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 /* use ethtool to change the level for any given device */
  86 static int msg_level = -1;
  87 module_param (msg_level, int, 0);
  88 MODULE_PARM_DESC (msg_level, "Override default message level");
  89
  90 /*-------------------------------------------------------------------------*/
  91
  92 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  93 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  94 {
  95         int                             tmp;
  96         struct usb_host_interface       *alt = NULL;
  97         struct usb_host_endpoint        *in = NULL, *out = NULL;
  98         struct usb_host_endpoint        *status = NULL;
  99
 100         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 101                 unsigned        ep;
 102
 103                 in = out = status = NULL;
 104                 alt = intf->altsetting + tmp;
 105
 106                 /* take the first altsetting with in-bulk + out-bulk;
 107                  * remember any status endpoint, just in case;
 108                  * ignore other endpoints and altsettings.
 109                  */
 110                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 111                         struct usb_host_endpoint        *e;
 112                         int                             intr = 0;
 113
 114                         e = alt->endpoint + ep;
 115
 116                         /* ignore endpoints which cannot transfer data */
 117                         if (!usb_endpoint_maxp(&e->desc))
 118                                 continue;
 119
 120                         switch (e->desc.bmAttributes) {
 121                         case USB_ENDPOINT_XFER_INT:
 122                                 if (!usb_endpoint_dir_in(&e->desc))
 123                                         continue;
 124                                 intr = 1;
 125                                 /* FALLTHROUGH */
 126                         case USB_ENDPOINT_XFER_BULK:
 127                                 break;
 128                         default:
 129                                 continue;
 130                         }
 131                         if (usb_endpoint_dir_in(&e->desc)) {
 132                                 if (!intr && !in)
 133                                         in = e;
 134                                 else if (intr && !status)
 135                                         status = e;
 136                         } else {
 137                                 if (!out)
 138                                         out = e;
 139                         }
 140                 }
 141                 if (in && out)
 142                         break;
 143         }
 144         if (!alt || !in || !out)
 145                 return -EINVAL;
 146
 147         if (alt->desc.bAlternateSetting != 0 ||
 148             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 149                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 150                                 alt->desc.bAlternateSetting);
 151                 if (tmp < 0)
 152                         return tmp;
 153         }
 154
 155         dev->in = usb_rcvbulkpipe (dev->udev,
 156                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 157         dev->out = usb_sndbulkpipe (dev->udev,
 158                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 159         dev->status = status;
 160         return 0;
 161 }
 162 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 163
 164 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 165 {
 166         int             tmp = -1, ret;
 167         unsigned char   buf [13];
 168
 169         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 170         if (ret == 12)
 171                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 172         if (tmp < 0) {
 173                 dev_dbg(&dev->udev->dev,
 174                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 175                 if (ret >= 0)
 176                         ret = -EINVAL;
 177                 return ret;
 178         }
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb)
 184 {
 185         struct usbnet   *dev = urb->context;
 186         int             status = urb->status;
 187
 188         switch (status) {
 189         /* success */
 190         case 0:
 191                 dev->driver_info->status(dev, urb);
 192                 break;
 193
 194         /* software-driven interface shutdown */
 195         case -ENOENT:           /* urb killed */
 196         case -ESHUTDOWN:        /* hardware gone */
 197                 netif_dbg(dev, ifdown, dev->net,
 198                           "intr shutdown, code %d\n", status);
 199                 return;
 200
 201         /* NOTE:  not throttling like RX/TX, since this endpoint
 202          * already polls infrequently
 203          */
 204         default:
 205                 netdev_dbg(dev->net, "intr status %d\n", status);
 206                 break;
 207         }
 208
 209         status = usb_submit_urb (urb, GFP_ATOMIC);
 210         if (status != 0)
 211                 netif_err(dev, timer, dev->net,
 212                           "intr resubmit --> %d\n", status);
 213 }
 214
 215 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 216 {
 217         char            *buf = NULL;
 218         unsigned        pipe = 0;
 219         unsigned        maxp;
 220         unsigned        period;
 221
 222         if (!dev->driver_info->status)
 223                 return 0;
 224
 225         pipe = usb_rcvintpipe (dev->udev,
 226                         dev->status->desc.bEndpointAddress
 227                                 & USB_ENDPOINT_NUMBER_MASK);
 228         maxp = usb_maxpacket (dev->udev, pipe, 0);
 229
 230         /* avoid 1 msec chatter:  min 8 msec poll rate */
 231         period = max ((int) dev->status->desc.bInterval,
 232                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 233
 234         buf = kmalloc (maxp, GFP_KERNEL);
 235         if (buf) {
 236                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 237                 if (!dev->interrupt) {
 238                         kfree (buf);
 239                         return -ENOMEM;
 240                 } else {
 241                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 242                                 buf, maxp, intr_complete, dev, period);
 243                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 244                         dev_dbg(&intf->dev,
 245                                 "status ep%din, %d bytes period %d\n",
 246                                 usb_pipeendpoint(pipe), maxp, period);
 247                 }
 248         }
 249         return 0;
 250 }
 251
 252 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 253 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 254 {
 255         int ret = 0;
 256
 257         WARN_ON_ONCE(dev->interrupt == NULL);
 258         if (dev->interrupt) {
 259                 mutex_lock(&dev->interrupt_mutex);
 260
 261                 if (++dev->interrupt_count == 1)
 262                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 263
 264                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 265                         dev->interrupt_count);
 266                 mutex_unlock(&dev->interrupt_mutex);
 267         }
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(usbnet_status_start);
 271
 272 /* For resume; submit interrupt URB if previously submitted */
 273 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 274 {
 275         int ret = 0;
 276
 277         mutex_lock(&dev->interrupt_mutex);
 278         if (dev->interrupt_count) {
 279                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 280                 dev_dbg(&dev->udev->dev,
 281                         "submitted interrupt URB for resume\n");
 282         }
 283         mutex_unlock(&dev->interrupt_mutex);
 284         return ret;
 285 }
 286
 287 /* Kill the interrupt URB if all submitters want it killed */
 288 void usbnet_status_stop(struct usbnet *dev)
 289 {
 290         if (dev->interrupt) {
 291                 mutex_lock(&dev->interrupt_mutex);
 292                 WARN_ON(dev->interrupt_count == 0);
 293
 294                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 295                         usb_kill_urb(dev->interrupt);
 296
 297                 dev_dbg(&dev->udev->dev,
 298                         "decremented interrupt URB count to %d\n",
 299                         dev->interrupt_count);
 300                 mutex_unlock(&dev->interrupt_mutex);
 301         }
 302 }
 303 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 304
 305 /* For suspend; always kill interrupt URB */
 306 static void __usbnet_status_stop_force(struct usbnet *dev)
 307 {
 308         if (dev->interrupt) {
 309                 mutex_lock(&dev->interrupt_mutex);
 310                 usb_kill_urb(dev->interrupt);
 311                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 312                 mutex_unlock(&dev->interrupt_mutex);
 313         }
 314 }
 315
 316 /* Passes this packet up the stack, updating its accounting.
