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