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/usb/cdc.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * The goal is to let the USB host controller be busy for 5msec or
  63  * more before an irq is required, under load.  Jumbograms change
  64  * the equation.
  65  */
  66 #define MAX_QUEUE_MEMORY        (60 * 1518)
  67 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  68 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  69
  70 // reawaken network queue this soon after stopping; else watchdog barks
  71 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  72
  73 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  74  * us (it polls at HZ/4 usually) before we report too many false errors.
  75  */
  76 #define THROTTLE_JIFFIES        (HZ/8)
  77
  78 // between wakeups
  79 #define UNLINK_TIMEOUT_MS       3
  80
  81 /*-------------------------------------------------------------------------*/
  82
  83 // randomly generated ethernet address
  84 static u8       node_id [ETH_ALEN];
  85
  86 static const char driver_name [] = "usbnet";
  87
  88 /* use ethtool to change the level for any given device */
  89 static int msg_level = -1;
  90 module_param (msg_level, int, 0);
  91 MODULE_PARM_DESC (msg_level, "Override default message level");
  92
  93 /*-------------------------------------------------------------------------*/
  94
  95 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  96 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  97 {
  98         int                             tmp;
  99         struct usb_host_interface       *alt = NULL;
 100         struct usb_host_endpoint        *in = NULL, *out = NULL;
 101         struct usb_host_endpoint        *status = NULL;
 102
 103         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 104                 unsigned        ep;
 105
 106                 in = out = status = NULL;
 107                 alt = intf->altsetting + tmp;
 108
 109                 /* take the first altsetting with in-bulk + out-bulk;
 110                  * remember any status endpoint, just in case;
 111                  * ignore other endpoints and altsettings.
 112                  */
 113                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 114                         struct usb_host_endpoint        *e;
 115                         int                             intr = 0;
 116
 117                         e = alt->endpoint + ep;
 118                         switch (e->desc.bmAttributes) {
 119                         case USB_ENDPOINT_XFER_INT:
 120                                 if (!usb_endpoint_dir_in(&e->desc))
 121                                         continue;
 122                                 intr = 1;
 123                                 /* FALLTHROUGH */
 124                         case USB_ENDPOINT_XFER_BULK:
 125                                 break;
 126                         default:
 127                                 continue;
 128                         }
 129                         if (usb_endpoint_dir_in(&e->desc)) {
 130                                 if (!intr && !in)
 131                                         in = e;
 132                                 else if (intr && !status)
 133                                         status = e;
 134                         } else {
 135                                 if (!out)
 136                                         out = e;
 137                         }
 138                 }
 139                 if (in && out)
 140                         break;
 141         }
 142         if (!alt || !in || !out)
 143                 return -EINVAL;
 144
 145         if (alt->desc.bAlternateSetting != 0 ||
 146             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 147                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 148                                 alt->desc.bAlternateSetting);
 149                 if (tmp < 0)
 150                         return tmp;
 151         }
 152
 153         dev->in = usb_rcvbulkpipe (dev->udev,
 154                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155         dev->out = usb_sndbulkpipe (dev->udev,
 156                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 157         dev->status = status;
 158         return 0;
 159 }
 160 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 161
 162 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 163 {
 164         int             tmp = -1, ret;
 165         unsigned char   buf [13];
 166
 167         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 168         if (ret == 12)
 169                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 170         if (tmp < 0) {
 171                 dev_dbg(&dev->udev->dev,
 172                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 173                 if (ret >= 0)
 174                         ret = -EINVAL;
 175                 return ret;
 176         }
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 180
 181 static void intr_complete (struct urb *urb)
 182 {
 183         struct usbnet   *dev = urb->context;
 184         int             status = urb->status;
 185
 186         switch (status) {
 187         /* success */
 188         case 0:
 189                 dev->driver_info->status(dev, urb);
 190                 break;
 191
 192         /* software-driven interface shutdown */
 193         case -ENOENT:           /* urb killed */
 194         case -ESHUTDOWN:        /* hardware gone */
 195                 netif_dbg(dev, ifdown, dev->net,
 196                           "intr shutdown, code %d\n", status);
 197                 return;
 198
 199         /* NOTE:  not throttling like RX/TX, since this endpoint
 200          * already polls infrequently
 201          */
 202         default:
 203                 netdev_dbg(dev->net, "intr status %d\n", status);
 204                 break;
 205         }
 206
 207         status = usb_submit_urb (urb, GFP_ATOMIC);
 208         if (status != 0)
 209                 netif_err(dev, timer, dev->net,
 210                           "intr resubmit --> %d\n", status);
 211 }
 212
 213 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 214 {
 215         char            *buf = NULL;
 216         unsigned        pipe = 0;
 217         unsigned        maxp;
 218         unsigned        period;
 219
 220         if (!dev->driver_info->status)
 221                 return 0;
 222
 223         pipe = usb_rcvintpipe (dev->udev,
 224                         dev->status->desc.bEndpointAddress
 225                                 & USB_ENDPOINT_NUMBER_MASK);
 226         maxp = usb_maxpacket (dev->udev, pipe, 0);
 227
 228         /* avoid 1 msec chatter:  min 8 msec poll rate */
 229         period = max ((int) dev->status->desc.bInterval,
 230                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 231
 232         buf = kmalloc (maxp, GFP_KERNEL);
 233         if (buf) {
 234                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 235                 if (!dev->interrupt) {
 236                         kfree (buf);
 237                         return -ENOMEM;
 238                 } else {
 239                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 240                                 buf, maxp, intr_complete, dev, period);
 241                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 242                         dev_dbg(&intf->dev,
 243                                 "status ep%din, %d bytes period %d\n",
 244                                 usb_pipeendpoint(pipe), maxp, period);
 245                 }
 246         }
 247         return 0;
 248 }
 249
 250 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 251 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 252 {
 253         int ret = 0;
 254
 255         WARN_ON_ONCE(dev->interrupt == NULL);
 256         if (dev->interrupt) {
 257                 mutex_lock(&dev->interrupt_mutex);
 258
 259                 if (++dev->interrupt_count == 1)
 260                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 261
 262                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 263                         dev->interrupt_count);
 264                 mutex_unlock(&dev->interrupt_mutex);
 265         }
 266         return ret;
 267 }
 268 EXPORT_SYMBOL_GPL(usbnet_status_start);
 269
 270 /* For resume; submit interrupt URB if previously submitted */
 271 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 272 {
 273         int ret = 0;
 274
 275         mutex_lock(&dev->interrupt_mutex);
 276         if (dev->interrupt_count) {
 277                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 278                 dev_dbg(&dev->udev->dev,
 279                         "submitted interrupt URB for resume\n");
 280         }
 281         mutex_unlock(&dev->interrupt_mutex);
 282         return ret;
 283 }
 284
 285 /* Kill the interrupt URB if all submitters want it killed */
 286 void usbnet_status_stop(struct usbnet *dev)
 287 {
 288         if (dev->interrupt) {
 289                 mutex_lock(&dev->interrupt_mutex);
 290                 WARN_ON(dev->interrupt_count == 0);
 291
 292                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 293                         usb_kill_urb(dev->interrupt);
 294
 295                 dev_dbg(&dev->udev->dev,
 296                         "decremented interrupt URB count to %d\n",
 297                         dev->interrupt_count);
 298                 mutex_unlock(&dev->interrupt_mutex);
 299         }
 300 }
 301 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 302
 303 /* For suspend; always kill interrupt URB */
 304 static void __usbnet_status_stop_force(struct usbnet *dev)
 305 {
 306         if (dev->interrupt) {
 307                 mutex_lock(&dev->interrupt_mutex);
 308                 usb_kill_urb(dev->interrupt);
 309                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 310                 mutex_unlock(&dev->interrupt_mutex);
 311         }
 312 }
 313
 314 /* Passes this packet up the stack, updating its accounting.
 315  * Some link protocols batch packets, so their rx_fixup paths
 316  * can return clones as well as just modify the original skb.
