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/usb/cdc.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * The goal is to let the USB host controller be busy for 5msec or
  63  * more before an irq is required, under load.  Jumbograms change
  64  * the equation.
  65  */
  66 #define MAX_QUEUE_MEMORY        (60 * 1518)
  67 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  68 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  69
  70 // reawaken network queue this soon after stopping; else watchdog barks
  71 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  72
  73 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  74  * us (it polls at HZ/4 usually) before we report too many false errors.
  75  */
  76 #define THROTTLE_JIFFIES        (HZ/8)
  77
  78 // between wakeups
  79 #define UNLINK_TIMEOUT_MS       3
  80
  81 /*-------------------------------------------------------------------------*/
  82
  83 // randomly generated ethernet address
  84 static u8       node_id [ETH_ALEN];
  85
  86 static const char driver_name [] = "usbnet";
  87
  88 /* use ethtool to change the level for any given device */
  89 static int msg_level = -1;
  90 module_param (msg_level, int, 0);
  91 MODULE_PARM_DESC (msg_level, "Override default message level");
  92
  93 /*-------------------------------------------------------------------------*/
  94
  95 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  96 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  97 {
  98         int                             tmp;
  99         struct usb_host_interface       *alt = NULL;
 100         struct usb_host_endpoint        *in = NULL, *out = NULL;
 101         struct usb_host_endpoint        *status = NULL;
 102
 103         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 104                 unsigned        ep;
 105
 106                 in = out = status = NULL;
 107                 alt = intf->altsetting + tmp;
 108
 109                 /* take the first altsetting with in-bulk + out-bulk;
 110                  * remember any status endpoint, just in case;
 111                  * ignore other endpoints and altsettings.
 112                  */
 113                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 114                         struct usb_host_endpoint        *e;
 115                         int                             intr = 0;
 116
 117                         e = alt->endpoint + ep;
 118                         switch (e->desc.bmAttributes) {
 119                         case USB_ENDPOINT_XFER_INT:
 120                                 if (!usb_endpoint_dir_in(&e->desc))
 121                                         continue;
 122                                 intr = 1;
 123                                 /* FALLTHROUGH */
 124                         case USB_ENDPOINT_XFER_BULK:
 125                                 break;
 126                         default:
 127                                 continue;
 128                         }
 129                         if (usb_endpoint_dir_in(&e->desc)) {
 130                                 if (!intr && !in)
 131                                         in = e;
 132                                 else if (intr && !status)
 133                                         status = e;
 134                         } else {
 135                                 if (!out)
 136                                         out = e;
 137                         }
 138                 }
 139                 if (in && out)
 140                         break;
 141         }
 142         if (!alt || !in || !out)
 143                 return -EINVAL;
 144
 145         if (alt->desc.bAlternateSetting != 0 ||
 146             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 147                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 148                                 alt->desc.bAlternateSetting);
 149                 if (tmp < 0)
 150                         return tmp;
 151         }
 152
 153         dev->in = usb_rcvbulkpipe (dev->udev,
 154                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155         dev->out = usb_sndbulkpipe (dev->udev,
 156                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 157         dev->status = status;
 158         return 0;
 159 }
 160 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 161
 162 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 163 {
 164         int             tmp = -1, ret;
 165         unsigned char   buf [13];
 166
 167         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 168         if (ret == 12)
 169                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 170         if (tmp < 0) {
 171                 dev_dbg(&dev->udev->dev,
 172                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 173                 if (ret >= 0)
 174                         ret = -EINVAL;
 175                 return ret;
 176         }
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 180
 181 static void intr_complete (struct urb *urb)
 182 {
 183         struct usbnet   *dev = urb->context;
 184         int             status = urb->status;
 185
 186         switch (status) {
 187         /* success */
 188         case 0:
 189                 dev->driver_info->status(dev, urb);
 190                 break;
 191
 192         /* software-driven interface shutdown */
 193         case -ENOENT:           /* urb killed */
 194         case -ESHUTDOWN:        /* hardware gone */
 195                 netif_dbg(dev, ifdown, dev->net,
 196                           "intr shutdown, code %d\n", status);
 197                 return;
 198
 199         /* NOTE:  not throttling like RX/TX, since this endpoint
 200          * already polls infrequently
 201          */
 202         default:
 203                 netdev_dbg(dev->net, "intr status %d\n", status);
 204                 break;
 205         }
 206
 207         status = usb_submit_urb (urb, GFP_ATOMIC);
 208         if (status != 0)
 209                 netif_err(dev, timer, dev->net,
 210                           "intr resubmit --> %d\n", status);
 211 }
 212
 213 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 214 {
 215         char            *buf = NULL;
 216         unsigned        pipe = 0;
 217         unsigned        maxp;
 218         unsigned        period;
 219
 220         if (!dev->driver_info->status)
 221                 return 0;
 222
 223         pipe = usb_rcvintpipe (dev->udev,
 224                         dev->status->desc.bEndpointAddress
 225                                 & USB_ENDPOINT_NUMBER_MASK);
 226         maxp = usb_maxpacket (dev->udev, pipe, 0);
 227
 228         /* avoid 1 msec chatter:  min 8 msec poll rate */
 229         period = max ((int) dev->status->desc.bInterval,
 230                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 231
 232         buf = kmalloc (maxp, GFP_KERNEL);
 233         if (buf) {
 234                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 235                 if (!dev->interrupt) {
 236                         kfree (buf);
 237                         return -ENOMEM;
 238                 } else {
 239                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 240                                 buf, maxp, intr_complete, dev, period);
 241                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 242                         dev_dbg(&intf->dev,
 243                                 "status ep%din, %d bytes period %d\n",
 244                                 usb_pipeendpoint(pipe), maxp, period);
 245                 }
 246         }
 247         return 0;
 248 }
 249
 250 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 251 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 252 {
 253         int ret = 0;
 254
 255         WARN_ON_ONCE(dev->interrupt == NULL);
 256         if (dev->interrupt) {
 257                 mutex_lock(&dev->interrupt_mutex);
 258
 259                 if (++dev->interrupt_count == 1)
 260                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 261
 262                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 263                         dev->interrupt_count);
 264                 mutex_unlock(&dev->interrupt_mutex);
 265         }
 266         return ret;
 267 }
 268 EXPORT_SYMBOL_GPL(usbnet_status_start);
 269
 270 /* For resume; submit interrupt URB if previously submitted */
 271 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 272 {
 273         int ret = 0;
 274
 275         mutex_lock(&dev->interrupt_mutex);
 276         if (dev->interrupt_count) {
 277                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 278                 dev_dbg(&dev->udev->dev,
 279                         "submitted interrupt URB for resume\n");
 280         }
 281         mutex_unlock(&dev->interrupt_mutex);
 282         return ret;
 283 }
 284
 285 /* Kill the interrupt URB if all submitters want it killed */
 286 void usbnet_status_stop(struct usbnet *dev)
 287 {
 288         if (dev->interrupt) {
 289                 mutex_lock(&dev->interrupt_mutex);
 290                 WARN_ON(dev->interrupt_count == 0);
 291
 292                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 293                         usb_kill_urb(dev->interrupt);
 294
 295                 dev_dbg(&dev->udev->dev,
 296                         "decremented interrupt URB count to %d\n",
 297                         dev->interrupt_count);
 298                 mutex_unlock(&dev->interrupt_mutex);
 299         }
 300 }
 301 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 302
 303 /* For suspend; always kill interrupt URB */
 304 static void __usbnet_status_stop_force(struct usbnet *dev)
 305 {
 306         if (dev->interrupt) {
 307                 mutex_lock(&dev->interrupt_mutex);
 308                 usb_kill_urb(dev->interrupt);
 309                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 310                 mutex_unlock(&dev->interrupt_mutex);
 311         }
 312 }
 313
 314 /* Passes this packet up the stack, updating its accounting.
 315  * Some link protocols batch packets, so their rx_fixup paths
 316  * can return clones as well as just modify the original skb.
