drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * This is a generic "USB networking" framework that works with several
  22  * kinds of full and high speed networking devices:  host-to-host cables,
  23  * smart usb peripherals, and actual Ethernet adapters.
  24  *
  25  * These devices usually differ in terms of control protocols (if they
  26  * even have one!) and sometimes they define new framing to wrap or batch
  27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29  * issues can usefully be addressed by this framework.
  30  */
  31
  32 // #define      DEBUG                   // error path messages, extra info
  33 // #define      VERBOSE                 // more; success messages
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/etherdevice.h>
  39 #include <linux/ctype.h>
  40 #include <linux/ethtool.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/mii.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/usbnet.h>
  45 #include <linux/slab.h>
  46 #include <linux/kernel.h>
  47 #include <linux/pm_runtime.h>
  48
  49 #define DRIVER_VERSION          "22-Aug-2005"
  50
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 /*
  55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56  * Several dozen bytes of IPv4 data can fit in two such transactions.
  57  * One maximum size Ethernet packet takes twenty four of them.
  58  * For high speed, each frame comfortably fits almost 36 max size
  59  * Ethernet packets (so queues should be bigger).
  60  *
  61  * The goal is to let the USB host controller be busy for 5msec or
  62  * more before an irq is required, under load.  Jumbograms change
  63  * the equation.
  64  */
  65 #define MAX_QUEUE_MEMORY        (60 * 1518)
  66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  68
  69 // reawaken network queue this soon after stopping; else watchdog barks
  70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73  * us (it polls at HZ/4 usually) before we report too many false errors.
  74  */
  75 #define THROTTLE_JIFFIES        (HZ/8)
  76
  77 // between wakeups
  78 #define UNLINK_TIMEOUT_MS       3
  79
  80 /*-------------------------------------------------------------------------*/
  81
  82 // randomly generated ethernet address
  83 static u8       node_id [ETH_ALEN];
  84
  85 static const char driver_name [] = "usbnet";
  86
  87 /* use ethtool to change the level for any given device */
  88 static int msg_level = -1;
  89 module_param (msg_level, int, 0);
  90 MODULE_PARM_DESC (msg_level, "Override default message level");
  91
  92 /*-------------------------------------------------------------------------*/
  93
  94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96 {
  97         int                             tmp;
  98         struct usb_host_interface       *alt = NULL;
  99         struct usb_host_endpoint        *in = NULL, *out = NULL;
 100         struct usb_host_endpoint        *status = NULL;
 101
 102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                 unsigned        ep;
 104
 105                 in = out = status = NULL;
 106                 alt = intf->altsetting + tmp;
 107
 108                 /* take the first altsetting with in-bulk + out-bulk;
 109                  * remember any status endpoint, just in case;
 110                  * ignore other endpoints and altsettings.
 111                  */
 112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                         struct usb_host_endpoint        *e;
 114                         int                             intr = 0;
 115
 116                         e = alt->endpoint + ep;
 117
 118                         /* ignore endpoints which cannot transfer data */
 119                         if (!usb_endpoint_maxp(&e->desc))
 120                                 continue;
 121
 122                         switch (e->desc.bmAttributes) {
 123                         case USB_ENDPOINT_XFER_INT:
 124                                 if (!usb_endpoint_dir_in(&e->desc))
 125                                         continue;
 126                                 intr = 1;
 127                                 /* FALLTHROUGH */
 128                         case USB_ENDPOINT_XFER_BULK:
 129                                 break;
 130                         default:
 131                                 continue;
 132                         }
 133                         if (usb_endpoint_dir_in(&e->desc)) {
 134                                 if (!intr && !in)
 135                                         in = e;
 136                                 else if (intr && !status)
 137                                         status = e;
 138                         } else {
 139                                 if (!out)
 140                                         out = e;
 141                         }
 142                 }
 143                 if (in && out)
 144                         break;
 145         }
 146         if (!alt || !in || !out)
 147                 return -EINVAL;
 148
 149         if (alt->desc.bAlternateSetting != 0 ||
 150             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 151                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 152                                 alt->desc.bAlternateSetting);
 153                 if (tmp < 0)
 154                         return tmp;
 155         }
 156
 157         dev->in = usb_rcvbulkpipe (dev->udev,
 158                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 159         dev->out = usb_sndbulkpipe (dev->udev,
 160                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 161         dev->status = status;
 162         return 0;
 163 }
 164 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 165
 166 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 167 {
 168         int             tmp = -1, ret;
 169         unsigned char   buf [13];
 170
 171         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 172         if (ret == 12)
 173                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 174         if (tmp < 0) {
 175                 dev_dbg(&dev->udev->dev,
 176                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 177                 if (ret >= 0)
 178                         ret = -EINVAL;
 179                 return ret;
 180         }
 181         return 0;
 182 }
 183 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 184
 185 static void intr_complete (struct urb *urb)
 186 {
 187         struct usbnet   *dev = urb->context;
 188         int             status = urb->status;
 189
 190         switch (status) {
 191         /* success */
 192         case 0:
 193                 dev->driver_info->status(dev, urb);
 194                 break;
 195
 196         /* software-driven interface shutdown */
 197         case -ENOENT:           /* urb killed */
 198         case -ESHUTDOWN:        /* hardware gone */
 199                 netif_dbg(dev, ifdown, dev->net,
 200                           "intr shutdown, code %d\n", status);
 201                 return;
 202
 203         /* NOTE:  not throttling like RX/TX, since this endpoint
 204          * already polls infrequently
 205          */
 206         default:
 207                 netdev_dbg(dev->net, "intr status %d\n", status);
 208                 break;
 209         }
 210
 211         status = usb_submit_urb (urb, GFP_ATOMIC);
 212         if (status != 0)
 213                 netif_err(dev, timer, dev->net,
 214                           "intr resubmit --> %d\n", status);
 215 }
 216
 217 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 218 {
 219         char            *buf = NULL;
 220         unsigned        pipe = 0;
 221         unsigned        maxp;
 222         unsigned        period;
 223
 224         if (!dev->driver_info->status)
 225                 return 0;
 226
 227         pipe = usb_rcvintpipe (dev->udev,
 228                         dev->status->desc.bEndpointAddress
 229                                 & USB_ENDPOINT_NUMBER_MASK);
 230         maxp = usb_maxpacket (dev->udev, pipe, 0);
 231
 232         /* avoid 1 msec chatter:  min 8 msec poll rate */
 233         period = max ((int) dev->status->desc.bInterval,
 234                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 235
 236         buf = kmalloc (maxp, GFP_KERNEL);
 237         if (buf) {
 238                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 239                 if (!dev->interrupt) {
 240                         kfree (buf);
 241                         return -ENOMEM;
 242                 } else {
 243                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 244                                 buf, maxp, intr_complete, dev, period);
 245                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 246                         dev_dbg(&intf->dev,
 247                                 "status ep%din, %d bytes period %d\n",
 248                                 usb_pipeendpoint(pipe), maxp, period);
 249                 }
 250         }
 251         return 0;
 252 }
 253
 254 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 255 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 256 {
 257         int ret = 0;
 258
 259         WARN_ON_ONCE(dev->interrupt == NULL);
 260         if (dev->interrupt) {
 261                 mutex_lock(&dev->interrupt_mutex);
 262
 263                 if (++dev->interrupt_count == 1)
 264                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 265
 266                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 267                         dev->interrupt_count);
 268                 mutex_unlock(&dev->interrupt_mutex);
 269         }
 270         return ret;
 271 }
 272 EXPORT_SYMBOL_GPL(usbnet_status_start);
 273
 274 /* For resume; submit interrupt URB if previously submitted */
 275 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 276 {
 277         int ret = 0;
 278
 279         mutex_lock(&dev->interrupt_mutex);
 280         if (dev->interrupt_count) {
 281                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 282                 dev_dbg(&dev->udev->dev,
 283                         "submitted interrupt URB for resume\n");
 284         }
 285         mutex_unlock(&dev->interrupt_mutex);
 286         return ret;
 287 }
 288
 289 /* Kill the interrupt URB if all submitters want it killed */
 290 void usbnet_status_stop(struct usbnet *dev)
 291 {
 292         if (dev->interrupt) {
 293                 mutex_lock(&dev->interrupt_mutex);
 294                 WARN_ON(dev->interrupt_count == 0);
 295
 296                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 297                         usb_kill_urb(dev->interrupt);
 298
 299                 dev_dbg(&dev->udev->dev,
 300                         "decremented interrupt URB count to %d\n",
 301                         dev->interrupt_count);
 302                 mutex_unlock(&dev->interrupt_mutex);
 303         }
 304 }
 305 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 306
 307 /* For suspend; always kill interrupt URB */
 308 static void __usbnet_status_stop_force(struct usbnet *dev)
 309 {
 310         if (dev->interrupt) {
 311                 mutex_lock(&dev->interrupt_mutex);
 312                 usb_kill_urb(dev->interrupt);
 313                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 314                 mutex_unlock(&dev->interrupt_mutex);
 315         }
 316 }
 317
 318 /* Passes this packet up the stack, updating its accounting.