 317  */
 318 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 319 {
 320         int     status;
 321
 322         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 323                 skb_queue_tail(&dev->rxq_pause, skb);
 324                 return;
 325         }
 326
 327         /* only update if unset to allow minidriver rx_fixup override */
 328         if (skb->protocol == 0)
 329                 skb->protocol = eth_type_trans (skb, dev->net);
 330
 331         dev->net->stats.rx_packets++;
 332         dev->net->stats.rx_bytes += skb->len;
 333
 334         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 335                   skb->len + sizeof (struct ethhdr), skb->protocol);
 336         memset (skb->cb, 0, sizeof (struct skb_data));
 337
 338         if (skb_defer_rx_timestamp(skb))
 339                 return;
 340
 341         status = netif_rx (skb);
 342         if (status != NET_RX_SUCCESS)
 343                 netif_dbg(dev, rx_err, dev->net,
 344                           "netif_rx status %d\n", status);
 345 }
 346 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 347
 348 /* must be called if hard_mtu or rx_urb_size changed */
 349 void usbnet_update_max_qlen(struct usbnet *dev)
 350 {
 351         enum usb_device_speed speed = dev->udev->speed;
 352
 353         switch (speed) {
 354         case USB_SPEED_HIGH:
 355                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 356                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 357                 break;
 358         case USB_SPEED_SUPER:
 359         case USB_SPEED_SUPER_PLUS:
 360                 /*
 361                  * Not take default 5ms qlen for super speed HC to
 362                  * save memory, and iperf tests show 2.5ms qlen can
 363                  * work well
 364                  */
 365                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 366                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 367                 break;
 368         default:
 369                 dev->rx_qlen = dev->tx_qlen = 4;
 370         }
 371 }
 372 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 373
 374 \f
 375 /*-------------------------------------------------------------------------
 376  *
 377  * Network Device Driver (peer link to "Host Device", from USB host)
 378  *
 379  *-------------------------------------------------------------------------*/
 380
 381 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 382 {
 383         struct usbnet   *dev = netdev_priv(net);
 384         int             ll_mtu = new_mtu + net->hard_header_len;
 385         int             old_hard_mtu = dev->hard_mtu;
 386         int             old_rx_urb_size = dev->rx_urb_size;
 387
 388         if (new_mtu <= 0)
 389                 return -EINVAL;
 390         // no second zero-length packet read wanted after mtu-sized packets
 391         if ((ll_mtu % dev->maxpacket) == 0)
 392                 return -EDOM;
 393         net->mtu = new_mtu;
 394
 395         dev->hard_mtu = net->mtu + net->hard_header_len;
 396         if (dev->rx_urb_size == old_hard_mtu) {
 397                 dev->rx_urb_size = dev->hard_mtu;
 398                 if (dev->rx_urb_size > old_rx_urb_size) {
 399                         usbnet_pause_rx(dev);
 400                         usbnet_unlink_rx_urbs(dev);
 401                         usbnet_resume_rx(dev);
 402                 }
 403         }
 404
 405         /* max qlen depend on hard_mtu and rx_urb_size */
 406         usbnet_update_max_qlen(dev);
 407
 408         return 0;
 409 }
 410 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 411
 412 /* The caller must hold list->lock */
 413 static void __usbnet_queue_skb(struct sk_buff_head *list,
 414                         struct sk_buff *newsk, enum skb_state state)
 415 {
 416         struct skb_data *entry = (struct skb_data *) newsk->cb;
 417
 418         __skb_queue_tail(list, newsk);
 419         entry->state = state;
 420 }
 421
 422 /*-------------------------------------------------------------------------*/
 423
 424 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 425  * completion callbacks.  2.5 should have fixed those bugs...
 426  */
 427
 428 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 429                 struct sk_buff_head *list, enum skb_state state)
 430 {
 431         unsigned long           flags;
 432         enum skb_state          old_state;
 433         struct skb_data *entry = (struct skb_data *) skb->cb;
 434
 435         spin_lock_irqsave(&list->lock, flags);
 436         old_state = entry->state;
 437         entry->state = state;
 438         __skb_unlink(skb, list);
 439
 440         /* defer_bh() is never called with list == &dev->done.
 441          * spin_lock_nested() tells lockdep that it is OK to take
 442          * dev->done.lock here with list->lock held.
 443          */
 444         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 445
 446         __skb_queue_tail(&dev->done, skb);
 447         if (dev->done.qlen == 1)
 448                 tasklet_schedule(&dev->bh);
 449         spin_unlock(&dev->done.lock);
 450         spin_unlock_irqrestore(&list->lock, flags);
 451         return old_state;
 452 }
 453
 454 /* some work can't be done in tasklets, so we use keventd
 455  *
 456  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 457  * but tasklet_schedule() doesn't.  hope the failure is rare.
 458  */
 459 void usbnet_defer_kevent (struct usbnet *dev, int work)
 460 {
 461         set_bit (work, &dev->flags);
 462         if (!schedule_work (&dev->kevent)) {
 463                 if (net_ratelimit())
 464                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 465         } else {
 466                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 467         }
 468 }
 469 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 470
 471 /*-------------------------------------------------------------------------*/
 472
 473 static void rx_complete (struct urb *urb);
 474
 475 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 476 {
 477         struct sk_buff          *skb;
 478         struct skb_data         *entry;
 479         int                     retval = 0;
 480         unsigned long           lockflags;
 481         size_t                  size = dev->rx_urb_size;
 482
 483         /* prevent rx skb allocation when error ratio is high */
 484         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 485                 usb_free_urb(urb);
 486                 return -ENOLINK;
 487         }
 488
 489         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 490         if (!skb) {
 491                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 492                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 493                 usb_free_urb (urb);
 494                 return -ENOMEM;
 495         }
 496
 497         entry = (struct skb_data *) skb->cb;
 498         entry->urb = urb;
 499         entry->dev = dev;
 500         entry->length = 0;
 501
 502         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 503                 skb->data, size, rx_complete, skb);
 504
 505         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 506
 507         if (netif_running (dev->net) &&
 508             netif_device_present (dev->net) &&
 509             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 510             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 511                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 512                 case -EPIPE:
 513                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 514                         break;
 515                 case -ENOMEM:
 516                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 517                         break;
 518                 case -ENODEV:
 519                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 520                         netif_device_detach (dev->net);
 521                         break;
 522                 case -EHOSTUNREACH:
 523                         retval = -ENOLINK;
 524                         break;
 525                 default:
 526                         netif_dbg(dev, rx_err, dev->net,
 527                                   "rx submit, %d\n", retval);
 528                         tasklet_schedule (&dev->bh);
 529                         break;
 530                 case 0:
 531                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 532                 }
 533         } else {
 534                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 535                 retval = -ENOLINK;
 536         }
 537         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 538         if (retval) {
 539                 dev_kfree_skb_any (skb);
 540                 usb_free_urb (urb);
 541         }
 542         return retval;
 543 }
 544
 545
 546 /*-------------------------------------------------------------------------*/
 547
 548 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 549 {
 550         if (dev->driver_info->rx_fixup &&
 551             !dev->driver_info->rx_fixup (dev, skb)) {
 552                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 553                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 554                         dev->net->stats.rx_errors++;
 555                 goto done;
 556         }
 557         // else network stack removes extra byte if we forced a short packet
 558
 559         /* all data was already cloned from skb inside the driver */
 560         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 561                 goto done;
 562
 563         if (skb->len < ETH_HLEN) {
 564                 dev->net->stats.rx_errors++;
 565                 dev->net->stats.rx_length_errors++;
 566                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 567         } else {
 568                 usbnet_skb_return(dev, skb);
 569                 return;
 570         }
 571
 572 done:
 573         skb_queue_tail(&dev->done, skb);
 574 }
 575
 576 /*-------------------------------------------------------------------------*/
 577
 578 static void rx_complete (struct urb *urb)
 579 {
 580         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 581         struct skb_data         *entry = (struct skb_data *) skb->cb;
 582         struct usbnet           *dev = entry->dev;
 583         int                     urb_status = urb->status;
 584         enum skb_state          state;
 585
 586         skb_put (skb, urb->actual_length);
 587         state = rx_done;
 588         entry->urb = NULL;
 589
 590         switch (urb_status) {
 591         /* success */
 592         case 0:
 593                 break;
 594
 595         /* stalls need manual reset. this is rare ... except that
 596          * when going through USB 2.0 TTs, unplug appears this way.
 597          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 598          * storm, recovering as needed.
 599          */
 600         case -EPIPE:
 601                 dev->net->stats.rx_errors++;
 602                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 603                 // FALLTHROUGH
 604
 605         /* software-driven interface shutdown */
 606         case -ECONNRESET:               /* async unlink */
 607         case -ESHUTDOWN:                /* hardware gone */
 608                 netif_dbg(dev, ifdown, dev->net,
 609                           "rx shutdown, code %d\n", urb_status);
 610                 goto block;
 611
 612         /* we get controller i/o faults during hub_wq disconnect() delays.
 613          * throttle down resubmits, to avoid log floods; just temporarily,
 614          * so we still recover when the fault isn't a hub_wq delay.
