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                         switch (e->desc.bmAttributes) {
 116                         case USB_ENDPOINT_XFER_INT:
 117                                 if (!usb_endpoint_dir_in(&e->desc))
 118                                         continue;
 119                                 intr = 1;
 120                                 /* FALLTHROUGH */
 121                         case USB_ENDPOINT_XFER_BULK:
 122                                 break;
 123                         default:
 124                                 continue;
 125                         }
 126                         if (usb_endpoint_dir_in(&e->desc)) {
 127                                 if (!intr && !in)
 128                                         in = e;
 129                                 else if (intr && !status)
 130                                         status = e;
 131                         } else {
 132                                 if (!out)
 133                                         out = e;
 134                         }
 135                 }
 136                 if (in && out)
 137                         break;
 138         }
 139         if (!alt || !in || !out)
 140                 return -EINVAL;
 141
 142         if (alt->desc.bAlternateSetting != 0 ||
 143             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 144                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 145                                 alt->desc.bAlternateSetting);
 146                 if (tmp < 0)
 147                         return tmp;
 148         }
 149
 150         dev->in = usb_rcvbulkpipe (dev->udev,
 151                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 152         dev->out = usb_sndbulkpipe (dev->udev,
 153                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->status = status;
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 158
 159 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 160 {
 161         int             tmp = -1, ret;
 162         unsigned char   buf [13];
 163
 164         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 165         if (ret == 12)
 166                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 167         if (tmp < 0) {
 168                 dev_dbg(&dev->udev->dev,
 169                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170                 if (ret >= 0)
 171                         ret = -EINVAL;
 172                 return ret;
 173         }
 174         return 0;
 175 }
 176 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 177
 178 static void intr_complete (struct urb *urb)
 179 {
 180         struct usbnet   *dev = urb->context;
 181         int             status = urb->status;
 182
 183         switch (status) {
 184         /* success */
 185         case 0:
 186                 dev->driver_info->status(dev, urb);
 187                 break;
 188
 189         /* software-driven interface shutdown */
 190         case -ENOENT:           /* urb killed */
 191         case -ESHUTDOWN:        /* hardware gone */
 192                 netif_dbg(dev, ifdown, dev->net,
 193                           "intr shutdown, code %d\n", status);
 194                 return;
 195
 196         /* NOTE:  not throttling like RX/TX, since this endpoint
 197          * already polls infrequently
 198          */
 199         default:
 200                 netdev_dbg(dev->net, "intr status %d\n", status);
 201                 break;
 202         }
 203
 204         status = usb_submit_urb (urb, GFP_ATOMIC);
 205         if (status != 0)
 206                 netif_err(dev, timer, dev->net,
 207                           "intr resubmit --> %d\n", status);
 208 }
 209
 210 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 211 {
 212         char            *buf = NULL;
 213         unsigned        pipe = 0;
 214         unsigned        maxp;
 215         unsigned        period;
 216
 217         if (!dev->driver_info->status)
 218                 return 0;
 219
 220         pipe = usb_rcvintpipe (dev->udev,
 221                         dev->status->desc.bEndpointAddress
 222                                 & USB_ENDPOINT_NUMBER_MASK);
 223         maxp = usb_maxpacket (dev->udev, pipe, 0);
 224
 225         /* avoid 1 msec chatter:  min 8 msec poll rate */
 226         period = max ((int) dev->status->desc.bInterval,
 227                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 228
 229         buf = kmalloc (maxp, GFP_KERNEL);
 230         if (buf) {
 231                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 232                 if (!dev->interrupt) {
 233                         kfree (buf);
 234                         return -ENOMEM;
 235                 } else {
 236                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 237                                 buf, maxp, intr_complete, dev, period);
 238                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 239                         dev_dbg(&intf->dev,
 240                                 "status ep%din, %d bytes period %d\n",
 241                                 usb_pipeendpoint(pipe), maxp, period);
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 248 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 249 {
 250         int ret = 0;
 251
 252         WARN_ON_ONCE(dev->interrupt == NULL);
 253         if (dev->interrupt) {
 254                 mutex_lock(&dev->interrupt_mutex);
 255
 256                 if (++dev->interrupt_count == 1)
 257                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 258
 259                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 260                         dev->interrupt_count);
 261                 mutex_unlock(&dev->interrupt_mutex);
 262         }
 263         return ret;
 264 }
 265 EXPORT_SYMBOL_GPL(usbnet_status_start);
 266
 267 /* For resume; submit interrupt URB if previously submitted */
 268 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 269 {
 270         int ret = 0;
 271
 272         mutex_lock(&dev->interrupt_mutex);
 273         if (dev->interrupt_count) {
 274                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 275                 dev_dbg(&dev->udev->dev,
 276                         "submitted interrupt URB for resume\n");
 277         }
 278         mutex_unlock(&dev->interrupt_mutex);
 279         return ret;
 280 }
 281
 282 /* Kill the interrupt URB if all submitters want it killed */
 283 void usbnet_status_stop(struct usbnet *dev)
 284 {
 285         if (dev->interrupt) {
 286                 mutex_lock(&dev->interrupt_mutex);
 287                 WARN_ON(dev->interrupt_count == 0);
 288
 289                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 290                         usb_kill_urb(dev->interrupt);
 291
 292                 dev_dbg(&dev->udev->dev,
 293                         "decremented interrupt URB count to %d\n",
 294                         dev->interrupt_count);
 295                 mutex_unlock(&dev->interrupt_mutex);
 296         }
 297 }
 298 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 299
 300 /* For suspend; always kill interrupt URB */
 301 static void __usbnet_status_stop_force(struct usbnet *dev)
 302 {
 303         if (dev->interrupt) {
 304                 mutex_lock(&dev->interrupt_mutex);
 305                 usb_kill_urb(dev->interrupt);
 306                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 307                 mutex_unlock(&dev->interrupt_mutex);
 308         }
 309 }
 310
 311 /* Passes this packet up the stack, updating its accounting.
 312  * Some link protocols batch packets, so their rx_fixup paths
 313  * can return clones as well as just modify the original skb.