 319  * Some link protocols batch packets, so their rx_fixup paths
 320  * can return clones as well as just modify the original skb.
 321  */
 322 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 323 {
 324         int     status;
 325
 326         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 327                 skb_queue_tail(&dev->rxq_pause, skb);
 328                 return;
 329         }
 330
 331         /* only update if unset to allow minidriver rx_fixup override */
 332         if (skb->protocol == 0)
 333                 skb->protocol = eth_type_trans (skb, dev->net);
 334
 335         dev->net->stats.rx_packets++;
 336         dev->net->stats.rx_bytes += skb->len;
 337
 338         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 339                   skb->len + sizeof (struct ethhdr), skb->protocol);
 340         memset (skb->cb, 0, sizeof (struct skb_data));
 341
 342         if (skb_defer_rx_timestamp(skb))
 343                 return;
 344
 345         status = netif_rx (skb);
 346         if (status != NET_RX_SUCCESS)
 347                 netif_dbg(dev, rx_err, dev->net,
 348                           "netif_rx status %d\n", status);
 349 }
 350 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 351
 352 /* must be called if hard_mtu or rx_urb_size changed */
 353 void usbnet_update_max_qlen(struct usbnet *dev)
 354 {
 355         enum usb_device_speed speed = dev->udev->speed;
 356
 357         if (!dev->rx_urb_size || !dev->hard_mtu)
 358                 goto insanity;
 359         switch (speed) {
 360         case USB_SPEED_HIGH:
 361                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 362                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 363                 break;
 364         case USB_SPEED_SUPER:
 365         case USB_SPEED_SUPER_PLUS:
 366                 /*
 367                  * Not take default 5ms qlen for super speed HC to
 368                  * save memory, and iperf tests show 2.5ms qlen can
 369                  * work well
 370                  */
 371                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 372                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 373                 break;
 374         default:
 375 insanity:
 376                 dev->rx_qlen = dev->tx_qlen = 4;
 377         }
 378 }
 379 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 380
 381 \f
 382 /*-------------------------------------------------------------------------
 383  *
 384  * Network Device Driver (peer link to "Host Device", from USB host)
 385  *
 386  *-------------------------------------------------------------------------*/
 387
 388 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 389 {
 390         struct usbnet   *dev = netdev_priv(net);
 391         int             ll_mtu = new_mtu + net->hard_header_len;
 392         int             old_hard_mtu = dev->hard_mtu;
 393         int             old_rx_urb_size = dev->rx_urb_size;
 394
 395         if (new_mtu <= 0)
 396                 return -EINVAL;
 397         // no second zero-length packet read wanted after mtu-sized packets
 398         if ((ll_mtu % dev->maxpacket) == 0)
 399                 return -EDOM;
 400         net->mtu = new_mtu;
 401
 402         dev->hard_mtu = net->mtu + net->hard_header_len;
 403         if (dev->rx_urb_size == old_hard_mtu) {
 404                 dev->rx_urb_size = dev->hard_mtu;
 405                 if (dev->rx_urb_size > old_rx_urb_size) {
 406                         usbnet_pause_rx(dev);
 407                         usbnet_unlink_rx_urbs(dev);
 408                         usbnet_resume_rx(dev);
 409                 }
 410         }
 411
 412         /* max qlen depend on hard_mtu and rx_urb_size */
 413         usbnet_update_max_qlen(dev);
 414
 415         return 0;
 416 }
 417 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 418
 419 /* The caller must hold list->lock */
 420 static void __usbnet_queue_skb(struct sk_buff_head *list,
 421                         struct sk_buff *newsk, enum skb_state state)
 422 {
 423         struct skb_data *entry = (struct skb_data *) newsk->cb;
 424
 425         __skb_queue_tail(list, newsk);
 426         entry->state = state;
 427 }
 428
 429 /*-------------------------------------------------------------------------*/
 430
 431 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 432  * completion callbacks.  2.5 should have fixed those bugs...
 433  */
 434
 435 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 436                 struct sk_buff_head *list, enum skb_state state)
 437 {
 438         unsigned long           flags;
 439         enum skb_state          old_state;
 440         struct skb_data *entry = (struct skb_data *) skb->cb;
 441
 442         spin_lock_irqsave(&list->lock, flags);
 443         old_state = entry->state;
 444         entry->state = state;
 445         __skb_unlink(skb, list);
 446
 447         /* defer_bh() is never called with list == &dev->done.
 448          * spin_lock_nested() tells lockdep that it is OK to take
 449          * dev->done.lock here with list->lock held.
 450          */
 451         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 452
 453         __skb_queue_tail(&dev->done, skb);
 454         if (dev->done.qlen == 1)
 455                 tasklet_schedule(&dev->bh);
 456         spin_unlock(&dev->done.lock);
 457         spin_unlock_irqrestore(&list->lock, flags);
 458         return old_state;
 459 }
 460
 461 /* some work can't be done in tasklets, so we use keventd
 462  *
 463  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 464  * but tasklet_schedule() doesn't.  hope the failure is rare.
 465  */
 466 void usbnet_defer_kevent (struct usbnet *dev, int work)
 467 {
 468         set_bit (work, &dev->flags);
 469         if (!schedule_work (&dev->kevent)) {
 470                 if (net_ratelimit())
 471                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 472         } else {
 473                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 474         }
 475 }
 476 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 477
 478 /*-------------------------------------------------------------------------*/
 479
 480 static void rx_complete (struct urb *urb);
 481
 482 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 483 {
 484         struct sk_buff          *skb;
 485         struct skb_data         *entry;
 486         int                     retval = 0;
 487         unsigned long           lockflags;
 488         size_t                  size = dev->rx_urb_size;
 489
 490         /* prevent rx skb allocation when error ratio is high */
 491         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 492                 usb_free_urb(urb);
 493                 return -ENOLINK;
 494         }
 495
 496         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 497                 skb = __netdev_alloc_skb(dev->net, size, flags);
 498         else
 499                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 500         if (!skb) {
 501                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 502                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 503                 usb_free_urb (urb);
 504                 return -ENOMEM;
 505         }
 506
 507         entry = (struct skb_data *) skb->cb;
 508         entry->urb = urb;
 509         entry->dev = dev;
 510         entry->length = 0;
 511
 512         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 513                 skb->data, size, rx_complete, skb);
 514
 515         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 516
 517         if (netif_running (dev->net) &&
 518             netif_device_present (dev->net) &&
 519             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 520             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 521             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 522                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 523                 case -EPIPE:
 524                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 525                         break;
 526                 case -ENOMEM:
 527                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 528                         break;
 529                 case -ENODEV:
 530                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 531                         netif_device_detach (dev->net);
 532                         break;
 533                 case -EHOSTUNREACH:
 534                         retval = -ENOLINK;
 535                         break;
 536                 default:
 537                         netif_dbg(dev, rx_err, dev->net,
 538                                   "rx submit, %d\n", retval);
 539                         tasklet_schedule (&dev->bh);
 540                         break;
 541                 case 0:
 542                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 543                 }
 544         } else {
 545                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 546                 retval = -ENOLINK;
 547         }
 548         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 549         if (retval) {
 550                 dev_kfree_skb_any (skb);
 551                 usb_free_urb (urb);
 552         }
 553         return retval;
 554 }
 555
 556
 557 /*-------------------------------------------------------------------------*/
 558
 559 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 560 {
 561         if (dev->driver_info->rx_fixup &&
 562             !dev->driver_info->rx_fixup (dev, skb)) {
 563                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 564                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 565                         dev->net->stats.rx_errors++;
 566                 goto done;
 567         }
 568         // else network stack removes extra byte if we forced a short packet
 569
 570         /* all data was already cloned from skb inside the driver */
 571         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 572                 goto done;
 573
 574         if (skb->len < ETH_HLEN) {
 575                 dev->net->stats.rx_errors++;
 576                 dev->net->stats.rx_length_errors++;
 577                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 578         } else {
 579                 usbnet_skb_return(dev, skb);
 580                 return;
 581         }
 582
 583 done:
 584         skb_queue_tail(&dev->done, skb);
 585 }
 586
 587 /*-------------------------------------------------------------------------*/
 588
 589 static void rx_complete (struct urb *urb)
 590 {
 591         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 592         struct skb_data         *entry = (struct skb_data *) skb->cb;
 593         struct usbnet           *dev = entry->dev;
 594         int                     urb_status = urb->status;
 595         enum skb_state          state;
 596
 597         skb_put (skb, urb->actual_length);
 598         state = rx_done;
 599         entry->urb = NULL;
 600
 601         switch (urb_status) {
 602         /* success */
 603         case 0:
 604                 break;
 605
 606         /* stalls need manual reset. this is rare ... except that
 607          * when going through USB 2.0 TTs, unplug appears this way.