 615          */
 616         case -EPROTO:
 617         case -ETIME:
 618         case -EILSEQ:
 619                 dev->net->stats.rx_errors++;
 620                 if (!timer_pending (&dev->delay)) {
 621                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 622                         netif_dbg(dev, link, dev->net,
 623                                   "rx throttle %d\n", urb_status);
 624                 }
 625 block:
 626                 state = rx_cleanup;
 627                 entry->urb = urb;
 628                 urb = NULL;
 629                 break;
 630
 631         /* data overrun ... flush fifo? */
 632         case -EOVERFLOW:
 633                 dev->net->stats.rx_over_errors++;
 634                 // FALLTHROUGH
 635
 636         default:
 637                 state = rx_cleanup;
 638                 dev->net->stats.rx_errors++;
 639                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 640                 break;
 641         }
 642
 643         /* stop rx if packet error rate is high */
 644         if (++dev->pkt_cnt > 30) {
 645                 dev->pkt_cnt = 0;
 646                 dev->pkt_err = 0;
 647         } else {
 648                 if (state == rx_cleanup)
 649                         dev->pkt_err++;
 650                 if (dev->pkt_err > 20)
 651                         set_bit(EVENT_RX_KILL, &dev->flags);
 652         }
 653
 654         state = defer_bh(dev, skb, &dev->rxq, state);
 655
 656         if (urb) {
 657                 if (netif_running (dev->net) &&
 658                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 659                     state != unlink_start) {
 660                         rx_submit (dev, urb, GFP_ATOMIC);
 661                         usb_mark_last_busy(dev->udev);
 662                         return;
 663                 }
 664                 usb_free_urb (urb);
 665         }
 666         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 667 }
 668
 669 /*-------------------------------------------------------------------------*/
 670 void usbnet_pause_rx(struct usbnet *dev)
 671 {
 672         set_bit(EVENT_RX_PAUSED, &dev->flags);
 673
 674         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 675 }
 676 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 677
 678 void usbnet_resume_rx(struct usbnet *dev)
 679 {
 680         struct sk_buff *skb;
 681         int num = 0;
 682
 683         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 686                 usbnet_skb_return(dev, skb);
 687                 num++;
 688         }
 689
 690         tasklet_schedule(&dev->bh);
 691
 692         netif_dbg(dev, rx_status, dev->net,
 693                   "paused rx queue disabled, %d skbs requeued\n", num);
 694 }
 695 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 696
 697 void usbnet_purge_paused_rxq(struct usbnet *dev)
 698 {
 699         skb_queue_purge(&dev->rxq_pause);
 700 }
 701 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 702
 703 /*-------------------------------------------------------------------------*/
 704
 705 // unlink pending rx/tx; completion handlers do all other cleanup
 706
 707 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 708 {
 709         unsigned long           flags;
 710         struct sk_buff          *skb;
 711         int                     count = 0;
 712
 713         spin_lock_irqsave (&q->lock, flags);
 714         while (!skb_queue_empty(q)) {
 715                 struct skb_data         *entry;
 716                 struct urb              *urb;
 717                 int                     retval;
 718
 719                 skb_queue_walk(q, skb) {
 720                         entry = (struct skb_data *) skb->cb;
 721                         if (entry->state != unlink_start)
 722                                 goto found;
 723                 }
 724                 break;
 725 found:
 726                 entry->state = unlink_start;
 727                 urb = entry->urb;
 728
 729                 /*
 730                  * Get reference count of the URB to avoid it to be
 731                  * freed during usb_unlink_urb, which may trigger
 732                  * use-after-free problem inside usb_unlink_urb since
 733                  * usb_unlink_urb is always racing with .complete
 734                  * handler(include defer_bh).
 735                  */
 736                 usb_get_urb(urb);
 737                 spin_unlock_irqrestore(&q->lock, flags);
 738                 // during some PM-driven resume scenarios,
 739                 // these (async) unlinks complete immediately
 740                 retval = usb_unlink_urb (urb);
 741                 if (retval != -EINPROGRESS && retval != 0)
 742                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 743                 else
 744                         count++;
 745                 usb_put_urb(urb);
 746                 spin_lock_irqsave(&q->lock, flags);
 747         }
 748         spin_unlock_irqrestore (&q->lock, flags);
 749         return count;
 750 }
 751
 752 // Flush all pending rx urbs
 753 // minidrivers may need to do this when the MTU changes
 754
 755 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 756 {
 757         if (netif_running(dev->net)) {
 758                 (void) unlink_urbs (dev, &dev->rxq);
 759                 tasklet_schedule(&dev->bh);
 760         }
 761 }
 762 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 763
 764 /*-------------------------------------------------------------------------*/
 765
 766 static void wait_skb_queue_empty(struct sk_buff_head *q)
 767 {
 768         unsigned long flags;
 769
 770         spin_lock_irqsave(&q->lock, flags);
 771         while (!skb_queue_empty(q)) {
 772                 spin_unlock_irqrestore(&q->lock, flags);
 773                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 774                 set_current_state(TASK_UNINTERRUPTIBLE);
 775                 spin_lock_irqsave(&q->lock, flags);
 776         }
 777         spin_unlock_irqrestore(&q->lock, flags);
 778 }
 779
 780 // precondition: never called in_interrupt
 781 static void usbnet_terminate_urbs(struct usbnet *dev)
 782 {
 783         DECLARE_WAITQUEUE(wait, current);
 784         int temp;
 785
 786         /* ensure there are no more active urbs */
 787         add_wait_queue(&dev->wait, &wait);
 788         set_current_state(TASK_UNINTERRUPTIBLE);
 789         temp = unlink_urbs(dev, &dev->txq) +
 790                 unlink_urbs(dev, &dev->rxq);
 791
 792         /* maybe wait for deletions to finish. */
 793         wait_skb_queue_empty(&dev->rxq);
 794         wait_skb_queue_empty(&dev->txq);
 795         wait_skb_queue_empty(&dev->done);
 796         netif_dbg(dev, ifdown, dev->net,
 797                   "waited for %d urb completions\n", temp);
 798         set_current_state(TASK_RUNNING);
 799         remove_wait_queue(&dev->wait, &wait);
 800 }
 801
 802 int usbnet_stop (struct net_device *net)
 803 {
 804         struct usbnet           *dev = netdev_priv(net);
 805         struct driver_info      *info = dev->driver_info;
 806         int                     retval, pm, mpn;
 807
 808         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 809         netif_stop_queue (net);
 810
 811         netif_info(dev, ifdown, dev->net,
 812                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 813                    net->stats.rx_packets, net->stats.tx_packets,
 814                    net->stats.rx_errors, net->stats.tx_errors);
 815
 816         /* to not race resume */
 817         pm = usb_autopm_get_interface(dev->intf);
 818         /* allow minidriver to stop correctly (wireless devices to turn off
 819          * radio etc) */
 820         if (info->stop) {
 821                 retval = info->stop(dev);
 822                 if (retval < 0)
 823                         netif_info(dev, ifdown, dev->net,
 824                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 825                                    retval,
 826                                    dev->udev->bus->bus_name, dev->udev->devpath,
 827                                    info->description);
 828         }
 829
 830         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 831                 usbnet_terminate_urbs(dev);
 832
 833         usbnet_status_stop(dev);
 834
 835         usbnet_purge_paused_rxq(dev);
 836
 837         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 838
 839         /* deferred work (task, timer, softirq) must also stop.
 840          * can't flush_scheduled_work() until we drop rtnl (later),
 841          * else workers could deadlock; so make workers a NOP.
 842          */
 843         dev->flags = 0;
 844         del_timer_sync (&dev->delay);
 845         tasklet_kill (&dev->bh);
 846         if (!pm)
 847                 usb_autopm_put_interface(dev->intf);
 848
 849         if (info->manage_power && mpn)
 850                 info->manage_power(dev, 0);
 851         else
 852                 usb_autopm_put_interface(dev->intf);
 853
 854         return 0;
 855 }
 856 EXPORT_SYMBOL_GPL(usbnet_stop);
 857
 858 /*-------------------------------------------------------------------------*/
 859
 860 // posts reads, and enables write queuing
 861
 862 // precondition: never called in_interrupt
 863
 864 int usbnet_open (struct net_device *net)
 865 {
 866         struct usbnet           *dev = netdev_priv(net);
 867         int                     retval;
 868         struct driver_info      *info = dev->driver_info;
 869
 870         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 871                 netif_info(dev, ifup, dev->net,
 872                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 873                            retval,
 874                            dev->udev->bus->bus_name,
 875                            dev->udev->devpath,
 876                            info->description);
 877                 goto done_nopm;
 878         }
 879
 880         // put into "known safe" state
 881         if (info->reset && (retval = info->reset (dev)) < 0) {
 882                 netif_info(dev, ifup, dev->net,
 883                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 884                            retval,
 885                            dev->udev->bus->bus_name,
 886                            dev->udev->devpath,
 887                            info->description);
 888                 goto done;
 889         }
 890
 891         /* hard_mtu or rx_urb_size may change in reset() */
 892         usbnet_update_max_qlen(dev);
 893
 894         // insist peer be connected
 895         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 896                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 897                 goto done;
 898         }
 899
 900         /* start any status interrupt transfer */
 901         if (dev->interrupt) {
 902                 retval = usbnet_status_start(dev, GFP_KERNEL);
 903                 if (retval < 0) {
 904                         netif_err(dev, ifup, dev->net,
 905                                   "intr submit %d\n", retval);
 906                         goto done;
 907                 }
 908         }
 909
 910         set_bit(EVENT_DEV_OPEN, &dev->flags);
 911         netif_start_queue (net);
 912         netif_info(dev, ifup, dev->net,
 913                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 914                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 915                    dev->net->mtu,
 916                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 917                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 918                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 919                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 920                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 921                    "simple");
 922
 923         /* reset rx error state */
 924         dev->pkt_cnt = 0;
 925         dev->pkt_err = 0;
 926         clear_bit(EVENT_RX_KILL, &dev->flags);
 927
 928         // delay posting reads until we're fully open
 929         tasklet_schedule (&dev->bh);
 930         if (info->manage_power) {
 931                 retval = info->manage_power(dev, 1);
 932                 if (retval < 0) {
 933                         retval = 0;
 934                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 935                 } else {
 936                         usb_autopm_put_interface(dev->intf);
 937                 }
 938         }
 939         return retval;
 940 done:
 941         usb_autopm_put_interface(dev->intf);
 942 done_nopm:
 943         return retval;
 944 }
 945 EXPORT_SYMBOL_GPL(usbnet_open);
 946
 947 /*-------------------------------------------------------------------------*/
 948
 949 /* ethtool methods; minidrivers may need to add some more, but
 950  * they'll probably want to use this base set.
