;
 339         struct skb_data *entry = (struct skb_data *) skb->cb;
 340
 341         spin_lock_irqsave(&list->lock, flags);
 342         old_state = entry->state;
 343         entry->state = state;
 344         __skb_unlink(skb, list);
 345         spin_unlock(&list->lock);
 346         spin_lock(&dev->done.lock);
 347         __skb_queue_tail(&dev->done, skb);
 348         if (dev->done.qlen == 1)
 349                 tasklet_schedule(&dev->bh);
 350         spin_unlock_irqrestore(&dev->done.lock, flags);
 351         return old_state;
 352 }
 353
 354 /* some work can't be done in tasklets, so we use keventd
 355  *
 356  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 357  * but tasklet_schedule() doesn't.  hope the failure is rare.
 358  */
 359 void usbnet_defer_kevent (struct usbnet *dev, int work)
 360 {
 361         set_bit (work, &dev->flags);
 362         if (!schedule_work (&dev->kevent)) {
 363                 if (net_ratelimit())
 364                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 365         } else {
 366                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 367         }
 368 }
 369 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 370
 371 /*-------------------------------------------------------------------------*/
 372
 373 static void rx_complete (struct urb *urb);
 374
 375 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 376 {
 377         struct sk_buff          *skb;
 378         struct skb_data         *entry;
 379         int                     retval = 0;
 380         unsigned long           lockflags;
 381         size_t                  size = dev->rx_urb_size;
 382
 383         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 384         if (!skb) {
 385                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 386                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 387                 usb_free_urb (urb);
 388                 return -ENOMEM;
 389         }
 390
 391         entry = (struct skb_data *) skb->cb;
 392         entry->urb = urb;
 393         entry->dev = dev;
 394         entry->length = 0;
 395
 396         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 397                 skb->data, size, rx_complete, skb);
 398
 399         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 400
 401         if (netif_running (dev->net) &&
 402             netif_device_present (dev->net) &&
 403             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 404             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 405                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 406                 case -EPIPE:
 407                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 408                         break;
 409                 case -ENOMEM:
 410                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 411                         break;
 412                 case -ENODEV:
 413                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 414                         netif_device_detach (dev->net);
 415                         break;
 416                 case -EHOSTUNREACH:
 417                         retval = -ENOLINK;
 418                         break;
 419                 default:
 420                         netif_dbg(dev, rx_err, dev->net,
 421                                   "rx submit, %d\n", retval);
 422                         tasklet_schedule (&dev->bh);
 423                         break;
 424                 case 0:
 425                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 426                 }
 427         } else {
 428                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 429                 retval = -ENOLINK;
 430         }
 431         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 432         if (retval) {
 433                 dev_kfree_skb_any (skb);
 434                 usb_free_urb (urb);
 435         }
 436         return retval;
 437 }
 438
 439
 440 /*-------------------------------------------------------------------------*/
 441
 442 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 443 {
 444         if (dev->driver_info->rx_fixup &&
 445             !dev->driver_info->rx_fixup (dev, skb)) {
 446                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 447                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 448                         dev->net->stats.rx_errors++;
 449                 goto done;
 450         }
 451         // else network stack removes extra byte if we forced a short packet
 452
 453         if (skb->len) {
 454                 /* all data was already cloned from skb inside the driver */
 455                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 456                         dev_kfree_skb_any(skb);
 457                 else
 458                         usbnet_skb_return(dev, skb);
 459                 return;
 460         }
 461
 462         netif_dbg(dev, rx_err, dev->net, "drop\n");
 463         dev->net->stats.rx_errors++;
 464 done:
 465         skb_queue_tail(&dev->done, skb);
 466 }
 467
 468 /*-------------------------------------------------------------------------*/
 469
 470 static void rx_complete (struct urb *urb)
 471 {
 472         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 473         struct skb_data         *entry = (struct skb_data *) skb->cb;
 474         struct usbnet           *dev = entry->dev;
 475         int                     urb_status = urb->status;
 476         enum skb_state          state;
 477
 478         skb_put (skb, urb->actual_length);
 479         state = rx_done;
 480         entry->urb = NULL;
 481
 482         switch (urb_status) {
 483         /* success */
 484         case 0:
 485                 if (skb->len < dev->net->hard_header_len) {
 486                         state = rx_cleanup;
 487                         dev->net->stats.rx_errors++;
 488                         dev->net->stats.rx_length_errors++;
 489                         netif_dbg(dev, rx_err, dev->net,
 490                                   "rx length %d\n", skb->len);
 491                 }
 492                 break;
 493
 494         /* stalls need manual reset. this is rare ... except that
 495          * when going through USB 2.0 TTs, unplug appears this way.
 496          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 497          * storm, recovering as needed.
 498          */
 499         case -EPIPE:
 500                 dev->net->stats.rx_errors++;
 501                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 502                 // FALLTHROUGH
 503
 504         /* software-driven interface shutdown */
 505         case -ECONNRESET:               /* async unlink */
 506         case -ESHUTDOWN:                /* hardware gone */
 507                 netif_dbg(dev, ifdown, dev->net,
 508                           "rx shutdown, code %d\n", urb_status);
 509                 goto block;
 510
 511         /* we get controller i/o faults during khubd disconnect() delays.
 512          * throttle down resubmits, to avoid log floods; just temporarily,
 513          * so we still recover when the fault isn't a khubd delay.