 317  */
 318 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 319 {
 320         int     status;
 321
 322         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 323                 skb_queue_tail(&dev->rxq_pause, skb);
 324                 return;
 325         }
 326
 327         /* only update if unset to allow minidriver rx_fixup override */
 328         if (skb->protocol == 0)
 329                 skb->protocol = eth_type_trans (skb, dev->net);
 330
 331         dev->net->stats.rx_packets++;
 332         dev->net->stats.rx_bytes += skb->len;
 333
 334         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 335                   skb->len + sizeof (struct ethhdr), skb->protocol);
 336         memset (skb->cb, 0, sizeof (struct skb_data));
 337
 338         if (skb_defer_rx_timestamp(skb))
 339                 return;
 340
 341         status = netif_rx (skb);
 342         if (status != NET_RX_SUCCESS)
 343                 netif_dbg(dev, rx_err, dev->net,
 344                           "netif_rx status %d\n", status);
 345 }
 346 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 347
 348 /* must be called if hard_mtu or rx_urb_size changed */
 349 void usbnet_update_max_qlen(struct usbnet *dev)
 350 {
 351         enum usb_device_speed speed = dev->udev->speed;
 352
 353         switch (speed) {
 354         case USB_SPEED_HIGH:
 355                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 356                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 357                 break;
 358         case USB_SPEED_SUPER:
 359                 /*
 360                  * Not take default 5ms qlen for super speed HC to
 361                  * save memory, and iperf tests show 2.5ms qlen can
 362                  * work well
 363                  */
 364                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 366                 break;
 367         default:
 368                 dev->rx_qlen = dev->tx_qlen = 4;
 369         }
 370 }
 371 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 372
 373 \f
 374 /*-------------------------------------------------------------------------
 375  *
 376  * Network Device Driver (peer link to "Host Device", from USB host)
 377  *
 378  *-------------------------------------------------------------------------*/
 379
 380 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 381 {
 382         struct usbnet   *dev = netdev_priv(net);
 383         int             ll_mtu = new_mtu + net->hard_header_len;
 384         int             old_hard_mtu = dev->hard_mtu;
 385         int             old_rx_urb_size = dev->rx_urb_size;
 386
 387         if (new_mtu <= 0)
 388                 return -EINVAL;
 389         // no second zero-length packet read wanted after mtu-sized packets
 390         if ((ll_mtu % dev->maxpacket) == 0)
 391                 return -EDOM;
 392         net->mtu = new_mtu;
 393
 394         dev->hard_mtu = net->mtu + net->hard_header_len;
 395         if (dev->rx_urb_size == old_hard_mtu) {
 396                 dev->rx_urb_size = dev->hard_mtu;
 397                 if (dev->rx_urb_size > old_rx_urb_size)
 398                         usbnet_unlink_rx_urbs(dev);
 399         }
 400
 401         /* max qlen depend on hard_mtu and rx_urb_size */
 402         usbnet_update_max_qlen(dev);
 403
 404         return 0;
 405 }
 406 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 407
 408 /* The caller must hold list->lock */
 409 static void __usbnet_queue_skb(struct sk_buff_head *list,
 410                         struct sk_buff *newsk, enum skb_state state)
 411 {
 412         struct skb_data *entry = (struct skb_data *) newsk->cb;
 413
 414         __skb_queue_tail(list, newsk);
 415         entry->state = state;
 416 }
 417
 418 /*-------------------------------------------------------------------------*/
 419
 420 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 421  * completion callbacks.  2.5 should have fixed those bugs...
 422  */
 423
 424 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 425                 struct sk_buff_head *list, enum skb_state state)
 426 {
 427         unsigned long           flags;
 428         enum skb_state          old_state;
 429         struct skb_data *entry = (struct skb_data *) skb->cb;
 430
 431         spin_lock_irqsave(&list->lock, flags);
 432         old_state = entry->state;
 433         entry->state = state;
 434         __skb_unlink(skb, list);
 435
 436         /* defer_bh() is never called with list == &dev->done.
 437          * spin_lock_nested() tells lockdep that it is OK to take
 438          * dev->done.lock here with list->lock held.
 439          */
 440         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 441
 442         __skb_queue_tail(&dev->done, skb);
 443         if (dev->done.qlen == 1)
 444                 tasklet_schedule(&dev->bh);
 445         spin_unlock(&dev->done.lock);
 446         spin_unlock_irqrestore(&list->lock, flags);
 447         return old_state;
 448 }
 449
 450 /* some work can't be done in tasklets, so we use keventd
 451  *
 452  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 453  * but tasklet_schedule() doesn't.  hope the failure is rare.
 454  */
 455 void usbnet_defer_kevent (struct usbnet *dev, int work)
 456 {
 457         set_bit (work, &dev->flags);
 458         if (!schedule_work (&dev->kevent)) {
 459                 if (net_ratelimit())
 460                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 461         } else {
 462                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 463         }
 464 }
 465 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 466
 467 /*-------------------------------------------------------------------------*/
 468
 469 static void rx_complete (struct urb *urb);
 470
 471 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 472 {
 473         struct sk_buff          *skb;
 474         struct skb_data         *entry;
 475         int                     retval = 0;
 476         unsigned long           lockflags;
 477         size_t                  size = dev->rx_urb_size;
 478
 479         /* prevent rx skb allocation when error ratio is high */
 480         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 481                 usb_free_urb(urb);
 482                 return -ENOLINK;
 483         }
 484
 485         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 486         if (!skb) {
 487                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 488                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 489                 usb_free_urb (urb);
 490                 return -ENOMEM;
 491         }
 492
 493         entry = (struct skb_data *) skb->cb;
 494         entry->urb = urb;
 495         entry->dev = dev;
 496         entry->length = 0;
 497
 498         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 499                 skb->data, size, rx_complete, skb);
 500
 501         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 502
 503         if (netif_running (dev->net) &&
 504             netif_device_present (dev->net) &&
 505             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 506             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 507                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 508                 case -EPIPE:
 509                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 510                         break;
 511                 case -ENOMEM:
 512                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 513                         break;
 514                 case -ENODEV:
 515                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 516                         netif_device_detach (dev->net);
 517                         break;
 518                 case -EHOSTUNREACH:
 519                         retval = -ENOLINK;
 520                         break;
 521                 default:
 522                         netif_dbg(dev, rx_err, dev->net,
 523                                   "rx submit, %d\n", retval);
 524                         tasklet_schedule (&dev->bh);
 525                         break;
 526                 case 0:
 527                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 528                 }
 529         } else {
 530                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 531                 retval = -ENOLINK;
 532         }
 533         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 534         if (retval) {
 535                 dev_kfree_skb_any (skb);
 536                 usb_free_urb (urb);
 537         }
 538         return retval;
 539 }
 540
 541
 542 /*-------------------------------------------------------------------------*/
 543
 544 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 545 {
 546         if (dev->driver_info->rx_fixup &&
 547             !dev->driver_info->rx_fixup (dev, skb)) {
 548                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 549                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 550                         dev->net->stats.rx_errors++;
 551                 goto done;
 552         }
 553         // else network stack removes extra byte if we forced a short packet
 554
 555         /* all data was already cloned from skb inside the driver */
 556         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 557                 goto done;
 558
 559         if (skb->len < ETH_HLEN) {
 560                 dev->net->stats.rx_errors++;
 561                 dev->net->stats.rx_length_errors++;
 562                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 563         } else {
 564                 usbnet_skb_return(dev, skb);
 565                 return;
 566         }
 567
 568 done:
 569         skb_queue_tail(&dev->done, skb);
 570 }
 571
 572 /*-------------------------------------------------------------------------*/
 573
 574 static void rx_complete (struct urb *urb)
 575 {
 576         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 577         struct skb_data         *entry = (struct skb_data *) skb->cb;
 578         struct usbnet           *dev = entry->dev;
 579         int                     urb_status = urb->status;
 580         enum skb_state          state;
 581
 582         skb_put (skb, urb->actual_length);
 583         state = rx_done;
 584         entry->urb = NULL;
 585
 586         switch (urb_status) {
 587         /* success */
 588         case 0:
 589                 break;
 590
 591         /* stalls need manual reset. this is rare ... except that
 592          * when going through USB 2.0 TTs, unplug appears this way.
 593          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 594          * storm, recovering as needed.
 595          */
 596         case -EPIPE:
 597                 dev->net->stats.rx_errors++;
 598                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 599                 // FALLTHROUGH
 600
 601         /* software-driven interface shutdown */
 602         case -ECONNRESET:               /* async unlink */
 603         case -ESHUTDOWN:                /* hardware gone */
 604                 netif_dbg(dev, ifdown, dev->net,
 605                           "rx shutdown, code %d\n", urb_status);
 606                 goto block;
 607
 608         /* we get controller i/o faults during hub_wq disconnect() delays.
 609          * throttle down resubmits, to avoid log floods; just temporarily,
 610          * so we still recover when the fault isn't a hub_wq delay.