 951  */
 952
 953 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 954 {
 955         struct usbnet *dev = netdev_priv(net);
 956
 957         if (!dev->mii.mdio_read)
 958                 return -EOPNOTSUPP;
 959
 960         return mii_ethtool_gset(&dev->mii, cmd);
 961 }
 962 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 963
 964 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 965 {
 966         struct usbnet *dev = netdev_priv(net);
 967         int retval;
 968
 969         if (!dev->mii.mdio_write)
 970                 return -EOPNOTSUPP;
 971
 972         retval = mii_ethtool_sset(&dev->mii, cmd);
 973
 974         /* link speed/duplex might have changed */
 975         if (dev->driver_info->link_reset)
 976                 dev->driver_info->link_reset(dev);
 977
 978         /* hard_mtu or rx_urb_size may change in link_reset() */
 979         usbnet_update_max_qlen(dev);
 980
 981         return retval;
 982
 983 }
 984 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 985
 986 u32 usbnet_get_link (struct net_device *net)
 987 {
 988         struct usbnet *dev = netdev_priv(net);
 989
 990         /* If a check_connect is defined, return its result */
 991         if (dev->driver_info->check_connect)
 992                 return dev->driver_info->check_connect (dev) == 0;
 993
 994         /* if the device has mii operations, use those */
 995         if (dev->mii.mdio_read)
 996                 return mii_link_ok(&dev->mii);
 997
 998         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 999         return ethtool_op_get_link(net);
1000 }
1001 EXPORT_SYMBOL_GPL(usbnet_get_link);
1002
1003 int usbnet_nway_reset(struct net_device *net)
1004 {
1005         struct usbnet *dev = netdev_priv(net);
1006
1007         if (!dev->mii.mdio_write)
1008                 return -EOPNOTSUPP;
1009
1010         return mii_nway_restart(&dev->mii);
1011 }
1012 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1013
1014 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1015 {
1016         struct usbnet *dev = netdev_priv(net);
1017
1018         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1019         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1020         strlcpy (info->fw_version, dev->driver_info->description,
1021                 sizeof info->fw_version);
1022         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1023 }
1024 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1025
1026 u32 usbnet_get_msglevel (struct net_device *net)
1027 {
1028         struct usbnet *dev = netdev_priv(net);
1029
1030         return dev->msg_enable;
1031 }
1032 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1033
1034 void usbnet_set_msglevel (struct net_device *net, u32 level)
1035 {
1036         struct usbnet *dev = netdev_priv(net);
1037
1038         dev->msg_enable = level;
1039 }
1040 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1041
1042 /* drivers may override default ethtool_ops in their bind() routine */
1043 static const struct ethtool_ops usbnet_ethtool_ops = {
1044         .get_settings           = usbnet_get_settings,
1045         .set_settings           = usbnet_set_settings,
1046         .get_link               = usbnet_get_link,
1047         .nway_reset             = usbnet_nway_reset,
1048         .get_drvinfo            = usbnet_get_drvinfo,
1049         .get_msglevel           = usbnet_get_msglevel,
1050         .set_msglevel           = usbnet_set_msglevel,
1051         .get_ts_info            = ethtool_op_get_ts_info,
1052 };
1053
1054 /*-------------------------------------------------------------------------*/
1055
1056 static void __handle_link_change(struct usbnet *dev)
1057 {
1058         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1059                 return;
1060
1061         if (!netif_carrier_ok(dev->net)) {
1062                 /* kill URBs for reading packets to save bus bandwidth */
1063                 unlink_urbs(dev, &dev->rxq);
1064
1065                 /*
1066                  * tx_timeout will unlink URBs for sending packets and
1067                  * tx queue is stopped by netcore after link becomes off
1068                  */
1069         } else {
1070                 /* submitting URBs for reading packets */
1071                 tasklet_schedule(&dev->bh);
1072         }
1073
1074         /* hard_mtu or rx_urb_size may change during link change */
1075         usbnet_update_max_qlen(dev);
1076
1077         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1078 }
1079
1080 static void usbnet_set_rx_mode(struct net_device *net)
1081 {
1082         struct usbnet           *dev = netdev_priv(net);
1083
1084         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1085 }
1086
1087 static void __handle_set_rx_mode(struct usbnet *dev)
1088 {
1089         if (dev->driver_info->set_rx_mode)
1090                 (dev->driver_info->set_rx_mode)(dev);
1091
1092         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1093 }
1094
1095 /* work that cannot be done in interrupt context uses keventd.
1096  *
1097  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1098  * especially now that control transfers can be queued.
1099  */
1100 static void
1101 usbnet_deferred_kevent (struct work_struct *work)
1102 {
1103         struct usbnet           *dev =
1104                 container_of(work, struct usbnet, kevent);
1105         int                     status;
1106
1107         /* usb_clear_halt() needs a thread context */
1108         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1109                 unlink_urbs (dev, &dev->txq);
1110                 status = usb_autopm_get_interface(dev->intf);
1111                 if (status < 0)
1112                         goto fail_pipe;
1113                 status = usb_clear_halt (dev->udev, dev->out);
1114                 usb_autopm_put_interface(dev->intf);
1115                 if (status < 0 &&
1116                     status != -EPIPE &&
1117                     status != -ESHUTDOWN) {
1118                         if (netif_msg_tx_err (dev))
1119 fail_pipe:
1120                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1121                                            status);
1122                 } else {
1123                         clear_bit (EVENT_TX_HALT, &dev->flags);
1124                         if (status != -ESHUTDOWN)
1125                                 netif_wake_queue (dev->net);
1126                 }
1127         }
1128         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1129                 unlink_urbs (dev, &dev->rxq);
1130                 status = usb_autopm_get_interface(dev->intf);
1131                 if (status < 0)
1132                         goto fail_halt;
1133                 status = usb_clear_halt (dev->udev, dev->in);
1134                 usb_autopm_put_interface(dev->intf);
1135                 if (status < 0 &&
1136                     status != -EPIPE &&
1137                     status != -ESHUTDOWN) {
1138                         if (netif_msg_rx_err (dev))
1139 fail_halt:
1140                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1141                                            status);
1142                 } else {
1143                         clear_bit (EVENT_RX_HALT, &dev->flags);
1144                         tasklet_schedule (&dev->bh);
1145                 }
1146         }
1147
1148         /* tasklet could resubmit itself forever if memory is tight */
1149         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1150                 struct urb      *urb = NULL;
1151                 int resched = 1;
1152
1153                 if (netif_running (dev->net))
1154                         urb = usb_alloc_urb (0, GFP_KERNEL);
1155                 else
1156                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1157                 if (urb != NULL) {
1158                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1159                         status = usb_autopm_get_interface(dev->intf);
1160                         if (status < 0) {
1161                                 usb_free_urb(urb);
1162                                 goto fail_lowmem;
1163                         }
1164                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1165                                 resched = 0;
1166                         usb_autopm_put_interface(dev->intf);
1167 fail_lowmem:
1168                         if (resched)
1169                                 tasklet_schedule (&dev->bh);
1170                 }
1171         }
1172
1173         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1174                 struct driver_info      *info = dev->driver_info;
1175                 int                     retval = 0;
1176
1177                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1178                 status = usb_autopm_get_interface(dev->intf);
1179                 if (status < 0)
1180                         goto skip_reset;
1181                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1182                         usb_autopm_put_interface(dev->intf);
1183 skip_reset:
1184                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1185                                     retval,
1186                                     dev->udev->bus->bus_name,
1187                                     dev->udev->devpath,
1188                                     info->description);
1189                 } else {
1190                         usb_autopm_put_interface(dev->intf);
1191                 }
1192
1193                 /* handle link change from link resetting */
1194                 __handle_link_change(dev);
1195         }
1196
1197         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1198                 __handle_link_change(dev);
1199
1200         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1201                 __handle_set_rx_mode(dev);
1202
1203
1204         if (dev->flags)
1205                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1206 }
1207
1208 /*-------------------------------------------------------------------------*/
1209
1210 static void tx_complete (struct urb *urb)
1211 {
1212         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1213         struct skb_data         *entry = (struct skb_data *) skb->cb;
1214         struct usbnet           *dev = entry->dev;
1215
1216         if (urb->status == 0) {
1217                 dev->net->stats.tx_packets += entry->packets;
1218                 dev->net->stats.tx_bytes += entry->length;
1219         } else {
1220                 dev->net->stats.tx_errors++;
1221
1222                 switch (urb->status) {
1223                 case -EPIPE:
1224                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1225                         break;
1226
1227                 /* software-driven interface shutdown */
1228                 case -ECONNRESET:               // async unlink
1229                 case -ESHUTDOWN:                // hardware gone
1230                         break;
1231
1232                 /* like rx, tx gets controller i/o faults during hub_wq
1233                  * delays and so it uses the same throttling mechanism.
