linux/drivers/net/usb/usbnet.c
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   1/*
   2 * USB Network driver infrastructure
   3 * Copyright (C) 2000-2005 by David Brownell
   4 * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20/*
  21 * This is a generic "USB networking" framework that works with several
  22 * kinds of full and high speed networking devices:  host-to-host cables,
  23 * smart usb peripherals, and actual Ethernet adapters.
  24 *
  25 * These devices usually differ in terms of control protocols (if they
  26 * even have one!) and sometimes they define new framing to wrap or batch
  27 * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28 * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29 * issues can usefully be addressed by this framework.
  30 */
  31
  32// #define      DEBUG                   // error path messages, extra info
  33// #define      VERBOSE                 // more; success messages
  34
  35#include <linux/module.h>
  36#include <linux/init.h>
  37#include <linux/netdevice.h>
  38#include <linux/etherdevice.h>
  39#include <linux/ctype.h>
  40#include <linux/ethtool.h>
  41#include <linux/workqueue.h>
  42#include <linux/mii.h>
  43#include <linux/usb.h>
  44#include <linux/usb/usbnet.h>
  45#include <linux/slab.h>
  46#include <linux/kernel.h>
  47#include <linux/pm_runtime.h>
  48
  49#define DRIVER_VERSION          "22-Aug-2005"
  50
  51
  52/*-------------------------------------------------------------------------*/
  53
  54/*
  55 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56 * Several dozen bytes of IPv4 data can fit in two such transactions.
  57 * One maximum size Ethernet packet takes twenty four of them.
  58 * For high speed, each frame comfortably fits almost 36 max size
  59 * Ethernet packets (so queues should be bigger).
  60 *
  61 * The goal is to let the USB host controller be busy for 5msec or
  62 * more before an irq is required, under load.  Jumbograms change
  63 * the equation.
  64 */
  65#define MAX_QUEUE_MEMORY        (60 * 1518)
  66#define RX_QLEN(dev)            ((dev)->rx_qlen)
  67#define TX_QLEN(dev)            ((dev)->tx_qlen)
  68
  69// reawaken network queue this soon after stopping; else watchdog barks
  70#define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73 * us (it polls at HZ/4 usually) before we report too many false errors.
  74 */
  75#define THROTTLE_JIFFIES        (HZ/8)
  76
  77// between wakeups
  78#define UNLINK_TIMEOUT_MS       3
  79
  80/*-------------------------------------------------------------------------*/
  81
  82// randomly generated ethernet address
  83static u8       node_id [ETH_ALEN];
  84
  85static const char driver_name [] = "usbnet";
  86
  87/* use ethtool to change the level for any given device */
  88static int msg_level = -1;
  89module_param (msg_level, int, 0);
  90MODULE_PARM_DESC (msg_level, "Override default message level");
  91
  92/*-------------------------------------------------------------------------*/
  93
  94/* handles CDC Ethernet and many other network "bulk data" interfaces */
  95int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96{
  97        int                             tmp;
  98        struct usb_host_interface       *alt = NULL;
  99        struct usb_host_endpoint        *in = NULL, *out = NULL;
 100        struct usb_host_endpoint        *status = NULL;
 101
 102        for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                unsigned        ep;
 104
 105                in = out = status = NULL;
 106                alt = intf->altsetting + tmp;
 107
 108                /* take the first altsetting with in-bulk + out-bulk;
 109                 * remember any status endpoint, just in case;
 110                 * ignore other endpoints and altsettings.
 111                 */
 112                for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                        struct usb_host_endpoint        *e;
 114                        int                             intr = 0;
 115
 116                        e = alt->endpoint + ep;
 117                        switch (e->desc.bmAttributes) {
 118                        case USB_ENDPOINT_XFER_INT:
 119                                if (!usb_endpoint_dir_in(&e->desc))
 120                                        continue;
 121                                intr = 1;
 122                                /* FALLTHROUGH */
 123                        case USB_ENDPOINT_XFER_BULK:
 124                                break;
 125                        default:
 126                                continue;
 127                        }
 128                        if (usb_endpoint_dir_in(&e->desc)) {
 129                                if (!intr && !in)
 130                                        in = e;
 131                                else if (intr && !status)
 132                                        status = e;
 133                        } else {
 134                                if (!out)
 135                                        out = e;
 136                        }
 137                }
 138                if (in && out)
 139                        break;
 140        }
 141        if (!alt || !in || !out)
 142                return -EINVAL;
 143
 144        if (alt->desc.bAlternateSetting != 0 ||
 145            !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 146                tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 147                                alt->desc.bAlternateSetting);
 148                if (tmp < 0)
 149                        return tmp;
 150        }
 151
 152        dev->in = usb_rcvbulkpipe (dev->udev,
 153                        in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154        dev->out = usb_sndbulkpipe (dev->udev,
 155                        out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156        dev->status = status;
 157        return 0;
 158}
 159EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 160
 161int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 162{
 163        int             tmp = -1, ret;
 164        unsigned char   buf [13];
 165
 166        ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167        if (ret == 12)
 168                tmp = hex2bin(dev->net->dev_addr, buf, 6);
 169        if (tmp < 0) {
 170                dev_dbg(&dev->udev->dev,
 171                        "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                if (ret >= 0)
 173                        ret = -EINVAL;
 174                return ret;
 175        }
 176        return 0;
 177}
 178EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 179
 180static void intr_complete (struct urb *urb)
 181{
 182        struct usbnet   *dev = urb->context;
 183        int             status = urb->status;
 184
 185        switch (status) {
 186        /* success */
 187        case 0:
 188                dev->driver_info->status(dev, urb);
 189                break;
 190
 191        /* software-driven interface shutdown */
 192        case -ENOENT:           /* urb killed */
 193        case -ESHUTDOWN:        /* hardware gone */
 194                netif_dbg(dev, ifdown, dev->net,
 195                          "intr shutdown, code %d\n", status);
 196                return;
 197
 198        /* NOTE:  not throttling like RX/TX, since this endpoint
 199         * already polls infrequently
 200         */
 201        default:
 202                netdev_dbg(dev->net, "intr status %d\n", status);
 203                break;
 204        }
 205
 206        status = usb_submit_urb (urb, GFP_ATOMIC);
 207        if (status != 0)
 208                netif_err(dev, timer, dev->net,
 209                          "intr resubmit --> %d\n", status);
 210}
 211
 212static int init_status (struct usbnet *dev, struct usb_interface *intf)
 213{
 214        char            *buf = NULL;
 215        unsigned        pipe = 0;
 216        unsigned        maxp;
 217        unsigned        period;
 218
 219        if (!dev->driver_info->status)
 220                return 0;
 221
 222        pipe = usb_rcvintpipe (dev->udev,
 223                        dev->status->desc.bEndpointAddress
 224                                & USB_ENDPOINT_NUMBER_MASK);
 225        maxp = usb_maxpacket (dev->udev, pipe, 0);
 226
 227        /* avoid 1 msec chatter:  min 8 msec poll rate */
 228        period = max ((int) dev->status->desc.bInterval,
 229                (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 230
 231        buf = kmalloc (maxp, GFP_KERNEL);
 232        if (buf) {
 233                dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 234                if (!dev->interrupt) {
 235                        kfree (buf);
 236                        return -ENOMEM;
 237                } else {
 238                        usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 239                                buf, maxp, intr_complete, dev, period);
 240                        dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 241                        dev_dbg(&intf->dev,
 242                                "status ep%din, %d bytes period %d\n",
 243                                usb_pipeendpoint(pipe), maxp, period);
 244                }
 245        }
 246        return 0;
 247}
 248
 249/* Submit the interrupt URB if not previously submitted, increasing refcount */
 250int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 251{
 252        int ret = 0;
 253
 254        WARN_ON_ONCE(dev->interrupt == NULL);
 255        if (dev->interrupt) {
 256                mutex_lock(&dev->interrupt_mutex);
 257
 258                if (++dev->interrupt_count == 1)
 259                        ret = usb_submit_urb(dev->interrupt, mem_flags);
 260
 261                dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 262                        dev->interrupt_count);
 263                mutex_unlock(&dev->interrupt_mutex);
 264        }
 265        return ret;
 266}
 267EXPORT_SYMBOL_GPL(usbnet_status_start);
 268
 269/* For resume; submit interrupt URB if previously submitted */
 270static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 271{
 272        int ret = 0;
 273
 274        mutex_lock(&dev->interrupt_mutex);
 275        if (dev->interrupt_count) {
 276                ret = usb_submit_urb(dev->interrupt, mem_flags);
 277                dev_dbg(&dev->udev->dev,
 278                        "submitted interrupt URB for resume\n");
 279        }
 280        mutex_unlock(&dev->interrupt_mutex);
 281        return ret;
 282}
 283
 284/* Kill the interrupt URB if all submitters want it killed */
 285void usbnet_status_stop(struct usbnet *dev)
 286{
 287        if (dev->interrupt) {
 288                mutex_lock(&dev->interrupt_mutex);
 289                WARN_ON(dev->interrupt_count == 0);
 290
 291                if (dev->interrupt_count && --dev->interrupt_count == 0)
 292                        usb_kill_urb(dev->interrupt);
 293
 294                dev_dbg(&dev->udev->dev,
 295                        "decremented interrupt URB count to %d\n",
 296                        dev->interrupt_count);
 297                mutex_unlock(&dev->interrupt_mutex);
 298        }
 299}
 300EXPORT_SYMBOL_GPL(usbnet_status_stop);
 301
 302/* For suspend; always kill interrupt URB */
 303static void __usbnet_status_stop_force(struct usbnet *dev)
 304{
 305        if (dev->interrupt) {
 306                mutex_lock(&dev->interrupt_mutex);
 307                usb_kill_urb(dev->interrupt);
 308                dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 309                mutex_unlock(&dev->interrupt_mutex);
 310        }
 311}
 312
 313/* Passes this packet up the stack, updating its accounting.