 314  */
 315 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 316 {
 317         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 318         unsigned long flags;
 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         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 331         stats64->rx_packets++;
 332         stats64->rx_bytes += skb->len;
 333         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 334
 335         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 336                   skb->len + sizeof (struct ethhdr), skb->protocol);
 337         memset (skb->cb, 0, sizeof (struct skb_data));
 338
 339         if (skb_defer_rx_timestamp(skb))
 340                 return;
 341
 342         status = netif_rx (skb);
 343         if (status != NET_RX_SUCCESS)
 344                 netif_dbg(dev, rx_err, dev->net,
 345                           "netif_rx status %d\n", status);
 346 }
 347 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 348
 349 /* must be called if hard_mtu or rx_urb_size changed */
 350 void usbnet_update_max_qlen(struct usbnet *dev)
 351 {
 352         enum usb_device_speed speed = dev->udev->speed;
 353
 354         switch (speed) {
 355         case USB_SPEED_HIGH:
 356                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 357                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 358                 break;
 359         case USB_SPEED_SUPER:
 360         case USB_SPEED_SUPER_PLUS:
 361                 /*
 362                  * Not take default 5ms qlen for super speed HC to
 363                  * save memory, and iperf tests show 2.5ms qlen can
 364                  * work well
 365                  */
 366                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 367                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 368                 break;
 369         default:
 370                 dev->rx_qlen = dev->tx_qlen = 4;
 371         }
 372 }
 373 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 374
 375 \f
 376 /*-------------------------------------------------------------------------
 377  *
 378  * Network Device Driver (peer link to "Host Device", from USB host)
 379  *
 380  *-------------------------------------------------------------------------*/
 381
 382 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 383 {
 384         struct usbnet   *dev = netdev_priv(net);
 385         int             ll_mtu = new_mtu + net->hard_header_len;
 386         int             old_hard_mtu = dev->hard_mtu;
 387         int             old_rx_urb_size = dev->rx_urb_size;
 388
 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                 netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 463         else
 464                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 465 }
 466 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 467
 468 /*-------------------------------------------------------------------------*/
 469
 470 static void rx_complete (struct urb *urb);
 471
 472 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 473 {
 474         struct sk_buff          *skb;
 475         struct skb_data         *entry;
 476         int                     retval = 0;
 477         unsigned long           lockflags;
 478         size_t                  size = dev->rx_urb_size;
 479
 480         /* prevent rx skb allocation when error ratio is high */
 481         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 482                 usb_free_urb(urb);
 483                 return -ENOLINK;
 484         }
 485
 486         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 487                 skb = __netdev_alloc_skb(dev->net, size, flags);
 488         else
 489                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 490         if (!skb) {
 491                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 492                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 493                 usb_free_urb (urb);
 494                 return -ENOMEM;
 495         }
 496
 497         entry = (struct skb_data *) skb->cb;
 498         entry->urb = urb;
 499         entry->dev = dev;
 500         entry->length = 0;
 501
 502         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 503                 skb->data, size, rx_complete, skb);
 504
 505         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 506
 507         if (netif_running (dev->net) &&
 508             netif_device_present (dev->net) &&
 509             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 510             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 511                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 512                 case -EPIPE:
 513                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 514                         break;
 515                 case -ENOMEM:
 516                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 517                         break;
 518                 case -ENODEV:
 519                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 520                         netif_device_detach (dev->net);
 521                         break;
 522                 case -EHOSTUNREACH:
 523                         retval = -ENOLINK;
 524                         break;
 525                 default:
 526                         netif_dbg(dev, rx_err, dev->net,
 527                                   "rx submit, %d\n", retval);
 528                         tasklet_schedule (&dev->bh);
 529                         break;
 530                 case 0:
 531                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 532                 }
 533         } else {
 534                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 535                 retval = -ENOLINK;
 536         }
 537         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 538         if (retval) {
 539                 dev_kfree_skb_any (skb);
 540                 usb_free_urb (urb);
 541         }
 542         return retval;
 543 }
 544
 545
 546 /*-------------------------------------------------------------------------*/
 547
 548 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 549 {
 550         if (dev->driver_info->rx_fixup &&
 551             !dev->driver_info->rx_fixup (dev, skb)) {
 552                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 553                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 554                         dev->net->stats.rx_errors++;
 555                 goto done;
 556         }
 557         // else network stack removes extra byte if we forced a short packet
 558
 559         /* all data was already cloned from skb inside the driver */
 560         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 561                 goto done;
 562
 563         if (skb->len < ETH_HLEN) {
 564                 dev->net->stats.rx_errors++;
 565                 dev->net->stats.rx_length_errors++;
 566                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 567         } else {
 568                 usbnet_skb_return(dev, skb);
 569                 return;
 570         }
 571
 572 done:
 573         skb_queue_tail(&dev->done, skb);
 574 }
 575
 576 /*-------------------------------------------------------------------------*/
 577
 578 static void rx_complete (struct urb *urb)
 579 {
 580         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 581         struct skb_data         *entry = (struct skb_data *) skb->cb;
 582         struct usbnet           *dev = entry->dev;
 583         int                     urb_status = urb->status;
 584         enum skb_state          state;
 585
 586         skb_put (skb, urb->actual_length);
 587         state = rx_done;
 588         entry->urb = NULL;
 589
 590         switch (urb_status) {
 591         /* success */
 592         case 0:
 593                 break;
 594
 595         /* stalls need manual reset. this is rare ... except that
 596          * when going through USB 2.0 TTs, unplug appears this way.
 597          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 598          * storm, recovering as needed.
 599          */
 600         case -EPIPE:
 601                 dev->net->stats.rx_errors++;
 602                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 603                 // FALLTHROUGH
 604
 605         /* software-driven interface shutdown */
 606         case -ECONNRESET:               /* async unlink */
 607         case -ESHUTDOWN:                /* hardware gone */
 608                 netif_dbg(dev, ifdown, dev->net,
 609                           "rx shutdown, code %d\n", urb_status);
 610                 goto block;
 611
 612         /* we get controller i/o faults during hub_wq disconnect() delays.
 613          * throttle down resubmits, to avoid log floods; just temporarily,
 614          * so we still recover when the fault isn't a hub_wq delay.
 615          */
 616         case -EPROTO:
 617         case -ETIME:
 618         case -EILSEQ:
 619                 dev->net->stats.rx_errors++;
 620                 if (!timer_pending (&dev->delay)) {
 621                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 622                         netif_dbg(dev, link, dev->net,
 623                                   "rx throttle %d\n", urb_status);
 624                 }
 625 block:
 626                 state = rx_cleanup;
 627                 entry->urb = urb;
 628                 urb = NULL;
 629                 break;
 630
 631         /* data overrun ... flush fifo? */
 632         case -EOVERFLOW:
 633                 dev->net->stats.rx_over_errors++;
 634                 // FALLTHROUGH
 635
 636         default:
 637                 state = rx_cleanup;
 638                 dev->net->stats.rx_errors++;
 639                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 640                 break;
 641         }
 642
 643         /* stop rx if packet error rate is high */
 644         if (++dev->pkt_cnt > 30) {
 645                 dev->pkt_cnt = 0;
 646                 dev->pkt_err = 0;
 647         } else {
 648                 if (state == rx_cleanup)
 649                         dev->pkt_err++;
 650                 if (dev->pkt_err > 20)
 651                         set_bit(EVENT_RX_KILL, &dev->flags);
 652         }
 653
 654         state = defer_bh(dev, skb, &dev->rxq, state);
 655
 656         if (urb) {
 657                 if (netif_running (dev->net) &&
 658                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 659                     state != unlink_start) {
 660                         rx_submit (dev, urb, GFP_ATOMIC);
 661                         usb_mark_last_busy(dev->udev);
 662                         return;
 663                 }
 664                 usb_free_urb (urb);
 665         }
 666         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 667 }
 668
 669 /*-------------------------------------------------------------------------*/
 670 void usbnet_pause_rx(struct usbnet *dev)
 671 {
 672         set_bit(EVENT_RX_PAUSED, &dev->flags);
 673
 674         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 675 }
 676 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 677
 678 void usbnet_resume_rx(struct usbnet *dev)
 679 {
 680         struct sk_buff *skb;
 681         int num = 0;
 682
 683         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 686                 usbnet_skb_return(dev, skb);
 687                 num++;
 688         }
 689
 690         tasklet_schedule(&dev->bh);
 691
 692         netif_dbg(dev, rx_status, dev->net,
 693                   "paused rx queue disabled, %d skbs requeued\n", num);
 694 }
 695 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 696
 697 void usbnet_purge_paused_rxq(struct usbnet *dev)
 698 {
 699         skb_queue_purge(&dev->rxq_pause);
 700 }
 701 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 702
 703 /*-------------------------------------------------------------------------*/
 704
 705 // unlink pending rx/tx; completion handlers do all other cleanup
 706
 707 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 708 {
 709         unsigned long           flags;
 710         struct sk_buff          *skb;
 711         int                     count = 0;
 712
 713         spin_lock_irqsave (&q->lock, flags);
 714         while (!skb_queue_empty(q)) {
 715                 struct skb_data         *entry;
 716                 struct urb              *urb;
 717                 int                     retval;
 718
 719                 skb_queue_walk(q, skb) {
 720                         entry = (struct skb_data *) skb->cb;
 721                         if (entry->state != unlink_start)
 722                                 goto found;
 723                 }
 724                 break;
 725 found:
 726                 entry->state = unlink_start;
 727                 urb = entry->urb;
 728
 729                 /*
 730                  * Get reference count of the URB to avoid it to be
 731                  * freed during usb_unlink_urb, which may trigger
 732                  * use-after-free problem inside usb_unlink_urb since
 733                  * usb_unlink_urb is always racing with .complete
 734                  * handler(include defer_bh).