 514          */
 515         case -EPROTO:
 516         case -ETIME:
 517         case -EILSEQ:
 518                 dev->net->stats.rx_errors++;
 519                 if (!timer_pending (&dev->delay)) {
 520                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 521                         netif_dbg(dev, link, dev->net,
 522                                   "rx throttle %d\n", urb_status);
 523                 }
 524 block:
 525                 state = rx_cleanup;
 526                 entry->urb = urb;
 527                 urb = NULL;
 528                 break;
 529
 530         /* data overrun ... flush fifo? */
 531         case -EOVERFLOW:
 532                 dev->net->stats.rx_over_errors++;
 533                 // FALLTHROUGH
 534
 535         default:
 536                 state = rx_cleanup;
 537                 dev->net->stats.rx_errors++;
 538                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 539                 break;
 540         }
 541
 542         state = defer_bh(dev, skb, &dev->rxq, state);
 543
 544         if (urb) {
 545                 if (netif_running (dev->net) &&
 546                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 547                     state != unlink_start) {
 548                         rx_submit (dev, urb, GFP_ATOMIC);
 549                         usb_mark_last_busy(dev->udev);
 550                         return;
 551                 }
 552                 usb_free_urb (urb);
 553         }
 554         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 555 }
 556
 557 /*-------------------------------------------------------------------------*/
 558 void usbnet_pause_rx(struct usbnet *dev)
 559 {
 560         set_bit(EVENT_RX_PAUSED, &dev->flags);
 561
 562         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 563 }
 564 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 565
 566 void usbnet_resume_rx(struct usbnet *dev)
 567 {
 568         struct sk_buff *skb;
 569         int num = 0;
 570
 571         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 572
 573         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 574                 usbnet_skb_return(dev, skb);
 575                 num++;
 576         }
 577
 578         tasklet_schedule(&dev->bh);
 579
 580         netif_dbg(dev, rx_status, dev->net,
 581                   "paused rx queue disabled, %d skbs requeued\n", num);
 582 }
 583 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 584
 585 void usbnet_purge_paused_rxq(struct usbnet *dev)
 586 {
 587         skb_queue_purge(&dev->rxq_pause);
 588 }
 589 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 590
 591 /*-------------------------------------------------------------------------*/
 592
 593 // unlink pending rx/tx; completion handlers do all other cleanup
 594
 595 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 596 {
 597         unsigned long           flags;
 598         struct sk_buff          *skb;
 599         int                     count = 0;
 600
 601         spin_lock_irqsave (&q->lock, flags);
 602         while (!skb_queue_empty(q)) {
 603                 struct skb_data         *entry;
 604                 struct urb              *urb;
 605                 int                     retval;
 606
 607                 skb_queue_walk(q, skb) {
 608                         entry = (struct skb_data *) skb->cb;
 609                         if (entry->state != unlink_start)
 610                                 goto found;
 611                 }
 612                 break;
 613 found:
 614                 entry->state = unlink_start;
 615                 urb = entry->urb;
 616
 617                 /*
 618                  * Get reference count of the URB to avoid it to be
 619                  * freed during usb_unlink_urb, which may trigger
 620                  * use-after-free problem inside usb_unlink_urb since
 621                  * usb_unlink_urb is always racing with .complete
 622                  * handler(include defer_bh).
 623                  */
 624                 usb_get_urb(urb);
 625                 spin_unlock_irqrestore(&q->lock, flags);
 626                 // during some PM-driven resume scenarios,
 627                 // these (async) unlinks complete immediately
 628                 retval = usb_unlink_urb (urb);
 629                 if (retval != -EINPROGRESS && retval != 0)
 630                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 631                 else
 632                         count++;
 633                 usb_put_urb(urb);
 634                 spin_lock_irqsave(&q->lock, flags);
 635         }
 636         spin_unlock_irqrestore (&q->lock, flags);
 637         return count;
 638 }
 639
 640 // Flush all pending rx urbs
 641 // minidrivers may need to do this when the MTU changes
 642
 643 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 644 {
 645         if (netif_running(dev->net)) {
 646                 (void) unlink_urbs (dev, &dev->rxq);
 647                 tasklet_schedule(&dev->bh);
 648         }
 649 }
 650 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 651
 652 /*-------------------------------------------------------------------------*/
 653
 654 // precondition: never called in_interrupt
 655 static void usbnet_terminate_urbs(struct usbnet *dev)
 656 {
 657         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 658         DECLARE_WAITQUEUE(wait, current);
 659         int temp;
 660
 661         /* ensure there are no more active urbs */
 662         add_wait_queue(&unlink_wakeup, &wait);
 663         set_current_state(TASK_UNINTERRUPTIBLE);
 664         dev->wait = &unlink_wakeup;
 665         temp = unlink_urbs(dev, &dev->txq) +
 666                 unlink_urbs(dev, &dev->rxq);
 667
 668         /* maybe wait for deletions to finish. */
 669         while (!skb_queue_empty(&dev->rxq)
 670                 && !skb_queue_empty(&dev->txq)
 671                 && !skb_queue_empty(&dev->done)) {
 672                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 673                         set_current_state(TASK_UNINTERRUPTIBLE);
 674                         netif_dbg(dev, ifdown, dev->net,
 675                                   "waited for %d urb completions\n", temp);
 676         }
 677         set_current_state(TASK_RUNNING);
 678         dev->wait = NULL;
 679         remove_wait_queue(&unlink_wakeup, &wait);
 680 }
 681
 682 int usbnet_stop (struct net_device *net)
 683 {
 684         struct usbnet           *dev = netdev_priv(net);
 685         struct driver_info      *info = dev->driver_info;
 686         int                     retval;
 687
 688         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 689         netif_stop_queue (net);
 690
 691         netif_info(dev, ifdown, dev->net,
 692                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 693                    net->stats.rx_packets, net->stats.tx_packets,
 694                    net->stats.rx_errors, net->stats.tx_errors);
 695
 696         /* allow minidriver to stop correctly (wireless devices to turn off
 697          * radio etc) */
 698         if (info->stop) {
 699                 retval = info->stop(dev);
 700                 if (retval < 0)
 701                         netif_info(dev, ifdown, dev->net,
 702                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 703                                    retval,
 704                                    dev->udev->bus->bus_name, dev->udev->devpath,
 705                                    info->description);
 706         }
 707
 708         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 709                 usbnet_terminate_urbs(dev);
 710
 711         usb_kill_urb(dev->interrupt);
 712
 713         usbnet_purge_paused_rxq(dev);
 714
 715         /* deferred work (task, timer, softirq) must also stop.