 317  * Some link protocols batch packets, so their rx_fixup paths
 318  * can return clones as well as just modify the original skb.
 319  */
 320 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 321 {
 322         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 323         unsigned long flags;
 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         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 336         stats64->rx_packets++;
 337         stats64->rx_bytes += skb->len;
 338         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 339
 340         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 341                   skb->len + sizeof (struct ethhdr), skb->protocol);
 342         memset (skb->cb, 0, sizeof (struct skb_data));
 343
 344         if (skb_defer_rx_timestamp(skb))
 345                 return;
 346
 347         status = netif_rx (skb);
 348         if (status != NET_RX_SUCCESS)
 349                 netif_dbg(dev, rx_err, dev->net,
 350                           "netif_rx status %d\n", status);
 351 }
 352 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 353
 354 /* must be called if hard_mtu or rx_urb_size changed */
 355 void usbnet_update_max_qlen(struct usbnet *dev)
 356 {
 357         enum usb_device_speed speed = dev->udev->speed;
 358
 359         if (!dev->rx_urb_size || !dev->hard_mtu)
 360                 goto insanity;
 361         switch (speed) {
 362         case USB_SPEED_HIGH:
 363                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 364                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 365                 break;
 366         case USB_SPEED_SUPER:
 367         case USB_SPEED_SUPER_PLUS:
 368                 /*
 369                  * Not take default 5ms qlen for super speed HC to
 370                  * save memory, and iperf tests show 2.5ms qlen can
 371                  * work well
 372                  */
 373                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 374                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 375                 break;
 376         default:
 377 insanity:
 378                 dev->rx_qlen = dev->tx_qlen = 4;
 379         }
 380 }
 381 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 382
 383 \f
 384 /*-------------------------------------------------------------------------
 385  *
 386  * Network Device Driver (peer link to "Host Device", from USB host)
 387  *
 388  *-------------------------------------------------------------------------*/
 389
 390 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 391 {
 392         struct usbnet   *dev = netdev_priv(net);
 393         int             ll_mtu = new_mtu + net->hard_header_len;
 394         int             old_hard_mtu = dev->hard_mtu;
 395         int             old_rx_urb_size = dev->rx_urb_size;
 396
 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 (timer, softirq, task) must also stop */
 851         dev->flags = 0;
 852         del_timer_sync (&dev->delay);
 853         tasklet_kill (&dev->bh);
 854         cancel_work_sync(&dev->kevent);
 855         if (!pm)
 856                 usb_autopm_put_interface(dev->intf);
 857
 858         if (info->manage_power && mpn)
 859                 info->manage_power(dev, 0);
 860         else
 861                 usb_autopm_put_interface(dev->intf);
 862
 863         return 0;
 864 }
 865 EXPORT_SYMBOL_GPL(usbnet_stop);
 866
 867 /*-------------------------------------------------------------------------*/
 868
 869 // posts reads, and enables write queuing
 870
 871 // precondition: never called in_interrupt
 872
 873 int usbnet_open (struct net_device *net)
 874 {
 875         struct usbnet           *dev = netdev_priv(net);
 876         int                     retval;
 877         struct driver_info      *info = dev->driver_info;
 878
 879         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 880                 netif_info(dev, ifup, dev->net,
 881                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 882                            retval,
 883                            dev->udev->bus->bus_name,
 884                            dev->udev->devpath,
 885                            info->description);
 886                 goto done_nopm;
 887         }
 888
 889         // put into "known safe" state
 890         if (info->reset && (retval = info->reset (dev)) < 0) {
 891                 netif_info(dev, ifup, dev->net,
 892                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 893                            retval,
 894                            dev->udev->bus->bus_name,
 895                            dev->udev->devpath,
 896                            info->description);
 897                 goto done;
 898         }
 899
 900         /* hard_mtu or rx_urb_size may change in reset() */
 901         usbnet_update_max_qlen(dev);
 902
 903         // insist peer be connected
 904         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 905                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 906                 goto done;
 907         }
 908
 909         /* start any status interrupt transfer */
 910         if (dev->interrupt) {
 911                 retval = usbnet_status_start(dev, GFP_KERNEL);
 912                 if (retval < 0) {
 913                         netif_err(dev, ifup, dev->net,
 914                                   "intr submit %d\n", retval);
 915                         goto done;
 916                 }
 917         }
 918
 919         set_bit(EVENT_DEV_OPEN, &dev->flags);
 920         netif_start_queue (net);
 921         netif_info(dev, ifup, dev->net,
 922                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 923                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 924                    dev->net->mtu,
 925                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 926                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 927                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 928                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 929                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 930                    "simple");
 931
 932         /* reset rx error state */
 933         dev->pkt_cnt = 0;
 934         dev->pkt_err = 0;
 935         clear_bit(EVENT_RX_KILL, &dev->flags);
 936
 937         // delay posting reads until we're fully open
 938         tasklet_schedule (&dev->bh);
 939         if (info->manage_power) {
 940                 retval = info->manage_power(dev, 1);
 941                 if (retval < 0) {
 942                         retval = 0;
 943                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 944                 } else {
 945                         usb_autopm_put_interface(dev->intf);
 946                 }
 947         }
 948         return retval;
 949 done:
 950         usb_autopm_put_interface(dev->intf);
 951 done_nopm:
 952         return retval;
 953 }
 954 EXPORT_SYMBOL_GPL(usbnet_open);
 955
 956 /*-------------------------------------------------------------------------*/
 957
 958 /* ethtool methods; minidrivers may need to add some more, but
 959  * they'll probably want to use this base set.
