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