 314 * Some link protocols batch packets, so their rx_fixup paths
 315 * can return clones as well as just modify the original skb.
 316 */
 317void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 318{
 319        int     status;
 320
 321        if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322                skb_queue_tail(&dev->rxq_pause, skb);
 323                return;
 324        }
 325
 326        /* only update if unset to allow minidriver rx_fixup override */
 327        if (skb->protocol == 0)
 328                skb->protocol = eth_type_trans (skb, dev->net);
 329
 330        dev->net->stats.rx_packets++;
 331        dev->net->stats.rx_bytes += skb->len;
 332
 333        netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 334                  skb->len + sizeof (struct ethhdr), skb->protocol);
 335        memset (skb->cb, 0, sizeof (struct skb_data));
 336
 337        if (skb_defer_rx_timestamp(skb))
 338                return;
 339
 340        status = netif_rx (skb);
 341        if (status != NET_RX_SUCCESS)
 342                netif_dbg(dev, rx_err, dev->net,
 343                          "netif_rx status %d\n", status);
 344}
 345EXPORT_SYMBOL_GPL(usbnet_skb_return);
 346
 347/* must be called if hard_mtu or rx_urb_size changed */
 348void usbnet_update_max_qlen(struct usbnet *dev)
 349{
 350        enum usb_device_speed speed = dev->udev->speed;
 351
 352        switch (speed) {
 353        case USB_SPEED_HIGH:
 354                dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 355                dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 356                break;
 357        case USB_SPEED_SUPER:
 358        case USB_SPEED_SUPER_PLUS:
 359                /*
 360                 * Not take default 5ms qlen for super speed HC to
 361                 * save memory, and iperf tests show 2.5ms qlen can
 362                 * work well
 363                 */
 364                dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365                dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 366                break;
 367        default:
 368                dev->rx_qlen = dev->tx_qlen = 4;
 369        }
 370}
 371EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 372
 373
 374/*-------------------------------------------------------------------------
 375 *
 376 * Network Device Driver (peer link to "Host Device", from USB host)
 377 *
 378 *-------------------------------------------------------------------------*/
 379
 380int usbnet_change_mtu (struct net_device *net, int new_mtu)
 381{
 382        struct usbnet   *dev = netdev_priv(net);
 383        int             ll_mtu = new_mtu + net->hard_header_len;
 384        int             old_hard_mtu = dev->hard_mtu;
 385        int             old_rx_urb_size = dev->rx_urb_size;
 386
 387        if (new_mtu <= 0)
 388                return -EINVAL;
 389        // no second zero-length packet read wanted after mtu-sized packets
 390        if ((ll_mtu % dev->maxpacket) == 0)
 391                return -EDOM;
 392        net->mtu = new_mtu;
 393
 394        dev->hard_mtu = net->mtu + net->hard_header_len;
 395        if (dev->rx_urb_size == old_hard_mtu) {
 396                dev->rx_urb_size = dev->hard_mtu;
 397                if (dev->rx_urb_size > old_rx_urb_size) {
 398                        usbnet_pause_rx(dev);
 399                        usbnet_unlink_rx_urbs(dev);
 400                        usbnet_resume_rx(dev);
 401                }
 402        }
 403
 404        /* max qlen depend on hard_mtu and rx_urb_size */
 405        usbnet_update_max_qlen(dev);
 406
 407        return 0;
 408}
 409EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 410
 411/* The caller must hold list->lock */
 412static void __usbnet_queue_skb(struct sk_buff_head *list,
 413                        struct sk_buff *newsk, enum skb_state state)
 414{
 415        struct skb_data *entry = (struct skb_data *) newsk->cb;
 416
 417        __skb_queue_tail(list, newsk);
 418        entry->state = state;
 419}
 420
 421/*-------------------------------------------------------------------------*/
 422
 423/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 424 * completion callbacks.  2.5 should have fixed those bugs...
 425 */
 426
 427static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 428                struct sk_buff_head *list, enum skb_state state)
 429{
 430        unsigned long           flags;
 431        enum skb_state          old_state;
 432        struct skb_data *entry = (struct skb_data *) skb->cb;
 433
 434        spin_lock_irqsave(&list->lock, flags);
 435        old_state = entry->state;
 436        entry->state = state;
 437        __skb_unlink(skb, list);
 438
 439        /* defer_bh() is never called with list == &dev->done.
 440         * spin_lock_nested() tells lockdep that it is OK to take
 441         * dev->done.lock here with list->lock held.
 442         */
 443        spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 444
 445        __skb_queue_tail(&dev->done, skb);
 446        if (dev->done.qlen == 1)
 447                tasklet_schedule(&dev->bh);
 448        spin_unlock(&dev->done.lock);
 449        spin_unlock_irqrestore(&list->lock, flags);
 450        return old_state;
 451}
 452
 453/* some work can't be done in tasklets, so we use keventd
 454 *
 455 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 456 * but tasklet_schedule() doesn't.  hope the failure is rare.
 457 */
 458void usbnet_defer_kevent (struct usbnet *dev, int work)
 459{
 460        set_bit (work, &dev->flags);
 461        if (!schedule_work (&dev->kevent)) {
 462                if (net_ratelimit())
 463                        netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 464        } else {
 465                netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 466        }
 467}
 468EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 469
 470/*-------------------------------------------------------------------------*/
 471
 472static void rx_complete (struct urb *urb);
 473
 474static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 475{
 476        struct sk_buff          *skb;
 477        struct skb_data         *entry;
 478        int                     retval = 0;
 479        unsigned long           lockflags;
 480        size_t                  size = dev->rx_urb_size;
 481
 482        /* prevent rx skb allocation when error ratio is high */
 483        if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 484                usb_free_urb(urb);
 485                return -ENOLINK;
 486        }
 487
 488        skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 489        if (!skb) {
 490                netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 491                usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 492                usb_free_urb (urb);
 493                return -ENOMEM;
 494        }
 495
 496        entry = (struct skb_data *) skb->cb;
 497        entry->urb = urb;
 498        entry->dev = dev;
 499        entry->length = 0;
 500
 501        usb_fill_bulk_urb (urb, dev->udev, dev->in,
 502                skb->data, size, rx_complete, skb);
 503
 504        spin_lock_irqsave (&dev->rxq.lock, lockflags);
 505
 506        if (netif_running (dev->net) &&
 507            netif_device_present (dev->net) &&
 508            !test_bit (EVENT_RX_HALT, &dev->flags) &&
 509            !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 510                switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 511                case -EPIPE:
 512                        usbnet_defer_kevent (dev, EVENT_RX_HALT);
 513                        break;
 514                case -ENOMEM:
 515                        usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 516                        break;
 517                case -ENODEV:
 518                        netif_dbg(dev, ifdown, dev->net, "device gone\n");
 519                        netif_device_detach (dev->net);
 520                        break;
 521                case -EHOSTUNREACH:
 522                        retval = -ENOLINK;
 523                        break;
 524                default:
 525                        netif_dbg(dev, rx_err, dev->net,
 526                                  "rx submit, %d\n", retval);
 527                        tasklet_schedule (&dev->bh);
 528                        break;
 529                case 0:
 530                        __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 531                }
 532        } else {
 533                netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 534                retval = -ENOLINK;
 535        }
 536        spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 537        if (retval) {
 538                dev_kfree_skb_any (skb);
 539                usb_free_urb (urb);
 540        }
 541        return retval;
 542}
 543
 544
 545/*-------------------------------------------------------------------------*/
 546
 547static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 548{
 549        if (dev->driver_info->rx_fixup &&
 550            !dev->driver_info->rx_fixup (dev, skb)) {
 551                /* With RX_ASSEMBLE, rx_fixup() must update counters */
 552                if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 553                        dev->net->stats.rx_errors++;
 554                goto done;
 555        }
 556        // else network stack removes extra byte if we forced a short packet
 557
 558        /* all data was already cloned from skb inside the driver */
 559        if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 560                goto done;
 561
 562        if (skb->len < ETH_HLEN) {
 563                dev->net->stats.rx_errors++;
 564                dev->net->stats.rx_length_errors++;
 565                netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 566        } else {
 567                usbnet_skb_return(dev, skb);
 568                return;
 569        }
 570
 571done:
 572        skb_queue_tail(&dev->done, skb);
 573}
 574
 575/*-------------------------------------------------------------------------*/
 576
 577static void rx_complete (struct urb *urb)
 578{
 579        struct sk_buff          *skb = (struct sk_buff *) urb->context;
 580        struct skb_data         *entry = (struct skb_data *) skb->cb;
 581        struct usbnet           *dev = entry->dev;
 582        int                     urb_status = urb->status;
 583        enum skb_state          state;
 584
 585        skb_put (skb, urb->actual_length);
 586        state = rx_done;
 587        entry->urb = NULL;
 588
 589        switch (urb_status) {
 590        /* success */
 591        case 0:
 592                break;
 593
 594        /* stalls need manual reset. this is rare ... except that
 595         * when going through USB 2.0 TTs, unplug appears this way.