 960  */
 961
 962 int usbnet_get_link_ksettings(struct net_device *net,
 963                               struct ethtool_link_ksettings *cmd)
 964 {
 965         struct usbnet *dev = netdev_priv(net);
 966
 967         if (!dev->mii.mdio_read)
 968                 return -EOPNOTSUPP;
 969
 970         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 971
 972         return 0;
 973 }
 974 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 975
 976 int usbnet_set_link_ksettings(struct net_device *net,
 977                               const struct ethtool_link_ksettings *cmd)
 978 {
 979         struct usbnet *dev = netdev_priv(net);
 980         int retval;
 981
 982         if (!dev->mii.mdio_write)
 983                 return -EOPNOTSUPP;
 984
 985         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 986
 987         /* link speed/duplex might have changed */
 988         if (dev->driver_info->link_reset)
 989                 dev->driver_info->link_reset(dev);
 990
 991         /* hard_mtu or rx_urb_size may change in link_reset() */
 992         usbnet_update_max_qlen(dev);
 993
 994         return retval;
 995 }
 996 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 997
 998 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 999 {
1000         struct usbnet *dev = netdev_priv(net);
1001         unsigned int start;
1002         int cpu;
1003
1004         netdev_stats_to_stats64(stats, &net->stats);
1005
1006         for_each_possible_cpu(cpu) {
1007                 struct pcpu_sw_netstats *stats64;
1008                 u64 rx_packets, rx_bytes;
1009                 u64 tx_packets, tx_bytes;
1010
1011                 stats64 = per_cpu_ptr(dev->stats64, cpu);
1012
1013                 do {
1014                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1015                         rx_packets = stats64->rx_packets;
1016                         rx_bytes = stats64->rx_bytes;
1017                         tx_packets = stats64->tx_packets;
1018                         tx_bytes = stats64->tx_bytes;
1019                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1020
1021                 stats->rx_packets += rx_packets;
1022                 stats->rx_bytes += rx_bytes;
1023                 stats->tx_packets += tx_packets;
1024                 stats->tx_bytes += tx_bytes;
1025         }
1026 }
1027 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1028
1029 u32 usbnet_get_link (struct net_device *net)
1030 {
1031         struct usbnet *dev = netdev_priv(net);
1032
1033         /* If a check_connect is defined, return its result */
1034         if (dev->driver_info->check_connect)
1035                 return dev->driver_info->check_connect (dev) == 0;
1036
1037         /* if the device has mii operations, use those */
1038         if (dev->mii.mdio_read)
1039                 return mii_link_ok(&dev->mii);
1040
1041         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1042         return ethtool_op_get_link(net);
1043 }
1044 EXPORT_SYMBOL_GPL(usbnet_get_link);
1045
1046 int usbnet_nway_reset(struct net_device *net)
1047 {
1048         struct usbnet *dev = netdev_priv(net);
1049
1050         if (!dev->mii.mdio_write)
1051                 return -EOPNOTSUPP;
1052
1053         return mii_nway_restart(&dev->mii);
1054 }
1055 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1056
1057 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1058 {
1059         struct usbnet *dev = netdev_priv(net);
1060
1061         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1062         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1063         strlcpy (info->fw_version, dev->driver_info->description,
1064                 sizeof info->fw_version);
1065         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1066 }
1067 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1068
1069 u32 usbnet_get_msglevel (struct net_device *net)
1070 {
1071         struct usbnet *dev = netdev_priv(net);
1072
1073         return dev->msg_enable;
1074 }
1075 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1076
1077 void usbnet_set_msglevel (struct net_device *net, u32 level)
1078 {
1079         struct usbnet *dev = netdev_priv(net);
1080
1081         dev->msg_enable = level;
1082 }
1083 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1084
1085 /* drivers may override default ethtool_ops in their bind() routine */
1086 static const struct ethtool_ops usbnet_ethtool_ops = {
1087         .get_link               = usbnet_get_link,
1088         .nway_reset             = usbnet_nway_reset,
1089         .get_drvinfo            = usbnet_get_drvinfo,
1090         .get_msglevel           = usbnet_get_msglevel,
1091         .set_msglevel           = usbnet_set_msglevel,
1092         .get_ts_info            = ethtool_op_get_ts_info,
1093         .get_link_ksettings     = usbnet_get_link_ksettings,
1094         .set_link_ksettings     = usbnet_set_link_ksettings,
1095 };
1096
1097 /*-------------------------------------------------------------------------*/
1098
1099 static void __handle_link_change(struct usbnet *dev)
1100 {
1101         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1102                 return;
1103
1104         if (!netif_carrier_ok(dev->net)) {
1105                 /* kill URBs for reading packets to save bus bandwidth */
1106                 unlink_urbs(dev, &dev->rxq);
1107
1108                 /*
1109                  * tx_timeout will unlink URBs for sending packets and
1110                  * tx queue is stopped by netcore after link becomes off
1111                  */
1112         } else {
1113                 /* submitting URBs for reading packets */
1114                 tasklet_schedule(&dev->bh);
1115         }
1116
1117         /* hard_mtu or rx_urb_size may change during link change */
1118         usbnet_update_max_qlen(dev);
1119
1120         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1121 }
1122
1123 static void usbnet_set_rx_mode(struct net_device *net)
1124 {
1125         struct usbnet           *dev = netdev_priv(net);
1126
1127         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1128 }
1129
1130 static void __handle_set_rx_mode(struct usbnet *dev)
1131 {
1132         if (dev->driver_info->set_rx_mode)
1133                 (dev->driver_info->set_rx_mode)(dev);
1134
1135         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1136 }
1137
1138 /* work that cannot be done in interrupt context uses keventd.
1139  *
1140  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1141  * especially now that control transfers can be queued.