 611          */
 612         case -EPROTO:
 613         case -ETIME:
 614         case -EILSEQ:
 615                 dev->net->stats.rx_errors++;
 616                 if (!timer_pending (&dev->delay)) {
 617                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 618                         netif_dbg(dev, link, dev->net,
 619                                   "rx throttle %d\n", urb_status);
 620                 }
 621 block:
 622                 state = rx_cleanup;
 623                 entry->urb = urb;
 624                 urb = NULL;
 625                 break;
 626
 627         /* data overrun ... flush fifo? */
 628         case -EOVERFLOW:
 629                 dev->net->stats.rx_over_errors++;
 630                 // FALLTHROUGH
 631
 632         default:
 633                 state = rx_cleanup;
 634                 dev->net->stats.rx_errors++;
 635                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 636                 break;
 637         }
 638
 639         /* stop rx if packet error rate is high */
 640         if (++dev->pkt_cnt > 30) {
 641                 dev->pkt_cnt = 0;
 642                 dev->pkt_err = 0;
 643         } else {
 644                 if (state == rx_cleanup)
 645                         dev->pkt_err++;
 646                 if (dev->pkt_err > 20)
 647                         set_bit(EVENT_RX_KILL, &dev->flags);
 648         }
 649
 650         state = defer_bh(dev, skb, &dev->rxq, state);
 651
 652         if (urb) {
 653                 if (netif_running (dev->net) &&
 654                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 655                     state != unlink_start) {
 656                         rx_submit (dev, urb, GFP_ATOMIC);
 657                         usb_mark_last_busy(dev->udev);
 658                         return;
 659                 }
 660                 usb_free_urb (urb);
 661         }
 662         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 663 }
 664
 665 /*-------------------------------------------------------------------------*/
 666 void usbnet_pause_rx(struct usbnet *dev)
 667 {
 668         set_bit(EVENT_RX_PAUSED, &dev->flags);
 669
 670         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 671 }
 672 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 673
 674 void usbnet_resume_rx(struct usbnet *dev)
 675 {
 676         struct sk_buff *skb;
 677         int num = 0;
 678
 679         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 680
 681         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 682                 usbnet_skb_return(dev, skb);
 683                 num++;
 684         }
 685
 686         tasklet_schedule(&dev->bh);
 687
 688         netif_dbg(dev, rx_status, dev->net,
 689                   "paused rx queue disabled, %d skbs requeued\n", num);
 690 }
 691 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 692
 693 void usbnet_purge_paused_rxq(struct usbnet *dev)
 694 {
 695         skb_queue_purge(&dev->rxq_pause);
 696 }
 697 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 698
 699 /*-------------------------------------------------------------------------*/
 700
 701 // unlink pending rx/tx; completion handlers do all other cleanup
 702
 703 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 704 {
 705         unsigned long           flags;
 706         struct sk_buff          *skb;
 707         int                     count = 0;
 708
 709         spin_lock_irqsave (&q->lock, flags);
 710         while (!skb_queue_empty(q)) {
 711                 struct skb_data         *entry;
 712                 struct urb              *urb;
 713                 int                     retval;
 714
 715                 skb_queue_walk(q, skb) {
 716                         entry = (struct skb_data *) skb->cb;
 717                         if (entry->state != unlink_start)
 718                                 goto found;
 719                 }
 720                 break;
 721 found:
 722                 entry->state = unlink_start;
 723                 urb = entry->urb;
 724
 725                 /*
 726                  * Get reference count of the URB to avoid it to be
 727                  * freed during usb_unlink_urb, which may trigger
 728                  * use-after-free problem inside usb_unlink_urb since
 729                  * usb_unlink_urb is always racing with .complete
 730                  * handler(include defer_bh).
 731                  */
 732                 usb_get_urb(urb);
 733                 spin_unlock_irqrestore(&q->lock, flags);
 734                 // during some PM-driven resume scenarios,
 735                 // these (async) unlinks complete immediately
 736                 retval = usb_unlink_urb (urb);
 737                 if (retval != -EINPROGRESS && retval != 0)
 738                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 739                 else
 740                         count++;
 741                 usb_put_urb(urb);
 742                 spin_lock_irqsave(&q->lock, flags);
 743         }
 744         spin_unlock_irqrestore (&q->lock, flags);
 745         return count;
 746 }
 747
 748 // Flush all pending rx urbs
 749 // minidrivers may need to do this when the MTU changes
 750
 751 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 752 {
 753         if (netif_running(dev->net)) {
 754                 (void) unlink_urbs (dev, &dev->rxq);
 755                 tasklet_schedule(&dev->bh);
 756         }
 757 }
 758 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 759
 760 /*-------------------------------------------------------------------------*/
 761
 762 static void wait_skb_queue_empty(struct sk_buff_head *q)
 763 {
 764         unsigned long flags;
 765
 766         spin_lock_irqsave(&q->lock, flags);
 767         while (!skb_queue_empty(q)) {
 768                 spin_unlock_irqrestore(&q->lock, flags);
 769                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 770                 set_current_state(TASK_UNINTERRUPTIBLE);
 771                 spin_lock_irqsave(&q->lock, flags);
 772         }
 773         spin_unlock_irqrestore(&q->lock, flags);
 774 }
 775
 776 // precondition: never called in_interrupt
 777 static void usbnet_terminate_urbs(struct usbnet *dev)
 778 {
 779         DECLARE_WAITQUEUE(wait, current);
 780         int temp;
 781
 782         /* ensure there are no more active urbs */
 783         add_wait_queue(&dev->wait, &wait);
 784         set_current_state(TASK_UNINTERRUPTIBLE);
 785         temp = unlink_urbs(dev, &dev->txq) +
 786                 unlink_urbs(dev, &dev->rxq);
 787
 788         /* maybe wait for deletions to finish. */
 789         wait_skb_queue_empty(&dev->rxq);
 790         wait_skb_queue_empty(&dev->txq);
 791         wait_skb_queue_empty(&dev->done);
 792         netif_dbg(dev, ifdown, dev->net,
 793                   "waited for %d urb completions\n", temp);
 794         set_current_state(TASK_RUNNING);
 795         remove_wait_queue(&dev->wait, &wait);
 796 }
 797
 798 int usbnet_stop (struct net_device *net)
 799 {
 800         struct usbnet           *dev = netdev_priv(net);
 801         struct driver_info      *info = dev->driver_info;
 802         int                     retval, pm, mpn;
 803
 804         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 805         netif_stop_queue (net);
 806
 807         netif_info(dev, ifdown, dev->net,
 808                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 809                    net->stats.rx_packets, net->stats.tx_packets,
 810                    net->stats.rx_errors, net->stats.tx_errors);
 811
 812         /* to not race resume */
 813         pm = usb_autopm_get_interface(dev->intf);
 814         /* allow minidriver to stop correctly (wireless devices to turn off
 815          * radio etc) */
 816         if (info->stop) {
 817                 retval = info->stop(dev);
 818                 if (retval < 0)
 819                         netif_info(dev, ifdown, dev->net,
 820                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 821                                    retval,
 822                                    dev->udev->bus->bus_name, dev->udev->devpath,
 823                                    info->description);
 824         }
 825
 826         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 827                 usbnet_terminate_urbs(dev);
 828
 829         usbnet_status_stop(dev);
 830
 831         usbnet_purge_paused_rxq(dev);
 832
 833         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 834
 835         /* deferred work (task, timer, softirq) must also stop.
 836          * can't flush_scheduled_work() until we drop rtnl (later),
 837          * else workers could deadlock; so make workers a NOP.
 838          */
 839         dev->flags = 0;
 840         del_timer_sync (&dev->delay);
 841         tasklet_kill (&dev->bh);
 842         if (!pm)
 843                 usb_autopm_put_interface(dev->intf);
 844
 845         if (info->manage_power && mpn)
 846                 info->manage_power(dev, 0);
 847         else
 848                 usb_autopm_put_interface(dev->intf);
 849
 850         return 0;
 851 }
 852 EXPORT_SYMBOL_GPL(usbnet_stop);
 853
 854 /*-------------------------------------------------------------------------*/
 855
 856 // posts reads, and enables write queuing
 857
 858 // precondition: never called in_interrupt
 859
 860 int usbnet_open (struct net_device *net)
 861 {
 862         struct usbnet           *dev = netdev_priv(net);
 863         int                     retval;
 864         struct driver_info      *info = dev->driver_info;
 865
 866         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 867                 netif_info(dev, ifup, dev->net,
 868                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 869                            retval,
 870                            dev->udev->bus->bus_name,
 871                            dev->udev->devpath,
 872                            info->description);
 873                 goto done_nopm;
 874         }
 875
 876         // put into "known safe" state
 877         if (info->reset && (retval = info->reset (dev)) < 0) {
 878                 netif_info(dev, ifup, dev->net,
 879                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 880                            retval,
 881                            dev->udev->bus->bus_name,
 882                            dev->udev->devpath,
 883                            info->description);
 884                 goto done;
 885         }
 886
 887         /* hard_mtu or rx_urb_size may change in reset() */
 888         usbnet_update_max_qlen(dev);
 889
 890         // insist peer be connected
 891         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 892                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 893                 goto done;
 894         }
 895
 896         /* start any status interrupt transfer */
 897         if (dev->interrupt) {
 898                 retval = usbnet_status_start(dev, GFP_KERNEL);
 899                 if (retval < 0) {
 900                         netif_err(dev, ifup, dev->net,
 901                                   "intr submit %d\n", retval);
 902                         goto done;
 903                 }
 904         }
 905
 906         set_bit(EVENT_DEV_OPEN, &dev->flags);
 907         netif_start_queue (net);
 908         netif_info(dev, ifup, dev->net,
 909                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 910                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 911                    dev->net->mtu,
 912                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 913                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 914                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 915                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 916                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 917                    "simple");
 918
 919         /* reset rx error state */
 920         dev->pkt_cnt = 0;
 921         dev->pkt_err = 0;
 922         clear_bit(EVENT_RX_KILL, &dev->flags);
 923
 924         // delay posting reads until we're fully open
 925         tasklet_schedule (&dev->bh);
 926         if (info->manage_power) {
 927                 retval = info->manage_power(dev, 1);
 928                 if (retval < 0) {
 929                         retval = 0;
 930                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 931                 } else {
 932                         usb_autopm_put_interface(dev->intf);
 933                 }
 934         }
 935         return retval;
 936 done:
 937         usb_autopm_put_interface(dev->intf);
 938 done_nopm:
 939         return retval;
 940 }
 941 EXPORT_SYMBOL_GPL(usbnet_open);
 942
 943 /*-------------------------------------------------------------------------*/
 944
 945 /* ethtool methods; minidrivers may need to add some more, but
 946  * they'll probably want to use this base set.