 608          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 609          * storm, recovering as needed.
 610          */
 611         case -EPIPE:
 612                 dev->net->stats.rx_errors++;
 613                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 614                 // FALLTHROUGH
 615
 616         /* software-driven interface shutdown */
 617         case -ECONNRESET:               /* async unlink */
 618         case -ESHUTDOWN:                /* hardware gone */
 619                 netif_dbg(dev, ifdown, dev->net,
 620                           "rx shutdown, code %d\n", urb_status);
 621                 goto block;
 622
 623         /* we get controller i/o faults during hub_wq disconnect() delays.
 624          * throttle down resubmits, to avoid log floods; just temporarily,
 625          * so we still recover when the fault isn't a hub_wq delay.
 626          */
 627         case -EPROTO:
 628         case -ETIME:
 629         case -EILSEQ:
 630                 dev->net->stats.rx_errors++;
 631                 if (!timer_pending (&dev->delay)) {
 632                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 633                         netif_dbg(dev, link, dev->net,
 634                                   "rx throttle %d\n", urb_status);
 635                 }
 636 block:
 637                 state = rx_cleanup;
 638                 entry->urb = urb;
 639                 urb = NULL;
 640                 break;
 641
 642         /* data overrun ... flush fifo? */
 643         case -EOVERFLOW:
 644                 dev->net->stats.rx_over_errors++;
 645                 // FALLTHROUGH
 646
 647         default:
 648                 state = rx_cleanup;
 649                 dev->net->stats.rx_errors++;
 650                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 651                 break;
 652         }
 653
 654         /* stop rx if packet error rate is high */
 655         if (++dev->pkt_cnt > 30) {
 656                 dev->pkt_cnt = 0;
 657                 dev->pkt_err = 0;
 658         } else {
 659                 if (state == rx_cleanup)
 660                         dev->pkt_err++;
 661                 if (dev->pkt_err > 20)
 662                         set_bit(EVENT_RX_KILL, &dev->flags);
 663         }
 664
 665         state = defer_bh(dev, skb, &dev->rxq, state);
 666
 667         if (urb) {
 668                 if (netif_running (dev->net) &&
 669                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 670                     state != unlink_start) {
 671                         rx_submit (dev, urb, GFP_ATOMIC);
 672                         usb_mark_last_busy(dev->udev);
 673                         return;
 674                 }
 675                 usb_free_urb (urb);
 676         }
 677         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 678 }
 679
 680 /*-------------------------------------------------------------------------*/
 681 void usbnet_pause_rx(struct usbnet *dev)
 682 {
 683         set_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 686 }
 687 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 688
 689 void usbnet_resume_rx(struct usbnet *dev)
 690 {
 691         struct sk_buff *skb;
 692         int num = 0;
 693
 694         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 695
 696         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 697                 usbnet_skb_return(dev, skb);
 698                 num++;
 699         }
 700
 701         tasklet_schedule(&dev->bh);
 702
 703         netif_dbg(dev, rx_status, dev->net,
 704                   "paused rx queue disabled, %d skbs requeued\n", num);
 705 }
 706 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 707
 708 void usbnet_purge_paused_rxq(struct usbnet *dev)
 709 {
 710         skb_queue_purge(&dev->rxq_pause);
 711 }
 712 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 713
 714 /*-------------------------------------------------------------------------*/
 715
 716 // unlink pending rx/tx; completion handlers do all other cleanup
 717
 718 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 719 {
 720         unsigned long           flags;
 721         struct sk_buff          *skb;
 722         int                     count = 0;
 723
 724         spin_lock_irqsave (&q->lock, flags);
 725         while (!skb_queue_empty(q)) {
 726                 struct skb_data         *entry;
 727                 struct urb              *urb;
 728                 int                     retval;
 729
 730                 skb_queue_walk(q, skb) {
 731                         entry = (struct skb_data *) skb->cb;
 732                         if (entry->state != unlink_start)
 733                                 goto found;
 734                 }
 735                 break;
 736 found:
 737                 entry->state = unlink_start;
 738                 urb = entry->urb;
 739
 740                 /*
 741                  * Get reference count of the URB to avoid it to be
 742                  * freed during usb_unlink_urb, which may trigger
 743                  * use-after-free problem inside usb_unlink_urb since
 744                  * usb_unlink_urb is always racing with .complete
 745                  * handler(include defer_bh).
 746                  */
 747                 usb_get_urb(urb);
 748                 spin_unlock_irqrestore(&q->lock, flags);
 749                 // during some PM-driven resume scenarios,
 750                 // these (async) unlinks complete immediately
 751                 retval = usb_unlink_urb (urb);
 752                 if (retval != -EINPROGRESS && retval != 0)
 753                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 754                 else
 755                         count++;
 756                 usb_put_urb(urb);
 757                 spin_lock_irqsave(&q->lock, flags);
 758         }
 759         spin_unlock_irqrestore (&q->lock, flags);
 760         return count;
 761 }
 762
 763 // Flush all pending rx urbs
 764 // minidrivers may need to do this when the MTU changes
 765
 766 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 767 {
 768         if (netif_running(dev->net)) {
 769                 (void) unlink_urbs (dev, &dev->rxq);
 770                 tasklet_schedule(&dev->bh);
 771         }
 772 }
 773 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 774
 775 /*-------------------------------------------------------------------------*/
 776
 777 static void wait_skb_queue_empty(struct sk_buff_head *q)
 778 {
 779         unsigned long flags;
 780
 781         spin_lock_irqsave(&q->lock, flags);
 782         while (!skb_queue_empty(q)) {
 783                 spin_unlock_irqrestore(&q->lock, flags);
 784                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 785                 set_current_state(TASK_UNINTERRUPTIBLE);
 786                 spin_lock_irqsave(&q->lock, flags);
 787         }
 788         spin_unlock_irqrestore(&q->lock, flags);
 789 }
 790
 791 // precondition: never called in_interrupt
 792 static void usbnet_terminate_urbs(struct usbnet *dev)
 793 {
 794         DECLARE_WAITQUEUE(wait, current);
 795         int temp;
 796
 797         /* ensure there are no more active urbs */
 798         add_wait_queue(&dev->wait, &wait);
 799         set_current_state(TASK_UNINTERRUPTIBLE);
 800         temp = unlink_urbs(dev, &dev->txq) +
 801                 unlink_urbs(dev, &dev->rxq);
 802
 803         /* maybe wait for deletions to finish. */
 804         wait_skb_queue_empty(&dev->rxq);
 805         wait_skb_queue_empty(&dev->txq);
 806         wait_skb_queue_empty(&dev->done);
 807         netif_dbg(dev, ifdown, dev->net,
 808                   "waited for %d urb completions\n", temp);
 809         set_current_state(TASK_RUNNING);
 810         remove_wait_queue(&dev->wait, &wait);
 811 }
 812
 813 int usbnet_stop (struct net_device *net)
 814 {
 815         struct usbnet           *dev = netdev_priv(net);
 816         struct driver_info      *info = dev->driver_info;
 817         int                     retval, pm, mpn;
 818
 819         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 820         netif_stop_queue (net);
 821
 822         netif_info(dev, ifdown, dev->net,
 823                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 824                    net->stats.rx_packets, net->stats.tx_packets,
 825                    net->stats.rx_errors, net->stats.tx_errors);
 826
 827         /* to not race resume */
 828         pm = usb_autopm_get_interface(dev->intf);
 829         /* allow minidriver to stop correctly (wireless devices to turn off
 830          * radio etc) */
 831         if (info->stop) {
 832                 retval = info->stop(dev);
 833                 if (retval < 0)
 834                         netif_info(dev, ifdown, dev->net,
 835                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 836                                    retval,
 837                                    dev->udev->bus->bus_name, dev->udev->devpath,
 838                                    info->description);
 839         }
 840
 841         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 842                 usbnet_terminate_urbs(dev);
 843
 844         usbnet_status_stop(dev);
 845
 846         usbnet_purge_paused_rxq(dev);
 847
 848         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 849