1142  */
1143 static void
1144 usbnet_deferred_kevent (struct work_struct *work)
1145 {
1146         struct usbnet           *dev =
1147                 container_of(work, struct usbnet, kevent);
1148         int                     status;
1149
1150         /* usb_clear_halt() needs a thread context */
1151         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1152                 unlink_urbs (dev, &dev->txq);
1153                 status = usb_autopm_get_interface(dev->intf);
1154                 if (status < 0)
1155                         goto fail_pipe;
1156                 status = usb_clear_halt (dev->udev, dev->out);
1157                 usb_autopm_put_interface(dev->intf);
1158                 if (status < 0 &&
1159                     status != -EPIPE &&
1160                     status != -ESHUTDOWN) {
1161                         if (netif_msg_tx_err (dev))
1162 fail_pipe:
1163                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1164                                            status);
1165                 } else {
1166                         clear_bit (EVENT_TX_HALT, &dev->flags);
1167                         if (status != -ESHUTDOWN)
1168                                 netif_wake_queue (dev->net);
1169                 }
1170         }
1171         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1172                 unlink_urbs (dev, &dev->rxq);
1173                 status = usb_autopm_get_interface(dev->intf);
1174                 if (status < 0)
1175                         goto fail_halt;
1176                 status = usb_clear_halt (dev->udev, dev->in);
1177                 usb_autopm_put_interface(dev->intf);
1178                 if (status < 0 &&
1179                     status != -EPIPE &&
1180                     status != -ESHUTDOWN) {
1181                         if (netif_msg_rx_err (dev))
1182 fail_halt:
1183                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1184                                            status);
1185                 } else {
1186                         clear_bit (EVENT_RX_HALT, &dev->flags);
1187                         tasklet_schedule (&dev->bh);
1188                 }
1189         }
1190
1191         /* tasklet could resubmit itself forever if memory is tight */
1192         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1193                 struct urb      *urb = NULL;
1194                 int resched = 1;
1195
1196                 if (netif_running (dev->net))
1197                         urb = usb_alloc_urb (0, GFP_KERNEL);
1198                 else
1199                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1200                 if (urb != NULL) {
1201                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1202                         status = usb_autopm_get_interface(dev->intf);
1203                         if (status < 0) {
1204                                 usb_free_urb(urb);
1205                                 goto fail_lowmem;
1206                         }
1207                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1208                                 resched = 0;
1209                         usb_autopm_put_interface(dev->intf);
1210 fail_lowmem:
1211                         if (resched)
1212                                 tasklet_schedule (&dev->bh);
1213                 }
1214         }
1215
1216         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1217                 struct driver_info      *info = dev->driver_info;
1218                 int                     retval = 0;
1219
1220                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1221                 status = usb_autopm_get_interface(dev->intf);
1222                 if (status < 0)
1223                         goto skip_reset;
1224                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1225                         usb_autopm_put_interface(dev->intf);
1226 skip_reset:
1227                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1228                                     retval,
1229                                     dev->udev->bus->bus_name,
1230                                     dev->udev->devpath,
1231                                     info->description);
1232                 } else {
1233                         usb_autopm_put_interface(dev->intf);
1234                 }
1235
1236                 /* handle link change from link resetting */
1237                 __handle_link_change(dev);
1238         }
1239
1240         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1241                 __handle_link_change(dev);
1242
1243         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1244                 __handle_set_rx_mode(dev);
1245
1246
1247         if (dev->flags)
1248                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1249 }
1250
1251 /*-------------------------------------------------------------------------*/
1252
1253 static void tx_complete (struct urb *urb)
1254 {
1255         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1256         struct skb_data         *entry = (struct skb_data *) skb->cb;
1257         struct usbnet           *dev = entry->dev;
1258
1259         if (urb->status == 0) {
1260                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1261                 unsigned long flags;
1262
1263                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1264                 stats64->tx_packets += entry->packets;
1265                 stats64->tx_bytes += entry->length;
1266                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1267         } else {
1268                 dev->net->stats.tx_errors++;
1269
1270                 switch (urb->status) {
1271                 case -EPIPE:
1272                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1273                         break;
1274
1275                 /* software-driven interface shutdown */
1276                 case -ECONNRESET:               // async unlink
1277                 case -ESHUTDOWN:                // hardware gone
1278                         break;
1279
1280                 /* like rx, tx gets controller i/o faults during hub_wq
1281                  * delays and so it uses the same throttling mechanism.
1282                  */
1283                 case -EPROTO:
1284                 case -ETIME:
1285                 case -EILSEQ:
1286                         usb_mark_last_busy(dev->udev);
1287                         if (!timer_pending (&dev->delay)) {
1288                                 mod_timer (&dev->delay,
1289                                         jiffies + THROTTLE_JIFFIES);
1290                                 netif_dbg(dev, link, dev->net,
1291                                           "tx throttle %d\n", urb->status);
1292                         }
1293                         netif_stop_queue (dev->net);
1294                         break;
1295                 default:
1296                         netif_dbg(dev, tx_err, dev->net,
1297                                   "tx err %d\n", entry->urb->status);
1298                         break;
1299                 }
1300         }
1301
1302         usb_autopm_put_interface_async(dev->intf);
1303         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1304 }
1305
1306 /*-------------------------------------------------------------------------*/
1307
1308 void usbnet_tx_timeout (struct net_device *net)
1309 {
1310         struct usbnet           *dev = netdev_priv(net);
1311
1312         unlink_urbs (dev, &dev->txq);
1313         tasklet_schedule (&dev->bh);
1314         /* this needs to be handled individually because the generic layer
1315          * doesn't know what is sufficient and could not restore private
1316          * information if a remedy of an unconditional reset were used.
1317          */
1318         if (dev->driver_info->recover)
1319                 (dev->driver_info->recover)(dev);
1320 }
1321 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1322
1323 /*-------------------------------------------------------------------------*/
1324
1325 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1326 {
1327         unsigned num_sgs, total_len = 0;
1328         int i, s = 0;
1329
1330         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1331         if (num_sgs == 1)
1332                 return 0;
1333
1334         /* reserve one for zero packet */
1335         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1336                           GFP_ATOMIC);
1337         if (!urb->sg)
1338                 return -ENOMEM;
1339
1340         urb->num_sgs = num_sgs;
1341         sg_init_table(urb->sg, urb->num_sgs + 1);
1342
1343         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1344         total_len += skb_headlen(skb);
1345
1346         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1347                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1348
1349                 total_len += skb_frag_size(f);
1350                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1351                                 f->page_offset);
1352         }
1353         urb->transfer_buffer_length = total_len;
1354
1355         return 1;
1356 }
1357
1358 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1359                                      struct net_device *net)
1360 {
1361         struct usbnet           *dev = netdev_priv(net);
1362         unsigned int                    length;
1363         struct urb              *urb = NULL;
1364         struct skb_data         *entry;
1365         struct driver_info      *info = dev->driver_info;
1366         unsigned long           flags;
1367         int retval;
1368
1369         if (skb)
1370                 skb_tx_timestamp(skb);
1371
1372         // some devices want funky USB-level framing, for
1373         // win32 driver (usually) and/or hardware quirks
1374         if (info->tx_fixup) {
1375                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1376                 if (!skb) {
1377                         /* packet collected; minidriver waiting for more */
1378                         if (info->flags & FLAG_MULTI_PACKET)
1379                                 goto not_drop;
1380                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1381                         goto drop;
1382                 }
1383         }
1384
1385         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1386                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1387                 goto drop;
1388         }
1389
1390         entry = (struct skb_data *) skb->cb;
1391         entry->urb = urb;
1392         entry->dev = dev;
1393
1394         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1395                         skb->data, skb->len, tx_complete, skb);
1396         if (dev->can_dma_sg) {
1397                 if (build_dma_sg(skb, urb) < 0)
1398                         goto drop;
1399         }
1400         length = urb->transfer_buffer_length;
1401
1402         /* don't assume the hardware handles USB_ZERO_PACKET
1403          * NOTE:  strictly conforming cdc-ether devices should expect
1404          * the ZLP here, but ignore the one-byte packet.
