drivers/net/usb/usbnet.c

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