sound/usb/card.c

   1 /*
   2  *   (Tentative) USB Audio Driver for ALSA
   3  *
   4  *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
   5  *
   6  *   Many codes borrowed from audio.c by
   7  *          Alan Cox (alan@lxorguk.ukuu.org.uk)
   8  *          Thomas Sailer (sailer@ife.ee.ethz.ch)
   9  *
  10  *
  11  *   This program is free software; you can redistribute it and/or modify
  12  *   it under the terms of the GNU General Public License as published by
  13  *   the Free Software Foundation; either version 2 of the License, or
  14  *   (at your option) any later version.
  15  *
  16  *   This program is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with this program; if not, write to the Free Software
  23  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24  *
  25  *
  26  *  NOTES:
  27  *
  28  *   - async unlink should be used for avoiding the sleep inside lock.
  29  *     2.4.22 usb-uhci seems buggy for async unlinking and results in
  30  *     oops.  in such a cse, pass async_unlink=0 option.
  31  *   - the linked URBs would be preferred but not used so far because of
  32  *     the instability of unlinking.
  33  *   - type II is not supported properly.  there is no device which supports
  34  *     this type *correctly*.  SB extigy looks as if it supports, but it's
  35  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
  36  */
  37
  38
  39 #include <linux/bitops.h>
  40 #include <linux/init.h>
  41 #include <linux/list.h>
  42 #include <linux/slab.h>
  43 #include <linux/string.h>
  44 #include <linux/usb.h>
  45 #include <linux/moduleparam.h>
  46 #include <linux/mutex.h>
  47 #include <linux/usb/audio.h>
  48 #include <linux/usb/audio-v2.h>
  49
  50 #include <sound/core.h>
  51 #include <sound/info.h>
  52 #include <sound/pcm.h>
  53 #include <sound/pcm_params.h>
  54 #include <sound/initval.h>
  55
  56 #include "usbaudio.h"
  57 #include "card.h"
  58 #include "midi.h"
  59 #include "mixer.h"
  60 #include "proc.h"
  61 #include "quirks.h"
  62 #include "endpoint.h"
  63 #include "helper.h"
  64 #include "debug.h"
  65 #include "pcm.h"
  66 #include "urb.h"
  67 #include "format.h"
  68 #include "power.h"
  69
  70 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  71 MODULE_DESCRIPTION("USB Audio");
  72 MODULE_LICENSE("GPL");
  73 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
  74
  75
  76 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  77 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  78 static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
  79 /* Vendor/product IDs for this card */
  80 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  81 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  82 static int nrpacks = 8;         /* max. number of packets per urb */
  83 static int async_unlink = 1;
  84 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
  85 static int ignore_ctl_error;
  86
  87 module_param_array(index, int, NULL, 0444);
  88 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
  89 module_param_array(id, charp, NULL, 0444);
  90 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
  91 module_param_array(enable, bool, NULL, 0444);
  92 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
  93 module_param_array(vid, int, NULL, 0444);
  94 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
  95 module_param_array(pid, int, NULL, 0444);
  96 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
  97 module_param(nrpacks, int, 0644);
  98 MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
  99 module_param(async_unlink, bool, 0444);
 100 MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
 101 module_param_array(device_setup, int, NULL, 0444);
 102 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
 103 module_param(ignore_ctl_error, bool, 0444);
 104 MODULE_PARM_DESC(ignore_ctl_error,
 105                  "Ignore errors from USB controller for mixer interfaces.");
 106
 107 /*
 108  * we keep the snd_usb_audio_t instances by ourselves for merging
 109  * the all interfaces on the same card as one sound device.