1234                  */
1235                 case -EPROTO:
1236                 case -ETIME:
1237                 case -EILSEQ:
1238                         usb_mark_last_busy(dev->udev);
1239                         if (!timer_pending (&dev->delay)) {
1240                                 mod_timer (&dev->delay,
1241                                         jiffies + THROTTLE_JIFFIES);
1242                                 netif_dbg(dev, link, dev->net,
1243                                           "tx throttle %d\n", urb->status);
1244                         }
1245                         netif_stop_queue (dev->net);
1246                         break;
1247                 default:
1248                         netif_dbg(dev, tx_err, dev->net,
1249                                   "tx err %d\n", entry->urb->status);
1250                         break;
1251                 }
1252         }
1253
1254         usb_autopm_put_interface_async(dev->intf);
1255         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1256 }
1257
1258 /*-------------------------------------------------------------------------*/
1259
1260 void usbnet_tx_timeout (struct net_device *net)
1261 {
1262         struct usbnet           *dev = netdev_priv(net);
1263
1264         unlink_urbs (dev, &dev->txq);
1265         tasklet_schedule (&dev->bh);
1266         /* this needs to be handled individually because the generic layer
1267          * doesn't know what is sufficient and could not restore private
1268          * information if a remedy of an unconditional reset were used.
1269          */
1270         if (dev->driver_info->recover)
1271                 (dev->driver_info->recover)(dev);
1272 }
1273 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1274
1275 /*-------------------------------------------------------------------------*/
1276
1277 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1278 {
1279         unsigned num_sgs, total_len = 0;
1280         int i, s = 0;
1281
1282         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1283         if (num_sgs == 1)
1284                 return 0;
1285
1286         /* reserve one for zero packet */
1287         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1288                           GFP_ATOMIC);
1289         if (!urb->sg)
1290                 return -ENOMEM;
1291
1292         urb->num_sgs = num_sgs;
1293         sg_init_table(urb->sg, urb->num_sgs + 1);
1294
1295         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1296         total_len += skb_headlen(skb);
1297
1298         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1299                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1300
1301                 total_len += skb_frag_size(f);
1302                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1303                                 f->page_offset);
1304         }
1305         urb->transfer_buffer_length = total_len;
1306
1307         return 1;
1308 }
1309
1310 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1311                                      struct net_device *net)
1312 {
1313         struct usbnet           *dev = netdev_priv(net);
1314         unsigned int                    length;
1315         struct urb              *urb = NULL;
1316         struct skb_data         *entry;
1317         struct driver_info      *info = dev->driver_info;
1318         unsigned long           flags;
1319         int retval;
1320
1321         if (skb)
1322                 skb_tx_timestamp(skb);
1323
1324         // some devices want funky USB-level framing, for
1325         // win32 driver (usually) and/or hardware quirks
1326         if (info->tx_fixup) {
1327                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1328                 if (!skb) {
1329                         /* packet collected; minidriver waiting for more */
1330                         if (info->flags & FLAG_MULTI_PACKET)
1331                                 goto not_drop;
1332                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1333                         goto drop;
1334                 }
1335         }
1336
1337         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1338                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1339                 goto drop;
1340         }
1341
1342         entry = (struct skb_data *) skb->cb;
1343         entry->urb = urb;
1344         entry->dev = dev;
1345
1346         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1347                         skb->data, skb->len, tx_complete, skb);
1348         if (dev->can_dma_sg) {
1349                 if (build_dma_sg(skb, urb) < 0)
1350                         goto drop;
1351         }
1352         length = urb->transfer_buffer_length;
1353
1354         /* don't assume the hardware handles USB_ZERO_PACKET
1355          * NOTE:  strictly conforming cdc-ether devices should expect
1356          * the ZLP here, but ignore the one-byte packet.
1357          * NOTE2: CDC NCM specification is different from CDC ECM when
1358          * handling ZLP/short packets, so cdc_ncm driver will make short
1359          * packet itself if needed.
1360          */
1361         if (length % dev->maxpacket == 0) {
1362                 if (!(info->flags & FLAG_SEND_ZLP)) {
1363                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1364                                 length++;
1365                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1366                                         skb->data[skb->len] = 0;
1367                                         __skb_put(skb, 1);
1368                                 } else if (urb->num_sgs)
1369                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1370                                                         dev->padding_pkt, 1);
1371                         }
1372                 } else
1373                         urb->transfer_flags |= URB_ZERO_PACKET;
1374         }
1375         urb->transfer_buffer_length = length;
1376
1377         if (info->flags & FLAG_MULTI_PACKET) {
1378                 /* Driver has set number of packets and a length delta.
1379                  * Calculate the complete length and ensure that it's
1380                  * positive.
1381                  */
1382                 entry->length += length;
1383                 if (WARN_ON_ONCE(entry->length <= 0))
1384                         entry->length = length;
1385         } else {
1386                 usbnet_set_skb_tx_stats(skb, 1, length);
1387         }
1388
1389         spin_lock_irqsave(&dev->txq.lock, flags);
1390         retval = usb_autopm_get_interface_async(dev->intf);
1391         if (retval < 0) {
1392                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1393                 goto drop;
1394         }
1395
1396 #ifdef CONFIG_PM
1397         /* if this triggers the device is still a sleep */
1398         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1399                 /* transmission will be done in resume */
1400                 usb_anchor_urb(urb, &dev->deferred);
1401                 /* no use to process more packets */
1402                 netif_stop_queue(net);
1403                 usb_put_urb(urb);
1404                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1405                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1406                 goto deferred;
1407         }
1408 #endif
1409
1410         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1411         case -EPIPE:
1412                 netif_stop_queue (net);
1413                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1414                 usb_autopm_put_interface_async(dev->intf);
1415                 break;
1416         default:
1417                 usb_autopm_put_interface_async(dev->intf);
1418                 netif_dbg(dev, tx_err, dev->net,
1419                           "tx: submit urb err %d\n", retval);
1420                 break;
1421         case 0:
1422                 netif_trans_update(net);
1423                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1424                 if (dev->txq.qlen >= TX_QLEN (dev))
1425                         netif_stop_queue (net);
1426         }
1427         spin_unlock_irqrestore (&dev->txq.lock, flags);
1428
1429         if (retval) {
1430                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1431 drop:
1432                 dev->net->stats.tx_dropped++;
1433 not_drop:
1434                 if (skb)
1435                         dev_kfree_skb_any (skb);
1436                 if (urb) {
1437                         kfree(urb->sg);
1438                         usb_free_urb(urb);
1439                 }
1440         } else
1441                 netif_dbg(dev, tx_queued, dev->net,
1442                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1443 #ifdef CONFIG_PM
1444 deferred:
1445 #endif
1446         return NETDEV_TX_OK;
1447 }
1448 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1449
1450 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1451 {
1452         struct urb      *urb;
1453         int             i;
1454         int             ret = 0;
1455
1456         /* don't refill the queue all at once */
1457         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1458                 urb = usb_alloc_urb(0, flags);
1459                 if (urb != NULL) {
1460                         ret = rx_submit(dev, urb, flags);
1461                         if (ret)
1462                                 goto err;
1463                 } else {
1464                         ret = -ENOMEM;
1465                         goto err;
1466                 }
1467         }
1468 err:
1469         return ret;
1470 }
1471
1472 /*-------------------------------------------------------------------------*/
1473
1474 // tasklet (work deferred from completions, in_irq) or timer
1475
1476 static void usbnet_bh (unsigned long param)
1477 {
1478         struct usbnet           *dev = (struct usbnet *) param;
1479         struct sk_buff          *skb;
1480         struct skb_data         *entry;
1481
1482         while ((skb = skb_dequeue (&dev->done))) {
1483                 entry = (struct skb_data *) skb->cb;
1484                 switch (entry->state) {
1485                 case rx_done:
1486                         entry->state = rx_cleanup;
1487                         rx_process (dev, skb);
1488                         continue;
1489                 case tx_done:
1490                         kfree(entry->urb->sg);
1491                 case rx_cleanup:
1492                         usb_free_urb (entry->urb);
1493                         dev_kfree_skb (skb);
1494                         continue;
1495                 default:
1496                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1497                 }
1498         }
1499
1500         /* restart RX again after disabling due to high error rate */
1501         clear_bit(EVENT_RX_KILL, &dev->flags);
1502
1503         /* waiting for all pending urbs to complete?