 735                  */
 736                 usb_get_urb(urb);
 737                 spin_unlock_irqrestore(&q->lock, flags);
 738                 // during some PM-driven resume scenarios,
 739                 // these (async) unlinks complete immediately
 740                 retval = usb_unlink_urb (urb);
 741                 if (retval != -EINPROGRESS && retval != 0)
 742                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 743                 else
 744                         count++;
 745                 usb_put_urb(urb);
 746                 spin_lock_irqsave(&q->lock, flags);
 747         }
 748         spin_unlock_irqrestore (&q->lock, flags);
 749         return count;
 750 }
 751
 752 // Flush all pending rx urbs
 753 // minidrivers may need to do this when the MTU changes
 754
 755 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 756 {
 757         if (netif_running(dev->net)) {
 758                 (void) unlink_urbs (dev, &dev->rxq);
 759                 tasklet_schedule(&dev->bh);
 760         }
 761 }
 762 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 763
 764 /*-------------------------------------------------------------------------*/
 765
 766 static void wait_skb_queue_empty(struct sk_buff_head *q)
 767 {
 768         unsigned long flags;
 769
 770         spin_lock_irqsave(&q->lock, flags);
 771         while (!skb_queue_empty(q)) {
 772                 spin_unlock_irqrestore(&q->lock, flags);
 773                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 774                 set_current_state(TASK_UNINTERRUPTIBLE);
 775                 spin_lock_irqsave(&q->lock, flags);
 776         }
 777         spin_unlock_irqrestore(&q->lock, flags);
 778 }
 779
 780 // precondition: never called in_interrupt
 781 static void usbnet_terminate_urbs(struct usbnet *dev)
 782 {
 783         DECLARE_WAITQUEUE(wait, current);
 784         int temp;
 785
 786         /* ensure there are no more active urbs */
 787         add_wait_queue(&dev->wait, &wait);
 788         set_current_state(TASK_UNINTERRUPTIBLE);
 789         temp = unlink_urbs(dev, &dev->txq) +
 790                 unlink_urbs(dev, &dev->rxq);
 791
 792         /* maybe wait for deletions to finish. */
 793         wait_skb_queue_empty(&dev->rxq);
 794         wait_skb_queue_empty(&dev->txq);
 795         wait_skb_queue_empty(&dev->done);
 796         netif_dbg(dev, ifdown, dev->net,
 797                   "waited for %d urb completions\n", temp);
 798         set_current_state(TASK_RUNNING);
 799         remove_wait_queue(&dev->wait, &wait);
 800 }
 801
 802 int usbnet_stop (struct net_device *net)
 803 {
 804         struct usbnet           *dev = netdev_priv(net);
 805         struct driver_info      *info = dev->driver_info;
 806         int                     retval, pm, mpn;
 807
 808         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 809         netif_stop_queue (net);
 810
 811         netif_info(dev, ifdown, dev->net,
 812                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 813                    net->stats.rx_packets, net->stats.tx_packets,
 814                    net->stats.rx_errors, net->stats.tx_errors);
 815
 816         /* to not race resume */
 817         pm = usb_autopm_get_interface(dev->intf);
 818         /* allow minidriver to stop correctly (wireless devices to turn off
 819          * radio etc) */
 820         if (info->stop) {
 821                 retval = info->stop(dev);
 822                 if (retval < 0)
 823                         netif_info(dev, ifdown, dev->net,
 824                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 825                                    retval,
 826                                    dev->udev->bus->bus_name, dev->udev->devpath,
 827                                    info->description);
 828         }
 829
 830         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 831                 usbnet_terminate_urbs(dev);
 832
 833         usbnet_status_stop(dev);
 834
 835         usbnet_purge_paused_rxq(dev);
 836
 837         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 838
 839         /* deferred work (task, timer, softirq) must also stop.
 840          * can't flush_scheduled_work() until we drop rtnl (later),
 841          * else workers could deadlock; so make workers a NOP.
 842          */
 843         dev->flags = 0;
 844         del_timer_sync (&dev->delay);
 845         tasklet_kill (&dev->bh);
 846         if (!pm)
 847                 usb_autopm_put_interface(dev->intf);
 848
 849         if (info->manage_power && mpn)
 850                 info->manage_power(dev, 0);
 851         else
 852                 usb_autopm_put_interface(dev->intf);
 853
 854         return 0;
 855 }
 856 EXPORT_SYMBOL_GPL(usbnet_stop);
 857
 858 /*-------------------------------------------------------------------------*/
 859
 860 // posts reads, and enables write queuing
 861
 862 // precondition: never called in_interrupt
 863
 864 int usbnet_open (struct net_device *net)
 865 {
 866         struct usbnet           *dev = netdev_priv(net);
 867         int                     retval;
 868         struct driver_info      *info = dev->driver_info;
 869
 870         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 871                 netif_info(dev, ifup, dev->net,
 872                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 873                            retval,
 874                            dev->udev->bus->bus_name,
 875                            dev->udev->devpath,
 876                            info->description);
 877                 goto done_nopm;
 878         }
 879
 880         // put into "known safe" state
 881         if (info->reset && (retval = info->reset (dev)) < 0) {
 882                 netif_info(dev, ifup, dev->net,
 883                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 884                            retval,
 885                            dev->udev->bus->bus_name,
 886                            dev->udev->devpath,
 887                            info->description);
 888                 goto done;
 889         }
 890
 891         /* hard_mtu or rx_urb_size may change in reset() */
 892         usbnet_update_max_qlen(dev);
 893
 894         // insist peer be connected
 895         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 896                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 897                 goto done;
 898         }
 899
 900         /* start any status interrupt transfer */
 901         if (dev->interrupt) {
 902                 retval = usbnet_status_start(dev, GFP_KERNEL);
 903                 if (retval < 0) {
 904                         netif_err(dev, ifup, dev->net,
 905                                   "intr submit %d\n", retval);
 906                         goto done;
 907                 }
 908         }
 909
 910         set_bit(EVENT_DEV_OPEN, &dev->flags);
 911         netif_start_queue (net);
 912         netif_info(dev, ifup, dev->net,
 913                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 914                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 915                    dev->net->mtu,
 916                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 917                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 918                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 919                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 920                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 921                    "simple");
 922
 923         /* reset rx error state */
 924         dev->pkt_cnt = 0;
 925         dev->pkt_err = 0;
 926         clear_bit(EVENT_RX_KILL, &dev->flags);
 927
 928         // delay posting reads until we're fully open
 929         tasklet_schedule (&dev->bh);
 930         if (info->manage_power) {
 931                 retval = info->manage_power(dev, 1);
 932                 if (retval < 0) {
 933                         retval = 0;
 934                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 935                 } else {
 936                         usb_autopm_put_interface(dev->intf);
 937                 }
 938         }
 939         return retval;
 940 done:
 941         usb_autopm_put_interface(dev->intf);
 942 done_nopm:
 943         return retval;
 944 }
 945 EXPORT_SYMBOL_GPL(usbnet_open);
 946
 947 /*-------------------------------------------------------------------------*/
 948
 949 /* ethtool methods; minidrivers may need to add some more, but
 950  * they'll probably want to use this base set.