 596         * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 597         * storm, recovering as needed.
 598         */
 599        case -EPIPE:
 600                dev->net->stats.rx_errors++;
 601                usbnet_defer_kevent (dev, EVENT_RX_HALT);
 602                // FALLTHROUGH
 603
 604        /* software-driven interface shutdown */
 605        case -ECONNRESET:               /* async unlink */
 606        case -ESHUTDOWN:                /* hardware gone */
 607                netif_dbg(dev, ifdown, dev->net,
 608                          "rx shutdown, code %d\n", urb_status);
 609                goto block;
 610
 611        /* we get controller i/o faults during hub_wq disconnect() delays.
 612         * throttle down resubmits, to avoid log floods; just temporarily,
 613         * so we still recover when the fault isn't a hub_wq delay.
 614         */
 615        case -EPROTO:
 616        case -ETIME:
 617        case -EILSEQ:
 618                dev->net->stats.rx_errors++;
 619                if (!timer_pending (&dev->delay)) {
 620                        mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 621                        netif_dbg(dev, link, dev->net,
 622                                  "rx throttle %d\n", urb_status);
 623                }
 624block:
 625                state = rx_cleanup;
 626                entry->urb = urb;
 627                urb = NULL;
 628                break;
 629
 630        /* data overrun ... flush fifo? */
 631        case -EOVERFLOW:
 632                dev->net->stats.rx_over_errors++;
 633                // FALLTHROUGH
 634
 635        default:
 636                state = rx_cleanup;
 637                dev->net->stats.rx_errors++;
 638                netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 639                break;
 640        }
 641
 642        /* stop rx if packet error rate is high */
 643        if (++dev->pkt_cnt > 30) {
 644                dev->pkt_cnt = 0;
 645                dev->pkt_err = 0;
 646        } else {
 647                if (state == rx_cleanup)
 648                        dev->pkt_err++;
 649                if (dev->pkt_err > 20)
 650                        set_bit(EVENT_RX_KILL, &dev->flags);
 651        }
 652
 653        state = defer_bh(dev, skb, &dev->rxq, state);
 654
 655        if (urb) {
 656                if (netif_running (dev->net) &&
 657                    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 658                    state != unlink_start) {
 659                        rx_submit (dev, urb, GFP_ATOMIC);
 660                        usb_mark_last_busy(dev->udev);
 661                        return;
 662                }
 663                usb_free_urb (urb);
 664        }
 665        netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 666}
 667
 668/*-------------------------------------------------------------------------*/
 669void usbnet_pause_rx(struct usbnet *dev)
 670{
 671        set_bit(EVENT_RX_PAUSED, &dev->flags);
 672
 673        netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 674}
 675EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 676
 677void usbnet_resume_rx(struct usbnet *dev)
 678{
 679        struct sk_buff *skb;
 680        int num = 0;
 681
 682        clear_bit(EVENT_RX_PAUSED, &dev->flags);
 683
 684        while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 685                usbnet_skb_return(dev, skb);
 686                num++;
 687        }
 688
 689        tasklet_schedule(&dev->bh);
 690
 691        netif_dbg(dev, rx_status, dev->net,
 692                  "paused rx queue disabled, %d skbs requeued\n", num);
 693}
 694EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 695
 696void usbnet_purge_paused_rxq(struct usbnet *dev)
 697{
 698        skb_queue_purge(&dev->rxq_pause);
 699}
 700EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 701
 702/*-------------------------------------------------------------------------*/
 703
 704// unlink pending rx/tx; completion handlers do all other cleanup
 705
 706static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 707{
 708        unsigned long           flags;
 709        struct sk_buff          *skb;
 710        int                     count = 0;
 711
 712        spin_lock_irqsave (&q->lock, flags);
 713        while (!skb_queue_empty(q)) {
 714                struct skb_data         *entry;
 715                struct urb              *urb;
 716                int                     retval;
 717
 718                skb_queue_walk(q, skb) {
 719                        entry = (struct skb_data *) skb->cb;
 720                        if (entry->state != unlink_start)
 721                                goto found;
 722                }
 723                break;
 724found:
 725                entry->state = unlink_start;
 726                urb = entry->urb;
 727
 728                /*
 729                 * Get reference count of the URB to avoid it to be
 730                 * freed during usb_unlink_urb, which may trigger
 731                 * use-after-free problem inside usb_unlink_urb since
 732                 * usb_unlink_urb is always racing with .complete
 733                 * handler(include defer_bh).
 734                 */
 735                usb_get_urb(urb);
 736                spin_unlock_irqrestore(&q->lock, flags);
 737                // during some PM-driven resume scenarios,
 738                // these (async) unlinks complete immediately
 739                retval = usb_unlink_urb (urb);
 740                if (retval != -EINPROGRESS && retval != 0)
 741                        netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 742                else
 743                        count++;
 744                usb_put_urb(urb);
 745                spin_lock_irqsave(&q->lock, flags);
 746        }
 747        spin_unlock_irqrestore (&q->lock, flags);
 748        return count;
 749}
 750
 751// Flush all pending rx urbs
 752// minidrivers may need to do this when the MTU changes
 753
 754void usbnet_unlink_rx_urbs(struct usbnet *dev)
 755{
 756        if (netif_running(dev->net)) {
 757                (void) unlink_urbs (dev, &dev->rxq);
 758                tasklet_schedule(&dev->bh);
 759        }
 760}
 761EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 762
 763/*-------------------------------------------------------------------------*/
 764
 765static void wait_skb_queue_empty(struct sk_buff_head *q)
 766{
 767        unsigned long flags;
 768
 769        spin_lock_irqsave(&q->lock, flags);
 770        while (!skb_queue_empty(q)) {
 771                spin_unlock_irqrestore(&q->lock, flags);
 772                schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 773                set_current_state(TASK_UNINTERRUPTIBLE);
 774                spin_lock_irqsave(&q->lock, flags);
 775        }
 776        spin_unlock_irqrestore(&q->lock, flags);
 777}
 778
 779// precondition: never called in_interrupt
 780static void usbnet_terminate_urbs(struct usbnet *dev)
 781{
 782        DECLARE_WAITQUEUE(wait, current);
 783        int temp;
 784
 785        /* ensure there are no more active urbs */
 786        add_wait_queue(&dev->wait, &wait);
 787        set_current_state(TASK_UNINTERRUPTIBLE);
 788        temp = unlink_urbs(dev, &dev->txq) +
 789                unlink_urbs(dev, &dev->rxq);
 790
 791        /* maybe wait for deletions to finish. */
 792        wait_skb_queue_empty(&dev->rxq);
 793        wait_skb_queue_empty(&dev->txq);
 794        wait_skb_queue_empty(&dev->done);
 795        netif_dbg(dev, ifdown, dev->net,
 796                  "waited for %d urb completions\n", temp);
 797        set_current_state(TASK_RUNNING);
 798        remove_wait_queue(&dev->wait, &wait);
 799}
 800
 801int usbnet_stop (struct net_device *net)
 802{
 803        struct usbnet           *dev = netdev_priv(net);
 804        struct driver_info      *info = dev->driver_info;
 805        int                     retval, pm, mpn;
 806
 807        clear_bit(EVENT_DEV_OPEN, &dev->flags);
 808        netif_stop_queue (net);
 809
 810        netif_info(dev, ifdown, dev->net,
 811                   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 812                   net->stats.rx_packets, net->stats.tx_packets,
 813                   net->stats.rx_errors, net->stats.tx_errors);
 814
 815        /* to not race resume */
 816        pm = usb_autopm_get_interface(dev->intf);
 817        /* allow minidriver to stop correctly (wireless devices to turn off
 818         * radio etc) */
 819        if (info->stop) {
 820                retval = info->stop(dev);
 821                if (retval < 0)
 822                        netif_info(dev, ifdown, dev->net,
 823                                   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 824                                   retval,
 825                                   dev->udev->bus->bus_name, dev->udev->devpath,
 826                                   info->description);
 827        }
 828
 829        if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 830                usbnet_terminate_urbs(dev);
 831
 832        usbnet_status_stop(dev);
 833
 834        usbnet_purge_paused_rxq(dev);
 835
 836        mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 837
 838        /* deferred work (task, timer, softirq) must also stop.
