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