 947  */
 948
 949 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 950 {
 951         struct usbnet *dev = netdev_priv(net);
 952
 953         if (!dev->mii.mdio_read)
 954                 return -EOPNOTSUPP;
 955
 956         return mii_ethtool_gset(&dev->mii, cmd);
 957 }
 958 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 959
 960 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 961 {
 962         struct usbnet *dev = netdev_priv(net);
 963         int retval;
 964
 965         if (!dev->mii.mdio_write)
 966                 return -EOPNOTSUPP;
 967
 968         retval = mii_ethtool_sset(&dev->mii, cmd);
 969
 970         /* link speed/duplex might have changed */
 971         if (dev->driver_info->link_reset)
 972                 dev->driver_info->link_reset(dev);
 973
 974         /* hard_mtu or rx_urb_size may change in link_reset() */
 975         usbnet_update_max_qlen(dev);
 976
 977         return retval;
 978
 979 }
 980 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 981
 982 u32 usbnet_get_link (struct net_device *net)
 983 {
 984         struct usbnet *dev = netdev_priv(net);
 985
 986         /* If a check_connect is defined, return its result */
 987         if (dev->driver_info->check_connect)
 988                 return dev->driver_info->check_connect (dev) == 0;
 989
 990         /* if the device has mii operations, use those */
 991         if (dev->mii.mdio_read)
 992                 return mii_link_ok(&dev->mii);
 993
 994         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 995         return ethtool_op_get_link(net);
 996 }
 997 EXPORT_SYMBOL_GPL(usbnet_get_link);
 998
 999 int usbnet_nway_reset(struct net_device *net)
1000 {
1001         struct usbnet *dev = netdev_priv(net);
1002
1003         if (!dev->mii.mdio_write)
1004                 return -EOPNOTSUPP;
1005
1006         return mii_nway_restart(&dev->mii);
1007 }
1008 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1009
1010 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1011 {
1012         struct usbnet *dev = netdev_priv(net);
1013
1014         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1015         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1016         strlcpy (info->fw_version, dev->driver_info->description,
1017                 sizeof info->fw_version);
1018         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1019 }
1020 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1021
1022 u32 usbnet_get_msglevel (struct net_device *net)
1023 {
1024         struct usbnet *dev = netdev_priv(net);
1025
1026         return dev->msg_enable;
1027 }
1028 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1029
1030 void usbnet_set_msglevel (struct net_device *net, u32 level)
1031 {
1032         struct usbnet *dev = netdev_priv(net);
1033
1034         dev->msg_enable = level;
1035 }
1036 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1037
1038 /* drivers may override default ethtool_ops in their bind() routine */
1039 static const struct ethtool_ops usbnet_ethtool_ops = {
1040         .get_settings           = usbnet_get_settings,
1041         .set_settings           = usbnet_set_settings,
1042         .get_link               = usbnet_get_link,
1043         .nway_reset             = usbnet_nway_reset,
1044         .get_drvinfo            = usbnet_get_drvinfo,
1045         .get_msglevel           = usbnet_get_msglevel,
1046         .set_msglevel           = usbnet_set_msglevel,
1047         .get_ts_info            = ethtool_op_get_ts_info,
1048 };
1049
1050 /*-------------------------------------------------------------------------*/
1051
1052 static void __handle_link_change(struct usbnet *dev)
1053 {
1054         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1055                 return;
1056
1057         if (!netif_carrier_ok(dev->net)) {
1058                 /* kill URBs for reading packets to save bus bandwidth */
1059                 unlink_urbs(dev, &dev->rxq);
1060
1061                 /*
1062                  * tx_timeout will unlink URBs for sending packets and
1063                  * tx queue is stopped by netcore after link becomes off
1064                  */
1065         } else {
1066                 /* submitting URBs for reading packets */
1067                 tasklet_schedule(&dev->bh);
1068         }
1069
1070         /* hard_mtu or rx_urb_size may change during link change */
1071         usbnet_update_max_qlen(dev);
1072
1073         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1074 }
1075
1076 static void usbnet_set_rx_mode(struct net_device *net)
1077 {
1078         struct usbnet           *dev = netdev_priv(net);
1079
1080         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1081 }
1082
1083 static void __handle_set_rx_mode(struct usbnet *dev)
1084 {
1085         if (dev->driver_info->set_rx_mode)
1086                 (dev->driver_info->set_rx_mode)(dev);
1087
1088         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1089 }
1090
1091 /* work that cannot be done in interrupt context uses keventd.
1092  *
1093  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1094  * especially now that control transfers can be queued.
1095  */
1096 static void
1097 usbnet_deferred_kevent (struct work_struct *work)
1098 {
1099         struct usbnet           *dev =
1100                 container_of(work, struct usbnet, kevent);
1101         int                     status;
1102
1103         /* usb_clear_halt() needs a thread context */
1104         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1105                 unlink_urbs (dev, &dev->txq);
1106                 status = usb_autopm_get_interface(dev->intf);
1107                 if (status < 0)
1108                         goto fail_pipe;
1109                 status = usb_clear_halt (dev->udev, dev->out);
1110                 usb_autopm_put_interface(dev->intf);
1111                 if (status < 0 &&
1112                     status != -EPIPE &&
1113                     status != -ESHUTDOWN) {
1114                         if (netif_msg_tx_err (dev))
1115 fail_pipe:
1116                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1117                                            status);
1118                 } else {
1119                         clear_bit (EVENT_TX_HALT, &dev->flags);
1120                         if (status != -ESHUTDOWN)
1121                                 netif_wake_queue (dev->net);
1122                 }
1123         }
1124         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1125                 unlink_urbs (dev, &dev->rxq);
1126                 status = usb_autopm_get_interface(dev->intf);
1127                 if (status < 0)
1128                         goto fail_halt;
1129                 status = usb_clear_halt (dev->udev, dev->in);
1130                 usb_autopm_put_interface(dev->intf);
1131                 if (status < 0 &&
1132                     status != -EPIPE &&
1133                     status != -ESHUTDOWN) {
1134                         if (netif_msg_rx_err (dev))
1135 fail_halt:
1136                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1137                                            status);
1138                 } else {
1139                         clear_bit (EVENT_RX_HALT, &dev->flags);
1140                         tasklet_schedule (&dev->bh);
1141                 }
1142         }
1143
1144         /* tasklet could resubmit itself forever if memory is tight */
1145         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1146                 struct urb      *urb = NULL;
1147                 int resched = 1;
1148
1149                 if (netif_running (dev->net))
1150                         urb = usb_alloc_urb (0, GFP_KERNEL);
1151                 else
1152                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1153                 if (urb != NULL) {
1154                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1155                         status = usb_autopm_get_interface(dev->intf);
1156                         if (status < 0) {
1157                                 usb_free_urb(urb);
1158                                 goto fail_lowmem;
1159                         }
1160                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1161                                 resched = 0;
1162                         usb_autopm_put_interface(dev->intf);
1163 fail_lowmem:
1164                         if (resched)
1165                                 tasklet_schedule (&dev->bh);
1166                 }
1167         }
1168
1169         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1170                 struct driver_info      *info = dev->driver_info;
1171                 int                     retval = 0;
1172
1173                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1174                 status = usb_autopm_get_interface(dev->intf);
1175                 if (status < 0)
1176                         goto skip_reset;
1177                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1178                         usb_autopm_put_interface(dev->intf);
1179 skip_reset:
1180                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1181                                     retval,
1182                                     dev->udev->bus->bus_name,
1183                                     dev->udev->devpath,
1184                                     info->description);
1185                 } else {
1186                         usb_autopm_put_interface(dev->intf);
1187                 }
1188
1189                 /* handle link change from link resetting */
1190                 __handle_link_change(dev);
1191         }
1192
1193         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1194                 __handle_link_change(dev);
1195
1196         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1197                 __handle_set_rx_mode(dev);
1198
1199
1200         if (dev->flags)
1201                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1202 }
1203
1204 /*-------------------------------------------------------------------------*/
1205
1206 static void tx_complete (struct urb *urb)
1207 {
1208         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1209         struct skb_data         *entry = (struct skb_data *) skb->cb;
1210         struct usbnet           *dev = entry->dev;
1211
1212         if (urb->status == 0) {
1213                 dev->net->stats.tx_packets += entry->packets;
1214                 dev->net->stats.tx_bytes += entry->length;
1215         } else {
1216                 dev->net->stats.tx_errors++;
1217
1218                 switch (urb->status) {
1219                 case -EPIPE:
1220                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1221                         break;
1222
1223                 /* software-driven interface shutdown */
1224                 case -ECONNRESET:               // async unlink
1225                 case -ESHUTDOWN:                // hardware gone
1226                         break;
1227
1228                 /* like rx, tx gets controller i/o faults during hub_wq
1229                  * delays and so it uses the same throttling mechanism.