 951  */
 952
 953 int usbnet_get_link_ksettings(struct net_device *net,
 954                               struct ethtool_link_ksettings *cmd)
 955 {
 956         struct usbnet *dev = netdev_priv(net);
 957
 958         if (!dev->mii.mdio_read)
 959                 return -EOPNOTSUPP;
 960
 961         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 962
 963         return 0;
 964 }
 965 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 966
 967 int usbnet_set_link_ksettings(struct net_device *net,
 968                               const struct ethtool_link_ksettings *cmd)
 969 {
 970         struct usbnet *dev = netdev_priv(net);
 971         int retval;
 972
 973         if (!dev->mii.mdio_write)
 974                 return -EOPNOTSUPP;
 975
 976         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 977
 978         /* link speed/duplex might have changed */
 979         if (dev->driver_info->link_reset)
 980                 dev->driver_info->link_reset(dev);
 981
 982         /* hard_mtu or rx_urb_size may change in link_reset() */
 983         usbnet_update_max_qlen(dev);
 984
 985         return retval;
 986 }
 987 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 988
 989 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 990 {
 991         struct usbnet *dev = netdev_priv(net);
 992         unsigned int start;
 993         int cpu;
 994
 995         netdev_stats_to_stats64(stats, &net->stats);
 996
 997         for_each_possible_cpu(cpu) {
 998                 struct pcpu_sw_netstats *stats64;
 999                 u64 rx_packets, rx_bytes;
1000                 u64 tx_packets, tx_bytes;
1001
1002                 stats64 = per_cpu_ptr(dev->stats64, cpu);
1003
1004                 do {
1005                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1006                         rx_packets = stats64->rx_packets;
1007                         rx_bytes = stats64->rx_bytes;
1008                         tx_packets = stats64->tx_packets;
1009                         tx_bytes = stats64->tx_bytes;
1010                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1011
1012                 stats->rx_packets += rx_packets;
1013                 stats->rx_bytes += rx_bytes;
1014                 stats->tx_packets += tx_packets;
1015                 stats->tx_bytes += tx_bytes;
1016         }
1017 }
1018 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1019
1020 u32 usbnet_get_link (struct net_device *net)
1021 {
1022         struct usbnet *dev = netdev_priv(net);
1023
1024         /* If a check_connect is defined, return its result */
1025         if (dev->driver_info->check_connect)
1026                 return dev->driver_info->check_connect (dev) == 0;
1027
1028         /* if the device has mii operations, use those */
1029         if (dev->mii.mdio_read)
1030                 return mii_link_ok(&dev->mii);
1031
1032         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1033         return ethtool_op_get_link(net);
1034 }
1035 EXPORT_SYMBOL_GPL(usbnet_get_link);
1036
1037 int usbnet_nway_reset(struct net_device *net)
1038 {
1039         struct usbnet *dev = netdev_priv(net);
1040
1041         if (!dev->mii.mdio_write)
1042                 return -EOPNOTSUPP;
1043
1044         return mii_nway_restart(&dev->mii);
1045 }
1046 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1047
1048 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1049 {
1050         struct usbnet *dev = netdev_priv(net);
1051
1052         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1053         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1054         strlcpy (info->fw_version, dev->driver_info->description,
1055                 sizeof info->fw_version);
1056         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1057 }
1058 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1059
1060 u32 usbnet_get_msglevel (struct net_device *net)
1061 {
1062         struct usbnet *dev = netdev_priv(net);
1063
1064         return dev->msg_enable;
1065 }
1066 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1067
1068 void usbnet_set_msglevel (struct net_device *net, u32 level)
1069 {
1070         struct usbnet *dev = netdev_priv(net);
1071
1072         dev->msg_enable = level;
1073 }
1074 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1075
1076 /* drivers may override default ethtool_ops in their bind() routine */
1077 static const struct ethtool_ops usbnet_ethtool_ops = {
1078         .get_link               = usbnet_get_link,
1079         .nway_reset             = usbnet_nway_reset,
1080         .get_drvinfo            = usbnet_get_drvinfo,
1081         .get_msglevel           = usbnet_get_msglevel,
1082         .set_msglevel           = usbnet_set_msglevel,
1083         .get_ts_info            = ethtool_op_get_ts_info,
1084         .get_link_ksettings     = usbnet_get_link_ksettings,
1085         .set_link_ksettings     = usbnet_set_link_ksettings,
1086 };
1087
1088 /*-------------------------------------------------------------------------*/
1089
1090 static void __handle_link_change(struct usbnet *dev)
1091 {
1092         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1093                 return;
1094
1095         if (!netif_carrier_ok(dev->net)) {
1096                 /* kill URBs for reading packets to save bus bandwidth */
1097                 unlink_urbs(dev, &dev->rxq);
1098
1099                 /*
1100                  * tx_timeout will unlink URBs for sending packets and
1101                  * tx queue is stopped by netcore after link becomes off
1102                  */
1103         } else {
1104                 /* submitting URBs for reading packets */
1105                 tasklet_schedule(&dev->bh);
1106         }
1107
1108         /* hard_mtu or rx_urb_size may change during link change */
1109         usbnet_update_max_qlen(dev);
1110
1111         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1112 }
1113
1114 static void usbnet_set_rx_mode(struct net_device *net)
1115 {
1116         struct usbnet           *dev = netdev_priv(net);
1117
1118         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1119 }
1120
1121 static void __handle_set_rx_mode(struct usbnet *dev)
1122 {
1123         if (dev->driver_info->set_rx_mode)
1124                 (dev->driver_info->set_rx_mode)(dev);
1125
1126         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1127 }
1128
1129 /* work that cannot be done in interrupt context uses keventd.
1130  *
1131  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1132  * especially now that control transfers can be queued.
1133  */
1134 static void
1135 usbnet_deferred_kevent (struct work_struct *work)
1136 {
1137         struct usbnet           *dev =
1138                 container_of(work, struct usbnet, kevent);
1139         int                     status;
1140
1141         /* usb_clear_halt() needs a thread context */
1142         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1143                 unlink_urbs (dev, &dev->txq);
1144                 status = usb_autopm_get_interface(dev->intf);
1145                 if (status < 0)
1146                         goto fail_pipe;
1147                 status = usb_clear_halt (dev->udev, dev->out);
1148                 usb_autopm_put_interface(dev->intf);
1149                 if (status < 0 &&
1150                     status != -EPIPE &&
1151                     status != -ESHUTDOWN) {
1152                         if (netif_msg_tx_err (dev))
1153 fail_pipe:
1154                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1155                                            status);
1156                 } else {
1157                         clear_bit (EVENT_TX_HALT, &dev->flags);
1158                         if (status != -ESHUTDOWN)
1159                                 netif_wake_queue (dev->net);
1160                 }
1161         }
1162         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1163                 unlink_urbs (dev, &dev->rxq);
1164                 status = usb_autopm_get_interface(dev->intf);
1165                 if (status < 0)
1166                         goto fail_halt;
1167                 status = usb_clear_halt (dev->udev, dev->in);
1168                 usb_autopm_put_interface(dev->intf);
1169                 if (status < 0 &&
1170                     status != -EPIPE &&
1171                     status != -ESHUTDOWN) {
1172                         if (netif_msg_rx_err (dev))
1173 fail_halt:
1174                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1175                                            status);
1176                 } else {
1177                         clear_bit (EVENT_RX_HALT, &dev->flags);
1178                         tasklet_schedule (&dev->bh);
1179                 }
1180         }
1181
1182         /* tasklet could resubmit itself forever if memory is tight */
1183         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1184                 struct urb      *urb = NULL;
1185                 int resched = 1;
1186
1187                 if (netif_running (dev->net))
1188                         urb = usb_alloc_urb (0, GFP_KERNEL);
1189                 else
1190                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1191                 if (urb != NULL) {
1192                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1193                         status = usb_autopm_get_interface(dev->intf);
1194                         if (status < 0) {
1195                                 usb_free_urb(urb);
1196                                 goto fail_lowmem;
1197                         }
1198                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1199                                 resched = 0;
1200                         usb_autopm_put_interface(dev->intf);
1201 fail_lowmem:
1202                         if (resched)
1203                                 tasklet_schedule (&dev->bh);
1204                 }
1205         }
1206
1207         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1208                 struct driver_info      *info = dev->driver_info;
1209                 int                     retval = 0;
1210
1211                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1212                 status = usb_autopm_get_interface(dev->intf);
1213                 if (status < 0)
1214                         goto skip_reset;
1215                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1216                         usb_autopm_put_interface(dev->intf);
1217 skip_reset:
1218                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1219                                     retval,
1220                                     dev->udev->bus->bus_name,
1221                                     dev->udev->devpath,
1222                                     info->description);
1223                 } else {
1224                         usb_autopm_put_interface(dev->intf);
1225                 }
1226
1227                 /* handle link change from link resetting */
1228                 __handle_link_change(dev);
1229         }
1230
1231         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1232                 __handle_link_change(dev);
1233
1234         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1235                 __handle_set_rx_mode(dev);
1236
1237
1238         if (dev->flags)
1239                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1240 }
1241
1242 /*-------------------------------------------------------------------------*/
1243
1244 static void tx_complete (struct urb *urb)
1245 {
1246         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1247         struct skb_data         *entry = (struct skb_data *) skb->cb;
1248         struct usbnet           *dev = entry->dev;
1249
1250         if (urb->status == 0) {
1251                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1252                 unsigned long flags;
1253
1254                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1255                 stats64->tx_packets += entry->packets;
1256                 stats64->tx_bytes += entry->length;
1257                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1258         } else {
1259                 dev->net->stats.tx_errors++;
1260
1261                 switch (urb->status) {
1262                 case -EPIPE:
1263                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1264                         break;
1265
1266                 /* software-driven interface shutdown */
1267                 case -ECONNRESET:               // async unlink
1268                 case -ESHUTDOWN:                // hardware gone
1269                         break;
1270
1271                 /* like rx, tx gets controller i/o faults during hub_wq
1272                  * delays and so it uses the same throttling mechanism.