 716          * can't flush_scheduled_work() until we drop rtnl (later),
 717          * else workers could deadlock; so make workers a NOP.
 718          */
 719         dev->flags = 0;
 720         del_timer_sync (&dev->delay);
 721         tasklet_kill (&dev->bh);
 722         if (info->manage_power)
 723                 info->manage_power(dev, 0);
 724         else
 725                 usb_autopm_put_interface(dev->intf);
 726
 727         return 0;
 728 }
 729 EXPORT_SYMBOL_GPL(usbnet_stop);
 730
 731 /*-------------------------------------------------------------------------*/
 732
 733 // posts reads, and enables write queuing
 734
 735 // precondition: never called in_interrupt
 736
 737 int usbnet_open (struct net_device *net)
 738 {
 739         struct usbnet           *dev = netdev_priv(net);
 740         int                     retval;
 741         struct driver_info      *info = dev->driver_info;
 742
 743         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 744                 netif_info(dev, ifup, dev->net,
 745                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 746                            retval,
 747                            dev->udev->bus->bus_name,
 748                            dev->udev->devpath,
 749                            info->description);
 750                 goto done_nopm;
 751         }
 752
 753         // put into "known safe" state
 754         if (info->reset && (retval = info->reset (dev)) < 0) {
 755                 netif_info(dev, ifup, dev->net,
 756                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 757                            retval,
 758                            dev->udev->bus->bus_name,
 759                            dev->udev->devpath,
 760                            info->description);
 761                 goto done;
 762         }
 763
 764         // insist peer be connected
 765         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 766                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 767                 goto done;
 768         }
 769
 770         /* start any status interrupt transfer */
 771         if (dev->interrupt) {
 772                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 773                 if (retval < 0) {
 774                         netif_err(dev, ifup, dev->net,
 775                                   "intr submit %d\n", retval);
 776                         goto done;
 777                 }
 778         }
 779
 780         set_bit(EVENT_DEV_OPEN, &dev->flags);
 781         netif_start_queue (net);
 782         netif_info(dev, ifup, dev->net,
 783                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 784                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 785                    dev->net->mtu,
 786                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 787                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 788                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 789                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 790                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 791                    "simple");
 792
 793         // delay posting reads until we're fully open
 794         tasklet_schedule (&dev->bh);
 795         if (info->manage_power) {
 796                 retval = info->manage_power(dev, 1);
 797                 if (retval < 0)
 798                         goto done_manage_power_error;
 799                 usb_autopm_put_interface(dev->intf);
 800         }
 801         return retval;
 802
 803 done_manage_power_error:
 804         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 805 done:
 806         usb_autopm_put_interface(dev->intf);
 807 done_nopm:
 808         return retval;
 809 }
 810 EXPORT_SYMBOL_GPL(usbnet_open);
 811
 812 /*-------------------------------------------------------------------------*/
 813
 814 /* ethtool methods; minidrivers may need to add some more, but
 815  * they'll probably want to use this base set.
 816  */
 817
 818 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 819 {
 820         struct usbnet *dev = netdev_priv(net);
 821
 822         if (!dev->mii.mdio_read)
 823                 return -EOPNOTSUPP;
 824
 825         return mii_ethtool_gset(&dev->mii, cmd);
 826 }
 827 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 828
 829 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 830 {
 831         struct usbnet *dev = netdev_priv(net);
 832         int retval;
 833
 834         if (!dev->mii.mdio_write)
 835                 return -EOPNOTSUPP;
 836
 837         retval = mii_ethtool_sset(&dev->mii, cmd);
 838
 839         /* link speed/duplex might have changed */
 840         if (dev->driver_info->link_reset)
 841                 dev->driver_info->link_reset(dev);
 842
 843         return retval;
 844
 845 }
 846 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 847
 848 u32 usbnet_get_link (struct net_device *net)
 849 {
 850         struct usbnet *dev = netdev_priv(net);
 851
 852         /* If a check_connect is defined, return its result */
 853         if (dev->driver_info->check_connect)
 854                 return dev->driver_info->check_connect (dev) == 0;
 855
 856         /* if the device has mii operations, use those */
 857         if (dev->mii.mdio_read)
 858                 return mii_link_ok(&dev->mii);
 859
 860         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 861         return ethtool_op_get_link(net);
 862 }
 863 EXPORT_SYMBOL_GPL(usbnet_get_link);
 864
 865 int usbnet_nway_reset(struct net_device *net)
 866 {
 867         struct usbnet *dev = netdev_priv(net);
 868
 869         if (!dev->mii.mdio_write)
 870                 return -EOPNOTSUPP;
 871
 872         return mii_nway_restart(&dev->mii);
 873 }
 874 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 875
 876 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 877 {
 878         struct usbnet *dev = netdev_priv(net);
 879
 880         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 881         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 882         strlcpy (info->fw_version, dev->driver_info->description,
 883                 sizeof info->fw_version);
 884         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 885 }
 886 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 887
 888 u32 usbnet_get_msglevel (struct net_device *net)
 889 {
 890         struct usbnet *dev = netdev_priv(net);
 891
 892         return dev->msg_enable;
 893 }
 894 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 895
 896 void usbnet_set_msglevel (struct net_device *net, u32 level)
 897 {
 898         struct usbnet *dev = netdev_priv(net);
 899
 900         dev->msg_enable = level;
 901 }
 902 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 903
 904 /* drivers may override default ethtool_ops in their bind() routine */
 905 static const struct ethtool_ops usbnet_ethtool_ops = {
 906         .get_settings           = usbnet_get_settings,
 907         .set_settings           = usbnet_set_settings,
 908         .get_link               = usbnet_get_link,
 909         .nway_reset             = usbnet_nway_reset,
 910         .get_drvinfo            = usbnet_get_drvinfo,
 911         .get_msglevel           = usbnet_get_msglevel,
 912         .set_msglevel           = usbnet_set_msglevel,
 913         .get_ts_info            = ethtool_op_get_ts_info,
 914 };
 915
 916 /*-------------------------------------------------------------------------*/
 917
 918 /* work that cannot be done in interrupt context uses keventd.