1230                  */
1231                 case -EPROTO:
1232                 case -ETIME:
1233                 case -EILSEQ:
1234                         usb_mark_last_busy(dev->udev);
1235                         if (!timer_pending (&dev->delay)) {
1236                                 mod_timer (&dev->delay,
1237                                         jiffies + THROTTLE_JIFFIES);
1238                                 netif_dbg(dev, link, dev->net,
1239                                           "tx throttle %d\n", urb->status);
1240                         }
1241                         netif_stop_queue (dev->net);
1242                         break;
1243                 default:
1244                         netif_dbg(dev, tx_err, dev->net,
1245                                   "tx err %d\n", entry->urb->status);
1246                         break;
1247                 }
1248         }
1249
1250         usb_autopm_put_interface_async(dev->intf);
1251         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1252 }
1253
1254 /*-------------------------------------------------------------------------*/
1255
1256 void usbnet_tx_timeout (struct net_device *net)
1257 {
1258         struct usbnet           *dev = netdev_priv(net);
1259
1260         unlink_urbs (dev, &dev->txq);
1261         tasklet_schedule (&dev->bh);
1262         /* this needs to be handled individually because the generic layer
1263          * doesn't know what is sufficient and could not restore private
1264          * information if a remedy of an unconditional reset were used.
1265          */
1266         if (dev->driver_info->recover)
1267                 (dev->driver_info->recover)(dev);
1268 }
1269 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1270
1271 /*-------------------------------------------------------------------------*/
1272
1273 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1274 {
1275         unsigned num_sgs, total_len = 0;
1276         int i, s = 0;
1277
1278         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1279         if (num_sgs == 1)
1280                 return 0;
1281
1282         /* reserve one for zero packet */
1283         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1284                           GFP_ATOMIC);
1285         if (!urb->sg)
1286                 return -ENOMEM;
1287
1288         urb->num_sgs = num_sgs;
1289         sg_init_table(urb->sg, urb->num_sgs + 1);
1290
1291         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1292         total_len += skb_headlen(skb);
1293
1294         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1295                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1296
1297                 total_len += skb_frag_size(f);
1298                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1299                                 f->page_offset);
1300         }
1301         urb->transfer_buffer_length = total_len;
1302
1303         return 1;
1304 }
1305
1306 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1307                                      struct net_device *net)
1308 {
1309         struct usbnet           *dev = netdev_priv(net);
1310         unsigned int                    length;
1311         struct urb              *urb = NULL;
1312         struct skb_data         *entry;
1313         struct driver_info      *info = dev->driver_info;
1314         unsigned long           flags;
1315         int retval;
1316
1317         if (skb)
1318                 skb_tx_timestamp(skb);
1319
1320         // some devices want funky USB-level framing, for
1321         // win32 driver (usually) and/or hardware quirks
1322         if (info->tx_fixup) {
1323                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1324                 if (!skb) {
1325                         /* packet collected; minidriver waiting for more */
1326                         if (info->flags & FLAG_MULTI_PACKET)
1327                                 goto not_drop;
1328                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1329                         goto drop;
1330                 }
1331         }
1332
1333         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1334                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1335                 goto drop;
1336         }
1337
1338         entry = (struct skb_data *) skb->cb;
1339         entry->urb = urb;
1340         entry->dev = dev;
1341
1342         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1343                         skb->data, skb->len, tx_complete, skb);
1344         if (dev->can_dma_sg) {
1345                 if (build_dma_sg(skb, urb) < 0)
1346                         goto drop;
1347         }
1348         length = urb->transfer_buffer_length;
1349
1350         /* don't assume the hardware handles USB_ZERO_PACKET
1351          * NOTE:  strictly conforming cdc-ether devices should expect
1352          * the ZLP here, but ignore the one-byte packet.
1353          * NOTE2: CDC NCM specification is different from CDC ECM when
1354          * handling ZLP/short packets, so cdc_ncm driver will make short
1355          * packet itself if needed.
1356          */
1357         if (length % dev->maxpacket == 0) {
1358                 if (!(info->flags & FLAG_SEND_ZLP)) {
1359                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1360                                 length++;
1361                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1362                                         skb->data[skb->len] = 0;
1363                                         __skb_put(skb, 1);
1364                                 } else if (urb->num_sgs)
1365                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1366                                                         dev->padding_pkt, 1);
1367                         }
1368                 } else
1369                         urb->transfer_flags |= URB_ZERO_PACKET;
1370         }
1371         urb->transfer_buffer_length = length;
1372
1373         if (info->flags & FLAG_MULTI_PACKET) {
1374                 /* Driver has set number of packets and a length delta.
1375                  * Calculate the complete length and ensure that it's
1376                  * positive.
1377                  */
1378                 entry->length += length;
1379                 if (WARN_ON_ONCE(entry->length <= 0))
1380                         entry->length = length;
1381         } else {
1382                 usbnet_set_skb_tx_stats(skb, 1, length);
1383         }
1384
1385         spin_lock_irqsave(&dev->txq.lock, flags);
1386         retval = usb_autopm_get_interface_async(dev->intf);
1387         if (retval < 0) {
1388                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1389                 goto drop;
1390         }
1391
1392 #ifdef CONFIG_PM
1393         /* if this triggers the device is still a sleep */
1394         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1395                 /* transmission will be done in resume */
1396                 usb_anchor_urb(urb, &dev->deferred);
1397                 /* no use to process more packets */
1398                 netif_stop_queue(net);
1399                 usb_put_urb(urb);
1400                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1401                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1402                 goto deferred;
1403         }
1404 #endif
1405
1406         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1407         case -EPIPE:
1408                 netif_stop_queue (net);
1409                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1410                 usb_autopm_put_interface_async(dev->intf);
1411                 break;
1412         default:
1413                 usb_autopm_put_interface_async(dev->intf);
1414                 netif_dbg(dev, tx_err, dev->net,
1415                           "tx: submit urb err %d\n", retval);
1416                 break;
1417         case 0:
1418                 net->trans_start = jiffies;
1419                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1420                 if (dev->txq.qlen >= TX_QLEN (dev))
1421                         netif_stop_queue (net);
1422         }
1423         spin_unlock_irqrestore (&dev->txq.lock, flags);
1424
1425         if (retval) {
1426                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1427 drop:
1428                 dev->net->stats.tx_dropped++;
1429 not_drop:
1430                 if (skb)
1431                         dev_kfree_skb_any (skb);
1432                 if (urb) {
1433                         kfree(urb->sg);
1434                         usb_free_urb(urb);
1435                 }
1436         } else
1437                 netif_dbg(dev, tx_queued, dev->net,
1438                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1439 #ifdef CONFIG_PM
1440 deferred:
1441 #endif
1442         return NETDEV_TX_OK;
1443 }
1444 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1445
1446 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1447 {
1448         struct urb      *urb;
1449         int             i;
1450         int             ret = 0;
1451
1452         /* don't refill the queue all at once */
1453         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1454                 urb = usb_alloc_urb(0, flags);
1455                 if (urb != NULL) {
1456                         ret = rx_submit(dev, urb, flags);
1457                         if (ret)
1458                                 goto err;
1459                 } else {
1460                         ret = -ENOMEM;
1461                         goto err;
1462                 }
1463         }
1464 err:
1465         return ret;
1466 }
1467
1468 /*-------------------------------------------------------------------------*/
1469
1470 // tasklet (work deferred from completions, in_irq) or timer
1471
1472 static void usbnet_bh (unsigned long param)
1473 {
1474         struct usbnet           *dev = (struct usbnet *) param;
1475         struct sk_buff          *skb;
1476         struct skb_data         *entry;
1477
1478         while ((skb = skb_dequeue (&dev->done))) {
1479                 entry = (struct skb_data *) skb->cb;
1480                 switch (entry->state) {
1481                 case rx_done:
1482                         entry->state = rx_cleanup;
1483                         rx_process (dev, skb);
1484                         continue;
1485                 case tx_done:
1486                         kfree(entry->urb->sg);
1487                 case rx_cleanup:
1488                         usb_free_urb (entry->urb);
1489                         dev_kfree_skb (skb);
1490                         continue;
1491                 default:
1492                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1493                 }
1494         }
1495
1496         /* restart RX again after disabling due to high error rate */
1497         clear_bit(EVENT_RX_KILL, &dev->flags);
1498
1499         /* waiting for all pending urbs to complete?