1273                  */
1274                 case -EPROTO:
1275                 case -ETIME:
1276                 case -EILSEQ:
1277                         usb_mark_last_busy(dev->udev);
1278                         if (!timer_pending (&dev->delay)) {
1279                                 mod_timer (&dev->delay,
1280                                         jiffies + THROTTLE_JIFFIES);
1281                                 netif_dbg(dev, link, dev->net,
1282                                           "tx throttle %d\n", urb->status);
1283                         }
1284                         netif_stop_queue (dev->net);
1285                         break;
1286                 default:
1287                         netif_dbg(dev, tx_err, dev->net,
1288                                   "tx err %d\n", entry->urb->status);
1289                         break;
1290                 }
1291         }
1292
1293         usb_autopm_put_interface_async(dev->intf);
1294         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1295 }
1296
1297 /*-------------------------------------------------------------------------*/
1298
1299 void usbnet_tx_timeout (struct net_device *net)
1300 {
1301         struct usbnet           *dev = netdev_priv(net);
1302
1303         unlink_urbs (dev, &dev->txq);
1304         tasklet_schedule (&dev->bh);
1305         /* this needs to be handled individually because the generic layer
1306          * doesn't know what is sufficient and could not restore private
1307          * information if a remedy of an unconditional reset were used.
1308          */
1309         if (dev->driver_info->recover)
1310                 (dev->driver_info->recover)(dev);
1311 }
1312 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1313
1314 /*-------------------------------------------------------------------------*/
1315
1316 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1317 {
1318         unsigned num_sgs, total_len = 0;
1319         int i, s = 0;
1320
1321         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1322         if (num_sgs == 1)
1323                 return 0;
1324
1325         /* reserve one for zero packet */
1326         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1327                                 GFP_ATOMIC);
1328         if (!urb->sg)
1329                 return -ENOMEM;
1330
1331         urb->num_sgs = num_sgs;
1332         sg_init_table(urb->sg, urb->num_sgs + 1);
1333
1334         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1335         total_len += skb_headlen(skb);
1336
1337         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1338                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1339
1340                 total_len += skb_frag_size(f);
1341                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1342                                 f->page_offset);
1343         }
1344         urb->transfer_buffer_length = total_len;
1345
1346         return 1;
1347 }
1348
1349 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1350                                      struct net_device *net)
1351 {
1352         struct usbnet           *dev = netdev_priv(net);
1353         unsigned int                    length;
1354         struct urb              *urb = NULL;
1355         struct skb_data         *entry;
1356         struct driver_info      *info = dev->driver_info;
1357         unsigned long           flags;
1358         int retval;
1359
1360         if (skb)
1361                 skb_tx_timestamp(skb);
1362
1363         // some devices want funky USB-level framing, for
1364         // win32 driver (usually) and/or hardware quirks
1365         if (info->tx_fixup) {
1366                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1367                 if (!skb) {
1368                         /* packet collected; minidriver waiting for more */
1369                         if (info->flags & FLAG_MULTI_PACKET)
1370                                 goto not_drop;
1371                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1372                         goto drop;
1373                 }
1374         }
1375
1376         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1377                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1378                 goto drop;
1379         }
1380
1381         entry = (struct skb_data *) skb->cb;
1382         entry->urb = urb;
1383         entry->dev = dev;
1384
1385         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1386                         skb->data, skb->len, tx_complete, skb);
1387         if (dev->can_dma_sg) {
1388                 if (build_dma_sg(skb, urb) < 0)
1389                         goto drop;
1390         }
1391         length = urb->transfer_buffer_length;
1392
1393         /* don't assume the hardware handles USB_ZERO_PACKET
1394          * NOTE:  strictly conforming cdc-ether devices should expect
1395          * the ZLP here, but ignore the one-byte packet.
1396          * NOTE2: CDC NCM specification is different from CDC ECM when
1397          * handling ZLP/short packets, so cdc_ncm driver will make short
1398          * packet itself if needed.
1399          */
1400         if (length % dev->maxpacket == 0) {
1401                 if (!(info->flags & FLAG_SEND_ZLP)) {
1402                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1403                                 length++;
1404                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1405                                         skb->data[skb->len] = 0;
1406                                         __skb_put(skb, 1);
1407                                 } else if (urb->num_sgs)
1408                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1409                                                         dev->padding_pkt, 1);
1410                         }
1411                 } else
1412                         urb->transfer_flags |= URB_ZERO_PACKET;
1413         }
1414         urb->transfer_buffer_length = length;
1415
1416         if (info->flags & FLAG_MULTI_PACKET) {
1417                 /* Driver has set number of packets and a length delta.
1418                  * Calculate the complete length and ensure that it's
1419                  * positive.