 850         /* deferred work (timer, softirq, task) must also stop */
 851         dev->flags = 0;
 852         del_timer_sync (&dev->delay);
 853         tasklet_kill (&dev->bh);
 854         cancel_work_sync(&dev->kevent);
 855         if (!pm)
 856                 usb_autopm_put_interface(dev->intf);
 857
 858         if (info->manage_power && mpn)
 859                 info->manage_power(dev, 0);
 860         else
 861                 usb_autopm_put_interface(dev->intf);
 862
 863         return 0;
 864 }
 865 EXPORT_SYMBOL_GPL(usbnet_stop);
 866
 867 /*-------------------------------------------------------------------------*/
 868
 869 // posts reads, and enables write queuing
 870
 871 // precondition: never called in_interrupt
 872
 873 int usbnet_open (struct net_device *net)
 874 {
 875         struct usbnet           *dev = netdev_priv(net);
 876         int                     retval;
 877         struct driver_info      *info = dev->driver_info;
 878
 879         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 880                 netif_info(dev, ifup, dev->net,
 881                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 882                            retval,
 883                            dev->udev->bus->bus_name,
 884                            dev->udev->devpath,
 885                            info->description);
 886                 goto done_nopm;
 887         }
 888
 889         // put into "known safe" state
 890         if (info->reset && (retval = info->reset (dev)) < 0) {
 891                 netif_info(dev, ifup, dev->net,
 892                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 893                            retval,
 894                            dev->udev->bus->bus_name,
 895                            dev->udev->devpath,
 896                            info->description);
 897                 goto done;
 898         }
 899
 900         /* hard_mtu or rx_urb_size may change in reset() */
 901         usbnet_update_max_qlen(dev);
 902
 903         // insist peer be connected
 904         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 905                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 906                 goto done;
 907         }
 908
 909         /* start any status interrupt transfer */
 910         if (dev->interrupt) {
 911                 retval = usbnet_status_start(dev, GFP_KERNEL);
 912                 if (retval < 0) {
 913                         netif_err(dev, ifup, dev->net,
 914                                   "intr submit %d\n", retval);
 915                         goto done;
 916                 }
 917         }
 918
 919         set_bit(EVENT_DEV_OPEN, &dev->flags);
 920         netif_start_queue (net);
 921         netif_info(dev, ifup, dev->net,
 922                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 923                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 924                    dev->net->mtu,
 925                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 926                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 927                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 928                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 929                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 930                    "simple");
 931
 932         /* reset rx error state */
 933         dev->pkt_cnt = 0;
 934         dev->pkt_err = 0;
 935         clear_bit(EVENT_RX_KILL, &dev->flags);
 936
 937         // delay posting reads until we're fully open
 938         tasklet_schedule (&dev->bh);
 939         if (info->manage_power) {
 940                 retval = info->manage_power(dev, 1);
 941                 if (retval < 0) {
 942                         retval = 0;
 943                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 944                 } else {
 945                         usb_autopm_put_interface(dev->intf);
 946                 }
 947         }
 948         return retval;
 949 done:
 950         usb_autopm_put_interface(dev->intf);
 951 done_nopm:
 952         return retval;
 953 }
 954 EXPORT_SYMBOL_GPL(usbnet_open);
 955
 956 /*-------------------------------------------------------------------------*/
 957
 958 /* ethtool methods; minidrivers may need to add some more, but
 959  * they'll probably want to use this base set.
 960  */
 961
 962 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 963 {
 964         struct usbnet *dev = netdev_priv(net);
 965
 966         if (!dev->mii.mdio_read)
 967                 return -EOPNOTSUPP;
 968
 969         return mii_ethtool_gset(&dev->mii, cmd);
 970 }
 971 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 972
 973 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 974 {
 975         struct usbnet *dev = netdev_priv(net);
 976         int retval;
 977
 978         if (!dev->mii.mdio_write)
 979                 return -EOPNOTSUPP;
 980
 981         retval = mii_ethtool_sset(&dev->mii, cmd);
 982
 983         /* link speed/duplex might have changed */
 984         if (dev->driver_info->link_reset)
 985                 dev->driver_info->link_reset(dev);
 986
 987         /* hard_mtu or rx_urb_size may change in link_reset() */
 988         usbnet_update_max_qlen(dev);
 989
 990         return retval;
 991
 992 }
 993 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 994
 995 u32 usbnet_get_link (struct net_device *net)
 996 {
 997         struct usbnet *dev = netdev_priv(net);
 998
 999         /* If a check_connect is defined, return its result */
1000         if (dev->driver_info->check_connect)
1001                 return dev->driver_info->check_connect (dev) == 0;
1002
1003         /* if the device has mii operations, use those */
1004         if (dev->mii.mdio_read)
1005                 return mii_link_ok(&dev->mii);
1006
1007         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1008         return ethtool_op_get_link(net);
1009 }
1010 EXPORT_SYMBOL_GPL(usbnet_get_link);
1011
1012 int usbnet_nway_reset(struct net_device *net)
1013 {
1014         struct usbnet *dev = netdev_priv(net);
1015
1016         if (!dev->mii.mdio_write)
1017                 return -EOPNOTSUPP;
1018
1019         return mii_nway_restart(&dev->mii);
1020 }
1021 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1022
1023 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1024 {
1025         struct usbnet *dev = netdev_priv(net);
1026
1027         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1028         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1029         strlcpy (info->fw_version, dev->driver_info->description,
1030                 sizeof info->fw_version);
1031         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1032 }
1033 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1034
1035 u32 usbnet_get_msglevel (struct net_device *net)
1036 {
1037         struct usbnet *dev = netdev_priv(net);
1038
1039         return dev->msg_enable;
1040 }
1041 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1042
1043 void usbnet_set_msglevel (struct net_device *net, u32 level)
1044 {
1045         struct usbnet *dev = netdev_priv(net);
1046
1047         dev->msg_enable = level;
1048 }
1049 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1050
1051 /* drivers may override default ethtool_ops in their bind() routine */
1052 static const struct ethtool_ops usbnet_ethtool_ops = {
1053         .get_settings           = usbnet_get_settings,
1054         .set_settings           = usbnet_set_settings,
1055         .get_link               = usbnet_get_link,
1056         .nway_reset             = usbnet_nway_reset,
1057         .get_drvinfo            = usbnet_get_drvinfo,
1058         .get_msglevel           = usbnet_get_msglevel,
1059         .set_msglevel           = usbnet_set_msglevel,
1060         .get_ts_info            = ethtool_op_get_ts_info,
1061 };
1062
1063 /*-------------------------------------------------------------------------*/
1064
1065 static void __handle_link_change(struct usbnet *dev)
1066 {
1067         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1068                 return;
1069
1070         if (!netif_carrier_ok(dev->net)) {
1071                 /* kill URBs for reading packets to save bus bandwidth */
1072                 unlink_urbs(dev, &dev->rxq);
1073
1074                 /*
1075                  * tx_timeout will unlink URBs for sending packets and
1076                  * tx queue is stopped by netcore after link becomes off
1077                  */
1078         } else {
1079                 /* submitting URBs for reading packets */
1080                 tasklet_schedule(&dev->bh);
1081         }
1082
1083         /* hard_mtu or rx_urb_size may change during link change */
1084         usbnet_update_max_qlen(dev);
1085
1086         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1087 }
1088
1089 static void usbnet_set_rx_mode(struct net_device *net)
1090 {
1091         struct usbnet           *dev = netdev_priv(net);
1092
1093         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1094 }
1095
1096 static void __handle_set_rx_mode(struct usbnet *dev)
1097 {
1098         if (dev->driver_info->set_rx_mode)
1099                 (dev->driver_info->set_rx_mode)(dev);
1100
1101         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1102 }
1103
1104 /* work that cannot be done in interrupt context uses keventd.