 919  *
 920  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 921  * especially now that control transfers can be queued.
 922  */
 923 static void
 924 kevent (struct work_struct *work)
 925 {
 926         struct usbnet           *dev =
 927                 container_of(work, struct usbnet, kevent);
 928         int                     status;
 929
 930         /* usb_clear_halt() needs a thread context */
 931         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 932                 unlink_urbs (dev, &dev->txq);
 933                 status = usb_autopm_get_interface(dev->intf);
 934                 if (status < 0)
 935                         goto fail_pipe;
 936                 status = usb_clear_halt (dev->udev, dev->out);
 937                 usb_autopm_put_interface(dev->intf);
 938                 if (status < 0 &&
 939                     status != -EPIPE &&
 940                     status != -ESHUTDOWN) {
 941                         if (netif_msg_tx_err (dev))
 942 fail_pipe:
 943                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 944                                            status);
 945                 } else {
 946                         clear_bit (EVENT_TX_HALT, &dev->flags);
 947                         if (status != -ESHUTDOWN)
 948                                 netif_wake_queue (dev->net);
 949                 }
 950         }
 951         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 952                 unlink_urbs (dev, &dev->rxq);
 953                 status = usb_autopm_get_interface(dev->intf);
 954                 if (status < 0)
 955                         goto fail_halt;
 956                 status = usb_clear_halt (dev->udev, dev->in);
 957                 usb_autopm_put_interface(dev->intf);
 958                 if (status < 0 &&
 959                     status != -EPIPE &&
 960                     status != -ESHUTDOWN) {
 961                         if (netif_msg_rx_err (dev))
 962 fail_halt:
 963                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 964                                            status);
 965                 } else {
 966                         clear_bit (EVENT_RX_HALT, &dev->flags);
 967                         tasklet_schedule (&dev->bh);
 968                 }
 969         }
 970
 971         /* tasklet could resubmit itself forever if memory is tight */
 972         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 973                 struct urb      *urb = NULL;
 974                 int resched = 1;
 975
 976                 if (netif_running (dev->net))
 977                         urb = usb_alloc_urb (0, GFP_KERNEL);
 978                 else
 979                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 980                 if (urb != NULL) {
 981                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 982                         status = usb_autopm_get_interface(dev->intf);
 983                         if (status < 0) {
 984                                 usb_free_urb(urb);
 985                                 goto fail_lowmem;
 986                         }
 987                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 988                                 resched = 0;
 989                         usb_autopm_put_interface(dev->intf);
 990 fail_lowmem:
 991                         if (resched)
 992                                 tasklet_schedule (&dev->bh);
 993                 }
 994         }
 995
 996         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 997                 struct driver_info      *info = dev->driver_info;
 998                 int                     retval = 0;
 999
1000                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1001                 status = usb_autopm_get_interface(dev->intf);
1002                 if (status < 0)
1003                         goto skip_reset;
1004                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1005                         usb_autopm_put_interface(dev->intf);
1006 skip_reset:
1007                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1008                                     retval,
1009                                     dev->udev->bus->bus_name,
1010                                     dev->udev->devpath,
1011                                     info->description);
1012                 } else {
1013                         usb_autopm_put_interface(dev->intf);
1014                 }
1015         }
1016
1017         if (dev->flags)
1018                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1019 }
1020
1021 /*-------------------------------------------------------------------------*/
1022
1023 static void tx_complete (struct urb *urb)
1024 {
1025         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1026         struct skb_data         *entry = (struct skb_data *) skb->cb;
1027         struct usbnet           *dev = entry->dev;
1028
1029         if (urb->status == 0) {
1030                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1031                         dev->net->stats.tx_packets++;
1032                 dev->net->stats.tx_bytes += entry->length;
1033         } else {
1034                 dev->net->stats.tx_errors++;
1035
1036                 switch (urb->status) {
1037                 case -EPIPE:
1038                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1039                         break;
1040
1041                 /* software-driven interface shutdown */
1042                 case -ECONNRESET:               // async unlink
1043                 case -ESHUTDOWN:                // hardware gone
1044                         break;
1045
1046                 // like rx, tx gets controller i/o faults during khubd delays
1047                 // and so it uses the same throttling mechanism.
1048                 case -EPROTO:
1049                 case -ETIME:
1050                 case -EILSEQ:
1051                         usb_mark_last_busy(dev->udev);
1052                         if (!timer_pending (&dev->delay)) {
1053                                 mod_timer (&dev->delay,
1054                                         jiffies + THROTTLE_JIFFIES);
1055                                 netif_dbg(dev, link, dev->net,
1056                                           "tx throttle %d\n", urb->status);
1057                         }
1058                         netif_stop_queue (dev->net);
1059                         break;
1060                 default:
1061                         netif_dbg(dev, tx_err, dev->net,
1062                                   "tx err %d\n", entry->urb->status);
1063                         break;
1064                 }
1065         }
1066
1067         usb_autopm_put_interface_async(dev->intf);
1068         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1069 }
1070
1071 /*-------------------------------------------------------------------------*/
1072
1073 void usbnet_tx_timeout (struct net_device *net)
1074 {
1075         struct usbnet           *dev = netdev_priv(net);
1076
1077         unlink_urbs (dev, &dev->txq);
1078         tasklet_schedule (&dev->bh);
1079
1080         // FIXME: device recovery -- reset?