 839         * can't flush_scheduled_work() until we drop rtnl (later),
 840         * else workers could deadlock; so make workers a NOP.
 841         */
 842        dev->flags = 0;
 843        del_timer_sync (&dev->delay);
 844        tasklet_kill (&dev->bh);
 845        if (!pm)
 846                usb_autopm_put_interface(dev->intf);
 847
 848        if (info->manage_power && mpn)
 849                info->manage_power(dev, 0);
 850        else
 851                usb_autopm_put_interface(dev->intf);
 852
 853        return 0;
 854}
 855EXPORT_SYMBOL_GPL(usbnet_stop);
 856
 857/*-------------------------------------------------------------------------*/
 858
 859// posts reads, and enables write queuing
 860
 861// precondition: never called in_interrupt
 862
 863int usbnet_open (struct net_device *net)
 864{
 865        struct usbnet           *dev = netdev_priv(net);
 866        int                     retval;
 867        struct driver_info      *info = dev->driver_info;
 868
 869        if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 870                netif_info(dev, ifup, dev->net,
 871                           "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 872                           retval,
 873                           dev->udev->bus->bus_name,
 874                           dev->udev->devpath,
 875                           info->description);
 876                goto done_nopm;
 877        }
 878
 879        // put into "known safe" state
 880        if (info->reset && (retval = info->reset (dev)) < 0) {
 881                netif_info(dev, ifup, dev->net,
 882                           "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 883                           retval,
 884                           dev->udev->bus->bus_name,
 885                           dev->udev->devpath,
 886                           info->description);
 887                goto done;
 888        }
 889
 890        /* hard_mtu or rx_urb_size may change in reset() */
 891        usbnet_update_max_qlen(dev);
 892
 893        // insist peer be connected
 894        if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 895                netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 896                goto done;
 897        }
 898
 899        /* start any status interrupt transfer */
 900        if (dev->interrupt) {
 901                retval = usbnet_status_start(dev, GFP_KERNEL);
 902                if (retval < 0) {
 903                        netif_err(dev, ifup, dev->net,
 904                                  "intr submit %d\n", retval);
 905                        goto done;
 906                }
 907        }
 908
 909        set_bit(EVENT_DEV_OPEN, &dev->flags);
 910        netif_start_queue (net);
 911        netif_info(dev, ifup, dev->net,
 912                   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 913                   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 914                   dev->net->mtu,
 915                   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 916                   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 917                   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 918                   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 919                   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 920                   "simple");
 921
 922        /* reset rx error state */
 923        dev->pkt_cnt = 0;
 924        dev->pkt_err = 0;
 925        clear_bit(EVENT_RX_KILL, &dev->flags);
 926
 927        // delay posting reads until we're fully open
 928        tasklet_schedule (&dev->bh);
 929        if (info->manage_power) {
 930                retval = info->manage_power(dev, 1);
 931                if (retval < 0) {
 932                        retval = 0;
 933                        set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 934                } else {
 935                        usb_autopm_put_interface(dev->intf);
 936                }
 937        }
 938        return retval;
 939done:
 940        usb_autopm_put_interface(dev->intf);
 941done_nopm:
 942        return retval;
 943}
 944EXPORT_SYMBOL_GPL(usbnet_open);
 945
 946/*-------------------------------------------------------------------------*/
 947
 948/* ethtool methods; minidrivers may need to add some more, but
 949 * they'll probably want to use this base set.
 950 */
 951
 952int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 953{
 954        struct usbnet *dev = netdev_priv(net);
 955
 956        if (!dev->mii.mdio_read)
 957                return -EOPNOTSUPP;
 958
 959        return mii_ethtool_gset(&dev->mii, cmd);
 960}
 961EXPORT_SYMBOL_GPL(usbnet_get_settings);
 962
 963int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 964{
 965        struct usbnet *dev = netdev_priv(net);
 966        int retval;
 967
 968        if (!dev->mii.mdio_write)
 969                return -EOPNOTSUPP;
 970
 971        retval = mii_ethtool_sset(&dev->mii, cmd);
 972
 973        /* link speed/duplex might have changed */
 974        if (dev->driver_info->link_reset)
 975                dev->driver_info->link_reset(dev);
 976
 977        /* hard_mtu or rx_urb_size may change in link_reset() */
 978        usbnet_update_max_qlen(dev);
 979
 980        return retval;
 981
 982}
 983EXPORT_SYMBOL_GPL(usbnet_set_settings);
 984
 985u32 usbnet_get_link (struct net_device *net)
 986{
 987        struct usbnet *dev = netdev_priv(net);
 988
 989        /* If a check_connect is defined, return its result */
 990        if (dev->driver_info->check_connect)
 991                return dev->driver_info->check_connect (dev) == 0;
 992
 993        /* if the device has mii operations, use those */
 994        if (dev->mii.mdio_read)
 995                return mii_link_ok(&dev->mii);
 996
 997        /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 998        return ethtool_op_get_link(net);
 999}
1000EXPORT_SYMBOL_GPL(usbnet_get_link);
1001
1002int usbnet_nway_reset(struct net_device *net)
1003{
1004        struct usbnet *dev = netdev_priv(net);
1005
1006        if (!dev->mii.mdio_write)
1007                return -EOPNOTSUPP;
1008
1009        return mii_nway_restart(&dev->mii);
1010}
1011EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1012
1013void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1014{
1015        struct usbnet *dev = netdev_priv(net);
1016
1017        strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1018        strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1019        strlcpy (info->fw_version, dev->driver_info->description,
1020                sizeof info->fw_version);
1021        usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1022}
1023EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1024
1025u32 usbnet_get_msglevel (struct net_device *net)
1026{
1027        struct usbnet *dev = netdev_priv(net);
1028
1029        return dev->msg_enable;
1030}
1031EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1032
1033void usbnet_set_msglevel (struct net_device *net, u32 level)
1034{
1035        struct usbnet *dev = netdev_priv(net);
1036
1037        dev->msg_enable = level;
1038}
1039EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1040
1041/* drivers may override default ethtool_ops in their bind() routine */
1042static const struct ethtool_ops usbnet_ethtool_ops = {
1043        .get_settings           = usbnet_get_settings,
1044        .set_settings           = usbnet_set_settings,
1045        .get_link               = usbnet_get_link,
1046        .nway_reset             = usbnet_nway_reset,
1047        .get_drvinfo            = usbnet_get_drvinfo,
1048        .get_msglevel           = usbnet_get_msglevel,
1049        .set_msglevel           = usbnet_set_msglevel,
1050        .get_ts_info            = ethtool_op_get_ts_info,
1051};
1052
1053/*-------------------------------------------------------------------------*/
1054
1055static void __handle_link_change(struct usbnet *dev)
1056{
1057        if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1058                return;
1059
1060        if (!netif_carrier_ok(dev->net)) {
1061                /* kill URBs for reading packets to save bus bandwidth */
1062                unlink_urbs(dev, &dev->rxq);
1063
1064                /*
1065                 * tx_timeout will unlink URBs for sending packets and
1066                 * tx queue is stopped by netcore after link becomes off
1067                 */
1068        } else {
1069                /* submitting URBs for reading packets */
1070                tasklet_schedule(&dev->bh);
1071        }
1072
1073        /* hard_mtu or rx_urb_size may change during link change */
1074        usbnet_update_max_qlen(dev);
1075
1076        clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1077}
1078
1079static void usbnet_set_rx_mode(struct net_device *net)
1080{
1081        struct usbnet           *dev = netdev_priv(net);
1082
1083        usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1084}
1085
1086static void __handle_set_rx_mode(struct usbnet *dev)
1087{
1088        if (dev->driver_info->set_rx_mode)
1089                (dev->driver_info->set_rx_mode)(dev);
1090
1091        clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1092}
1093
1094/* work that cannot be done in interrupt context uses keventd.