1504          * only then can we forgo submitting anew
1505          */
1506         if (waitqueue_active(&dev->wait)) {
1507                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1508                         wake_up_all(&dev->wait);
1509
1510         // or are we maybe short a few urbs?
1511         } else if (netif_running (dev->net) &&
1512                    netif_device_present (dev->net) &&
1513                    netif_carrier_ok(dev->net) &&
1514                    !timer_pending(&dev->delay) &&
1515                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1516                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1517                 int     temp = dev->rxq.qlen;
1518
1519                 if (temp < RX_QLEN(dev)) {
1520                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1521                                 return;
1522                         if (temp != dev->rxq.qlen)
1523                                 netif_dbg(dev, link, dev->net,
1524                                           "rxqlen %d --> %d\n",
1525                                           temp, dev->rxq.qlen);
1526                         if (dev->rxq.qlen < RX_QLEN(dev))
1527                                 tasklet_schedule (&dev->bh);
1528                 }
1529                 if (dev->txq.qlen < TX_QLEN (dev))
1530                         netif_wake_queue (dev->net);
1531         }
1532 }
1533
1534
1535 /*-------------------------------------------------------------------------
1536  *
1537  * USB Device Driver support
1538  *
1539  *-------------------------------------------------------------------------*/
1540
1541 // precondition: never called in_interrupt
1542
1543 void usbnet_disconnect (struct usb_interface *intf)
1544 {
1545         struct usbnet           *dev;
1546         struct usb_device       *xdev;
1547         struct net_device       *net;
1548
1549         dev = usb_get_intfdata(intf);
1550         usb_set_intfdata(intf, NULL);
1551         if (!dev)
1552                 return;
1553
1554         xdev = interface_to_usbdev (intf);
1555
1556         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1557                    intf->dev.driver->name,
1558                    xdev->bus->bus_name, xdev->devpath,
1559                    dev->driver_info->description);
1560
1561         net = dev->net;
1562         unregister_netdev (net);
1563
1564         cancel_work_sync(&dev->kevent);
1565
1566         usb_scuttle_anchored_urbs(&dev->deferred);
1567
1568         if (dev->driver_info->unbind)
1569                 dev->driver_info->unbind (dev, intf);
1570
1571         usb_kill_urb(dev->interrupt);
1572         usb_free_urb(dev->interrupt);
1573         kfree(dev->padding_pkt);
1574
1575         free_netdev(net);
1576 }
1577 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1578
1579 static const struct net_device_ops usbnet_netdev_ops = {
1580         .ndo_open               = usbnet_open,
1581         .ndo_stop               = usbnet_stop,
1582         .ndo_start_xmit         = usbnet_start_xmit,
1583         .ndo_tx_timeout         = usbnet_tx_timeout,
1584         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1585         .ndo_change_mtu         = usbnet_change_mtu,
1586         .ndo_set_mac_address    = eth_mac_addr,
1587         .ndo_validate_addr      = eth_validate_addr,
1588 };
1589
1590 /*-------------------------------------------------------------------------*/
1591
1592 // precondition: never called in_interrupt
1593
1594 static struct device_type wlan_type = {
1595         .name   = "wlan",
1596 };
1597
1598 static struct device_type wwan_type = {
1599         .name   = "wwan",
1600 };
1601
1602 int
1603 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1604 {
1605         struct usbnet                   *dev;
1606         struct net_device               *net;
1607         struct usb_host_interface       *interface;
1608         struct driver_info              *info;
1609         struct usb_device               *xdev;
1610         int                             status;
1611         const char                      *name;
1612         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1613
1614         /* usbnet already took usb runtime pm, so have to enable the feature
1615          * for usb interface, otherwise usb_autopm_get_interface may return
1616          * failure if RUNTIME_PM is enabled.
1617          */
1618         if (!driver->supports_autosuspend) {
1619                 driver->supports_autosuspend = 1;
1620                 pm_runtime_enable(&udev->dev);
1621         }
1622
1623         name = udev->dev.driver->name;
1624         info = (struct driver_info *) prod->driver_info;
1625         if (!info) {
1626                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1627                 return -ENODEV;
1628         }
1629         xdev = interface_to_usbdev (udev);
1630         interface = udev->cur_altsetting;
1631
1632         status = -ENOMEM;
1633
1634         // set up our own records
1635         net = alloc_etherdev(sizeof(*dev));
1636         if (!net)
1637                 goto out;
1638
1639         /* netdev_printk() needs this so do it as early as possible */
1640         SET_NETDEV_DEV(net, &udev->dev);
1641
1642         dev = netdev_priv(net);
1643         dev->udev = xdev;
1644         dev->intf = udev;
1645         dev->driver_info = info;
1646         dev->driver_name = name;
1647         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1648                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1649         init_waitqueue_head(&dev->wait);
1650         skb_queue_head_init (&dev->rxq);
1651         skb_queue_head_init (&dev->txq);
1652         skb_queue_head_init (&dev->done);
1653         skb_queue_head_init(&dev->rxq_pause);
1654         dev->bh.func = usbnet_bh;
1655         dev->bh.data = (unsigned long) dev;
1656         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1657         init_usb_anchor(&dev->deferred);
1658         dev->delay.function = usbnet_bh;
1659         dev->delay.data = (unsigned long) dev;
1660         init_timer (&dev->delay);
1661         mutex_init (&dev->phy_mutex);
1662         mutex_init(&dev->interrupt_mutex);
1663         dev->interrupt_count = 0;
1664
1665         dev->net = net;
1666         strcpy (net->name, "usb%d");
1667         memcpy (net->dev_addr, node_id, sizeof node_id);
1668
1669         /* rx and tx sides can use different message sizes;
1670          * bind() should set rx_urb_size in that case.
1671          */
1672         dev->hard_mtu = net->mtu + net->hard_header_len;
1673
1674         net->netdev_ops = &usbnet_netdev_ops;
1675         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1676         net->ethtool_ops = &usbnet_ethtool_ops;
1677
1678         // allow device-specific bind/init procedures
1679         // NOTE net->name still not usable ...
1680         if (info->bind) {
1681                 status = info->bind (dev, udev);
1682                 if (status < 0)
1683                         goto out1;
1684
1685                 // heuristic:  "usb%d" for links we know are two-host,
1686                 // else "eth%d" when there's reasonable doubt.  userspace
1687                 // can rename the link if it knows better.
1688                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1689                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1690                      (net->dev_addr [0] & 0x02) == 0))
1691                         strcpy (net->name, "eth%d");
1692                 /* WLAN devices should always be named "wlan%d" */
1693                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1694                         strcpy(net->name, "wlan%d");
1695                 /* WWAN devices should always be named "wwan%d" */
1696                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1697                         strcpy(net->name, "wwan%d");
1698
1699                 /* devices that cannot do ARP */
1700                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1701                         net->flags |= IFF_NOARP;
1702
1703                 /* maybe the remote can't receive an Ethernet MTU */
1704                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1705                         net->mtu = dev->hard_mtu - net->hard_header_len;
1706         } else if (!info->in || !info->out)
1707                 status = usbnet_get_endpoints (dev, udev);
1708         else {
1709                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1710                 dev->out = usb_sndbulkpipe (xdev, info->out);
1711                 if (!(info->flags & FLAG_NO_SETINT))
1712                         status = usb_set_interface (xdev,
1713                                 interface->desc.bInterfaceNumber,
1714                                 interface->desc.bAlternateSetting);
1715                 else
1716                         status = 0;
1717
1718         }
1719         if (status >= 0 && dev->status)
1720                 status = init_status (dev, udev);
1721         if (status < 0)
1722                 goto out3;
1723
1724         if (!dev->rx_urb_size)
1725                 dev->rx_urb_size = dev->hard_mtu;
1726         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1727
1728         /* let userspace know we have a random address */
1729         if (ether_addr_equal(net->dev_addr, node_id))
1730                 net->addr_assign_type = NET_ADDR_RANDOM;
1731
1732         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1733                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1734         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1735                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1736
1737         /* initialize max rx_qlen and tx_qlen */
1738         usbnet_update_max_qlen(dev);
1739
1740         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1741                 !(info->flags & FLAG_MULTI_PACKET)) {
1742                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1743                 if (!dev->padding_pkt) {
1744                         status = -ENOMEM;
1745                         goto out4;
1746                 }
1747         }
1748
1749         status = register_netdev (net);
1750         if (status)
1751                 goto out5;
1752         netif_info(dev, probe, dev->net,
1753                    "register '%s' at usb-%s-%s, %s, %pM\n",
1754                    udev->dev.driver->name,
1755                    xdev->bus->bus_name, xdev->devpath,
1756                    dev->driver_info->description,
1757                    net->dev_addr);
1758
1759         // ok, it's ready to go.