1081 }
1082 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1083
1084 /*-------------------------------------------------------------------------*/
1085
1086 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1087                                      struct net_device *net)
1088 {
1089         struct usbnet           *dev = netdev_priv(net);
1090         int                     length;
1091         struct urb              *urb = NULL;
1092         struct skb_data         *entry;
1093         struct driver_info      *info = dev->driver_info;
1094         unsigned long           flags;
1095         int retval;
1096
1097         if (skb)
1098                 skb_tx_timestamp(skb);
1099
1100         // some devices want funky USB-level framing, for
1101         // win32 driver (usually) and/or hardware quirks
1102         if (info->tx_fixup) {
1103                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1104                 if (!skb) {
1105                         if (netif_msg_tx_err(dev)) {
1106                                 netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1107                                 goto drop;
1108                         } else {
1109                                 /* cdc_ncm collected packet; waits for more */
1110                                 goto not_drop;
1111                         }
1112                 }
1113         }
1114         length = skb->len;
1115
1116         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1117                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1118                 goto drop;
1119         }
1120
1121         entry = (struct skb_data *) skb->cb;
1122         entry->urb = urb;
1123         entry->dev = dev;
1124         entry->length = length;
1125
1126         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1127                         skb->data, skb->len, tx_complete, skb);
1128
1129         /* don't assume the hardware handles USB_ZERO_PACKET
1130          * NOTE:  strictly conforming cdc-ether devices should expect
1131          * the ZLP here, but ignore the one-byte packet.
1132          * NOTE2: CDC NCM specification is different from CDC ECM when
1133          * handling ZLP/short packets, so cdc_ncm driver will make short
1134          * packet itself if needed.
1135          */
1136         if (length % dev->maxpacket == 0) {
1137                 if (!(info->flags & FLAG_SEND_ZLP)) {
1138                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1139                                 urb->transfer_buffer_length++;
1140                                 if (skb_tailroom(skb)) {
1141                                         skb->data[skb->len] = 0;
1142                                         __skb_put(skb, 1);
1143                                 }
1144                         }
1145                 } else
1146                         urb->transfer_flags |= URB_ZERO_PACKET;
1147         }
1148
1149         spin_lock_irqsave(&dev->txq.lock, flags);
1150         retval = usb_autopm_get_interface_async(dev->intf);
1151         if (retval < 0) {
1152                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1153                 goto drop;
1154         }
1155
1156 #ifdef CONFIG_PM
1157         /* if this triggers the device is still a sleep */
1158         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1159                 /* transmission will be done in resume */
1160                 usb_anchor_urb(urb, &dev->deferred);
1161                 /* no use to process more packets */
1162                 netif_stop_queue(net);
1163                 usb_put_urb(urb);
1164                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1165                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1166                 goto deferred;
1167         }
1168 #endif
1169
1170         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1171         case -EPIPE:
1172                 netif_stop_queue (net);
1173                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1174                 usb_autopm_put_interface_async(dev->intf);
1175                 break;
1176         default:
1177                 usb_autopm_put_interface_async(dev->intf);
1178                 netif_dbg(dev, tx_err, dev->net,
1179                           "tx: submit urb err %d\n", retval);
1180                 break;
1181         case 0:
1182                 net->trans_start = jiffies;
1183                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1184                 if (dev->txq.qlen >= TX_QLEN (dev))
1185                         netif_stop_queue (net);
1186         }
1187         spin_unlock_irqrestore (&dev->txq.lock, flags);
1188
1189         if (retval) {
1190                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1191 drop:
1192                 dev->net->stats.tx_dropped++;
1193 not_drop:
1194                 if (skb)
1195                         dev_kfree_skb_any (skb);
1196                 usb_free_urb (urb);
1197         } else
1198                 netif_dbg(dev, tx_queued, dev->net,
1199                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1200 #ifdef CONFIG_PM
1201 deferred:
1202 #endif
1203         return NETDEV_TX_OK;
1204 }
1205 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1206
1207 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1208 {
1209         struct urb      *urb;
1210         int             i;
1211         int             ret = 0;
1212
1213         /* don't refill the queue all at once */
1214         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1215                 urb = usb_alloc_urb(0, flags);
1216                 if (urb != NULL) {
1217                         ret = rx_submit(dev, urb, flags);
1218                         if (ret)
1219                                 goto err;
1220                 } else {
1221                         ret = -ENOMEM;
1222                         goto err;
1223                 }
1224         }
1225 err:
1226         return ret;
1227 }
1228
1229 /*-------------------------------------------------------------------------*/
1230
1231 // tasklet (work deferred from completions, in_irq) or timer
1232
1233 static void usbnet_bh (unsigned long param)
1234 {
1235         struct usbnet           *dev = (struct usbnet *) param;
1236         struct sk_buff          *skb;
1237         struct skb_data         *entry;
1238
1239         while ((skb = skb_dequeue (&dev->done))) {
1240                 entry = (struct skb_data *) skb->cb;
1241                 switch (entry->state) {
1242                 case rx_done:
1243                         entry->state = rx_cleanup;
1244                         rx_process (dev, skb);
1245                         continue;
1246                 case tx_done:
1247                 case rx_cleanup:
1248                         usb_free_urb (entry->urb);
1249                         dev_kfree_skb (skb);
1250                         continue;
1251                 default:
1252                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1253                 }
1254         }
1255
1256         // waiting for all pending urbs to complete?
1257         if (dev->wait) {
1258                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1259                         wake_up (dev->wait);
1260                 }
1261
1262         // or are we maybe short a few urbs?