1405          * NOTE2: CDC NCM specification is different from CDC ECM when
1406          * handling ZLP/short packets, so cdc_ncm driver will make short
1407          * packet itself if needed.
1408          */
1409         if (length % dev->maxpacket == 0) {
1410                 if (!(info->flags & FLAG_SEND_ZLP)) {
1411                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1412                                 length++;
1413                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1414                                         skb->data[skb->len] = 0;
1415                                         __skb_put(skb, 1);
1416                                 } else if (urb->num_sgs)
1417                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1418                                                         dev->padding_pkt, 1);
1419                         }
1420                 } else
1421                         urb->transfer_flags |= URB_ZERO_PACKET;
1422         }
1423         urb->transfer_buffer_length = length;
1424
1425         if (info->flags & FLAG_MULTI_PACKET) {
1426                 /* Driver has set number of packets and a length delta.
1427                  * Calculate the complete length and ensure that it's
1428                  * positive.
1429                  */
1430                 entry->length += length;
1431                 if (WARN_ON_ONCE(entry->length <= 0))
1432                         entry->length = length;
1433         } else {
1434                 usbnet_set_skb_tx_stats(skb, 1, length);
1435         }
1436
1437         spin_lock_irqsave(&dev->txq.lock, flags);
1438         retval = usb_autopm_get_interface_async(dev->intf);
1439         if (retval < 0) {
1440                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1441                 goto drop;
1442         }
1443         if (netif_queue_stopped(net)) {
1444                 usb_autopm_put_interface_async(dev->intf);
1445                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1446                 goto drop;
1447         }
1448
1449 #ifdef CONFIG_PM
1450         /* if this triggers the device is still a sleep */
1451         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1452                 /* transmission will be done in resume */
1453                 usb_anchor_urb(urb, &dev->deferred);
1454                 /* no use to process more packets */
1455                 netif_stop_queue(net);
1456                 usb_put_urb(urb);
1457                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1458                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1459                 goto deferred;
1460         }
1461 #endif
1462
1463         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1464         case -EPIPE:
1465                 netif_stop_queue (net);
1466                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1467                 usb_autopm_put_interface_async(dev->intf);
1468                 break;
1469         default:
1470                 usb_autopm_put_interface_async(dev->intf);
1471                 netif_dbg(dev, tx_err, dev->net,
1472                           "tx: submit urb err %d\n", retval);
1473                 break;
1474         case 0:
1475                 netif_trans_update(net);
1476                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1477                 if (dev->txq.qlen >= TX_QLEN (dev))
1478                         netif_stop_queue (net);
1479         }
1480         spin_unlock_irqrestore (&dev->txq.lock, flags);
1481
1482         if (retval) {
1483                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1484 drop:
1485                 dev->net->stats.tx_dropped++;
1486 not_drop:
1487                 if (skb)
1488                         dev_kfree_skb_any (skb);
1489                 if (urb) {
1490                         kfree(urb->sg);
1491                         usb_free_urb(urb);
1492                 }
1493         } else
1494                 netif_dbg(dev, tx_queued, dev->net,
1495                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1496 #ifdef CONFIG_PM
1497 deferred:
1498 #endif
1499         return NETDEV_TX_OK;
1500 }
1501 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1502
1503 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1504 {
1505         struct urb      *urb;
1506         int             i;
1507         int             ret = 0;
1508
1509         /* don't refill the queue all at once */
1510         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1511                 urb = usb_alloc_urb(0, flags);
1512                 if (urb != NULL) {
1513                         ret = rx_submit(dev, urb, flags);
1514                         if (ret)
1515                                 goto err;
1516                 } else {
1517                         ret = -ENOMEM;
1518                         goto err;
1519                 }
1520         }
1521 err:
1522         return ret;
1523 }
1524
1525 /*-------------------------------------------------------------------------*/
1526
1527 // tasklet (work deferred from completions, in_irq) or timer
1528
1529 static void usbnet_bh (unsigned long param)
1530 {
1531         struct usbnet           *dev = (struct usbnet *) param;
1532         struct sk_buff          *skb;
1533         struct skb_data         *entry;
1534
1535         while ((skb = skb_dequeue (&dev->done))) {
1536                 entry = (struct skb_data *) skb->cb;
1537                 switch (entry->state) {
1538                 case rx_done:
1539                         entry->state = rx_cleanup;
1540                         rx_process (dev, skb);
1541                         continue;
1542                 case tx_done:
1543                         kfree(entry->urb->sg);
1544                 case rx_cleanup:
1545                         usb_free_urb (entry->urb);
1546                         dev_kfree_skb (skb);
1547                         continue;
1548                 default:
1549                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1550                 }
1551         }
1552
1553         /* restart RX again after disabling due to high error rate */
1554         clear_bit(EVENT_RX_KILL, &dev->flags);
1555
1556         /* waiting for all pending urbs to complete?
1557          * only then can we forgo submitting anew
1558          */
1559         if (waitqueue_active(&dev->wait)) {
1560                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1561                         wake_up_all(&dev->wait);
1562
1563         // or are we maybe short a few urbs?