1420                  */
1421                 entry->length += length;
1422                 if (WARN_ON_ONCE(entry->length <= 0))
1423                         entry->length = length;
1424         } else {
1425                 usbnet_set_skb_tx_stats(skb, 1, length);
1426         }
1427
1428         spin_lock_irqsave(&dev->txq.lock, flags);
1429         retval = usb_autopm_get_interface_async(dev->intf);
1430         if (retval < 0) {
1431                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1432                 goto drop;
1433         }
1434
1435 #ifdef CONFIG_PM
1436         /* if this triggers the device is still a sleep */
1437         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1438                 /* transmission will be done in resume */
1439                 usb_anchor_urb(urb, &dev->deferred);
1440                 /* no use to process more packets */
1441                 netif_stop_queue(net);
1442                 usb_put_urb(urb);
1443                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1444                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1445                 goto deferred;
1446         }
1447 #endif
1448
1449         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1450         case -EPIPE:
1451                 netif_stop_queue (net);
1452                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1453                 usb_autopm_put_interface_async(dev->intf);
1454                 break;
1455         default:
1456                 usb_autopm_put_interface_async(dev->intf);
1457                 netif_dbg(dev, tx_err, dev->net,
1458                           "tx: submit urb err %d\n", retval);
1459                 break;
1460         case 0:
1461                 netif_trans_update(net);
1462                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1463                 if (dev->txq.qlen >= TX_QLEN (dev))
1464                         netif_stop_queue (net);
1465         }
1466         spin_unlock_irqrestore (&dev->txq.lock, flags);
1467
1468         if (retval) {
1469                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1470 drop:
1471                 dev->net->stats.tx_dropped++;
1472 not_drop:
1473                 if (skb)
1474                         dev_kfree_skb_any (skb);
1475                 if (urb) {
1476                         kfree(urb->sg);
1477                         usb_free_urb(urb);
1478                 }
1479         } else
1480                 netif_dbg(dev, tx_queued, dev->net,
1481                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1482 #ifdef CONFIG_PM
1483 deferred:
1484 #endif
1485         return NETDEV_TX_OK;
1486 }
1487 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1488
1489 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1490 {
1491         struct urb      *urb;
1492         int             i;
1493         int             ret = 0;
1494
1495         /* don't refill the queue all at once */
1496         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1497                 urb = usb_alloc_urb(0, flags);
1498                 if (urb != NULL) {
1499                         ret = rx_submit(dev, urb, flags);
1500                         if (ret)
1501                                 goto err;
1502                 } else {
1503                         ret = -ENOMEM;
1504                         goto err;
1505                 }
1506         }
1507 err:
1508         return ret;
1509 }
1510
1511 /*-------------------------------------------------------------------------*/
1512
1513 // tasklet (work deferred from completions, in_irq) or timer
1514
1515 static void usbnet_bh (struct timer_list *t)
1516 {
1517         struct usbnet           *dev = from_timer(dev, t, delay);
1518         struct sk_buff          *skb;
1519         struct skb_data         *entry;
1520
1521         while ((skb = skb_dequeue (&dev->done))) {
1522                 entry = (struct skb_data *) skb->cb;
1523                 switch (entry->state) {
1524                 case rx_done:
1525                         entry->state = rx_cleanup;
1526                         rx_process (dev, skb);
1527                         continue;
1528                 case tx_done:
1529                         kfree(entry->urb->sg);
1530                 case rx_cleanup:
1531                         usb_free_urb (entry->urb);
1532                         dev_kfree_skb (skb);
1533                         continue;
1534                 default:
1535                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1536                 }
1537         }
1538
1539         /* restart RX again after disabling due to high error rate */
1540         clear_bit(EVENT_RX_KILL, &dev->flags);
1541
1542         /* waiting for all pending urbs to complete?
1543          * only then can we forgo submitting anew
1544          */
1545         if (waitqueue_active(&dev->wait)) {
1546                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1547                         wake_up_all(&dev->wait);
1548
1549         // or are we maybe short a few urbs?
1550         } else if (netif_running (dev->net) &&
1551                    netif_device_present (dev->net) &&
1552                    netif_carrier_ok(dev->net) &&
1553                    !timer_pending(&dev->delay) &&
1554                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1555                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1556                 int     temp = dev->rxq.qlen;
1557
1558                 if (temp < RX_QLEN(dev)) {
1559                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1560                                 return;
1561                         if (temp != dev->rxq.qlen)
1562                                 netif_dbg(dev, link, dev->net,
1563                                           "rxqlen %d --> %d\n",
1564                                           temp, dev->rxq.qlen);
1565                         if (dev->rxq.qlen < RX_QLEN(dev))
1566                                 tasklet_schedule (&dev->bh);
1567                 }
1568                 if (dev->txq.qlen < TX_QLEN (dev))
1569                         netif_wake_queue (dev->net);
1570         }
1571 }
1572
1573
1574 /*-------------------------------------------------------------------------
1575  *
1576  * USB Device Driver support
1577  *
1578  *-------------------------------------------------------------------------*/
1579
1580 // precondition: never called in_interrupt
1581
1582 void usbnet_disconnect (struct usb_interface *intf)
1583 {
1584         struct usbnet           *dev;
1585         struct usb_device       *xdev;
1586         struct net_device       *net;
1587
1588         dev = usb_get_intfdata(intf);
1589         usb_set_intfdata(intf, NULL);
1590         if (!dev)
1591                 return;
1592
1593         xdev = interface_to_usbdev (intf);
1594
1595         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1596                    intf->dev.driver->name,
1597                    xdev->bus->bus_name, xdev->devpath,
1598                    dev->driver_info->description);
1599
1600         net = dev->net;
1601         unregister_netdev (net);
1602
1603         cancel_work_sync(&dev->kevent);
1604
1605         usb_scuttle_anchored_urbs(&dev->deferred);
1606
1607         if (dev->driver_info->unbind)
1608                 dev->driver_info->unbind (dev, intf);
1609
1610         usb_kill_urb(dev->interrupt);
1611         usb_free_urb(dev->interrupt);
1612         kfree(dev->padding_pkt);
1613
1614         free_percpu(dev->stats64);
1615         free_netdev(net);
1616 }
1617 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1618
1619 static const struct net_device_ops usbnet_netdev_ops = {
1620         .ndo_open               = usbnet_open,
1621         .ndo_stop               = usbnet_stop,
1622         .ndo_start_xmit         = usbnet_start_xmit,
1623         .ndo_tx_timeout         = usbnet_tx_timeout,
1624         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1625         .ndo_change_mtu         = usbnet_change_mtu,
1626         .ndo_get_stats64        = usbnet_get_stats64,
1627         .ndo_set_mac_address    = eth_mac_addr,
1628         .ndo_validate_addr      = eth_validate_addr,
1629 };
1630
1631 /*-------------------------------------------------------------------------*/
1632
1633 // precondition: never called in_interrupt
1634
1635 static struct device_type wlan_type = {
1636         .name   = "wlan",
1637 };
1638
1639 static struct device_type wwan_type = {
1640         .name   = "wwan",
1641 };
1642
1643 int
1644 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1645 {
1646         struct usbnet                   *dev;
1647         struct net_device               *net;
1648         struct usb_host_interface       *interface;
1649         struct driver_info              *info;
1650         struct usb_device               *xdev;
1651         int                             status;
1652         const char                      *name;
1653         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1654
1655         /* usbnet already took usb runtime pm, so have to enable the feature
1656          * for usb interface, otherwise usb_autopm_get_interface may return
1657          * failure if RUNTIME_PM is enabled.
1658          */
1659         if (!driver->supports_autosuspend) {
1660                 driver->supports_autosuspend = 1;
1661                 pm_runtime_enable(&udev->dev);
1662         }
1663
1664         name = udev->dev.driver->name;
1665         info = (struct driver_info *) prod->driver_info;
1666         if (!info) {
1667                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1668                 return -ENODEV;
1669         }
1670         xdev = interface_to_usbdev (udev);
1671         interface = udev->cur_altsetting;
1672
1673         status = -ENOMEM;
1674
1675         // set up our own records
1676         net = alloc_etherdev(sizeof(*dev));
1677         if (!net)
1678                 goto out;
1679
1680         /* netdev_printk() needs this so do it as early as possible */
1681         SET_NETDEV_DEV(net, &udev->dev);
1682
1683         dev = netdev_priv(net);
1684         dev->udev = xdev;
1685         dev->intf = udev;
1686         dev->driver_info = info;
1687         dev->driver_name = name;
1688
1689         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1690         if (!dev->stats64)
1691                 goto out0;
1692
1693         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1694                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1695         init_waitqueue_head(&dev->wait);
1696         skb_queue_head_init (&dev->rxq);
1697         skb_queue_head_init (&dev->txq);
1698         skb_queue_head_init (&dev->done);
1699         skb_queue_head_init(&dev->rxq_pause);
1700         dev->bh.func = (void (*)(unsigned long))usbnet_bh;
1701         dev->bh.data = (unsigned long)&dev->delay;
1702         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1703         init_usb_anchor(&dev->deferred);
1704         timer_setup(&dev->delay, usbnet_bh, 0);
1705         mutex_init (&dev->phy_mutex);
1706         mutex_init(&dev->interrupt_mutex);
1707         dev->interrupt_count = 0;
1708
1709         dev->net = net;
1710         strcpy (net->name, "usb%d");
1711         memcpy (net->dev_addr, node_id, sizeof node_id);
1712
1713         /* rx and tx sides can use different message sizes;
1714          * bind() should set rx_urb_size in that case.