1263         } else if (netif_running (dev->net) &&
1264                    netif_device_present (dev->net) &&
1265                    !timer_pending (&dev->delay) &&
1266                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1267                 int     temp = dev->rxq.qlen;
1268
1269                 if (temp < RX_QLEN(dev)) {
1270                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1271                                 return;
1272                         if (temp != dev->rxq.qlen)
1273                                 netif_dbg(dev, link, dev->net,
1274                                           "rxqlen %d --> %d\n",
1275                                           temp, dev->rxq.qlen);
1276                         if (dev->rxq.qlen < RX_QLEN(dev))
1277                                 tasklet_schedule (&dev->bh);
1278                 }
1279                 if (dev->txq.qlen < TX_QLEN (dev))
1280                         netif_wake_queue (dev->net);
1281         }
1282 }
1283
1284
1285 /*-------------------------------------------------------------------------
1286  *
1287  * USB Device Driver support
1288  *
1289  *-------------------------------------------------------------------------*/
1290
1291 // precondition: never called in_interrupt
1292
1293 void usbnet_disconnect (struct usb_interface *intf)
1294 {
1295         struct usbnet           *dev;
1296         struct usb_device       *xdev;
1297         struct net_device       *net;
1298
1299         dev = usb_get_intfdata(intf);
1300         usb_set_intfdata(intf, NULL);
1301         if (!dev)
1302                 return;
1303
1304         xdev = interface_to_usbdev (intf);
1305
1306         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1307                    intf->dev.driver->name,
1308                    xdev->bus->bus_name, xdev->devpath,
1309                    dev->driver_info->description);
1310
1311         net = dev->net;
1312         unregister_netdev (net);
1313
1314         cancel_work_sync(&dev->kevent);
1315
1316         usb_scuttle_anchored_urbs(&dev->deferred);
1317
1318         if (dev->driver_info->unbind)
1319                 dev->driver_info->unbind (dev, intf);
1320
1321         usb_kill_urb(dev->interrupt);
1322         usb_free_urb(dev->interrupt);
1323
1324         free_netdev(net);
1325 }
1326 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1327
1328 static const struct net_device_ops usbnet_netdev_ops = {
1329         .ndo_open               = usbnet_open,
1330         .ndo_stop               = usbnet_stop,
1331         .ndo_start_xmit         = usbnet_start_xmit,
1332         .ndo_tx_timeout         = usbnet_tx_timeout,
1333         .ndo_change_mtu         = usbnet_change_mtu,
1334         .ndo_set_mac_address    = eth_mac_addr,
1335         .ndo_validate_addr      = eth_validate_addr,
1336 };
1337
1338 /*-------------------------------------------------------------------------*/
1339
1340 // precondition: never called in_interrupt
1341
1342 static struct device_type wlan_type = {
1343         .name   = "wlan",
1344 };
1345
1346 static struct device_type wwan_type = {
1347         .name   = "wwan",
1348 };
1349
1350 int
1351 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1352 {
1353         struct usbnet                   *dev;
1354         struct net_device               *net;
1355         struct usb_host_interface       *interface;
1356         struct driver_info              *info;
1357         struct usb_device               *xdev;
1358         int                             status;
1359         const char                      *name;
1360         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1361
1362         /* usbnet already took usb runtime pm, so have to enable the feature
1363          * for usb interface, otherwise usb_autopm_get_interface may return
1364          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1365          */
1366         if (!driver->supports_autosuspend) {
1367                 driver->supports_autosuspend = 1;
1368                 pm_runtime_enable(&udev->dev);
1369         }
1370
1371         name = udev->dev.driver->name;
1372         info = (struct driver_info *) prod->driver_info;
1373         if (!info) {
1374                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1375                 return -ENODEV;
1376         }
1377         xdev = interface_to_usbdev (udev);
1378         interface = udev->cur_altsetting;
1379
1380         status = -ENOMEM;
1381
1382         // set up our own records
1383         net = alloc_etherdev(sizeof(*dev));
1384         if (!net)
1385                 goto out;
1386
1387         /* netdev_printk() needs this so do it as early as possible */
1388         SET_NETDEV_DEV(net, &udev->dev);
1389
1390         dev = netdev_priv(net);
1391         dev->udev = xdev;
1392         dev->intf = udev;
1393         dev->driver_info = info;
1394         dev->driver_name = name;
1395         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1396                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1397         skb_queue_head_init (&dev->rxq);
1398         skb_queue_head_init (&dev->txq);
1399         skb_queue_head_init (&dev->done);
1400         skb_queue_head_init(&dev->rxq_pause);
1401         dev->bh.func = usbnet_bh;
1402         dev->bh.data = (unsigned long) dev;
1403         INIT_WORK (&dev->kevent, kevent);
1404         init_usb_anchor(&dev->deferred);
1405         dev->delay.function = usbnet_bh;
1406         dev->delay.data = (unsigned long) dev;
1407         init_timer (&dev->delay);
1408         mutex_init (&dev->phy_mutex);
1409
1410         dev->net = net;
1411         strcpy (net->name, "usb%d");
1412         memcpy (net->dev_addr, node_id, sizeof node_id);
1413
1414         /* rx and tx sides can use different message sizes;
1415          * bind() should set rx_urb_size in that case.
1416          */
1417         dev->hard_mtu = net->mtu + net->hard_header_len;
1418 #if 0
1419 // dma_supported() is deeply broken on almost all architectures
1420         // possible with some EHCI controllers
1421         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1422                 net->features |= NETIF_F_HIGHDMA;
1423 #endif
1424
1425         net->netdev_ops = &usbnet_netdev_ops;
1426         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1427         net->ethtool_ops = &usbnet_ethtool_ops;
1428
1429         // allow device-specific bind/init procedures
1430         // NOTE net->name still not usable ...
1431         if (info->bind) {
1432                 status = info->bind (dev, udev);
1433                 if (status < 0)
1434                         goto out1;
1435
1436                 // heuristic:  "usb%d" for links we know are two-host,
1437                 // else "eth%d" when there's reasonable doubt.  userspace
1438                 // can rename the link if it knows better.