1105  *
1106  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1107  * especially now that control transfers can be queued.
1108  */
1109 static void
1110 usbnet_deferred_kevent (struct work_struct *work)
1111 {
1112         struct usbnet           *dev =
1113                 container_of(work, struct usbnet, kevent);
1114         int                     status;
1115
1116         /* usb_clear_halt() needs a thread context */
1117         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1118                 unlink_urbs (dev, &dev->txq);
1119                 status = usb_autopm_get_interface(dev->intf);
1120                 if (status < 0)
1121                         goto fail_pipe;
1122                 status = usb_clear_halt (dev->udev, dev->out);
1123                 usb_autopm_put_interface(dev->intf);
1124                 if (status < 0 &&
1125                     status != -EPIPE &&
1126                     status != -ESHUTDOWN) {
1127                         if (netif_msg_tx_err (dev))
1128 fail_pipe:
1129                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1130                                            status);
1131                 } else {
1132                         clear_bit (EVENT_TX_HALT, &dev->flags);
1133                         if (status != -ESHUTDOWN)
1134                                 netif_wake_queue (dev->net);
1135                 }
1136         }
1137         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1138                 unlink_urbs (dev, &dev->rxq);
1139                 status = usb_autopm_get_interface(dev->intf);
1140                 if (status < 0)
1141                         goto fail_halt;
1142                 status = usb_clear_halt (dev->udev, dev->in);
1143                 usb_autopm_put_interface(dev->intf);
1144                 if (status < 0 &&
1145                     status != -EPIPE &&
1146                     status != -ESHUTDOWN) {
1147                         if (netif_msg_rx_err (dev))
1148 fail_halt:
1149                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1150                                            status);
1151                 } else {
1152                         clear_bit (EVENT_RX_HALT, &dev->flags);
1153                         tasklet_schedule (&dev->bh);
1154                 }
1155         }
1156
1157         /* tasklet could resubmit itself forever if memory is tight */
1158         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1159                 struct urb      *urb = NULL;
1160                 int resched = 1;
1161
1162                 if (netif_running (dev->net))
1163                         urb = usb_alloc_urb (0, GFP_KERNEL);
1164                 else
1165                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1166                 if (urb != NULL) {
1167                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1168                         status = usb_autopm_get_interface(dev->intf);
1169                         if (status < 0) {
1170                                 usb_free_urb(urb);
1171                                 goto fail_lowmem;
1172                         }
1173                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1174                                 resched = 0;
1175                         usb_autopm_put_interface(dev->intf);
1176 fail_lowmem:
1177                         if (resched)
1178                                 tasklet_schedule (&dev->bh);
1179                 }
1180         }
1181
1182         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1183                 struct driver_info      *info = dev->driver_info;
1184                 int                     retval = 0;
1185
1186                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1187                 status = usb_autopm_get_interface(dev->intf);
1188                 if (status < 0)
1189                         goto skip_reset;
1190                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1191                         usb_autopm_put_interface(dev->intf);
1192 skip_reset:
1193                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1194                                     retval,
1195                                     dev->udev->bus->bus_name,
1196                                     dev->udev->devpath,
1197                                     info->description);
1198                 } else {
1199                         usb_autopm_put_interface(dev->intf);
1200                 }
1201
1202                 /* handle link change from link resetting */
1203                 __handle_link_change(dev);
1204         }
1205
1206         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1207                 __handle_link_change(dev);
1208
1209         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1210                 __handle_set_rx_mode(dev);
1211
1212
1213         if (dev->flags)
1214                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1215 }
1216
1217 /*-------------------------------------------------------------------------*/
1218
1219 static void tx_complete (struct urb *urb)
1220 {
1221         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1222         struct skb_data         *entry = (struct skb_data *) skb->cb;
1223         struct usbnet           *dev = entry->dev;
1224
1225         if (urb->status == 0) {
1226                 dev->net->stats.tx_packets += entry->packets;
1227                 dev->net->stats.tx_bytes += entry->length;
1228         } else {
1229                 dev->net->stats.tx_errors++;
1230
1231                 switch (urb->status) {
1232                 case -EPIPE:
1233                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1234                         break;
1235
1236                 /* software-driven interface shutdown */
1237                 case -ECONNRESET:               // async unlink
1238                 case -ESHUTDOWN:                // hardware gone
1239                         break;
1240
1241                 /* like rx, tx gets controller i/o faults during hub_wq
1242                  * delays and so it uses the same throttling mechanism.
1243                  */
1244                 case -EPROTO:
1245                 case -ETIME:
1246                 case -EILSEQ:
1247                         usb_mark_last_busy(dev->udev);
1248                         if (!timer_pending (&dev->delay)) {
1249                                 mod_timer (&dev->delay,
1250                                         jiffies + THROTTLE_JIFFIES);
1251                                 netif_dbg(dev, link, dev->net,
1252                                           "tx throttle %d\n", urb->status);
1253                         }
1254                         netif_stop_queue (dev->net);
1255                         break;
1256                 default:
1257                         netif_dbg(dev, tx_err, dev->net,
1258                                   "tx err %d\n", entry->urb->status);
1259                         break;
1260                 }
1261         }
1262
1263         usb_autopm_put_interface_async(dev->intf);
1264         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1265 }
1266
1267 /*-------------------------------------------------------------------------*/
1268
1269 void usbnet_tx_timeout (struct net_device *net)
1270 {
1271         struct usbnet           *dev = netdev_priv(net);
1272
1273         unlink_urbs (dev, &dev->txq);
1274         tasklet_schedule (&dev->bh);
1275         /* this needs to be handled individually because the generic layer
1276          * doesn't know what is sufficient and could not restore private
1277          * information if a remedy of an unconditional reset were used.
1278          */
1279         if (dev->driver_info->recover)
1280                 (dev->driver_info->recover)(dev);
1281 }
1282 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1283
1284 /*-------------------------------------------------------------------------*/
1285
1286 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1287 {
1288         unsigned num_sgs, total_len = 0;
1289         int i, s = 0;
1290
1291         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1292         if (num_sgs == 1)
1293                 return 0;
1294
1295         /* reserve one for zero packet */
1296         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1297                           GFP_ATOMIC);
1298         if (!urb->sg)
1299                 return -ENOMEM;
1300
1301         urb->num_sgs = num_sgs;
1302         sg_init_table(urb->sg, urb->num_sgs + 1);
1303
1304         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1305         total_len += skb_headlen(skb);
1306
1307         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1308                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1309
1310                 total_len += skb_frag_size(f);
1311                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1312                                 f->page_offset);
1313         }
1314         urb->transfer_buffer_length = total_len;
1315
1316         return 1;
1317 }
1318
1319 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1320                                      struct net_device *net)
1321 {
1322         struct usbnet           *dev = netdev_priv(net);
1323         unsigned int                    length;
1324         struct urb              *urb = NULL;
1325         struct skb_data         *entry;
1326         struct driver_info      *info = dev->driver_info;
1327         unsigned long           flags;
1328         int retval;
1329
1330         if (skb)
1331                 skb_tx_timestamp(skb);
1332
1333         // some devices want funky USB-level framing, for
1334         // win32 driver (usually) and/or hardware quirks
1335         if (info->tx_fixup) {
1336                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1337                 if (!skb) {
1338                         /* packet collected; minidriver waiting for more */
1339                         if (info->flags & FLAG_MULTI_PACKET)
1340                                 goto not_drop;
1341                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1342                         goto drop;
1343                 }
1344         }
1345
1346         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1347                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1348                 goto drop;
1349         }
1350
1351         entry = (struct skb_data *) skb->cb;
1352         entry->urb = urb;
1353         entry->dev = dev;
1354
1355         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1356                         skb->data, skb->len, tx_complete, skb);
1357         if (dev->can_dma_sg) {
1358                 if (build_dma_sg(skb, urb) < 0)
1359                         goto drop;
1360         }
1361         length = urb->transfer_buffer_length;
1362
1363         /* don't assume the hardware handles USB_ZERO_PACKET
1364          * NOTE:  strictly conforming cdc-ether devices should expect
1365          * the ZLP here, but ignore the one-byte packet.
1366          * NOTE2: CDC NCM specification is different from CDC ECM when
1367          * handling ZLP/short packets, so cdc_ncm driver will make short
1368          * packet itself if needed.