1500          * only then can we forgo submitting anew
1501          */
1502         if (waitqueue_active(&dev->wait)) {
1503                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1504                         wake_up_all(&dev->wait);
1505
1506         // or are we maybe short a few urbs?
1507         } else if (netif_running (dev->net) &&
1508                    netif_device_present (dev->net) &&
1509                    netif_carrier_ok(dev->net) &&
1510                    !timer_pending (&dev->delay) &&
1511                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1512                 int     temp = dev->rxq.qlen;
1513
1514                 if (temp < RX_QLEN(dev)) {
1515                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1516                                 return;
1517                         if (temp != dev->rxq.qlen)
1518                                 netif_dbg(dev, link, dev->net,
1519                                           "rxqlen %d --> %d\n",
1520                                           temp, dev->rxq.qlen);
1521                         if (dev->rxq.qlen < RX_QLEN(dev))
1522                                 tasklet_schedule (&dev->bh);
1523                 }
1524                 if (dev->txq.qlen < TX_QLEN (dev))
1525                         netif_wake_queue (dev->net);
1526         }
1527 }
1528
1529
1530 /*-------------------------------------------------------------------------
1531  *
1532  * USB Device Driver support
1533  *
1534  *-------------------------------------------------------------------------*/
1535
1536 // precondition: never called in_interrupt
1537
1538 void usbnet_disconnect (struct usb_interface *intf)
1539 {
1540         struct usbnet           *dev;
1541         struct usb_device       *xdev;
1542         struct net_device       *net;
1543
1544         dev = usb_get_intfdata(intf);
1545         usb_set_intfdata(intf, NULL);
1546         if (!dev)
1547                 return;
1548
1549         xdev = interface_to_usbdev (intf);
1550
1551         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1552                    intf->dev.driver->name,
1553                    xdev->bus->bus_name, xdev->devpath,
1554                    dev->driver_info->description);
1555
1556         net = dev->net;
1557         unregister_netdev (net);
1558
1559         cancel_work_sync(&dev->kevent);
1560
1561         usb_scuttle_anchored_urbs(&dev->deferred);
1562
1563         if (dev->driver_info->unbind)
1564                 dev->driver_info->unbind (dev, intf);
1565
1566         usb_kill_urb(dev->interrupt);
1567         usb_free_urb(dev->interrupt);
1568         kfree(dev->padding_pkt);
1569
1570         free_netdev(net);
1571 }
1572 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1573
1574 static const struct net_device_ops usbnet_netdev_ops = {
1575         .ndo_open               = usbnet_open,
1576         .ndo_stop               = usbnet_stop,
1577         .ndo_start_xmit         = usbnet_start_xmit,
1578         .ndo_tx_timeout         = usbnet_tx_timeout,
1579         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1580         .ndo_change_mtu         = usbnet_change_mtu,
1581         .ndo_set_mac_address    = eth_mac_addr,
1582         .ndo_validate_addr      = eth_validate_addr,
1583 };
1584
1585 /*-------------------------------------------------------------------------*/
1586
1587 // precondition: never called in_interrupt
1588
1589 static struct device_type wlan_type = {
1590         .name   = "wlan",
1591 };
1592
1593 static struct device_type wwan_type = {
1594         .name   = "wwan",
1595 };
1596
1597 int
1598 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1599 {
1600         struct usbnet                   *dev;
1601         struct net_device               *net;
1602         struct usb_host_interface       *interface;
1603         struct driver_info              *info;
1604         struct usb_device               *xdev;
1605         int                             status;
1606         const char                      *name;
1607         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1608
1609         /* usbnet already took usb runtime pm, so have to enable the feature
1610          * for usb interface, otherwise usb_autopm_get_interface may return
1611          * failure if RUNTIME_PM is enabled.
1612          */
1613         if (!driver->supports_autosuspend) {
1614                 driver->supports_autosuspend = 1;
1615                 pm_runtime_enable(&udev->dev);
1616         }
1617
1618         name = udev->dev.driver->name;
1619         info = (struct driver_info *) prod->driver_info;
1620         if (!info) {
1621                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1622                 return -ENODEV;
1623         }
1624         xdev = interface_to_usbdev (udev);
1625         interface = udev->cur_altsetting;
1626
1627         status = -ENOMEM;
1628
1629         // set up our own records
1630         net = alloc_etherdev(sizeof(*dev));
1631         if (!net)
1632                 goto out;
1633
1634         /* netdev_printk() needs this so do it as early as possible */
1635         SET_NETDEV_DEV(net, &udev->dev);
1636
1637         dev = netdev_priv(net);
1638         dev->udev = xdev;
1639         dev->intf = udev;
1640         dev->driver_info = info;
1641         dev->driver_name = name;
1642         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1643                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1644         init_waitqueue_head(&dev->wait);
1645         skb_queue_head_init (&dev->rxq);
1646         skb_queue_head_init (&dev->txq);
1647         skb_queue_head_init (&dev->done);
1648         skb_queue_head_init(&dev->rxq_pause);
1649         dev->bh.func = usbnet_bh;
1650         dev->bh.data = (unsigned long) dev;
1651         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1652         init_usb_anchor(&dev->deferred);
1653         dev->delay.function = usbnet_bh;
1654         dev->delay.data = (unsigned long) dev;
1655         init_timer (&dev->delay);
1656         mutex_init (&dev->phy_mutex);
1657         mutex_init(&dev->interrupt_mutex);
1658         dev->interrupt_count = 0;
1659
1660         dev->net = net;
1661         strcpy (net->name, "usb%d");
1662         memcpy (net->dev_addr, node_id, sizeof node_id);
1663
1664         /* rx and tx sides can use different message sizes;
1665          * bind() should set rx_urb_size in that case.
1666          */
1667         dev->hard_mtu = net->mtu + net->hard_header_len;
1668
1669         net->netdev_ops = &usbnet_netdev_ops;
1670         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1671         net->ethtool_ops = &usbnet_ethtool_ops;
1672
1673         // allow device-specific bind/init procedures
1674         // NOTE net->name still not usable ...
1675         if (info->bind) {
1676                 status = info->bind (dev, udev);
1677                 if (status < 0)
1678                         goto out1;
1679
1680                 // heuristic:  "usb%d" for links we know are two-host,
1681                 // else "eth%d" when there's reasonable doubt.  userspace
1682                 // can rename the link if it knows better.
1683                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1684                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1685                      (net->dev_addr [0] & 0x02) == 0))
1686                         strcpy (net->name, "eth%d");
1687                 /* WLAN devices should always be named "wlan%d" */
1688                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1689                         strcpy(net->name, "wlan%d");
1690                 /* WWAN devices should always be named "wwan%d" */
1691                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1692                         strcpy(net->name, "wwan%d");
1693
1694                 /* devices that cannot do ARP */
1695                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1696                         net->flags |= IFF_NOARP;
1697
1698                 /* maybe the remote can't receive an Ethernet MTU */
1699                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1700                         net->mtu = dev->hard_mtu - net->hard_header_len;
1701         } else if (!info->in || !info->out)
1702                 status = usbnet_get_endpoints (dev, udev);
1703         else {
1704                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1705                 dev->out = usb_sndbulkpipe (xdev, info->out);
1706                 if (!(info->flags & FLAG_NO_SETINT))
1707                         status = usb_set_interface (xdev,
1708                                 interface->desc.bInterfaceNumber,
1709                                 interface->desc.bAlternateSetting);
1710                 else
1711                         status = 0;
1712
1713         }
1714         if (status >= 0 && dev->status)
1715                 status = init_status (dev, udev);
1716         if (status < 0)
1717                 goto out3;
1718
1719         if (!dev->rx_urb_size)
1720                 dev->rx_urb_size = dev->hard_mtu;
1721         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1722
1723         /* let userspace know we have a random address */
1724         if (ether_addr_equal(net->dev_addr, node_id))
1725                 net->addr_assign_type = NET_ADDR_RANDOM;
1726
1727         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1728                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1729         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1730                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1731
1732         /* initialize max rx_qlen and tx_qlen */
1733         usbnet_update_max_qlen(dev);
1734
1735         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1736                 !(info->flags & FLAG_MULTI_PACKET)) {
1737                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1738                 if (!dev->padding_pkt) {
1739                         status = -ENOMEM;
1740                         goto out4;
1741                 }
1742         }
1743
1744         status = register_netdev (net);
1745         if (status)
1746                 goto out5;
1747         netif_info(dev, probe, dev->net,
1748                    "register '%s' at usb-%s-%s, %s, %pM\n",
1749                    udev->dev.driver->name,
1750                    xdev->bus->bus_name, xdev->devpath,
1751                    dev->driver_info->description,
1752                    net->dev_addr);
1753
1754         // ok, it's ready to go.