1095 *
1096 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1097 * especially now that control transfers can be queued.
1098 */
1099static void
1100usbnet_deferred_kevent (struct work_struct *work)
1101{
1102        struct usbnet           *dev =
1103                container_of(work, struct usbnet, kevent);
1104        int                     status;
1105
1106        /* usb_clear_halt() needs a thread context */
1107        if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1108                unlink_urbs (dev, &dev->txq);
1109                status = usb_autopm_get_interface(dev->intf);
1110                if (status < 0)
1111                        goto fail_pipe;
1112                status = usb_clear_halt (dev->udev, dev->out);
1113                usb_autopm_put_interface(dev->intf);
1114                if (status < 0 &&
1115                    status != -EPIPE &&
1116                    status != -ESHUTDOWN) {
1117                        if (netif_msg_tx_err (dev))
1118fail_pipe:
1119                                netdev_err(dev->net, "can't clear tx halt, status %d\n",
1120                                           status);
1121                } else {
1122                        clear_bit (EVENT_TX_HALT, &dev->flags);
1123                        if (status != -ESHUTDOWN)
1124                                netif_wake_queue (dev->net);
1125                }
1126        }
1127        if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1128                unlink_urbs (dev, &dev->rxq);
1129                status = usb_autopm_get_interface(dev->intf);
1130                if (status < 0)
1131                        goto fail_halt;
1132                status = usb_clear_halt (dev->udev, dev->in);
1133                usb_autopm_put_interface(dev->intf);
1134                if (status < 0 &&
1135                    status != -EPIPE &&
1136                    status != -ESHUTDOWN) {
1137                        if (netif_msg_rx_err (dev))
1138fail_halt:
1139                                netdev_err(dev->net, "can't clear rx halt, status %d\n",
1140                                           status);
1141                } else {
1142                        clear_bit (EVENT_RX_HALT, &dev->flags);
1143                        tasklet_schedule (&dev->bh);
1144                }
1145        }
1146
1147        /* tasklet could resubmit itself forever if memory is tight */
1148        if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1149                struct urb      *urb = NULL;
1150                int resched = 1;
1151
1152                if (netif_running (dev->net))
1153                        urb = usb_alloc_urb (0, GFP_KERNEL);
1154                else
1155                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
1156                if (urb != NULL) {
1157                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
1158                        status = usb_autopm_get_interface(dev->intf);
1159                        if (status < 0) {
1160                                usb_free_urb(urb);
1161                                goto fail_lowmem;
1162                        }
1163                        if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1164                                resched = 0;
1165                        usb_autopm_put_interface(dev->intf);
1166fail_lowmem:
1167                        if (resched)
1168                                tasklet_schedule (&dev->bh);
1169                }
1170        }
1171
1172        if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1173                struct driver_info      *info = dev->driver_info;
1174                int                     retval = 0;
1175
1176                clear_bit (EVENT_LINK_RESET, &dev->flags);
1177                status = usb_autopm_get_interface(dev->intf);
1178                if (status < 0)
1179                        goto skip_reset;
1180                if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1181                        usb_autopm_put_interface(dev->intf);
1182skip_reset:
1183                        netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1184                                    retval,
1185                                    dev->udev->bus->bus_name,
1186                                    dev->udev->devpath,
1187                                    info->description);
1188                } else {
1189                        usb_autopm_put_interface(dev->intf);
1190                }
1191
1192                /* handle link change from link resetting */
1193                __handle_link_change(dev);
1194        }
1195
1196        if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1197                __handle_link_change(dev);
1198
1199        if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1200                __handle_set_rx_mode(dev);
1201
1202
1203        if (dev->flags)
1204                netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1205}
1206
1207/*-------------------------------------------------------------------------*/
1208
1209static void tx_complete (struct urb *urb)
1210{
1211        struct sk_buff          *skb = (struct sk_buff *) urb->context;
1212        struct skb_data         *entry = (struct skb_data *) skb->cb;
1213        struct usbnet           *dev = entry->dev;
1214
1215        if (urb->status == 0) {
1216                dev->net->stats.tx_packets += entry->packets;
1217                dev->net->stats.tx_bytes += entry->length;
1218        } else {
1219                dev->net->stats.tx_errors++;
1220
1221                switch (urb->status) {
1222                case -EPIPE:
1223                        usbnet_defer_kevent (dev, EVENT_TX_HALT);
1224                        break;
1225
1226                /* software-driven interface shutdown */
1227                case -ECONNRESET:               // async unlink
1228                case -ESHUTDOWN:                // hardware gone
1229                        break;
1230
1231                /* like rx, tx gets controller i/o faults during hub_wq
1232                 * delays and so it uses the same throttling mechanism.
1233                 */
1234                case -EPROTO:
1235                case -ETIME:
1236                case -EILSEQ:
1237                        usb_mark_last_busy(dev->udev);
1238                        if (!timer_pending (&dev->delay)) {
1239                                mod_timer (&dev->delay,
1240                                        jiffies + THROTTLE_JIFFIES);
1241                                netif_dbg(dev, link, dev->net,
1242                                          "tx throttle %d\n", urb->status);
1243                        }
1244                        netif_stop_queue (dev->net);
1245                        break;
1246                default:
1247                        netif_dbg(dev, tx_err, dev->net,
1248                                  "tx err %d\n", entry->urb->status);
1249                        break;
1250                }
1251        }
1252
1253        usb_autopm_put_interface_async(dev->intf);
1254        (void) defer_bh(dev, skb, &dev->txq, tx_done);
1255}
1256
1257/*-------------------------------------------------------------------------*/
1258
1259void usbnet_tx_timeout (struct net_device *net)
1260{
1261        struct usbnet           *dev = netdev_priv(net);
1262
1263        unlink_urbs (dev, &dev->txq);
1264        tasklet_schedule (&dev->bh);
1265        /* this needs to be handled individually because the generic layer
1266         * doesn't know what is sufficient and could not restore private
1267         * information if a remedy of an unconditional reset were used.
1268         */
1269        if (dev->driver_info->recover)
1270                (dev->driver_info->recover)(dev);
1271}
1272EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1273
1274/*-------------------------------------------------------------------------*/
1275
1276static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1277{
1278        unsigned num_sgs, total_len = 0;
1279        int i, s = 0;
1280
1281        num_sgs = skb_shinfo(skb)->nr_frags + 1;
1282        if (num_sgs == 1)
1283                return 0;
1284
1285        /* reserve one for zero packet */
1286        urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1287                          GFP_ATOMIC);
1288        if (!urb->sg)
1289                return -ENOMEM;
1290
1291        urb->num_sgs = num_sgs;
1292        sg_init_table(urb->sg, urb->num_sgs + 1);
1293
1294        sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1295        total_len += skb_headlen(skb);
1296
1297        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1298                struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1299
1300                total_len += skb_frag_size(f);
1301                sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1302                                f->page_offset);
1303        }
1304        urb->transfer_buffer_length = total_len;
1305
1306        return 1;
1307}
1308
1309netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1310                                     struct net_device *net)
1311{
1312        struct usbnet           *dev = netdev_priv(net);
1313        unsigned int                    length;
1314        struct urb              *urb = NULL;
1315        struct skb_data         *entry;
1316        struct driver_info      *info = dev->driver_info;
1317        unsigned long           flags;
1318        int retval;
1319
1320        if (skb)
1321                skb_tx_timestamp(skb);
1322
1323        // some devices want funky USB-level framing, for
1324        // win32 driver (usually) and/or hardware quirks
1325        if (info->tx_fixup) {
1326                skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1327                if (!skb) {
1328                        /* packet collected; minidriver waiting for more */
1329                        if (info->flags & FLAG_MULTI_PACKET)
1330                                goto not_drop;
1331                        netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1332                        goto drop;
1333                }
1334        }
1335
1336        if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1337                netif_dbg(dev, tx_err, dev->net, "no urb\n");
1338                goto drop;
1339        }
1340
1341        entry = (struct skb_data *) skb->cb;
1342        entry->urb = urb;
1343        entry->dev = dev;
1344
1345        usb_fill_bulk_urb (urb, dev->udev, dev->out,
1346                        skb->data, skb->len, tx_complete, skb);
1347        if (dev->can_dma_sg) {
1348                if (build_dma_sg(skb, urb) < 0)
1349                        goto drop;
1350        }
1351        length = urb->transfer_buffer_length;
1352
1353        /* don't assume the hardware handles USB_ZERO_PACKET
1354         * NOTE:  strictly conforming cdc-ether devices should expect
1355         * the ZLP here, but ignore the one-byte packet.