1369          */
1370         if (length % dev->maxpacket == 0) {
1371                 if (!(info->flags & FLAG_SEND_ZLP)) {
1372                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1373                                 length++;
1374                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1375                                         skb->data[skb->len] = 0;
1376                                         __skb_put(skb, 1);
1377                                 } else if (urb->num_sgs)
1378                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1379                                                         dev->padding_pkt, 1);
1380                         }
1381                 } else
1382                         urb->transfer_flags |= URB_ZERO_PACKET;
1383         }
1384         urb->transfer_buffer_length = length;
1385
1386         if (info->flags & FLAG_MULTI_PACKET) {
1387                 /* Driver has set number of packets and a length delta.
1388                  * Calculate the complete length and ensure that it's
1389                  * positive.
1390                  */
1391                 entry->length += length;
1392                 if (WARN_ON_ONCE(entry->length <= 0))
1393                         entry->length = length;
1394         } else {
1395                 usbnet_set_skb_tx_stats(skb, 1, length);
1396         }
1397
1398         spin_lock_irqsave(&dev->txq.lock, flags);
1399         retval = usb_autopm_get_interface_async(dev->intf);
1400         if (retval < 0) {
1401                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1402                 goto drop;
1403         }
1404         if (netif_queue_stopped(net)) {
1405                 usb_autopm_put_interface_async(dev->intf);
1406                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1407                 goto drop;
1408         }
1409
1410 #ifdef CONFIG_PM
1411         /* if this triggers the device is still a sleep */
1412         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1413                 /* transmission will be done in resume */
1414                 usb_anchor_urb(urb, &dev->deferred);
1415                 /* no use to process more packets */
1416                 netif_stop_queue(net);
1417                 usb_put_urb(urb);
1418                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1419                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1420                 goto deferred;
1421         }
1422 #endif
1423
1424         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1425         case -EPIPE:
1426                 netif_stop_queue (net);
1427                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1428                 usb_autopm_put_interface_async(dev->intf);
1429                 break;
1430         default:
1431                 usb_autopm_put_interface_async(dev->intf);
1432                 netif_dbg(dev, tx_err, dev->net,
1433                           "tx: submit urb err %d\n", retval);
1434                 break;
1435         case 0:
1436                 netif_trans_update(net);
1437                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1438                 if (dev->txq.qlen >= TX_QLEN (dev))
1439                         netif_stop_queue (net);
1440         }
1441         spin_unlock_irqrestore (&dev->txq.lock, flags);
1442
1443         if (retval) {
1444                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1445 drop:
1446                 dev->net->stats.tx_dropped++;
1447 not_drop:
1448                 if (skb)
1449                         dev_kfree_skb_any (skb);
1450                 if (urb) {
1451                         kfree(urb->sg);
1452                         usb_free_urb(urb);
1453                 }
1454         } else
1455                 netif_dbg(dev, tx_queued, dev->net,
1456                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1457 #ifdef CONFIG_PM
1458 deferred:
1459 #endif
1460         return NETDEV_TX_OK;
1461 }
1462 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1463
1464 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1465 {
1466         struct urb      *urb;
1467         int             i;
1468         int             ret = 0;
1469
1470         /* don't refill the queue all at once */
1471         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1472                 urb = usb_alloc_urb(0, flags);
1473                 if (urb != NULL) {
1474                         ret = rx_submit(dev, urb, flags);
1475                         if (ret)
1476                                 goto err;
1477                 } else {
1478                         ret = -ENOMEM;
1479                         goto err;
1480                 }
1481         }
1482 err:
1483         return ret;
1484 }
1485
1486 /*-------------------------------------------------------------------------*/
1487
1488 // tasklet (work deferred from completions, in_irq) or timer
1489
1490 static void usbnet_bh (unsigned long param)
1491 {
1492         struct usbnet           *dev = (struct usbnet *) param;
1493         struct sk_buff          *skb;
1494         struct skb_data         *entry;
1495
1496         while ((skb = skb_dequeue (&dev->done))) {
1497                 entry = (struct skb_data *) skb->cb;
1498                 switch (entry->state) {
1499                 case rx_done:
1500                         entry->state = rx_cleanup;
1501                         rx_process (dev, skb);
1502                         continue;
1503                 case tx_done:
1504                         kfree(entry->urb->sg);
1505                 case rx_cleanup:
1506                         usb_free_urb (entry->urb);
1507                         dev_kfree_skb (skb);
1508                         continue;
1509                 default:
1510                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1511                 }
1512         }
1513
1514         /* restart RX again after disabling due to high error rate */
1515         clear_bit(EVENT_RX_KILL, &dev->flags);
1516
1517         /* waiting for all pending urbs to complete?
1518          * only then can we forgo submitting anew
1519          */
1520         if (waitqueue_active(&dev->wait)) {
1521                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1522                         wake_up_all(&dev->wait);
1523
1524         // or are we maybe short a few urbs?
1525         } else if (netif_running (dev->net) &&
1526                    netif_device_present (dev->net) &&
1527                    netif_carrier_ok(dev->net) &&
1528                    !timer_pending(&dev->delay) &&
1529                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1530                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1531                 int     temp = dev->rxq.qlen;
1532
1533                 if (temp < RX_QLEN(dev)) {
1534                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1535                                 return;
1536                         if (temp != dev->rxq.qlen)
1537                                 netif_dbg(dev, link, dev->net,
1538                                           "rxqlen %d --> %d\n",
1539                                           temp, dev->rxq.qlen);
1540                         if (dev->rxq.qlen < RX_QLEN(dev))
1541                                 tasklet_schedule (&dev->bh);
1542                 }
1543                 if (dev->txq.qlen < TX_QLEN (dev))
1544                         netif_wake_queue (dev->net);
1545         }
1546 }
1547
1548
1549 /*-------------------------------------------------------------------------
1550  *
1551  * USB Device Driver support
1552  *
1553  *-------------------------------------------------------------------------*/
1554
1555 // precondition: never called in_interrupt
1556
1557 void usbnet_disconnect (struct usb_interface *intf)
1558 {
1559         struct usbnet           *dev;
1560         struct usb_device       *xdev;
1561         struct net_device       *net;
1562         struct urb              *urb;
1563
1564         dev = usb_get_intfdata(intf);
1565         usb_set_intfdata(intf, NULL);
1566         if (!dev)
1567                 return;
1568
1569         xdev = interface_to_usbdev (intf);
1570
1571         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1572                    intf->dev.driver->name,
1573                    xdev->bus->bus_name, xdev->devpath,
1574                    dev->driver_info->description);
1575
1576         net = dev->net;
1577         unregister_netdev (net);
1578
1579         while ((urb = usb_get_from_anchor(&dev->deferred))) {
1580                 dev_kfree_skb(urb->context);
1581                 kfree(urb->sg);
1582                 usb_free_urb(urb);
1583         }
1584
1585         if (dev->driver_info->unbind)
1586                 dev->driver_info->unbind (dev, intf);
1587
1588         usb_kill_urb(dev->interrupt);
1589         usb_free_urb(dev->interrupt);
1590         kfree(dev->padding_pkt);
1591
1592         free_netdev(net);
1593 }
1594 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1595
1596 static const struct net_device_ops usbnet_netdev_ops = {
1597         .ndo_open               = usbnet_open,
1598         .ndo_stop               = usbnet_stop,
1599         .ndo_start_xmit         = usbnet_start_xmit,
1600         .ndo_tx_timeout         = usbnet_tx_timeout,
1601         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1602         .ndo_change_mtu         = usbnet_change_mtu,
1603         .ndo_set_mac_address    = eth_mac_addr,
1604         .ndo_validate_addr      = eth_validate_addr,
1605 };
1606
1607 /*-------------------------------------------------------------------------*/
1608
1609 // precondition: never called in_interrupt
1610
1611 static struct device_type wlan_type = {
1612         .name   = "wlan",
1613 };
1614
1615 static struct device_type wwan_type = {
1616         .name   = "wwan",
1617 };
1618
1619 int
1620 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1621 {
1622         struct usbnet                   *dev;
1623         struct net_device               *net;
1624         struct usb_host_interface       *interface;
1625         struct driver_info              *info;
1626         struct usb_device               *xdev;
1627         int                             status;
1628         const char                      *name;
1629         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1630
1631         /* usbnet already took usb runtime pm, so have to enable the feature
1632          * for usb interface, otherwise usb_autopm_get_interface may return
1633          * failure if RUNTIME_PM is enabled.