1755         usb_set_intfdata (udev, dev);
1756
1757         netif_device_attach (net);
1758
1759         if (dev->driver_info->flags & FLAG_LINK_INTR)
1760                 usbnet_link_change(dev, 0, 0);
1761
1762         return 0;
1763
1764 out5:
1765         kfree(dev->padding_pkt);
1766 out4:
1767         usb_free_urb(dev->interrupt);
1768 out3:
1769         if (info->unbind)
1770                 info->unbind (dev, udev);
1771 out1:
1772         /* subdrivers must undo all they did in bind() if they
1773          * fail it, but we may fail later and a deferred kevent
1774          * may trigger an error resubmitting itself and, worse,
1775          * schedule a timer. So we kill it all just in case.
1776          */
1777         cancel_work_sync(&dev->kevent);
1778         del_timer_sync(&dev->delay);
1779         free_netdev(net);
1780 out:
1781         return status;
1782 }
1783 EXPORT_SYMBOL_GPL(usbnet_probe);
1784
1785 /*-------------------------------------------------------------------------*/
1786
1787 /*
1788  * suspend the whole driver as soon as the first interface is suspended
1789  * resume only when the last interface is resumed
1790  */
1791
1792 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1793 {
1794         struct usbnet           *dev = usb_get_intfdata(intf);
1795
1796         if (!dev->suspend_count++) {
1797                 spin_lock_irq(&dev->txq.lock);
1798                 /* don't autosuspend while transmitting */
1799                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1800                         dev->suspend_count--;
1801                         spin_unlock_irq(&dev->txq.lock);
1802                         return -EBUSY;
1803                 } else {
1804                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1805                         spin_unlock_irq(&dev->txq.lock);
1806                 }
1807                 /*
1808                  * accelerate emptying of the rx and queues, to avoid
1809                  * having everything error out.
1810                  */
1811                 netif_device_detach (dev->net);
1812                 usbnet_terminate_urbs(dev);
1813                 __usbnet_status_stop_force(dev);
1814
1815                 /*
1816                  * reattach so runtime management can use and
1817                  * wake the device
1818                  */
1819                 netif_device_attach (dev->net);
1820         }
1821         return 0;
1822 }
1823 EXPORT_SYMBOL_GPL(usbnet_suspend);
1824
1825 int usbnet_resume (struct usb_interface *intf)
1826 {
1827         struct usbnet           *dev = usb_get_intfdata(intf);
1828         struct sk_buff          *skb;
1829         struct urb              *res;
1830         int                     retval;
1831
1832         if (!--dev->suspend_count) {
1833                 /* resume interrupt URB if it was previously submitted */
1834                 __usbnet_status_start_force(dev, GFP_NOIO);
1835
1836                 spin_lock_irq(&dev->txq.lock);
1837                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1838
1839                         skb = (struct sk_buff *)res->context;
1840                         retval = usb_submit_urb(res, GFP_ATOMIC);
1841                         if (retval < 0) {
1842                                 dev_kfree_skb_any(skb);
1843                                 kfree(res->sg);
1844                                 usb_free_urb(res);
1845                                 usb_autopm_put_interface_async(dev->intf);
1846                         } else {
1847                                 dev->net->trans_start = jiffies;
1848                                 __skb_queue_tail(&dev->txq, skb);
1849                         }
1850                 }
1851
1852                 smp_mb();
1853                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1854                 spin_unlock_irq(&dev->txq.lock);
1855
1856                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1857                         /* handle remote wakeup ASAP
1858                          * we cannot race against stop
1859                          */
1860                         if (netif_device_present(dev->net) &&
1861                                 !timer_pending(&dev->delay) &&
1862                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1863                                         rx_alloc_submit(dev, GFP_NOIO);
1864
1865                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1866                                 netif_tx_wake_all_queues(dev->net);
1867                         tasklet_schedule (&dev->bh);
1868                 }
1869         }
1870
1871         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1872                 usb_autopm_get_interface_no_resume(intf);
1873
1874         return 0;
1875 }
1876 EXPORT_SYMBOL_GPL(usbnet_resume);
1877
1878 /*
1879  * Either a subdriver implements manage_power, then it is assumed to always
1880  * be ready to be suspended or it reports the readiness to be suspended
1881  * explicitly
1882  */
1883 void usbnet_device_suggests_idle(struct usbnet *dev)
1884 {
1885         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1886                 dev->intf->needs_remote_wakeup = 1;
1887                 usb_autopm_put_interface_async(dev->intf);
1888         }
1889 }
1890 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1891
1892 /*
1893  * For devices that can do without special commands
1894  */
1895 int usbnet_manage_power(struct usbnet *dev, int on)
1896 {
1897         dev->intf->needs_remote_wakeup = on;
1898         return 0;
1899 }
1900 EXPORT_SYMBOL(usbnet_manage_power);
1901
1902 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1903 {
1904         /* update link after link is reseted */
1905         if (link && !need_reset)
1906                 netif_carrier_on(dev->net);
1907         else
1908                 netif_carrier_off(dev->net);
1909
1910         if (need_reset && link)
1911                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1912         else
1913                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1914 }
1915 EXPORT_SYMBOL(usbnet_link_change);
1916
1917 /*-------------------------------------------------------------------------*/
1918 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1919                              u16 value, u16 index, void *data, u16 size)
1920 {
1921         void *buf = NULL;
1922         int err = -ENOMEM;
1923
1924         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1925                    " value=0x%04x index=0x%04x size=%d\n",
1926                    cmd, reqtype, value, index, size);
1927
1928         if (data) {
1929                 buf = kmalloc(size, GFP_KERNEL);
1930                 if (!buf)
1931                         goto out;
1932         }
1933
1934         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1935                               cmd, reqtype, value, index, buf, size,
1936                               USB_CTRL_GET_TIMEOUT);
1937         if (err > 0 && err <= size)
1938                 memcpy(data, buf, err);
1939         kfree(buf);
1940 out:
1941         return err;
1942 }
1943
1944 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1945                               u16 value, u16 index, const void *data,
1946                               u16 size)
1947 {
1948         void *buf = NULL;
1949         int err = -ENOMEM;
1950
1951         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1952                    " value=0x%04x index=0x%04x size=%d\n",
1953                    cmd, reqtype, value, index, size);
1954
1955         if (data) {
1956                 buf = kmemdup(data, size, GFP_KERNEL);
1957                 if (!buf)
1958                         goto out;
1959         }
1960
1961         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1962                               cmd, reqtype, value, index, buf, size,
1963                               USB_CTRL_SET_TIMEOUT);
1964         kfree(buf);
1965
1966 out:
1967         return err;
1968 }
1969
1970 int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
1971                                 struct usb_interface *intf,
1972                                 u8 *buffer,
1973                                 int buflen)
1974 {
1975         /* duplicates are ignored */
1976         struct usb_cdc_union_desc *union_header = NULL;
1977
1978         /* duplicates are not tolerated */
1979         struct usb_cdc_header_desc *header = NULL;
1980         struct usb_cdc_ether_desc *ether = NULL;
1981         struct usb_cdc_mdlm_detail_desc *detail = NULL;
1982         struct usb_cdc_mdlm_desc *desc = NULL;
1983
1984         unsigned int elength;
1985         int cnt = 0;
1986
1987         memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
1988         hdr->phonet_magic_present = false;
1989         while (buflen > 0) {
1990                 elength = buffer[0];
1991                 if (!elength) {
1992                         dev_err(&intf->dev, "skipping garbage byte\n");
1993                         elength = 1;
1994                         goto next_desc;
1995                 }
1996                 if (buffer[1] != USB_DT_CS_INTERFACE) {
1997                         dev_err(&intf->dev, "skipping garbage\n");
1998                         goto next_desc;
1999                 }
2000
2001                 switch (buffer[2]) {
2002                 case USB_CDC_UNION_TYPE: /* we've found it */
2003                         if (elength < sizeof(struct usb_cdc_union_desc))
2004                                 goto next_desc;
2005                         if (union_header) {
2006                                 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2007                                 goto next_desc;
2008                         }
2009                         union_header = (struct usb_cdc_union_desc *)buffer;
2010                         break;
2011                 case USB_CDC_COUNTRY_TYPE:
2012                         if (elength < sizeof(struct usb_cdc_country_functional_desc))
2013                                 goto next_desc;
2014                         hdr->usb_cdc_country_functional_desc =
2015                                 (struct usb_cdc_country_functional_desc *)buffer;