1356         * NOTE2: CDC NCM specification is different from CDC ECM when
1357         * handling ZLP/short packets, so cdc_ncm driver will make short
1358         * packet itself if needed.
1359         */
1360        if (length % dev->maxpacket == 0) {
1361                if (!(info->flags & FLAG_SEND_ZLP)) {
1362                        if (!(info->flags & FLAG_MULTI_PACKET)) {
1363                                length++;
1364                                if (skb_tailroom(skb) && !urb->num_sgs) {
1365                                        skb->data[skb->len] = 0;
1366                                        __skb_put(skb, 1);
1367                                } else if (urb->num_sgs)
1368                                        sg_set_buf(&urb->sg[urb->num_sgs++],
1369                                                        dev->padding_pkt, 1);
1370                        }
1371                } else
1372                        urb->transfer_flags |= URB_ZERO_PACKET;
1373        }
1374        urb->transfer_buffer_length = length;
1375
1376        if (info->flags & FLAG_MULTI_PACKET) {
1377                /* Driver has set number of packets and a length delta.
1378                 * Calculate the complete length and ensure that it's
1379                 * positive.
1380                 */
1381                entry->length += length;
1382                if (WARN_ON_ONCE(entry->length <= 0))
1383                        entry->length = length;
1384        } else {
1385                usbnet_set_skb_tx_stats(skb, 1, length);
1386        }
1387
1388        spin_lock_irqsave(&dev->txq.lock, flags);
1389        retval = usb_autopm_get_interface_async(dev->intf);
1390        if (retval < 0) {
1391                spin_unlock_irqrestore(&dev->txq.lock, flags);
1392                goto drop;
1393        }
1394
1395#ifdef CONFIG_PM
1396        /* if this triggers the device is still a sleep */
1397        if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1398                /* transmission will be done in resume */
1399                usb_anchor_urb(urb, &dev->deferred);
1400                /* no use to process more packets */
1401                netif_stop_queue(net);
1402                usb_put_urb(urb);
1403                spin_unlock_irqrestore(&dev->txq.lock, flags);
1404                netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1405                goto deferred;
1406        }
1407#endif
1408
1409        switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1410        case -EPIPE:
1411                netif_stop_queue (net);
1412                usbnet_defer_kevent (dev, EVENT_TX_HALT);
1413                usb_autopm_put_interface_async(dev->intf);
1414                break;
1415        default:
1416                usb_autopm_put_interface_async(dev->intf);
1417                netif_dbg(dev, tx_err, dev->net,
1418                          "tx: submit urb err %d\n", retval);
1419                break;
1420        case 0:
1421                netif_trans_update(net);
1422                __usbnet_queue_skb(&dev->txq, skb, tx_start);
1423                if (dev->txq.qlen >= TX_QLEN (dev))
1424                        netif_stop_queue (net);
1425        }
1426        spin_unlock_irqrestore (&dev->txq.lock, flags);
1427
1428        if (retval) {
1429                netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1430drop:
1431                dev->net->stats.tx_dropped++;
1432not_drop:
1433                if (skb)
1434                        dev_kfree_skb_any (skb);
1435                if (urb) {
1436                        kfree(urb->sg);
1437                        usb_free_urb(urb);
1438                }
1439        } else
1440                netif_dbg(dev, tx_queued, dev->net,
1441                          "> tx, len %u, type 0x%x\n", length, skb->protocol);
1442#ifdef CONFIG_PM
1443deferred:
1444#endif
1445        return NETDEV_TX_OK;
1446}
1447EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1448
1449static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1450{
1451        struct urb      *urb;
1452        int             i;
1453        int             ret = 0;
1454
1455        /* don't refill the queue all at once */
1456        for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1457                urb = usb_alloc_urb(0, flags);
1458                if (urb != NULL) {
1459                        ret = rx_submit(dev, urb, flags);
1460                        if (ret)
1461                                goto err;
1462                } else {
1463                        ret = -ENOMEM;
1464                        goto err;
1465                }
1466        }
1467err:
1468        return ret;
1469}
1470
1471/*-------------------------------------------------------------------------*/
1472
1473// tasklet (work deferred from completions, in_irq) or timer
1474
1475static void usbnet_bh (unsigned long param)
1476{
1477        struct usbnet           *dev = (struct usbnet *) param;
1478        struct sk_buff          *skb;
1479        struct skb_data         *entry;
1480
1481        while ((skb = skb_dequeue (&dev->done))) {
1482                entry = (struct skb_data *) skb->cb;
1483                switch (entry->state) {
1484                case rx_done:
1485                        entry->state = rx_cleanup;
1486                        rx_process (dev, skb);
1487                        continue;
1488                case tx_done:
1489                        kfree(entry->urb->sg);
1490                case rx_cleanup:
1491                        usb_free_urb (entry->urb);
1492                        dev_kfree_skb (skb);
1493                        continue;
1494                default:
1495                        netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1496                }
1497        }
1498
1499        /* restart RX again after disabling due to high error rate */
1500        clear_bit(EVENT_RX_KILL, &dev->flags);
1501
1502        /* waiting for all pending urbs to complete?
1503         * only then can we forgo submitting anew
1504         */
1505        if (waitqueue_active(&dev->wait)) {
1506                if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1507                        wake_up_all(&dev->wait);
1508
1509        // or are we maybe short a few urbs?
1510        } else if (netif_running (dev->net) &&
1511                   netif_device_present (dev->net) &&
1512                   netif_carrier_ok(dev->net) &&
1513                   !timer_pending(&dev->delay) &&
1514                   !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1515                   !test_bit(EVENT_RX_HALT, &dev->flags)) {
1516                int     temp = dev->rxq.qlen;
1517
1518                if (temp < RX_QLEN(dev)) {
1519                        if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1520                                return;
1521                        if (temp != dev->rxq.qlen)
1522                                netif_dbg(dev, link, dev->net,
1523                                          "rxqlen %d --> %d\n",
1524                                          temp, dev->rxq.qlen);
1525                        if (dev->rxq.qlen < RX_QLEN(dev))
1526                                tasklet_schedule (&dev->bh);
1527                }
1528                if (dev->txq.qlen < TX_QLEN (dev))
1529                        netif_wake_queue (dev->net);
1530        }
1531}
1532
1533
1534/*-------------------------------------------------------------------------
1535 *
1536 * USB Device Driver support
1537 *
1538 *-------------------------------------------------------------------------*/
1539
1540// precondition: never called in_interrupt
1541
1542void usbnet_disconnect (struct usb_interface *intf)
1543{
1544        struct usbnet           *dev;
1545        struct usb_device       *xdev;
1546        struct net_device       *net;
1547
1548        dev = usb_get_intfdata(intf);
1549        usb_set_intfdata(intf, NULL);
1550        if (!dev)
1551                return;
1552
1553        xdev = interface_to_usbdev (intf);
1554
1555        netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1556                   intf->dev.driver->name,
1557                   xdev->bus->bus_name, xdev->devpath,
1558                   dev->driver_info->description);
1559
1560        net = dev->net;
1561        unregister_netdev (net);
1562
1563        cancel_work_sync(&dev->kevent);
1564
1565        usb_scuttle_anchored_urbs(&dev->deferred);
1566
1567        if (dev->driver_info->unbind)
1568                dev->driver_info->unbind (dev, intf);
1569
1570        usb_kill_urb(dev->interrupt);
1571        usb_free_urb(dev->interrupt);
1572        kfree(dev->padding_pkt);
1573
1574        free_netdev(net);
1575}
1576EXPORT_SYMBOL_GPL(usbnet_disconnect);
1577
1578static const struct net_device_ops usbnet_netdev_ops = {
1579        .ndo_open               = usbnet_open,
1580        .ndo_stop               = usbnet_stop,
1581        .ndo_start_xmit         = usbnet_start_xmit,
1582        .ndo_tx_timeout         = usbnet_tx_timeout,
1583        .ndo_set_rx_mode        = usbnet_set_rx_mode,
1584        .ndo_change_mtu_rh74    = usbnet_change_mtu,
1585        .ndo_set_mac_address    = eth_mac_addr,
1586        .ndo_validate_addr      = eth_validate_addr,
1587};
1588
1589/*-------------------------------------------------------------------------*/
1590
1591// precondition: never called in_interrupt
1592
1593static struct device_type wlan_type = {
1594        .name   = "wlan",
1595};
1596
1597static struct device_type wwan_type = {
1598        .name   = "wwan",
1599};
1600
1601int
1602usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1603{
1604        struct usbnet                   *dev;
1605        struct net_device               *net;
1606        struct usb_host_interface       *interface;
1607        struct driver_info              *info;
1608        struct usb_device               *xdev;
1609        int                             status;
1610        const char                      *name;
1611        struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1612
1613        /* usbnet already took usb runtime pm, so have to enable the feature
1614         * for usb interface, otherwise usb_autopm_get_interface may return
1615         * failure if RUNTIME_PM is enabled.