1634          */
1635         if (!driver->supports_autosuspend) {
1636                 driver->supports_autosuspend = 1;
1637                 pm_runtime_enable(&udev->dev);
1638         }
1639
1640         name = udev->dev.driver->name;
1641         info = (struct driver_info *) prod->driver_info;
1642         if (!info) {
1643                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1644                 return -ENODEV;
1645         }
1646         xdev = interface_to_usbdev (udev);
1647         interface = udev->cur_altsetting;
1648
1649         status = -ENOMEM;
1650
1651         // set up our own records
1652         net = alloc_etherdev(sizeof(*dev));
1653         if (!net)
1654                 goto out;
1655
1656         /* netdev_printk() needs this so do it as early as possible */
1657         SET_NETDEV_DEV(net, &udev->dev);
1658
1659         dev = netdev_priv(net);
1660         dev->udev = xdev;
1661         dev->intf = udev;
1662         dev->driver_info = info;
1663         dev->driver_name = name;
1664         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1665                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1666         init_waitqueue_head(&dev->wait);
1667         skb_queue_head_init (&dev->rxq);
1668         skb_queue_head_init (&dev->txq);
1669         skb_queue_head_init (&dev->done);
1670         skb_queue_head_init(&dev->rxq_pause);
1671         dev->bh.func = usbnet_bh;
1672         dev->bh.data = (unsigned long) dev;
1673         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1674         init_usb_anchor(&dev->deferred);
1675         dev->delay.function = usbnet_bh;
1676         dev->delay.data = (unsigned long) dev;
1677         init_timer (&dev->delay);
1678         mutex_init (&dev->phy_mutex);
1679         mutex_init(&dev->interrupt_mutex);
1680         dev->interrupt_count = 0;
1681
1682         dev->net = net;
1683         strcpy (net->name, "usb%d");
1684         memcpy (net->dev_addr, node_id, sizeof node_id);
1685
1686         /* rx and tx sides can use different message sizes;
1687          * bind() should set rx_urb_size in that case.
1688          */
1689         dev->hard_mtu = net->mtu + net->hard_header_len;
1690
1691         net->netdev_ops = &usbnet_netdev_ops;
1692         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1693         net->ethtool_ops = &usbnet_ethtool_ops;
1694
1695         // allow device-specific bind/init procedures
1696         // NOTE net->name still not usable ...
1697         if (info->bind) {
1698                 status = info->bind (dev, udev);
1699                 if (status < 0)
1700                         goto out1;
1701
1702                 // heuristic:  "usb%d" for links we know are two-host,
1703                 // else "eth%d" when there's reasonable doubt.  userspace
1704                 // can rename the link if it knows better.
1705                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1706                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1707                      (net->dev_addr [0] & 0x02) == 0))
1708                         strcpy (net->name, "eth%d");
1709                 /* WLAN devices should always be named "wlan%d" */
1710                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1711                         strcpy(net->name, "wlan%d");
1712                 /* WWAN devices should always be named "wwan%d" */
1713                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1714                         strcpy(net->name, "wwan%d");
1715
1716                 /* devices that cannot do ARP */
1717                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1718                         net->flags |= IFF_NOARP;
1719
1720                 /* maybe the remote can't receive an Ethernet MTU */
1721                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1722                         net->mtu = dev->hard_mtu - net->hard_header_len;
1723         } else if (!info->in || !info->out)
1724                 status = usbnet_get_endpoints (dev, udev);
1725         else {
1726                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1727                 dev->out = usb_sndbulkpipe (xdev, info->out);
1728                 if (!(info->flags & FLAG_NO_SETINT))
1729                         status = usb_set_interface (xdev,
1730                                 interface->desc.bInterfaceNumber,
1731                                 interface->desc.bAlternateSetting);
1732                 else
1733                         status = 0;
1734
1735         }
1736         if (status >= 0 && dev->status)
1737                 status = init_status (dev, udev);
1738         if (status < 0)
1739                 goto out3;
1740
1741         if (!dev->rx_urb_size)
1742                 dev->rx_urb_size = dev->hard_mtu;
1743         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1744         if (dev->maxpacket == 0) {
1745                 /* that is a broken device */
1746                 status = -ENODEV;
1747                 goto out4;
1748         }
1749
1750         /* let userspace know we have a random address */
1751         if (ether_addr_equal(net->dev_addr, node_id))
1752                 net->addr_assign_type = NET_ADDR_RANDOM;
1753
1754         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1755                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1756         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1757                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1758
1759         /* initialize max rx_qlen and tx_qlen */
1760         usbnet_update_max_qlen(dev);
1761
1762         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1763                 !(info->flags & FLAG_MULTI_PACKET)) {
1764                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1765                 if (!dev->padding_pkt) {
1766                         status = -ENOMEM;
1767                         goto out4;
1768                 }
1769         }
1770
1771         status = register_netdev (net);
1772         if (status)
1773                 goto out5;
1774         netif_info(dev, probe, dev->net,
1775                    "register '%s' at usb-%s-%s, %s, %pM\n",
1776                    udev->dev.driver->name,
1777                    xdev->bus->bus_name, xdev->devpath,
1778                    dev->driver_info->description,
1779                    net->dev_addr);
1780
1781         // ok, it's ready to go.
1782         usb_set_intfdata (udev, dev);
1783
1784         netif_device_attach (net);
1785
1786         if (dev->driver_info->flags & FLAG_LINK_INTR)
1787                 usbnet_link_change(dev, 0, 0);
1788
1789         return 0;
1790
1791 out5:
1792         kfree(dev->padding_pkt);
1793 out4:
1794         usb_free_urb(dev->interrupt);
1795 out3:
1796         if (info->unbind)
1797                 info->unbind (dev, udev);
1798 out1:
1799         /* subdrivers must undo all they did in bind() if they
1800          * fail it, but we may fail later and a deferred kevent
1801          * may trigger an error resubmitting itself and, worse,
1802          * schedule a timer. So we kill it all just in case.
1803          */
1804         cancel_work_sync(&dev->kevent);
1805         del_timer_sync(&dev->delay);
1806         free_netdev(net);
1807 out:
1808         return status;
1809 }
1810 EXPORT_SYMBOL_GPL(usbnet_probe);
1811
1812 /*-------------------------------------------------------------------------*/
1813
1814 /*
1815  * suspend the whole driver as soon as the first interface is suspended
1816  * resume only when the last interface is resumed
1817  */
1818
1819 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1820 {
1821         struct usbnet           *dev = usb_get_intfdata(intf);
1822
1823         if (!dev->suspend_count++) {
1824                 spin_lock_irq(&dev->txq.lock);
1825                 /* don't autosuspend while transmitting */
1826                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1827                         dev->suspend_count--;
1828                         spin_unlock_irq(&dev->txq.lock);
1829                         return -EBUSY;
1830                 } else {
1831                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1832                         spin_unlock_irq(&dev->txq.lock);
1833                 }
1834                 /*
1835                  * accelerate emptying of the rx and queues, to avoid
1836                  * having everything error out.