1715          */
1716         dev->hard_mtu = net->mtu + net->hard_header_len;
1717         net->min_mtu = 0;
1718         net->max_mtu = ETH_MAX_MTU;
1719
1720         net->netdev_ops = &usbnet_netdev_ops;
1721         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1722         net->ethtool_ops = &usbnet_ethtool_ops;
1723
1724         // allow device-specific bind/init procedures
1725         // NOTE net->name still not usable ...
1726         if (info->bind) {
1727                 status = info->bind (dev, udev);
1728                 if (status < 0)
1729                         goto out1;
1730
1731                 // heuristic:  "usb%d" for links we know are two-host,
1732                 // else "eth%d" when there's reasonable doubt.  userspace
1733                 // can rename the link if it knows better.
1734                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1735                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1736                      (net->dev_addr [0] & 0x02) == 0))
1737                         strcpy (net->name, "eth%d");
1738                 /* WLAN devices should always be named "wlan%d" */
1739                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1740                         strcpy(net->name, "wlan%d");
1741                 /* WWAN devices should always be named "wwan%d" */
1742                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1743                         strcpy(net->name, "wwan%d");
1744
1745                 /* devices that cannot do ARP */
1746                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1747                         net->flags |= IFF_NOARP;
1748
1749                 /* maybe the remote can't receive an Ethernet MTU */
1750                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1751                         net->mtu = dev->hard_mtu - net->hard_header_len;
1752         } else if (!info->in || !info->out)
1753                 status = usbnet_get_endpoints (dev, udev);
1754         else {
1755                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1756                 dev->out = usb_sndbulkpipe (xdev, info->out);
1757                 if (!(info->flags & FLAG_NO_SETINT))
1758                         status = usb_set_interface (xdev,
1759                                 interface->desc.bInterfaceNumber,
1760                                 interface->desc.bAlternateSetting);
1761                 else
1762                         status = 0;
1763
1764         }
1765         if (status >= 0 && dev->status)
1766                 status = init_status (dev, udev);
1767         if (status < 0)
1768                 goto out3;
1769
1770         if (!dev->rx_urb_size)
1771                 dev->rx_urb_size = dev->hard_mtu;
1772         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1773
1774         /* let userspace know we have a random address */
1775         if (ether_addr_equal(net->dev_addr, node_id))
1776                 net->addr_assign_type = NET_ADDR_RANDOM;
1777
1778         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1779                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1780         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1781                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1782
1783         /* initialize max rx_qlen and tx_qlen */
1784         usbnet_update_max_qlen(dev);
1785
1786         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1787                 !(info->flags & FLAG_MULTI_PACKET)) {
1788                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1789                 if (!dev->padding_pkt) {
1790                         status = -ENOMEM;
1791                         goto out4;
1792                 }
1793         }
1794
1795         status = register_netdev (net);
1796         if (status)
1797                 goto out5;
1798         netif_info(dev, probe, dev->net,
1799                    "register '%s' at usb-%s-%s, %s, %pM\n",
1800                    udev->dev.driver->name,
1801                    xdev->bus->bus_name, xdev->devpath,
1802                    dev->driver_info->description,
1803                    net->dev_addr);
1804
1805         // ok, it's ready to go.
1806         usb_set_intfdata (udev, dev);
1807
1808         netif_device_attach (net);
1809
1810         if (dev->driver_info->flags & FLAG_LINK_INTR)
1811                 usbnet_link_change(dev, 0, 0);
1812
1813         return 0;
1814
1815 out5:
1816         kfree(dev->padding_pkt);
1817 out4:
1818         usb_free_urb(dev->interrupt);
1819 out3:
1820         if (info->unbind)
1821                 info->unbind (dev, udev);
1822 out1:
1823         /* subdrivers must undo all they did in bind() if they
1824          * fail it, but we may fail later and a deferred kevent
1825          * may trigger an error resubmitting itself and, worse,
1826          * schedule a timer. So we kill it all just in case.
1827          */
1828         cancel_work_sync(&dev->kevent);
1829         del_timer_sync(&dev->delay);
1830         free_percpu(dev->stats64);
1831 out0:
1832         free_netdev(net);
1833 out:
1834         return status;
1835 }
1836 EXPORT_SYMBOL_GPL(usbnet_probe);
1837
1838 /*-------------------------------------------------------------------------*/
1839
1840 /*
1841  * suspend the whole driver as soon as the first interface is suspended
1842  * resume only when the last interface is resumed
1843  */
1844
1845 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1846 {
1847         struct usbnet           *dev = usb_get_intfdata(intf);
1848
1849         if (!dev->suspend_count++) {
1850                 spin_lock_irq(&dev->txq.lock);
1851                 /* don't autosuspend while transmitting */
1852                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1853                         dev->suspend_count--;
1854                         spin_unlock_irq(&dev->txq.lock);
1855                         return -EBUSY;
1856                 } else {
1857                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1858                         spin_unlock_irq(&dev->txq.lock);
1859                 }
1860                 /*
1861                  * accelerate emptying of the rx and queues, to avoid
1862                  * having everything error out.