1760         usb_set_intfdata (udev, dev);
1761
1762         netif_device_attach (net);
1763
1764         if (dev->driver_info->flags & FLAG_LINK_INTR)
1765                 usbnet_link_change(dev, 0, 0);
1766
1767         return 0;
1768
1769 out5:
1770         kfree(dev->padding_pkt);
1771 out4:
1772         usb_free_urb(dev->interrupt);
1773 out3:
1774         if (info->unbind)
1775                 info->unbind (dev, udev);
1776 out1:
1777         /* subdrivers must undo all they did in bind() if they
1778          * fail it, but we may fail later and a deferred kevent
1779          * may trigger an error resubmitting itself and, worse,
1780          * schedule a timer. So we kill it all just in case.
1781          */
1782         cancel_work_sync(&dev->kevent);
1783         del_timer_sync(&dev->delay);
1784         free_netdev(net);
1785 out:
1786         return status;
1787 }
1788 EXPORT_SYMBOL_GPL(usbnet_probe);
1789
1790 /*-------------------------------------------------------------------------*/
1791
1792 /*
1793  * suspend the whole driver as soon as the first interface is suspended
1794  * resume only when the last interface is resumed
1795  */
1796
1797 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1798 {
1799         struct usbnet           *dev = usb_get_intfdata(intf);
1800
1801         if (!dev->suspend_count++) {
1802                 spin_lock_irq(&dev->txq.lock);
1803                 /* don't autosuspend while transmitting */
1804                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1805                         dev->suspend_count--;
1806                         spin_unlock_irq(&dev->txq.lock);
1807                         return -EBUSY;
1808                 } else {
1809                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1810                         spin_unlock_irq(&dev->txq.lock);
1811                 }
1812                 /*
1813                  * accelerate emptying of the rx and queues, to avoid
1814                  * having everything error out.
1815                  */
1816                 netif_device_detach (dev->net);
1817                 usbnet_terminate_urbs(dev);
1818                 __usbnet_status_stop_force(dev);
1819
1820                 /*
1821                  * reattach so runtime management can use and
1822                  * wake the device
1823                  */
1824                 netif_device_attach (dev->net);
1825         }
1826         return 0;
1827 }
1828 EXPORT_SYMBOL_GPL(usbnet_suspend);
1829
1830 int usbnet_resume (struct usb_interface *intf)
1831 {
1832         struct usbnet           *dev = usb_get_intfdata(intf);
1833         struct sk_buff          *skb;
1834         struct urb              *res;
1835         int                     retval;
1836
1837         if (!--dev->suspend_count) {
1838                 /* resume interrupt URB if it was previously submitted */
1839                 __usbnet_status_start_force(dev, GFP_NOIO);
1840
1841                 spin_lock_irq(&dev->txq.lock);
1842                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1843
1844                         skb = (struct sk_buff *)res->context;
1845                         retval = usb_submit_urb(res, GFP_ATOMIC);
1846                         if (retval < 0) {
1847                                 dev_kfree_skb_any(skb);
1848                                 kfree(res->sg);
1849                                 usb_free_urb(res);
1850                                 usb_autopm_put_interface_async(dev->intf);
1851                         } else {
1852                                 netif_trans_update(dev->net);
1853                                 __skb_queue_tail(&dev->txq, skb);
1854                         }
1855                 }
1856
1857                 smp_mb();
1858                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1859                 spin_unlock_irq(&dev->txq.lock);
1860
1861                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1862                         /* handle remote wakeup ASAP
1863                          * we cannot race against stop
1864                          */
1865                         if (netif_device_present(dev->net) &&
1866                                 !timer_pending(&dev->delay) &&
1867                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1868                                         rx_alloc_submit(dev, GFP_NOIO);
1869
1870                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1871                                 netif_tx_wake_all_queues(dev->net);
1872                         tasklet_schedule (&dev->bh);
1873                 }
1874         }
1875
1876         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1877                 usb_autopm_get_interface_no_resume(intf);
1878
1879         return 0;
1880 }
1881 EXPORT_SYMBOL_GPL(usbnet_resume);
1882
1883 /*
1884  * Either a subdriver implements manage_power, then it is assumed to always
1885  * be ready to be suspended or it reports the readiness to be suspended
1886  * explicitly
1887  */
1888 void usbnet_device_suggests_idle(struct usbnet *dev)
1889 {
1890         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1891                 dev->intf->needs_remote_wakeup = 1;
1892                 usb_autopm_put_interface_async(dev->intf);
1893         }
1894 }
1895 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1896
1897 /*
1898  * For devices that can do without special commands
1899  */
1900 int usbnet_manage_power(struct usbnet *dev, int on)
1901 {
1902         dev->intf->needs_remote_wakeup = on;
1903         return 0;
1904 }
1905 EXPORT_SYMBOL(usbnet_manage_power);
1906
1907 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1908 {
1909         /* update link after link is reseted */
1910         if (link && !need_reset)
1911                 netif_carrier_on(dev->net);
1912         else
1913                 netif_carrier_off(dev->net);
1914
1915         if (need_reset && link)
1916                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1917         else
1918                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1919 }
1920 EXPORT_SYMBOL(usbnet_link_change);
1921
1922 /*-------------------------------------------------------------------------*/
1923 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1924                              u16 value, u16 index, void *data, u16 size)
1925 {
1926         void *buf = NULL;
1927         int err = -ENOMEM;
1928
1929         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1930                    " value=0x%04x index=0x%04x size=%d\n",
1931                    cmd, reqtype, value, index, size);
1932
1933         if (data) {
1934                 buf = kmalloc(size, GFP_KERNEL);
1935                 if (!buf)
1936                         goto out;
1937         }
1938
1939         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1940                               cmd, reqtype, value, index, buf, size,
1941                               USB_CTRL_GET_TIMEOUT);
1942         if (err > 0 && err <= size)
1943                 memcpy(data, buf, err);
1944         kfree(buf);
1945 out:
1946         return err;
1947 }
1948
1949 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1950                               u16 value, u16 index, const void *data,
1951                               u16 size)
1952 {
1953         void *buf = NULL;
1954         int err = -ENOMEM;
1955
1956         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1957                    " value=0x%04x index=0x%04x size=%d\n",
1958                    cmd, reqtype, value, index, size);
1959
1960         if (data) {
1961                 buf = kmemdup(data, size, GFP_KERNEL);
1962                 if (!buf)
1963                         goto out;
1964         }
1965
1966         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1967                               cmd, reqtype, value, index, buf, size,
1968                               USB_CTRL_SET_TIMEOUT);
1969         kfree(buf);
1970
1971 out:
1972         return err;
1973 }
1974
1975 int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
1976                                 struct usb_interface *intf,
1977                                 u8 *buffer,
1978                                 int buflen)
1979 {
1980         /* duplicates are ignored */
1981         struct usb_cdc_union_desc *union_header = NULL;
1982
1983         /* duplicates are not tolerated */
1984         struct usb_cdc_header_desc *header = NULL;
1985         struct usb_cdc_ether_desc *ether = NULL;
1986         struct usb_cdc_mdlm_detail_desc *detail = NULL;
1987         struct usb_cdc_mdlm_desc *desc = NULL;
1988
1989         unsigned int elength;
1990         int cnt = 0;
1991
1992         memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
1993         hdr->phonet_magic_present = false;
1994         while (buflen > 0) {
1995                 elength = buffer[0];
1996                 if (!elength) {
1997                         dev_err(&intf->dev, "skipping garbage byte\n");
1998                         elength = 1;
1999                         goto next_desc;
2000                 }
2001                 if (buffer[1] != USB_DT_CS_INTERFACE) {
2002                         dev_err(&intf->dev, "skipping garbage\n");
2003                         goto next_desc;
2004                 }
2005
2006                 switch (buffer[2]) {
2007                 case USB_CDC_UNION_TYPE: /* we've found it */
2008                         if (elength < sizeof(struct usb_cdc_union_desc))
2009                                 goto next_desc;
2010                         if (union_header) {
2011                                 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2012                                 goto next_desc;
2013                         }
2014                         union_header = (struct usb_cdc_union_desc *)buffer;
2015                         break;
2016                 case USB_CDC_COUNTRY_TYPE:
2017                         if (elength < sizeof(struct usb_cdc_country_functional_desc))
2018                                 goto next_desc;
2019                         hdr->usb_cdc_country_functional_desc =
2020                                 (struct usb_cdc_country_functional_desc *)buffer;