2016                         break;
2017                 case USB_CDC_HEADER_TYPE:
2018                         if (elength != sizeof(struct usb_cdc_header_desc))
2019                                 goto next_desc;
2020                         if (header)
2021                                 return -EINVAL;
2022                         header = (struct usb_cdc_header_desc *)buffer;
2023                         break;
2024                 case USB_CDC_ACM_TYPE:
2025                         if (elength < sizeof(struct usb_cdc_acm_descriptor))
2026                                 goto next_desc;
2027                         hdr->usb_cdc_acm_descriptor =
2028                                 (struct usb_cdc_acm_descriptor *)buffer;
2029                         break;
2030                 case USB_CDC_ETHERNET_TYPE:
2031                         if (elength != sizeof(struct usb_cdc_ether_desc))
2032                                 goto next_desc;
2033                         if (ether)
2034                                 return -EINVAL;
2035                         ether = (struct usb_cdc_ether_desc *)buffer;
2036                         break;
2037                 case USB_CDC_CALL_MANAGEMENT_TYPE:
2038                         if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2039                                 goto next_desc;
2040                         hdr->usb_cdc_call_mgmt_descriptor =
2041                                 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2042                         break;
2043                 case USB_CDC_DMM_TYPE:
2044                         if (elength < sizeof(struct usb_cdc_dmm_desc))
2045                                 goto next_desc;
2046                         hdr->usb_cdc_dmm_desc =
2047                                 (struct usb_cdc_dmm_desc *)buffer;
2048                         break;
2049                 case USB_CDC_MDLM_TYPE:
2050                         if (elength < sizeof(struct usb_cdc_mdlm_desc *))
2051                                 goto next_desc;
2052                         if (desc)
2053                                 return -EINVAL;
2054                         desc = (struct usb_cdc_mdlm_desc *)buffer;
2055                         break;
2056                 case USB_CDC_MDLM_DETAIL_TYPE:
2057                         if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *))
2058                                 goto next_desc;
2059                         if (detail)
2060                                 return -EINVAL;
2061                         detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2062                         break;
2063                 case USB_CDC_NCM_TYPE:
2064                         if (elength < sizeof(struct usb_cdc_ncm_desc))
2065                                 goto next_desc;
2066                         hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2067                         break;
2068                 case USB_CDC_MBIM_TYPE:
2069                         if (elength < sizeof(struct usb_cdc_mbim_desc))
2070                                 goto next_desc;
2071
2072                         hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2073                         break;
2074                 case USB_CDC_MBIM_EXTENDED_TYPE:
2075                         if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2076                                 break;
2077                         hdr->usb_cdc_mbim_extended_desc =
2078                                 (struct usb_cdc_mbim_extended_desc *)buffer;
2079                         break;
2080                 case CDC_PHONET_MAGIC_NUMBER:
2081                         hdr->phonet_magic_present = true;
2082                         break;
2083                 default:
2084                         /*
2085                          * there are LOTS more CDC descriptors that
2086                          * could legitimately be found here.
2087                          */
2088                         dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2089                                         buffer[2], elength);
2090                         goto next_desc;
2091                 }
2092                 cnt++;
2093 next_desc:
2094                 buflen -= elength;
2095                 buffer += elength;
2096         }
2097         hdr->usb_cdc_union_desc = union_header;
2098         hdr->usb_cdc_header_desc = header;
2099         hdr->usb_cdc_mdlm_detail_desc = detail;
2100         hdr->usb_cdc_mdlm_desc = desc;
2101         hdr->usb_cdc_ether_desc = ether;
2102         return cnt;
2103 }
2104
2105 EXPORT_SYMBOL(cdc_parse_cdc_header);
2106
2107 /*
2108  * The function can't be called inside suspend/resume callback,
2109  * otherwise deadlock will be caused.
2110  */
2111 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2112                     u16 value, u16 index, void *data, u16 size)
2113 {
2114         int ret;
2115
2116         if (usb_autopm_get_interface(dev->intf) < 0)
2117                 return -ENODEV;
2118         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2119                                 data, size);
2120         usb_autopm_put_interface(dev->intf);
2121         return ret;
2122 }
2123 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2124
2125 /*
2126  * The function can't be called inside suspend/resume callback,
2127  * otherwise deadlock will be caused.
2128  */
2129 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2130                      u16 value, u16 index, const void *data, u16 size)
2131 {
2132         int ret;
2133
2134         if (usb_autopm_get_interface(dev->intf) < 0)
2135                 return -ENODEV;
2136         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2137                                  data, size);
2138         usb_autopm_put_interface(dev->intf);
2139         return ret;
2140 }
2141 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2142
2143 /*
2144  * The function can be called inside suspend/resume callback safely
2145  * and should only be called by suspend/resume callback generally.
2146  */
2147 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2148                           u16 value, u16 index, void *data, u16 size)
2149 {
2150         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2151                                  data, size);
2152 }
2153 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2154
2155 /*
2156  * The function can be called inside suspend/resume callback safely
2157  * and should only be called by suspend/resume callback generally.
2158  */
2159 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2160                           u16 value, u16 index, const void *data,
2161                           u16 size)
2162 {
2163         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2164                                   data, size);
2165 }
2166 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2167
2168 static void usbnet_async_cmd_cb(struct urb *urb)
2169 {
2170         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2171         int status = urb->status;
2172
2173         if (status < 0)
2174                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2175                         __func__, status);
2176
2177         kfree(req);
2178         usb_free_urb(urb);
2179 }
2180
2181 /*
2182  * The caller must make sure that device can't be put into suspend
2183  * state until the control URB completes.
2184  */
2185 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2186                            u16 value, u16 index, const void *data, u16 size)
2187 {
2188         struct usb_ctrlrequest *req = NULL;
2189         struct urb *urb;
2190         int err = -ENOMEM;
2191         void *buf = NULL;
2192
2193         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2194                    " value=0x%04x index=0x%04x size=%d\n",
2195                    cmd, reqtype, value, index, size);
2196
2197         urb = usb_alloc_urb(0, GFP_ATOMIC);
2198         if (!urb) {
2199                 netdev_err(dev->net, "Error allocating URB in"
2200                            " %s!\n", __func__);
2201                 goto fail;
2202         }
2203
2204         if (data) {
2205                 buf = kmemdup(data, size, GFP_ATOMIC);
2206                 if (!buf) {
2207                         netdev_err(dev->net, "Error allocating buffer"
2208                                    " in %s!\n", __func__);
2209                         goto fail_free;
2210                 }
2211         }
2212
2213         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2214         if (!req)
2215                 goto fail_free_buf;
2216
2217         req->bRequestType = reqtype;
2218         req->bRequest = cmd;
2219         req->wValue = cpu_to_le16(value);
2220         req->wIndex = cpu_to_le16(index);
2221         req->wLength = cpu_to_le16(size);
2222
2223         usb_fill_control_urb(urb, dev->udev,
2224                              usb_sndctrlpipe(dev->udev, 0),
2225                              (void *)req, buf, size,
2226                              usbnet_async_cmd_cb, req);
2227         urb->transfer_flags |= URB_FREE_BUFFER;
2228
2229         err = usb_submit_urb(urb, GFP_ATOMIC);
2230         if (err < 0) {
2231                 netdev_err(dev->net, "Error submitting the control"
2232                            " message: status=%d\n", err);
2233                 goto fail_free;
2234         }
2235         return 0;
2236
2237 fail_free_buf:
2238         kfree(buf);
2239 fail_free:
2240         kfree(req);
2241         usb_free_urb(urb);
2242 fail:
2243         return err;
2244
2245 }
2246 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2247 /*-------------------------------------------------------------------------*/
2248
2249 static int __init usbnet_init(void)
2250 {
2251         /* Compiler should optimize this out. */
2252         BUILD_BUG_ON(
2253                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2254
2255         eth_random_addr(node_id);
2256         return 0;
2257 }
2258 module_init(usbnet_init);
2259
2260 static void __exit usbnet_exit(void)
2261 {
2262 }
2263 module_exit(usbnet_exit);
2264
2265 MODULE_AUTHOR("David Brownell");
2266 MODULE_DESCRIPTION("USB network driver framework");
2267 MODULE_LICENSE("GPL");