1616         */
1617        if (!driver->supports_autosuspend) {
1618                driver->supports_autosuspend = 1;
1619                pm_runtime_enable(&udev->dev);
1620        }
1621
1622        name = udev->dev.driver->name;
1623        info = (struct driver_info *) prod->driver_info;
1624        if (!info) {
1625                dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1626                return -ENODEV;
1627        }
1628        xdev = interface_to_usbdev (udev);
1629        interface = udev->cur_altsetting;
1630
1631        status = -ENOMEM;
1632
1633        // set up our own records
1634        net = alloc_etherdev(sizeof(*dev));
1635        if (!net)
1636                goto out;
1637
1638        /* netdev_printk() needs this so do it as early as possible */
1639        SET_NETDEV_DEV(net, &udev->dev);
1640
1641        dev = netdev_priv(net);
1642        dev->udev = xdev;
1643        dev->intf = udev;
1644        dev->driver_info = info;
1645        dev->driver_name = name;
1646        dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1647                                | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1648        init_waitqueue_head(&dev->wait);
1649        skb_queue_head_init (&dev->rxq);
1650        skb_queue_head_init (&dev->txq);
1651        skb_queue_head_init (&dev->done);
1652        skb_queue_head_init(&dev->rxq_pause);
1653        dev->bh.func = usbnet_bh;
1654        dev->bh.data = (unsigned long) dev;
1655        INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1656        init_usb_anchor(&dev->deferred);
1657        dev->delay.function = usbnet_bh;
1658        dev->delay.data = (unsigned long) dev;
1659        init_timer (&dev->delay);
1660        mutex_init (&dev->phy_mutex);
1661        mutex_init(&dev->interrupt_mutex);
1662        dev->interrupt_count = 0;
1663
1664        dev->net = net;
1665        strcpy (net->name, "usb%d");
1666        memcpy (net->dev_addr, node_id, sizeof node_id);
1667
1668        /* rx and tx sides can use different message sizes;
1669         * bind() should set rx_urb_size in that case.
1670         */
1671        dev->hard_mtu = net->mtu + net->hard_header_len;
1672
1673        net->netdev_ops = &usbnet_netdev_ops;
1674        net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1675        net->ethtool_ops = &usbnet_ethtool_ops;
1676
1677        // allow device-specific bind/init procedures
1678        // NOTE net->name still not usable ...
1679        if (info->bind) {
1680                status = info->bind (dev, udev);
1681                if (status < 0)
1682                        goto out1;
1683
1684                // heuristic:  "usb%d" for links we know are two-host,
1685                // else "eth%d" when there's reasonable doubt.  userspace
1686                // can rename the link if it knows better.
1687                if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1688                    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1689                     (net->dev_addr [0] & 0x02) == 0))
1690                        strcpy (net->name, "eth%d");
1691                /* WLAN devices should always be named "wlan%d" */
1692                if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1693                        strcpy(net->name, "wlan%d");
1694                /* WWAN devices should always be named "wwan%d" */
1695                if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1696                        strcpy(net->name, "wwan%d");
1697
1698                /* devices that cannot do ARP */
1699                if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1700                        net->flags |= IFF_NOARP;
1701
1702                /* maybe the remote can't receive an Ethernet MTU */
1703                if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1704                        net->mtu = dev->hard_mtu - net->hard_header_len;
1705        } else if (!info->in || !info->out)
1706                status = usbnet_get_endpoints (dev, udev);
1707        else {
1708                dev->in = usb_rcvbulkpipe (xdev, info->in);
1709                dev->out = usb_sndbulkpipe (xdev, info->out);
1710                if (!(info->flags & FLAG_NO_SETINT))
1711                        status = usb_set_interface (xdev,
1712                                interface->desc.bInterfaceNumber,
1713                                interface->desc.bAlternateSetting);
1714                else
1715                        status = 0;
1716
1717        }
1718        if (status >= 0 && dev->status)
1719                status = init_status (dev, udev);
1720        if (status < 0)
1721                goto out3;
1722
1723        if (!dev->rx_urb_size)
1724                dev->rx_urb_size = dev->hard_mtu;
1725        dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1726
1727        /* let userspace know we have a random address */
1728        if (ether_addr_equal(net->dev_addr, node_id))
1729                net->addr_assign_type = NET_ADDR_RANDOM;
1730
1731        if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1732                SET_NETDEV_DEVTYPE(net, &wlan_type);
1733        if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1734                SET_NETDEV_DEVTYPE(net, &wwan_type);
1735
1736        /* initialize max rx_qlen and tx_qlen */
1737        usbnet_update_max_qlen(dev);
1738
1739        if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1740                !(info->flags & FLAG_MULTI_PACKET)) {
1741                dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1742                if (!dev->padding_pkt) {
1743                        status = -ENOMEM;
1744                        goto out4;
1745                }
1746        }
1747
1748        status = register_netdev (net);
1749        if (status)
1750                goto out5;
1751        netif_info(dev, probe, dev->net,
1752                   "register '%s' at usb-%s-%s, %s, %pM\n",
1753                   udev->dev.driver->name,
1754                   xdev->bus->bus_name, xdev->devpath,
1755                   dev->driver_info->description,
1756                   net->dev_addr);
1757
1758        // ok, it's ready to go.
1759        usb_set_intfdata (udev, dev);
1760
1761        netif_device_attach (net);
1762
1763        if (dev->driver_info->flags & FLAG_LINK_INTR)
1764                usbnet_link_change(dev, 0, 0);
1765
1766        return 0;
1767
1768out5:
1769        kfree(dev->padding_pkt);
1770out4:
1771        usb_free_urb(dev->interrupt);
1772out3:
1773        if (info->unbind)
1774                info->unbind (dev, udev);
1775out1:
1776        /* subdrivers must undo all they did in bind() if they
1777         * fail it, but we may fail later and a deferred kevent
1778         * may trigger an error resubmitting itself and, worse,
1779         * schedule a timer. So we kill it all just in case.
1780         */
1781        cancel_work_sync(&dev->kevent);
1782        del_timer_sync(&dev->delay);
1783        free_netdev(net);
1784out:
1785        return status;
1786}
1787EXPORT_SYMBOL_GPL(usbnet_probe);
1788
1789/*-------------------------------------------------------------------------*/
1790
1791/*
1792 * suspend the whole driver as soon as the first interface is suspended
1793 * resume only when the last interface is resumed
1794 */
1795
1796int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1797{
1798        struct usbnet           *dev = usb_get_intfdata(intf);
1799
1800        if (!dev->suspend_count++) {
1801                spin_lock_irq(&dev->txq.lock);
1802                /* don't autosuspend while transmitting */
1803                if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1804                        dev->suspend_count--;
1805                        spin_unlock_irq(&dev->txq.lock);
1806                        return -EBUSY;
1807                } else {
1808                        set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1809                        spin_unlock_irq(&dev->txq.lock);
1810                }
1811                /*
1812                 * accelerate emptying of the rx and queues, to avoid
1813                 * having everything error out.