1439                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1440                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1441                      (net->dev_addr [0] & 0x02) == 0))
1442                         strcpy (net->name, "eth%d");
1443                 /* WLAN devices should always be named "wlan%d" */
1444                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1445                         strcpy(net->name, "wlan%d");
1446                 /* WWAN devices should always be named "wwan%d" */
1447                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1448                         strcpy(net->name, "wwan%d");
1449
1450                 /* maybe the remote can't receive an Ethernet MTU */
1451                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1452                         net->mtu = dev->hard_mtu - net->hard_header_len;
1453         } else if (!info->in || !info->out)
1454                 status = usbnet_get_endpoints (dev, udev);
1455         else {
1456                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1457                 dev->out = usb_sndbulkpipe (xdev, info->out);
1458                 if (!(info->flags & FLAG_NO_SETINT))
1459                         status = usb_set_interface (xdev,
1460                                 interface->desc.bInterfaceNumber,
1461                                 interface->desc.bAlternateSetting);
1462                 else
1463                         status = 0;
1464
1465         }
1466         if (status >= 0 && dev->status)
1467                 status = init_status (dev, udev);
1468         if (status < 0)
1469                 goto out3;
1470
1471         if (!dev->rx_urb_size)
1472                 dev->rx_urb_size = dev->hard_mtu;
1473         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1474
1475         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1476                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1477         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1478                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1479
1480         status = register_netdev (net);
1481         if (status)
1482                 goto out4;
1483         netif_info(dev, probe, dev->net,
1484                    "register '%s' at usb-%s-%s, %s, %pM\n",
1485                    udev->dev.driver->name,
1486                    xdev->bus->bus_name, xdev->devpath,
1487                    dev->driver_info->description,
1488                    net->dev_addr);
1489
1490         // ok, it's ready to go.
1491         usb_set_intfdata (udev, dev);
1492
1493         netif_device_attach (net);
1494
1495         if (dev->driver_info->flags & FLAG_LINK_INTR)
1496                 netif_carrier_off(net);
1497
1498         return 0;
1499
1500 out4:
1501         usb_free_urb(dev->interrupt);
1502 out3:
1503         if (info->unbind)
1504                 info->unbind (dev, udev);
1505 out1:
1506         free_netdev(net);
1507 out:
1508         return status;
1509 }
1510 EXPORT_SYMBOL_GPL(usbnet_probe);
1511
1512 /*-------------------------------------------------------------------------*/
1513
1514 /*
1515  * suspend the whole driver as soon as the first interface is suspended
1516  * resume only when the last interface is resumed
1517  */
1518
1519 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1520 {
1521         struct usbnet           *dev = usb_get_intfdata(intf);
1522
1523         if (!dev->suspend_count++) {
1524                 spin_lock_irq(&dev->txq.lock);
1525                 /* don't autosuspend while transmitting */
1526                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1527                         dev->suspend_count--;
1528                         spin_unlock_irq(&dev->txq.lock);
1529                         return -EBUSY;
1530                 } else {
1531                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1532                         spin_unlock_irq(&dev->txq.lock);
1533                 }
1534                 /*
1535                  * accelerate emptying of the rx and queues, to avoid
1536                  * having everything error out.
1537                  */
1538                 netif_device_detach (dev->net);
1539                 usbnet_terminate_urbs(dev);
1540                 usb_kill_urb(dev->interrupt);
1541
1542                 /*
1543                  * reattach so runtime management can use and
1544                  * wake the device
1545                  */
1546                 netif_device_attach (dev->net);
1547         }
1548         return 0;
1549 }
1550 EXPORT_SYMBOL_GPL(usbnet_suspend);
1551
1552 int usbnet_resume (struct usb_interface *intf)
1553 {
1554         struct usbnet           *dev = usb_get_intfdata(intf);
1555         struct sk_buff          *skb;
1556         struct urb              *res;
1557         int                     retval;
1558
1559         if (!--dev->suspend_count) {
1560                 /* resume interrupt URBs */
1561                 if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1562                         usb_submit_urb(dev->interrupt, GFP_NOIO);
1563
1564                 spin_lock_irq(&dev->txq.lock);
1565                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1566
1567                         skb = (struct sk_buff *)res->context;
1568                         retval = usb_submit_urb(res, GFP_ATOMIC);
1569                         if (retval < 0) {
1570                                 dev_kfree_skb_any(skb);
1571                                 usb_free_urb(res);
1572                                 usb_autopm_put_interface_async(dev->intf);
1573                         } else {
1574                                 dev->net->trans_start = jiffies;
1575                                 __skb_queue_tail(&dev->txq, skb);
1576                         }
1577                 }
1578
1579                 smp_mb();
1580                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1581                 spin_unlock_irq(&dev->txq.lock);
1582
1583                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1584                         /* handle remote wakeup ASAP */
1585                         if (!dev->wait &&
1586                                 netif_device_present(dev->net) &&
1587                                 !timer_pending(&dev->delay) &&
1588                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1589                                         rx_alloc_submit(dev, GFP_NOIO);
1590
1591                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1592                                 netif_tx_wake_all_queues(dev->net);
1593                         tasklet_schedule (&dev->bh);
1594                 }
1595         }
1596
1597         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1598                 usb_autopm_get_interface_no_resume(intf);
1599
1600         return 0;
1601 }
1602 EXPORT_SYMBOL_GPL(usbnet_resume);
1603
1604 /*
1605  * Either a subdriver implements manage_power, then it is assumed to always
1606  * be ready to be suspended or it reports the readiness to be suspended
1607  * explicitly
1608  */
1609 void usbnet_device_suggests_idle(struct usbnet *dev)
1610 {
1611         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1612                 dev->intf->needs_remote_wakeup = 1;
1613                 usb_autopm_put_interface_async(dev->intf);
1614         }
1615 }
1616 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1617
1618 /*-------------------------------------------------------------------------*/
1619 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1620                              u16 value, u16 index, void *data, u16 size)
1621 {
1622         void *buf = NULL;
1623         int err = -ENOMEM;
1624
1625         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1626                    " value=0x%04x index=0x%04x size=%d\n",
1627                    cmd, reqtype, value, index, size);
1628
1629         if (data) {
1630                 buf = kmalloc(size, GFP_KERNEL);
1631                 if (!buf)
1632                         goto out;
1633         }
1634
1635         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1636                               cmd, reqtype, value, index, buf, size,
1637                               USB_CTRL_GET_TIMEOUT);
1638         if (err > 0 && err <= size)
1639                 memcpy(data, buf, err);
1640         kfree(buf);
1641 out:
1642         return err;
1643 }
1644
1645 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1646                               u16 value, u16 index, const void *data,
1647                               u16 size)
1648 {
1649         void *buf = NULL;
1650         int err = -ENOMEM;
1651
1652         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1653                    " value=0x%04x index=0x%04x size=%d\n",
1654                    cmd, reqtype, value, index, size);
1655
1656         if (data) {
1657                 buf = kmemdup(data, size, GFP_KERNEL);
1658                 if (!buf)
1659                         goto out;
1660         }
1661
1662         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1663                               cmd, reqtype, value, index, buf, size,
1664                               USB_CTRL_SET_TIMEOUT);
1665         kfree(buf);
1666
1667 out:
1668         return err;
1669 }
1670
1671 /*
1672  * The function can't be called inside suspend/resume callback,
1673  * otherwise deadlock will be caused.
