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