1863                  */
1864                 netif_device_detach (dev->net);
1865                 usbnet_terminate_urbs(dev);
1866                 __usbnet_status_stop_force(dev);
1867
1868                 /*
1869                  * reattach so runtime management can use and
1870                  * wake the device
1871                  */
1872                 netif_device_attach (dev->net);
1873         }
1874         return 0;
1875 }
1876 EXPORT_SYMBOL_GPL(usbnet_suspend);
1877
1878 int usbnet_resume (struct usb_interface *intf)
1879 {
1880         struct usbnet           *dev = usb_get_intfdata(intf);
1881         struct sk_buff          *skb;
1882         struct urb              *res;
1883         int                     retval;
1884
1885         if (!--dev->suspend_count) {
1886                 /* resume interrupt URB if it was previously submitted */
1887                 __usbnet_status_start_force(dev, GFP_NOIO);
1888
1889                 spin_lock_irq(&dev->txq.lock);
1890                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1891
1892                         skb = (struct sk_buff *)res->context;
1893                         retval = usb_submit_urb(res, GFP_ATOMIC);
1894                         if (retval < 0) {
1895                                 dev_kfree_skb_any(skb);
1896                                 kfree(res->sg);
1897                                 usb_free_urb(res);
1898                                 usb_autopm_put_interface_async(dev->intf);
1899                         } else {
1900                                 netif_trans_update(dev->net);
1901                                 __skb_queue_tail(&dev->txq, skb);
1902                         }
1903                 }
1904
1905                 smp_mb();
1906                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1907                 spin_unlock_irq(&dev->txq.lock);
1908
1909                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1910                         /* handle remote wakeup ASAP
1911                          * we cannot race against stop
1912                          */
1913                         if (netif_device_present(dev->net) &&
1914                                 !timer_pending(&dev->delay) &&
1915                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1916                                         rx_alloc_submit(dev, GFP_NOIO);
1917
1918                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1919                                 netif_tx_wake_all_queues(dev->net);
1920                         tasklet_schedule (&dev->bh);
1921                 }
1922         }
1923
1924         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1925                 usb_autopm_get_interface_no_resume(intf);
1926
1927         return 0;
1928 }
1929 EXPORT_SYMBOL_GPL(usbnet_resume);
1930
1931 /*
1932  * Either a subdriver implements manage_power, then it is assumed to always
1933  * be ready to be suspended or it reports the readiness to be suspended
1934  * explicitly
1935  */
1936 void usbnet_device_suggests_idle(struct usbnet *dev)
1937 {
1938         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1939                 dev->intf->needs_remote_wakeup = 1;
1940                 usb_autopm_put_interface_async(dev->intf);
1941         }
1942 }
1943 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1944
1945 /*
1946  * For devices that can do without special commands
1947  */
1948 int usbnet_manage_power(struct usbnet *dev, int on)
1949 {
1950         dev->intf->needs_remote_wakeup = on;
1951         return 0;
1952 }
1953 EXPORT_SYMBOL(usbnet_manage_power);
1954
1955 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1956 {
1957         /* update link after link is reseted */
1958         if (link && !need_reset)
1959                 netif_carrier_on(dev->net);
1960         else
1961                 netif_carrier_off(dev->net);
1962
1963         if (need_reset && link)
1964                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1965         else
1966                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1967 }
1968 EXPORT_SYMBOL(usbnet_link_change);
1969
1970 /*-------------------------------------------------------------------------*/
1971 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1972                              u16 value, u16 index, void *data, u16 size)
1973 {
1974         void *buf = NULL;
1975         int err = -ENOMEM;
1976
1977         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1978                    " value=0x%04x index=0x%04x size=%d\n",
1979                    cmd, reqtype, value, index, size);
1980
1981         if (size) {
1982                 buf = kmalloc(size, GFP_KERNEL);
1983                 if (!buf)
1984                         goto out;
1985         }
1986
1987         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1988                               cmd, reqtype, value, index, buf, size,
1989                               USB_CTRL_GET_TIMEOUT);
1990         if (err > 0 && err <= size) {
1991         if (data)
1992             memcpy(data, buf, err);
1993         else
1994             netdev_dbg(dev->net,
1995                 "Huh? Data requested but thrown away.\n");
1996     }
1997         kfree(buf);
1998 out:
1999         return err;
2000 }
2001
2002 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2003                               u16 value, u16 index, const void *data,
2004                               u16 size)
2005 {
2006         void *buf = NULL;
2007         int err = -ENOMEM;
2008
2009         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2010                    " value=0x%04x index=0x%04x size=%d\n",
2011                    cmd, reqtype, value, index, size);
2012
2013         if (data) {
2014                 buf = kmemdup(data, size, GFP_KERNEL);
2015                 if (!buf)
2016                         goto out;
2017         } else {
2018         if (size) {
2019             WARN_ON_ONCE(1);
2020             err = -EINVAL;
2021             goto out;
2022         }
2023     }
2024
2025         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2026                               cmd, reqtype, value, index, buf, size,
2027                               USB_CTRL_SET_TIMEOUT);
2028         kfree(buf);
2029
2030 out:
2031         return err;
2032 }
2033
2034 /*
2035  * The function can't be called inside suspend/resume callback,
2036  * otherwise deadlock will be caused.
2037  */
2038 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2039                     u16 value, u16 index, void *data, u16 size)
2040 {
2041         int ret;
2042
2043         if (usb_autopm_get_interface(dev->intf) < 0)
2044                 return -ENODEV;
2045         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2046                                 data, size);
2047         usb_autopm_put_interface(dev->intf);
2048         return ret;
2049 }
2050 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2051
2052 /*
2053  * The function can't be called inside suspend/resume callback,
2054  * otherwise deadlock will be caused.
2055  */
2056 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2057                      u16 value, u16 index, const void *data, u16 size)
2058 {
2059         int ret;
2060
2061         if (usb_autopm_get_interface(dev->intf) < 0)
2062                 return -ENODEV;
2063         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2064                                  data, size);
2065         usb_autopm_put_interface(dev->intf);
2066         return ret;
2067 }
2068 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2069
2070 /*
2071  * The function can be called inside suspend/resume callback safely
2072  * and should only be called by suspend/resume callback generally.
2073  */
2074 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2075                           u16 value, u16 index, void *data, u16 size)
2076 {
2077         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2078                                  data, size);
2079 }
2080 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2081
2082 /*
2083  * The function can be called inside suspend/resume callback safely
2084  * and should only be called by suspend/resume callback generally.
2085  */
2086 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2087                           u16 value, u16 index, const void *data,
2088                           u16 size)
2089 {
2090         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2091                                   data, size);
2092 }
2093 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2094
2095 static void usbnet_async_cmd_cb(struct urb *urb)
2096 {
2097         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2098         int status = urb->status;
2099
2100         if (status < 0)
2101                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2102                         __func__, status);
2103
2104         kfree(req);
2105         usb_free_urb(urb);
2106 }
2107
2108 /*
2109  * The caller must make sure that device can't be put into suspend
2110  * state until the control URB completes.
2111  */
2112 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2113                            u16 value, u16 index, const void *data, u16 size)
2114 {
2115         struct usb_ctrlrequest *req = NULL;
2116         struct urb *urb;
2117         int err = -ENOMEM;
2118         void *buf = NULL;
2119
2120         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2121                    " value=0x%04x index=0x%04x size=%d\n",
2122                    cmd, reqtype, value, index, size);
2123
2124         urb = usb_alloc_urb(0, GFP_ATOMIC);
2125         if (!urb)
2126                 goto fail;
2127
2128         if (data) {
2129                 buf = kmemdup(data, size, GFP_ATOMIC);
2130                 if (!buf) {
2131                         netdev_err(dev->net, "Error allocating buffer"
2132                                    " in %s!\n", __func__);
2133                         goto fail_free;
2134                 }
2135         }
2136
2137         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2138         if (!req)
2139                 goto fail_free_buf;
2140
2141         req->bRequestType = reqtype;
2142         req->bRequest = cmd;
2143         req->wValue = cpu_to_le16(value);
2144         req->wIndex = cpu_to_le16(index);
2145         req->wLength = cpu_to_le16(size);
2146
2147         usb_fill_control_urb(urb, dev->udev,
2148                              usb_sndctrlpipe(dev->udev, 0),
2149                              (void *)req, buf, size,
2150                              usbnet_async_cmd_cb, req);
2151         urb->transfer_flags |= URB_FREE_BUFFER;
2152
2153         err = usb_submit_urb(urb, GFP_ATOMIC);
2154         if (err < 0) {
2155                 netdev_err(dev->net, "Error submitting the control"
2156                            " message: status=%d\n", err);
2157                 goto fail_free;
2158         }
2159         return 0;
2160
2161 fail_free_buf:
2162         kfree(buf);
2163 fail_free:
2164         kfree(req);
2165         usb_free_urb(urb);
2166 fail:
2167         return err;
2168
2169 }
2170 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2171 /*-------------------------------------------------------------------------*/
2172
2173 static int __init usbnet_init(void)
2174 {
2175         /* Compiler should optimize this out. */
2176         BUILD_BUG_ON(
2177                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2178
2179         eth_random_addr(node_id);
2180         return 0;
2181 }
2182 module_init(usbnet_init);
2183
2184 static void __exit usbnet_exit(void)
2185 {
2186 }
2187 module_exit(usbnet_exit);
2188
2189 MODULE_AUTHOR("David Brownell");
2190 MODULE_DESCRIPTION("USB network driver framework");
2191 MODULE_LICENSE("GPL");