2021                         break;
2022                 case USB_CDC_HEADER_TYPE:
2023                         if (elength != sizeof(struct usb_cdc_header_desc))
2024                                 goto next_desc;
2025                         if (header)
2026                                 return -EINVAL;
2027                         header = (struct usb_cdc_header_desc *)buffer;
2028                         break;
2029                 case USB_CDC_ACM_TYPE:
2030                         if (elength < sizeof(struct usb_cdc_acm_descriptor))
2031                                 goto next_desc;
2032                         hdr->usb_cdc_acm_descriptor =
2033                                 (struct usb_cdc_acm_descriptor *)buffer;
2034                         break;
2035                 case USB_CDC_ETHERNET_TYPE:
2036                         if (elength != sizeof(struct usb_cdc_ether_desc))
2037                                 goto next_desc;
2038                         if (ether)
2039                                 return -EINVAL;
2040                         ether = (struct usb_cdc_ether_desc *)buffer;
2041                         break;
2042                 case USB_CDC_CALL_MANAGEMENT_TYPE:
2043                         if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2044                                 goto next_desc;
2045                         hdr->usb_cdc_call_mgmt_descriptor =
2046                                 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2047                         break;
2048                 case USB_CDC_DMM_TYPE:
2049                         if (elength < sizeof(struct usb_cdc_dmm_desc))
2050                                 goto next_desc;
2051                         hdr->usb_cdc_dmm_desc =
2052                                 (struct usb_cdc_dmm_desc *)buffer;
2053                         break;
2054                 case USB_CDC_MDLM_TYPE:
2055                         if (elength < sizeof(struct usb_cdc_mdlm_desc *))
2056                                 goto next_desc;
2057                         if (desc)
2058                                 return -EINVAL;
2059                         desc = (struct usb_cdc_mdlm_desc *)buffer;
2060                         break;
2061                 case USB_CDC_MDLM_DETAIL_TYPE:
2062                         if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *))
2063                                 goto next_desc;
2064                         if (detail)
2065                                 return -EINVAL;
2066                         detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2067                         break;
2068                 case USB_CDC_NCM_TYPE:
2069                         if (elength < sizeof(struct usb_cdc_ncm_desc))
2070                                 goto next_desc;
2071                         hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2072                         break;
2073                 case USB_CDC_MBIM_TYPE:
2074                         if (elength < sizeof(struct usb_cdc_mbim_desc))
2075                                 goto next_desc;
2076
2077                         hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2078                         break;
2079                 case USB_CDC_MBIM_EXTENDED_TYPE:
2080                         if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2081                                 break;
2082                         hdr->usb_cdc_mbim_extended_desc =
2083                                 (struct usb_cdc_mbim_extended_desc *)buffer;
2084                         break;
2085                 case CDC_PHONET_MAGIC_NUMBER:
2086                         hdr->phonet_magic_present = true;
2087                         break;
2088                 default:
2089                         /*
2090                          * there are LOTS more CDC descriptors that
2091                          * could legitimately be found here.
2092                          */
2093                         dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2094                                         buffer[2], elength);
2095                         goto next_desc;
2096                 }
2097                 cnt++;
2098 next_desc:
2099                 buflen -= elength;
2100                 buffer += elength;
2101         }
2102         hdr->usb_cdc_union_desc = union_header;
2103         hdr->usb_cdc_header_desc = header;
2104         hdr->usb_cdc_mdlm_detail_desc = detail;
2105         hdr->usb_cdc_mdlm_desc = desc;
2106         hdr->usb_cdc_ether_desc = ether;
2107         return cnt;
2108 }
2109
2110 EXPORT_SYMBOL(cdc_parse_cdc_header);
2111
2112 /*
2113  * The function can't be called inside suspend/resume callback,
2114  * otherwise deadlock will be caused.
2115  */
2116 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2117                     u16 value, u16 index, void *data, u16 size)
2118 {
2119         int ret;
2120
2121         if (usb_autopm_get_interface(dev->intf) < 0)
2122                 return -ENODEV;
2123         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2124                                 data, size);
2125         usb_autopm_put_interface(dev->intf);
2126         return ret;
2127 }
2128 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2129
2130 /*
2131  * The function can't be called inside suspend/resume callback,
2132  * otherwise deadlock will be caused.
2133  */
2134 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2135                      u16 value, u16 index, const void *data, u16 size)
2136 {
2137         int ret;
2138
2139         if (usb_autopm_get_interface(dev->intf) < 0)
2140                 return -ENODEV;
2141         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2142                                  data, size);
2143         usb_autopm_put_interface(dev->intf);
2144         return ret;
2145 }
2146 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2147
2148 /*
2149  * The function can be called inside suspend/resume callback safely
2150  * and should only be called by suspend/resume callback generally.
2151  */
2152 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2153                           u16 value, u16 index, void *data, u16 size)
2154 {
2155         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2156                                  data, size);
2157 }
2158 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2159
2160 /*
2161  * The function can be called inside suspend/resume callback safely
2162  * and should only be called by suspend/resume callback generally.
2163  */
2164 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2165                           u16 value, u16 index, const void *data,
2166                           u16 size)
2167 {
2168         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2169                                   data, size);
2170 }
2171 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2172
2173 static void usbnet_async_cmd_cb(struct urb *urb)
2174 {
2175         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2176         int status = urb->status;
2177
2178         if (status < 0)
2179                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2180                         __func__, status);
2181
2182         kfree(req);
2183         usb_free_urb(urb);
2184 }
2185
2186 /*
2187  * The caller must make sure that device can't be put into suspend
2188  * state until the control URB completes.
2189  */
2190 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2191                            u16 value, u16 index, const void *data, u16 size)
2192 {
2193         struct usb_ctrlrequest *req = NULL;
2194         struct urb *urb;
2195         int err = -ENOMEM;
2196         void *buf = NULL;
2197
2198         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2199                    " value=0x%04x index=0x%04x size=%d\n",
2200                    cmd, reqtype, value, index, size);
2201
2202         urb = usb_alloc_urb(0, GFP_ATOMIC);
2203         if (!urb) {
2204                 netdev_err(dev->net, "Error allocating URB in"
2205                            " %s!\n", __func__);
2206                 goto fail;
2207         }
2208
2209         if (data) {
2210                 buf = kmemdup(data, size, GFP_ATOMIC);
2211                 if (!buf) {
2212                         netdev_err(dev->net, "Error allocating buffer"
2213                                    " in %s!\n", __func__);
2214                         goto fail_free;
2215                 }
2216         }
2217
2218         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2219         if (!req)
2220                 goto fail_free_buf;
2221
2222         req->bRequestType = reqtype;
2223         req->bRequest = cmd;
2224         req->wValue = cpu_to_le16(value);
2225         req->wIndex = cpu_to_le16(index);
2226         req->wLength = cpu_to_le16(size);
2227
2228         usb_fill_control_urb(urb, dev->udev,
2229                              usb_sndctrlpipe(dev->udev, 0),
2230                              (void *)req, buf, size,
2231                              usbnet_async_cmd_cb, req);
2232         urb->transfer_flags |= URB_FREE_BUFFER;
2233
2234         err = usb_submit_urb(urb, GFP_ATOMIC);
2235         if (err < 0) {
2236                 netdev_err(dev->net, "Error submitting the control"
2237                            " message: status=%d\n", err);
2238                 goto fail_free;
2239         }
2240         return 0;
2241
2242 fail_free_buf:
2243         kfree(buf);
2244 fail_free:
2245         kfree(req);
2246         usb_free_urb(urb);
2247 fail:
2248         return err;
2249
2250 }
2251 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2252 /*-------------------------------------------------------------------------*/
2253
2254 static int __init usbnet_init(void)
2255 {
2256         /* Compiler should optimize this out. */
2257         BUILD_BUG_ON(
2258                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2259
2260         eth_random_addr(node_id);
2261         return 0;
2262 }
2263 module_init(usbnet_init);
2264
2265 static void __exit usbnet_exit(void)
2266 {
2267 }
2268 module_exit(usbnet_exit);
2269
2270 MODULE_AUTHOR("David Brownell");
2271 MODULE_DESCRIPTION("USB network driver framework");
2272 MODULE_LICENSE("GPL");