1564         } else if (netif_running (dev->net) &&
1565                    netif_device_present (dev->net) &&
1566                    netif_carrier_ok(dev->net) &&
1567                    !timer_pending(&dev->delay) &&
1568                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1569                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1570                 int     temp = dev->rxq.qlen;
1571
1572                 if (temp < RX_QLEN(dev)) {
1573                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1574                                 return;
1575                         if (temp != dev->rxq.qlen)
1576                                 netif_dbg(dev, link, dev->net,
1577                                           "rxqlen %d --> %d\n",
1578                                           temp, dev->rxq.qlen);
1579                         if (dev->rxq.qlen < RX_QLEN(dev))
1580                                 tasklet_schedule (&dev->bh);
1581                 }
1582                 if (dev->txq.qlen < TX_QLEN (dev))
1583                         netif_wake_queue (dev->net);
1584         }
1585 }
1586
1587
1588 /*-------------------------------------------------------------------------
1589  *
1590  * USB Device Driver support
1591  *
1592  *-------------------------------------------------------------------------*/
1593
1594 // precondition: never called in_interrupt
1595
1596 void usbnet_disconnect (struct usb_interface *intf)
1597 {
1598         struct usbnet           *dev;
1599         struct usb_device       *xdev;
1600         struct net_device       *net;
1601         struct urb              *urb;
1602
1603         dev = usb_get_intfdata(intf);
1604         usb_set_intfdata(intf, NULL);
1605         if (!dev)
1606                 return;
1607
1608         xdev = interface_to_usbdev (intf);
1609
1610         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1611                    intf->dev.driver->name,
1612                    xdev->bus->bus_name, xdev->devpath,
1613                    dev->driver_info->description);
1614
1615         net = dev->net;
1616         unregister_netdev (net);
1617
1618         while ((urb = usb_get_from_anchor(&dev->deferred))) {
1619                 dev_kfree_skb(urb->context);
1620                 kfree(urb->sg);
1621                 usb_free_urb(urb);
1622         }
1623
1624         if (dev->driver_info->unbind)
1625                 dev->driver_info->unbind (dev, intf);
1626
1627         usb_kill_urb(dev->interrupt);
1628         usb_free_urb(dev->interrupt);
1629         kfree(dev->padding_pkt);
1630
1631         free_percpu(dev->stats64);
1632         free_netdev(net);
1633 }
1634 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1635
1636 static const struct net_device_ops usbnet_netdev_ops = {
1637         .ndo_open               = usbnet_open,
1638         .ndo_stop               = usbnet_stop,
1639         .ndo_start_xmit         = usbnet_start_xmit,
1640         .ndo_tx_timeout         = usbnet_tx_timeout,
1641         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1642         .ndo_change_mtu         = usbnet_change_mtu,
1643         .ndo_get_stats64        = usbnet_get_stats64,
1644         .ndo_set_mac_address    = eth_mac_addr,
1645         .ndo_validate_addr      = eth_validate_addr,
1646 };
1647
1648 /*-------------------------------------------------------------------------*/
1649
1650 // precondition: never called in_interrupt
1651
1652 static struct device_type wlan_type = {
1653         .name   = "wlan",
1654 };
1655
1656 static struct device_type wwan_type = {
1657         .name   = "wwan",
1658 };
1659
1660 int
1661 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1662 {
1663         struct usbnet                   *dev;
1664         struct net_device               *net;
1665         struct usb_host_interface       *interface;
1666         struct driver_info              *info;
1667         struct usb_device               *xdev;
1668         int                             status;
1669         const char                      *name;
1670         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1671
1672         /* usbnet already took usb runtime pm, so have to enable the feature
1673          * for usb interface, otherwise usb_autopm_get_interface may return
1674          * failure if RUNTIME_PM is enabled.
1675          */
1676         if (!driver->supports_autosuspend) {
1677                 driver->supports_autosuspend = 1;
1678                 pm_runtime_enable(&udev->dev);
1679         }
1680
1681         name = udev->dev.driver->name;
1682         info = (struct driver_info *) prod->driver_info;
1683         if (!info) {
1684                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1685                 return -ENODEV;
1686         }
1687         xdev = interface_to_usbdev (udev);
1688         interface = udev->cur_altsetting;
1689
1690         status = -ENOMEM;
1691
1692         // set up our own records
1693         net = alloc_etherdev(sizeof(*dev));
1694         if (!net)
1695                 goto out;
1696
1697         /* netdev_printk() needs this so do it as early as possible */
1698         SET_NETDEV_DEV(net, &udev->dev);
1699
1700         dev = netdev_priv(net);
1701         dev->udev = xdev;
1702         dev->intf = udev;
1703         dev->driver_info = info;
1704         dev->driver_name = name;
1705
1706         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1707         if (!dev->stats64)
1708                 goto out0;
1709
1710         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1711                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1712         init_waitqueue_head(&dev->wait);
1713         skb_queue_head_init (&dev->rxq);
1714         skb_queue_head_init (&dev->txq);
1715         skb_queue_head_init (&dev->done);
1716         skb_queue_head_init(&dev->rxq_pause);
1717         dev->bh.func = usbnet_bh;
1718         dev->bh.data = (unsigned long) dev;
1719         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1720         init_usb_anchor(&dev->deferred);
1721         dev->delay.function = usbnet_bh;
1722         dev->delay.data = (unsigned long) dev;
1723         init_timer (&dev->delay);
1724         mutex_init (&dev->phy_mutex);
1725         mutex_init(&dev->interrupt_mutex);
1726         dev->interrupt_count = 0;
1727
1728         dev->net = net;
1729         strcpy (net->name, "usb%d");
1730         memcpy (net->dev_addr, node_id, sizeof node_id);
1731
1732         /* rx and tx sides can use different message sizes;
1733          * bind() should set rx_urb_size in that case.
1734          */
1735         dev->hard_mtu = net->mtu + net->hard_header_len;
1736         net->min_mtu = 0;
1737         net->max_mtu = ETH_MAX_MTU;
1738
1739         net->netdev_ops = &usbnet_netdev_ops;
1740         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1741         net->ethtool_ops = &usbnet_ethtool_ops;
1742
1743         // allow device-specific bind/init procedures
1744         // NOTE net->name still not usable ...
1745         if (info->bind) {
1746                 status = info->bind (dev, udev);
1747                 if (status < 0)
1748                         goto out1;
1749
1750                 // heuristic:  "usb%d" for links we know are two-host,
1751                 // else "eth%d" when there's reasonable doubt.  userspace
1752                 // can rename the link if it knows better.