 110  */
 111
 112 static DEFINE_MUTEX(register_mutex);
 113 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 114 static struct usb_driver usb_audio_driver;
 115
 116 /*
 117  * disconnect streams
 118  * called from snd_usb_audio_disconnect()
 119  */
 120 static void snd_usb_stream_disconnect(struct list_head *head)
 121 {
 122         int idx;
 123         struct snd_usb_stream *as;
 124         struct snd_usb_substream *subs;
 125
 126         as = list_entry(head, struct snd_usb_stream, list);
 127         for (idx = 0; idx < 2; idx++) {
 128                 subs = &as->substream[idx];
 129                 if (!subs->num_formats)
 130                         continue;
 131                 snd_usb_release_substream_urbs(subs, 1);
 132                 subs->interface = -1;
 133         }
 134 }
 135
 136 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
 137 {
 138         struct usb_device *dev = chip->dev;
 139         struct usb_host_interface *alts;
 140         struct usb_interface_descriptor *altsd;
 141         struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
 142
 143         if (!iface) {
 144                 snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
 145                            dev->devnum, ctrlif, interface);
 146                 return -EINVAL;
 147         }
 148
 149         if (usb_interface_claimed(iface)) {
 150                 snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
 151                                                 dev->devnum, ctrlif, interface);
 152                 return -EINVAL;
 153         }
 154
 155         alts = &iface->altsetting[0];
 156         altsd = get_iface_desc(alts);
 157         if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
 158              altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
 159             altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
 160                 int err = snd_usbmidi_create(chip->card, iface,
 161                                              &chip->midi_list, NULL);
 162                 if (err < 0) {
 163                         snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
 164                                                 dev->devnum, ctrlif, interface);
 165                         return -EINVAL;
 166                 }
 167                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
 168
 169                 return 0;
 170         }
 171
 172         if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
 173              altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
 174             altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
 175                 snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
 176                                         dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
 177                 /* skip non-supported classes */
 178                 return -EINVAL;
 179         }
 180
 181         if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
 182                 snd_printk(KERN_ERR "low speed audio streaming not supported\n");
 183                 return -EINVAL;
 184         }
 185
 186         if (! snd_usb_parse_audio_endpoints(chip, interface)) {
 187                 usb_set_interface(dev, interface, 0); /* reset the current interface */
 188                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
 189                 return -EINVAL;
 190         }
 191
 192         return 0;
 193 }
 194
 195 /*
 196  * parse audio control descriptor and create pcm/midi streams
 197  */
 198 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 199 {
 200         struct usb_device *dev = chip->dev;
 201         struct usb_host_interface *host_iface;
 202         struct usb_interface_descriptor *altsd;
 203         void *control_header;
 204         int i, protocol;
 205
 206         /* find audiocontrol interface */
 207         host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
 208         control_header = snd_usb_find_csint_desc(host_iface->extra,
 209                                                  host_iface->extralen,
 210                                                  NULL, UAC_HEADER);
 211         altsd = get_iface_desc(host_iface);
 212         protocol = altsd->bInterfaceProtocol;
 213
 214         if (!control_header) {
 215                 snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
 216                 return -EINVAL;
 217         }
 218
 219         switch (protocol) {
 220         default:
 221                 snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
 222                             protocol);
 223                 /* fall through */
 224
 225         case UAC_VERSION_1: {
 226                 struct uac1_ac_header_descriptor *h1 = control_header;
 227
 228                 if (!h1->bInCollection) {
 229                         snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
 230                         return -EINVAL;
 231                 }
 232
 233                 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
 234                         snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
 235                         return -EINVAL;
 236                 }
 237
 238                 for (i = 0; i < h1->bInCollection; i++)
 239                         snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
 240
 241                 break;
 242         }
 243
 244         case UAC_VERSION_2: {
 245                 struct usb_interface_assoc_descriptor *assoc =
 246                         usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
 247
 248                 if (!assoc) {
 249                         snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
 250                         return -EINVAL;
 251                 }
 252
 253                 for (i = 0; i < assoc->bInterfaceCount; i++) {
 254                         int intf = assoc->bFirstInterface + i;
 255
 256                         if (intf != ctrlif)
 257                                 snd_usb_create_stream(chip, ctrlif, intf);
 258                 }
 259
 260                 break;
 261         }
 262         }
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * free the chip instance
 269  *
 270  * here we have to do not much, since pcm and controls are already freed
 271  *
 272  */
 273
 274 static int snd_usb_audio_free(struct snd_usb_audio *chip)
 275 {
 276         kfree(chip);
 277         return 0;
 278 }
 279
 280 static int snd_usb_audio_dev_free(struct snd_device *device)
 281 {
 282         struct snd_usb_audio *chip = device->device_data;
 283         return snd_usb_audio_free(chip);
 284 }
 285
 286
 287 /*
 288  * create a chip instance and set its names.