1837                  */
1838                 netif_device_detach (dev->net);
1839                 usbnet_terminate_urbs(dev);
1840                 __usbnet_status_stop_force(dev);
1841
1842                 /*
1843                  * reattach so runtime management can use and
1844                  * wake the device
1845                  */
1846                 netif_device_attach (dev->net);
1847         }
1848         return 0;
1849 }
1850 EXPORT_SYMBOL_GPL(usbnet_suspend);
1851
1852 int usbnet_resume (struct usb_interface *intf)
1853 {
1854         struct usbnet           *dev = usb_get_intfdata(intf);
1855         struct sk_buff          *skb;
1856         struct urb              *res;
1857         int                     retval;
1858
1859         if (!--dev->suspend_count) {
1860                 /* resume interrupt URB if it was previously submitted */
1861                 __usbnet_status_start_force(dev, GFP_NOIO);
1862
1863                 spin_lock_irq(&dev->txq.lock);
1864                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1865
1866                         skb = (struct sk_buff *)res->context;
1867                         retval = usb_submit_urb(res, GFP_ATOMIC);
1868                         if (retval < 0) {
1869                                 dev_kfree_skb_any(skb);
1870                                 kfree(res->sg);
1871                                 usb_free_urb(res);
1872                                 usb_autopm_put_interface_async(dev->intf);
1873                         } else {
1874                                 netif_trans_update(dev->net);
1875                                 __skb_queue_tail(&dev->txq, skb);
1876                         }
1877                 }
1878
1879                 smp_mb();
1880                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1881                 spin_unlock_irq(&dev->txq.lock);
1882
1883                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1884                         /* handle remote wakeup ASAP
1885                          * we cannot race against stop
1886                          */
1887                         if (netif_device_present(dev->net) &&
1888                                 !timer_pending(&dev->delay) &&
1889                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1890                                         rx_alloc_submit(dev, GFP_NOIO);
1891
1892                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1893                                 netif_tx_wake_all_queues(dev->net);
1894                         tasklet_schedule (&dev->bh);
1895                 }
1896         }
1897
1898         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1899                 usb_autopm_get_interface_no_resume(intf);
1900
1901         return 0;
1902 }
1903 EXPORT_SYMBOL_GPL(usbnet_resume);
1904
1905 /*
1906  * Either a subdriver implements manage_power, then it is assumed to always
1907  * be ready to be suspended or it reports the readiness to be suspended
1908  * explicitly
1909  */
1910 void usbnet_device_suggests_idle(struct usbnet *dev)
1911 {
1912         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1913                 dev->intf->needs_remote_wakeup = 1;
1914                 usb_autopm_put_interface_async(dev->intf);
1915         }
1916 }
1917 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1918
1919 /*
1920  * For devices that can do without special commands
1921  */
1922 int usbnet_manage_power(struct usbnet *dev, int on)
1923 {
1924         dev->intf->needs_remote_wakeup = on;
1925         return 0;
1926 }
1927 EXPORT_SYMBOL(usbnet_manage_power);
1928
1929 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1930 {
1931         /* update link after link is reseted */
1932         if (link && !need_reset)
1933                 netif_carrier_on(dev->net);
1934         else
1935                 netif_carrier_off(dev->net);
1936
1937         if (need_reset && link)
1938                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1939         else
1940                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1941 }
1942 EXPORT_SYMBOL(usbnet_link_change);
1943
1944 /*-------------------------------------------------------------------------*/
1945 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1946                              u16 value, u16 index, void *data, u16 size)
1947 {
1948         void *buf = NULL;
1949         int err = -ENOMEM;
1950
1951         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1952                    " value=0x%04x index=0x%04x size=%d\n",
1953                    cmd, reqtype, value, index, size);
1954
1955         if (size) {
1956                 buf = kmalloc(size, GFP_NOIO);
1957                 if (!buf)
1958                         goto out;
1959         }
1960
1961         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1962                               cmd, reqtype, value, index, buf, size,
1963                               USB_CTRL_GET_TIMEOUT);
1964         if (err > 0 && err <= size) {
1965         if (data)
1966             memcpy(data, buf, err);
1967         else
1968             netdev_dbg(dev->net,
1969                 "Huh? Data requested but thrown away.\n");
1970     }
1971         kfree(buf);
1972 out:
1973         return err;
1974 }
1975
1976 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1977                               u16 value, u16 index, const void *data,
1978                               u16 size)
1979 {
1980         void *buf = NULL;
1981         int err = -ENOMEM;
1982
1983         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1984                    " value=0x%04x index=0x%04x size=%d\n",
1985                    cmd, reqtype, value, index, size);
1986
1987         if (data) {
1988                 buf = kmemdup(data, size, GFP_NOIO);
1989                 if (!buf)
1990                         goto out;
1991         } else {
1992         if (size) {
1993             WARN_ON_ONCE(1);
1994             err = -EINVAL;
1995             goto out;
1996         }
1997     }
1998
1999         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2000                               cmd, reqtype, value, index, buf, size,
2001                               USB_CTRL_SET_TIMEOUT);
2002         kfree(buf);
2003
2004 out:
2005         return err;
2006 }
2007
2008 /*
2009  * The function can't be called inside suspend/resume callback,
2010  * otherwise deadlock will be caused.
2011  */
2012 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2013                     u16 value, u16 index, void *data, u16 size)
2014 {
2015         int ret;
2016
2017         if (usb_autopm_get_interface(dev->intf) < 0)
2018                 return -ENODEV;
2019         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2020                                 data, size);
2021         usb_autopm_put_interface(dev->intf);
2022         return ret;
2023 }
2024 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2025
2026 /*
2027  * The function can't be called inside suspend/resume callback,
2028  * otherwise deadlock will be caused.
2029  */
2030 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2031                      u16 value, u16 index, const void *data, u16 size)
2032 {
2033         int ret;
2034
2035         if (usb_autopm_get_interface(dev->intf) < 0)
2036                 return -ENODEV;
2037         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2038                                  data, size);
2039         usb_autopm_put_interface(dev->intf);
2040         return ret;
2041 }
2042 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2043
2044 /*
2045  * The function can be called inside suspend/resume callback safely
2046  * and should only be called by suspend/resume callback generally.
2047  */
2048 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2049                           u16 value, u16 index, void *data, u16 size)
2050 {
2051         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2052                                  data, size);
2053 }
2054 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2055
2056 /*
2057  * The function can be called inside suspend/resume callback safely
2058  * and should only be called by suspend/resume callback generally.
2059  */
2060 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2061                           u16 value, u16 index, const void *data,
2062                           u16 size)
2063 {
2064         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2065                                   data, size);
2066 }
2067 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2068
2069 static void usbnet_async_cmd_cb(struct urb *urb)
2070 {
2071         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2072         int status = urb->status;
2073
2074         if (status < 0)
2075                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2076                         __func__, status);
2077
2078         kfree(req);
2079         usb_free_urb(urb);
2080 }
2081
2082 /*
2083  * The caller must make sure that device can't be put into suspend
2084  * state until the control URB completes.
2085  */
2086 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2087                            u16 value, u16 index, const void *data, u16 size)
2088 {
2089         struct usb_ctrlrequest *req;
2090         struct urb *urb;
2091         int err = -ENOMEM;
2092         void *buf = NULL;
2093
2094         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2095                    " value=0x%04x index=0x%04x size=%d\n",
2096                    cmd, reqtype, value, index, size);
2097
2098         urb = usb_alloc_urb(0, GFP_ATOMIC);
2099         if (!urb)
2100                 goto fail;
2101
2102         if (data) {
2103                 buf = kmemdup(data, size, GFP_ATOMIC);
2104                 if (!buf) {
2105                         netdev_err(dev->net, "Error allocating buffer"
2106                                    " in %s!\n", __func__);
2107                         goto fail_free_urb;
2108                 }
2109         }
2110
2111         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2112         if (!req)
2113                 goto fail_free_buf;
2114
2115         req->bRequestType = reqtype;
2116         req->bRequest = cmd;
2117         req->wValue = cpu_to_le16(value);
2118         req->wIndex = cpu_to_le16(index);
2119         req->wLength = cpu_to_le16(size);
2120
2121         usb_fill_control_urb(urb, dev->udev,
2122                              usb_sndctrlpipe(dev->udev, 0),
2123                              (void *)req, buf, size,
2124                              usbnet_async_cmd_cb, req);
2125         urb->transfer_flags |= URB_FREE_BUFFER;
2126
2127         err = usb_submit_urb(urb, GFP_ATOMIC);
2128         if (err < 0) {
2129                 netdev_err(dev->net, "Error submitting the control"
2130                            " message: status=%d\n", err);
2131                 goto fail_free_all;
2132         }
2133         return 0;
2134
2135 fail_free_all:
2136         kfree(req);
2137 fail_free_buf:
2138         kfree(buf);
2139         /*
2140          * avoid a double free
2141          * needed because the flag can be set only
2142          * after filling the URB
2143          */
2144         urb->transfer_flags = 0;
2145 fail_free_urb:
2146         usb_free_urb(urb);
2147 fail:
2148         return err;
2149
2150 }
2151 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2152 /*-------------------------------------------------------------------------*/
2153
2154 static int __init usbnet_init(void)
2155 {
2156         /* Compiler should optimize this out. */
2157         BUILD_BUG_ON(
2158                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2159
2160         eth_random_addr(node_id);
2161         return 0;
2162 }
2163 module_init(usbnet_init);
2164
2165 static void __exit usbnet_exit(void)
2166 {
2167 }
2168 module_exit(usbnet_exit);
2169
2170 MODULE_AUTHOR("David Brownell");
2171 MODULE_DESCRIPTION("USB network driver framework");
2172 MODULE_LICENSE("GPL");