1674  */
1675 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1676                     u16 value, u16 index, void *data, u16 size)
1677 {
1678         int ret;
1679
1680         if (usb_autopm_get_interface(dev->intf) < 0)
1681                 return -ENODEV;
1682         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1683                                 data, size);
1684         usb_autopm_put_interface(dev->intf);
1685         return ret;
1686 }
1687 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1688
1689 /*
1690  * The function can't be called inside suspend/resume callback,
1691  * otherwise deadlock will be caused.
1692  */
1693 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1694                      u16 value, u16 index, const void *data, u16 size)
1695 {
1696         int ret;
1697
1698         if (usb_autopm_get_interface(dev->intf) < 0)
1699                 return -ENODEV;
1700         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1701                                  data, size);
1702         usb_autopm_put_interface(dev->intf);
1703         return ret;
1704 }
1705 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1706
1707 /*
1708  * The function can be called inside suspend/resume callback safely
1709  * and should only be called by suspend/resume callback generally.
1710  */
1711 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1712                           u16 value, u16 index, void *data, u16 size)
1713 {
1714         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1715                                  data, size);
1716 }
1717 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1718
1719 /*
1720  * The function can be called inside suspend/resume callback safely
1721  * and should only be called by suspend/resume callback generally.
1722  */
1723 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1724                           u16 value, u16 index, const void *data,
1725                           u16 size)
1726 {
1727         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1728                                   data, size);
1729 }
1730 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1731
1732 static void usbnet_async_cmd_cb(struct urb *urb)
1733 {
1734         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1735         int status = urb->status;
1736
1737         if (status < 0)
1738                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1739                         __func__, status);
1740
1741         kfree(req);
1742         usb_free_urb(urb);
1743 }
1744
1745 /*
1746  * The caller must make sure that device can't be put into suspend
1747  * state until the control URB completes.
1748  */
1749 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1750                            u16 value, u16 index, const void *data, u16 size)
1751 {
1752         struct usb_ctrlrequest *req = NULL;
1753         struct urb *urb;
1754         int err = -ENOMEM;
1755         void *buf = NULL;
1756
1757         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1758                    " value=0x%04x index=0x%04x size=%d\n",
1759                    cmd, reqtype, value, index, size);
1760
1761         urb = usb_alloc_urb(0, GFP_ATOMIC);
1762         if (!urb) {
1763                 netdev_err(dev->net, "Error allocating URB in"
1764                            " %s!\n", __func__);
1765                 goto fail;
1766         }
1767
1768         if (data) {
1769                 buf = kmemdup(data, size, GFP_ATOMIC);
1770                 if (!buf) {
1771                         netdev_err(dev->net, "Error allocating buffer"
1772                                    " in %s!\n", __func__);
1773                         goto fail_free;
1774                 }
1775         }
1776
1777         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
1778         if (!req) {
1779                 netdev_err(dev->net, "Failed to allocate memory for %s\n",
1780                            __func__);
1781                 goto fail_free_buf;
1782         }
1783
1784         req->bRequestType = reqtype;
1785         req->bRequest = cmd;
1786         req->wValue = cpu_to_le16(value);
1787         req->wIndex = cpu_to_le16(index);
1788         req->wLength = cpu_to_le16(size);
1789
1790         usb_fill_control_urb(urb, dev->udev,
1791                              usb_sndctrlpipe(dev->udev, 0),
1792                              (void *)req, buf, size,
1793                              usbnet_async_cmd_cb, req);
1794         urb->transfer_flags |= URB_FREE_BUFFER;
1795
1796         err = usb_submit_urb(urb, GFP_ATOMIC);
1797         if (err < 0) {
1798                 netdev_err(dev->net, "Error submitting the control"
1799                            " message: status=%d\n", err);
1800                 goto fail_free;
1801         }
1802         return 0;
1803
1804 fail_free_buf:
1805         kfree(buf);
1806 fail_free:
1807         kfree(req);
1808         usb_free_urb(urb);
1809 fail:
1810         return err;
1811
1812 }
1813 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
1814 /*-------------------------------------------------------------------------*/
1815
1816 static int __init usbnet_init(void)
1817 {
1818         /* Compiler should optimize this out. */
1819         BUILD_BUG_ON(
1820                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1821
1822         eth_random_addr(node_id);
1823         return 0;
1824 }
1825 module_init(usbnet_init);
1826
1827 static void __exit usbnet_exit(void)
1828 {
1829 }
1830 module_exit(usbnet_exit);
1831
1832 MODULE_AUTHOR("David Brownell");
1833 MODULE_DESCRIPTION("USB network driver framework");
1834 MODULE_LICENSE("GPL");