1753                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1754                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1755                      (net->dev_addr [0] & 0x02) == 0))
1756                         strcpy (net->name, "eth%d");
1757                 /* WLAN devices should always be named "wlan%d" */
1758                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1759                         strcpy(net->name, "wlan%d");
1760                 /* WWAN devices should always be named "wwan%d" */
1761                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1762                         strcpy(net->name, "wwan%d");
1763
1764                 /* devices that cannot do ARP */
1765                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1766                         net->flags |= IFF_NOARP;
1767
1768                 /* maybe the remote can't receive an Ethernet MTU */
1769                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1770                         net->mtu = dev->hard_mtu - net->hard_header_len;
1771         } else if (!info->in || !info->out)
1772                 status = usbnet_get_endpoints (dev, udev);
1773         else {
1774                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1775                 dev->out = usb_sndbulkpipe (xdev, info->out);
1776                 if (!(info->flags & FLAG_NO_SETINT))
1777                         status = usb_set_interface (xdev,
1778                                 interface->desc.bInterfaceNumber,
1779                                 interface->desc.bAlternateSetting);
1780                 else
1781                         status = 0;
1782
1783         }
1784         if (status >= 0 && dev->status)
1785                 status = init_status (dev, udev);
1786         if (status < 0)
1787                 goto out3;
1788
1789         if (!dev->rx_urb_size)
1790                 dev->rx_urb_size = dev->hard_mtu;
1791         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1792         if (dev->maxpacket == 0) {
1793                 /* that is a broken device */
1794                 status = -ENODEV;
1795                 goto out4;
1796         }
1797
1798         /* let userspace know we have a random address */
1799         if (ether_addr_equal(net->dev_addr, node_id))
1800                 net->addr_assign_type = NET_ADDR_RANDOM;
1801
1802         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1803                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1804         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1805                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1806
1807         /* initialize max rx_qlen and tx_qlen */
1808         usbnet_update_max_qlen(dev);
1809
1810         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1811                 !(info->flags & FLAG_MULTI_PACKET)) {
1812                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1813                 if (!dev->padding_pkt) {
1814                         status = -ENOMEM;
1815                         goto out4;
1816                 }
1817         }
1818
1819         status = register_netdev (net);
1820         if (status)
1821                 goto out5;
1822         netif_info(dev, probe, dev->net,
1823                    "register '%s' at usb-%s-%s, %s, %pM\n",
1824                    udev->dev.driver->name,
1825                    xdev->bus->bus_name, xdev->devpath,
1826                    dev->driver_info->description,
1827                    net->dev_addr);
1828
1829         // ok, it's ready to go.
1830         usb_set_intfdata (udev, dev);
1831
1832         netif_device_attach (net);
1833
1834         if (dev->driver_info->flags & FLAG_LINK_INTR)
1835                 usbnet_link_change(dev, 0, 0);
1836
1837         return 0;
1838
1839 out5:
1840         kfree(dev->padding_pkt);
1841 out4:
1842         usb_free_urb(dev->interrupt);
1843 out3:
1844         if (info->unbind)
1845                 info->unbind (dev, udev);
1846 out1:
1847         /* subdrivers must undo all they did in bind() if they
1848          * fail it, but we may fail later and a deferred kevent
1849          * may trigger an error resubmitting itself and, worse,
1850          * schedule a timer. So we kill it all just in case.
1851          */
1852         cancel_work_sync(&dev->kevent);
1853         del_timer_sync(&dev->delay);
1854         free_percpu(dev->stats64);
1855 out0:
1856         free_netdev(net);
1857 out:
1858         return status;
1859 }
1860 EXPORT_SYMBOL_GPL(usbnet_probe);
1861
1862 /*-------------------------------------------------------------------------*/
1863
1864 /*
1865  * suspend the whole driver as soon as the first interface is suspended
1866  * resume only when the last interface is resumed
1867  */
1868
1869 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1870 {
1871         struct usbnet           *dev = usb_get_intfdata(intf);
1872
1873         if (!dev->suspend_count++) {
1874                 spin_lock_irq(&dev->txq.lock);
1875                 /* don't autosuspend while transmitting */
1876                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1877                         dev->suspend_count--;
1878                         spin_unlock_irq(&dev->txq.lock);
1879                         return -EBUSY;
1880                 } else {
1881                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1882                         spin_unlock_irq(&dev->txq.lock);
1883                 }
1884                 /*
1885                  * accelerate emptying of the rx and queues, to avoid
1886                  * having everything error out.
1887                  */
1888                 netif_device_detach (dev->net);
1889                 usbnet_terminate_urbs(dev);
1890                 __usbnet_status_stop_force(dev);
1891
1892                 /*
1893                  * reattach so runtime management can use and
1894                  * wake the device
1895                  */
1896                 netif_device_attach (dev->net);
1897         }
1898         return 0;
1899 }
1900 EXPORT_SYMBOL_GPL(usbnet_suspend);
1901
1902 int usbnet_resume (struct usb_interface *intf)
1903 {
1904         struct usbnet           *dev = usb_get_intfdata(intf);
1905         struct sk_buff          *skb;
1906         struct urb              *res;
1907         int                     retval;
1908
1909         if (!--dev->suspend_count) {
1910                 /* resume interrupt URB if it was previously submitted */
1911                 __usbnet_status_start_force(dev, GFP_NOIO);
1912
1913                 spin_lock_irq(&dev->txq.lock);
1914                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1915
1916                         skb = (struct sk_buff *)res->context;
1917                         retval = usb_submit_urb(res, GFP_ATOMIC);
1918                         if (retval < 0) {
1919                                 dev_kfree_skb_any(skb);
1920                                 kfree(res->sg);
1921                                 usb_free_urb(res);
1922                                 usb_autopm_put_interface_async(dev->intf);
1923                         } else {
1924                                 netif_trans_update(dev->net);
1925                                 __skb_queue_tail(&dev->txq, skb);
1926                         }
1927                 }
1928
1929                 smp_mb();
1930                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1931                 spin_unlock_irq(&dev->txq.lock);
1932
1933                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1934                         /* handle remote wakeup ASAP
1935                          * we cannot race against stop
1936                          */
1937                         if (netif_device_present(dev->net) &&
1938                                 !timer_pending(&dev->delay) &&
1939                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1940                                         rx_alloc_submit(dev, GFP_NOIO);
1941
1942                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1943                                 netif_tx_wake_all_queues(dev->net);
1944                         tasklet_schedule (&dev->bh);
1945                 }
1946         }
1947
1948         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1949                 usb_autopm_get_interface_no_resume(intf);
1950
1951         return 0;
1952 }
1953 EXPORT_SYMBOL_GPL(usbnet_resume);
1954
1955 /*
1956  * Either a subdriver implements manage_power, then it is assumed to always
1957  * be ready to be suspended or it reports the readiness to be suspended
1958  * explicitly
1959  */
1960 void usbnet_device_suggests_idle(struct usbnet *dev)
1961 {
1962         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1963                 dev->intf->needs_remote_wakeup = 1;