1814                 */
1815                netif_device_detach (dev->net);
1816                usbnet_terminate_urbs(dev);
1817                __usbnet_status_stop_force(dev);
1818
1819                /*
1820                 * reattach so runtime management can use and
1821                 * wake the device
1822                 */
1823                netif_device_attach (dev->net);
1824        }
1825        return 0;
1826}
1827EXPORT_SYMBOL_GPL(usbnet_suspend);
1828
1829int usbnet_resume (struct usb_interface *intf)
1830{
1831        struct usbnet           *dev = usb_get_intfdata(intf);
1832        struct sk_buff          *skb;
1833        struct urb              *res;
1834        int                     retval;
1835
1836        if (!--dev->suspend_count) {
1837                /* resume interrupt URB if it was previously submitted */
1838                __usbnet_status_start_force(dev, GFP_NOIO);
1839
1840                spin_lock_irq(&dev->txq.lock);
1841                while ((res = usb_get_from_anchor(&dev->deferred))) {
1842
1843                        skb = (struct sk_buff *)res->context;
1844                        retval = usb_submit_urb(res, GFP_ATOMIC);
1845                        if (retval < 0) {
1846                                dev_kfree_skb_any(skb);
1847                                kfree(res->sg);
1848                                usb_free_urb(res);
1849                                usb_autopm_put_interface_async(dev->intf);
1850                        } else {
1851                                netif_trans_update(dev->net);
1852                                __skb_queue_tail(&dev->txq, skb);
1853                        }
1854                }
1855
1856                smp_mb();
1857                clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1858                spin_unlock_irq(&dev->txq.lock);
1859
1860                if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1861                        /* handle remote wakeup ASAP
1862                         * we cannot race against stop
1863                         */
1864                        if (netif_device_present(dev->net) &&
1865                                !timer_pending(&dev->delay) &&
1866                                !test_bit(EVENT_RX_HALT, &dev->flags))
1867                                        rx_alloc_submit(dev, GFP_NOIO);
1868
1869                        if (!(dev->txq.qlen >= TX_QLEN(dev)))
1870                                netif_tx_wake_all_queues(dev->net);
1871                        tasklet_schedule (&dev->bh);
1872                }
1873        }
1874
1875        if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1876                usb_autopm_get_interface_no_resume(intf);
1877
1878        return 0;
1879}
1880EXPORT_SYMBOL_GPL(usbnet_resume);
1881
1882/*
1883 * Either a subdriver implements manage_power, then it is assumed to always
1884 * be ready to be suspended or it reports the readiness to be suspended
1885 * explicitly
1886 */
1887void usbnet_device_suggests_idle(struct usbnet *dev)
1888{
1889        if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1890                dev->intf->needs_remote_wakeup = 1;
1891                usb_autopm_put_interface_async(dev->intf);
1892        }
1893}
1894EXPORT_SYMBOL(usbnet_device_suggests_idle);
1895
1896/*
1897 * For devices that can do without special commands
1898 */
1899int usbnet_manage_power(struct usbnet *dev, int on)
1900{
1901        dev->intf->needs_remote_wakeup = on;
1902        return 0;
1903}
1904EXPORT_SYMBOL(usbnet_manage_power);
1905
1906void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1907{
1908        /* update link after link is reseted */
1909        if (link && !need_reset)
1910                netif_carrier_on(dev->net);
1911        else
1912                netif_carrier_off(dev->net);
1913
1914        if (need_reset && link)
1915                usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1916        else
1917                usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1918}
1919EXPORT_SYMBOL(usbnet_link_change);
1920
1921/*-------------------------------------------------------------------------*/
1922static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1923                             u16 value, u16 index, void *data, u16 size)
1924{
1925        void *buf = NULL;
1926        int err = -ENOMEM;
1927
1928        netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1929                   " value=0x%04x index=0x%04x size=%d\n",
1930                   cmd, reqtype, value, index, size);
1931
1932        if (size) {
1933                buf = kmalloc(size, GFP_KERNEL);
1934                if (!buf)
1935                        goto out;
1936        }
1937
1938        err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1939                              cmd, reqtype, value, index, buf, size,
1940                              USB_CTRL_GET_TIMEOUT);
1941        if (err > 0 && err <= size) {
1942        if (data)
1943            memcpy(data, buf, err);
1944        else
1945            netdev_dbg(dev->net,
1946                "Huh? Data requested but thrown away.\n");
1947    }
1948        kfree(buf);
1949out:
1950        return err;
1951}
1952
1953static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1954                              u16 value, u16 index, const void *data,
1955                              u16 size)
1956{
1957        void *buf = NULL;
1958        int err = -ENOMEM;
1959
1960        netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1961                   " value=0x%04x index=0x%04x size=%d\n",
1962                   cmd, reqtype, value, index, size);
1963
1964        if (data) {
1965                buf = kmemdup(data, size, GFP_KERNEL);
1966                if (!buf)
1967                        goto out;
1968        } else {
1969        if (size) {
1970            WARN_ON_ONCE(1);
1971            err = -EINVAL;
1972            goto out;
1973        }
1974    }
1975
1976        err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1977                              cmd, reqtype, value, index, buf, size,
1978                              USB_CTRL_SET_TIMEOUT);
1979        kfree(buf);
1980
1981out:
1982        return err;
1983}
1984
1985/*
1986 * The function can't be called inside suspend/resume callback,
1987 * otherwise deadlock will be caused.
1988 */
1989int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1990                    u16 value, u16 index, void *data, u16 size)
1991{
1992        int ret;
1993
1994        if (usb_autopm_get_interface(dev->intf) < 0)
1995                return -ENODEV;
1996        ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1997                                data, size);
1998        usb_autopm_put_interface(dev->intf);
1999        return ret;
2000}
2001EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2002
2003/*
2004 * The function can't be called inside suspend/resume callback,
2005 * otherwise deadlock will be caused.
2006 */
2007int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2008                     u16 value, u16 index, const void *data, u16 size)
2009{
2010        int ret;
2011
2012        if (usb_autopm_get_interface(dev->intf) < 0)
2013                return -ENODEV;
2014        ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2015                                 data, size);
2016        usb_autopm_put_interface(dev->intf);
2017        return ret;
2018}
2019EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2020
2021/*
2022 * The function can be called inside suspend/resume callback safely
2023 * and should only be called by suspend/resume callback generally.
2024 */
2025int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2026                          u16 value, u16 index, void *data, u16 size)
2027{
2028        return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2029                                 data, size);
2030}
2031EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2032
2033/*
2034 * The function can be called inside suspend/resume callback safely
2035 * and should only be called by suspend/resume callback generally.
2036 */
2037int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2038                          u16 value, u16 index, const void *data,
2039                          u16 size)
2040{
2041        return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2042                                  data, size);
2043}
2044EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2045
2046static void usbnet_async_cmd_cb(struct urb *urb)
2047{
2048        struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2049        int status = urb->status;
2050
2051        if (status < 0)
2052                dev_dbg(&urb->dev->dev, "%s failed with %d",
2053                        __func__, status);
2054
2055        kfree(req);
2056        usb_free_urb(urb);
2057}
2058
2059/*
2060 * The caller must make sure that device can't be put into suspend
2061 * state until the control URB completes.
2062 */
2063int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2064                           u16 value, u16 index, const void *data, u16 size)
2065{
2066        struct usb_ctrlrequest *req = NULL;
2067        struct urb *urb;
2068        int err = -ENOMEM;
2069        void *buf = NULL;
2070
2071        netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2072                   " value=0x%04x index=0x%04x size=%d\n",
2073                   cmd, reqtype, value, index, size);
2074
2075        urb = usb_alloc_urb(0, GFP_ATOMIC);
2076        if (!urb)
2077                goto fail;
2078
2079        if (data) {
2080                buf = kmemdup(data, size, GFP_ATOMIC);
2081                if (!buf) {
2082                        netdev_err(dev->net, "Error allocating buffer"
2083                                   " in %s!\n", __func__);
2084                        goto fail_free;
2085                }
2086        }
2087
2088        req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2089        if (!req)
2090                goto fail_free_buf;
2091
2092        req->bRequestType = reqtype;
2093        req->bRequest = cmd;
2094        req->wValue = cpu_to_le16(value);
2095        req->wIndex = cpu_to_le16(index);
2096        req->wLength = cpu_to_le16(size);
2097
2098        usb_fill_control_urb(urb, dev->udev,
2099                             usb_sndctrlpipe(dev->udev, 0),
2100                             (void *)req, buf, size,
2101                             usbnet_async_cmd_cb, req);
2102        urb->transfer_flags |= URB_FREE_BUFFER;
2103
2104        err = usb_submit_urb(urb, GFP_ATOMIC);
2105        if (err < 0) {
2106                netdev_err(dev->net, "Error submitting the control"
2107                           " message: status=%d\n", err);
2108                goto fail_free;
2109        }
2110        return 0;
2111
2112fail_free_buf:
2113        kfree(buf);
2114fail_free:
2115        kfree(req);
2116        usb_free_urb(urb);
2117fail:
2118        return err;
2119
2120}
2121EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2122/*-------------------------------------------------------------------------*/
2123
2124static int __init usbnet_init(void)
2125{
2126        /* Compiler should optimize this out. */
2127        BUILD_BUG_ON(
2128                FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2129
2130        eth_random_addr(node_id);
2131        return 0;
2132}
2133module_init(usbnet_init);
2134
2135static void __exit usbnet_exit(void)
2136{
2137}
2138module_exit(usbnet_exit);
2139
2140MODULE_AUTHOR("David Brownell");
2141MODULE_DESCRIPTION("USB network driver framework");
2142MODULE_LICENSE("GPL");
2143