1964                 usb_autopm_put_interface_async(dev->intf);
1965         }
1966 }
1967 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1968
1969 /*
1970  * For devices that can do without special commands
1971  */
1972 int usbnet_manage_power(struct usbnet *dev, int on)
1973 {
1974         dev->intf->needs_remote_wakeup = on;
1975         return 0;
1976 }
1977 EXPORT_SYMBOL(usbnet_manage_power);
1978
1979 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1980 {
1981         /* update link after link is reseted */
1982         if (link && !need_reset)
1983                 netif_carrier_on(dev->net);
1984         else
1985                 netif_carrier_off(dev->net);
1986
1987         if (need_reset && link)
1988                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1989         else
1990                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1991 }
1992 EXPORT_SYMBOL(usbnet_link_change);
1993
1994 /*-------------------------------------------------------------------------*/
1995 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1996                              u16 value, u16 index, void *data, u16 size)
1997 {
1998         void *buf = NULL;
1999         int err = -ENOMEM;
2000
2001         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
2002                    " value=0x%04x index=0x%04x size=%d\n",
2003                    cmd, reqtype, value, index, size);
2004
2005         if (size) {
2006                 buf = kmalloc(size, GFP_NOIO);
2007                 if (!buf)
2008                         goto out;
2009         }
2010
2011         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2012                               cmd, reqtype, value, index, buf, size,
2013                               USB_CTRL_GET_TIMEOUT);
2014         if (err > 0 && err <= size) {
2015         if (data)
2016             memcpy(data, buf, err);
2017         else
2018             netdev_dbg(dev->net,
2019                 "Huh? Data requested but thrown away.\n");
2020     }
2021         kfree(buf);
2022 out:
2023         return err;
2024 }
2025
2026 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2027                               u16 value, u16 index, const void *data,
2028                               u16 size)
2029 {
2030         void *buf = NULL;
2031         int err = -ENOMEM;
2032
2033         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2034                    " value=0x%04x index=0x%04x size=%d\n",
2035                    cmd, reqtype, value, index, size);
2036
2037         if (data) {
2038                 buf = kmemdup(data, size, GFP_NOIO);
2039                 if (!buf)
2040                         goto out;
2041         } else {
2042         if (size) {
2043             WARN_ON_ONCE(1);
2044             err = -EINVAL;
2045             goto out;
2046         }
2047     }
2048
2049         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2050                               cmd, reqtype, value, index, buf, size,
2051                               USB_CTRL_SET_TIMEOUT);
2052         kfree(buf);
2053
2054 out:
2055         return err;
2056 }
2057
2058 /*
2059  * The function can't be called inside suspend/resume callback,
2060  * otherwise deadlock will be caused.
2061  */
2062 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2063                     u16 value, u16 index, void *data, u16 size)
2064 {
2065         int ret;
2066
2067         if (usb_autopm_get_interface(dev->intf) < 0)
2068                 return -ENODEV;
2069         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2070                                 data, size);
2071         usb_autopm_put_interface(dev->intf);
2072         return ret;
2073 }
2074 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2075
2076 /*
2077  * The function can't be called inside suspend/resume callback,
2078  * otherwise deadlock will be caused.
2079  */
2080 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2081                      u16 value, u16 index, const void *data, u16 size)
2082 {
2083         int ret;
2084
2085         if (usb_autopm_get_interface(dev->intf) < 0)
2086                 return -ENODEV;
2087         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2088                                  data, size);
2089         usb_autopm_put_interface(dev->intf);
2090         return ret;
2091 }
2092 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2093
2094 /*
2095  * The function can be called inside suspend/resume callback safely
2096  * and should only be called by suspend/resume callback generally.
2097  */
2098 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2099                           u16 value, u16 index, void *data, u16 size)
2100 {
2101         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2102                                  data, size);
2103 }
2104 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2105
2106 /*
2107  * The function can be called inside suspend/resume callback safely
2108  * and should only be called by suspend/resume callback generally.
2109  */
2110 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2111                           u16 value, u16 index, const void *data,
2112                           u16 size)
2113 {
2114         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2115                                   data, size);
2116 }
2117 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2118
2119 static void usbnet_async_cmd_cb(struct urb *urb)
2120 {
2121         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2122         int status = urb->status;
2123
2124         if (status < 0)
2125                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2126                         __func__, status);
2127
2128         kfree(req);
2129         usb_free_urb(urb);
2130 }
2131
2132 /*
2133  * The caller must make sure that device can't be put into suspend
2134  * state until the control URB completes.
2135  */
2136 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2137                            u16 value, u16 index, const void *data, u16 size)
2138 {
2139         struct usb_ctrlrequest *req;
2140         struct urb *urb;
2141         int err = -ENOMEM;
2142         void *buf = NULL;
2143
2144         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2145                    " value=0x%04x index=0x%04x size=%d\n",
2146                    cmd, reqtype, value, index, size);
2147
2148         urb = usb_alloc_urb(0, GFP_ATOMIC);
2149         if (!urb)
2150                 goto fail;
2151
2152         if (data) {
2153                 buf = kmemdup(data, size, GFP_ATOMIC);
2154                 if (!buf) {
2155                         netdev_err(dev->net, "Error allocating buffer"
2156                                    " in %s!\n", __func__);
2157                         goto fail_free_urb;
2158                 }
2159         }
2160
2161         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2162         if (!req)
2163                 goto fail_free_buf;
2164
2165         req->bRequestType = reqtype;
2166         req->bRequest = cmd;
2167         req->wValue = cpu_to_le16(value);
2168         req->wIndex = cpu_to_le16(index);
2169         req->wLength = cpu_to_le16(size);
2170
2171         usb_fill_control_urb(urb, dev->udev,
2172                              usb_sndctrlpipe(dev->udev, 0),
2173                              (void *)req, buf, size,
2174                              usbnet_async_cmd_cb, req);
2175         urb->transfer_flags |= URB_FREE_BUFFER;
2176
2177         err = usb_submit_urb(urb, GFP_ATOMIC);
2178         if (err < 0) {
2179                 netdev_err(dev->net, "Error submitting the control"
2180                            " message: status=%d\n", err);
2181                 goto fail_free_all;
2182         }
2183         return 0;
2184
2185 fail_free_all:
2186         kfree(req);
2187 fail_free_buf:
2188         kfree(buf);
2189         /*
2190          * avoid a double free
2191          * needed because the flag can be set only
2192          * after filling the URB
2193          */
2194         urb->transfer_flags = 0;
2195 fail_free_urb:
2196         usb_free_urb(urb);
2197 fail:
2198         return err;
2199
2200 }
2201 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2202 /*-------------------------------------------------------------------------*/
2203
2204 static int __init usbnet_init(void)
2205 {
2206         /* Compiler should optimize this out. */
2207         BUILD_BUG_ON(
2208                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2209
2210         eth_random_addr(node_id);
2211         return 0;
2212 }
2213 module_init(usbnet_init);
2214
2215 static void __exit usbnet_exit(void)
2216 {
2217 }
2218 module_exit(usbnet_exit);
2219
2220 MODULE_AUTHOR("David Brownell");
2221 MODULE_DESCRIPTION("USB network driver framework");
2222 MODULE_LICENSE("GPL");