 289  */
 290 static int snd_usb_audio_create(struct usb_device *dev, int idx,
 291                                 const struct snd_usb_audio_quirk *quirk,
 292                                 struct snd_usb_audio **rchip)
 293 {
 294         struct snd_card *card;
 295         struct snd_usb_audio *chip;
 296         int err, len;
 297         char component[14];
 298         static struct snd_device_ops ops = {
 299                 .dev_free =     snd_usb_audio_dev_free,
 300         };
 301
 302         *rchip = NULL;
 303
 304         switch (snd_usb_get_speed(dev)) {
 305         case USB_SPEED_LOW:
 306         case USB_SPEED_FULL:
 307         case USB_SPEED_HIGH:
 308         case USB_SPEED_SUPER:
 309                 break;
 310         default:
 311                 snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
 312                 return -ENXIO;
 313         }
 314
 315         err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
 316         if (err < 0) {
 317                 snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
 318                 return err;
 319         }
 320
 321         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 322         if (! chip) {
 323                 snd_card_free(card);
 324                 return -ENOMEM;
 325         }
 326
 327         mutex_init(&chip->shutdown_mutex);
 328         chip->index = idx;
 329         chip->dev = dev;
 330         chip->card = card;
 331         chip->setup = device_setup[idx];
 332         chip->nrpacks = nrpacks;
 333         chip->async_unlink = async_unlink;
 334         chip->probing = 1;
 335
 336         chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 337                               le16_to_cpu(dev->descriptor.idProduct));
 338         INIT_LIST_HEAD(&chip->pcm_list);
 339         INIT_LIST_HEAD(&chip->midi_list);
 340         INIT_LIST_HEAD(&chip->mixer_list);
 341
 342         if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
 343                 snd_usb_audio_free(chip);
 344                 snd_card_free(card);
 345                 return err;
 346         }
 347
 348         strcpy(card->driver, "USB-Audio");
 349         sprintf(component, "USB%04x:%04x",
 350                 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
 351         snd_component_add(card, component);
 352
 353         /* retrieve the device string as shortname */
 354         if (quirk && quirk->product_name) {
 355                 strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
 356         } else {
 357                 if (!dev->descriptor.iProduct ||
 358                     usb_string(dev, dev->descriptor.iProduct,
 359                     card->shortname, sizeof(card->shortname)) <= 0) {
 360                         /* no name available from anywhere, so use ID */
 361                         sprintf(card->shortname, "USB Device %#04x:%#04x",
 362                                 USB_ID_VENDOR(chip->usb_id),
 363                                 USB_ID_PRODUCT(chip->usb_id));
 364                 }
 365         }
 366
 367         /* retrieve the vendor and device strings as longname */
 368         if (quirk && quirk->vendor_name) {
 369                 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
 370         } else {
 371                 if (dev->descriptor.iManufacturer)
 372                         len = usb_string(dev, dev->descriptor.iManufacturer,
 373                                          card->longname, sizeof(card->longname));
 374                 else
 375                         len = 0;
 376                 /* we don't really care if there isn't any vendor string */
 377         }
 378         if (len > 0)
 379                 strlcat(card->longname, " ", sizeof(card->longname));
 380
 381         strlcat(card->longname, card->shortname, sizeof(card->longname));
 382
 383         len = strlcat(card->longname, " at ", sizeof(card->longname));
 384
 385         if (len < sizeof(card->longname))
 386                 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
 387
 388         switch (snd_usb_get_speed(dev)) {
 389         case USB_SPEED_LOW:
 390                 strlcat(card->longname, ", low speed", sizeof(card->longname));
 391                 break;
 392         case USB_SPEED_FULL:
 393                 strlcat(card->longname, ", full speed", sizeof(card->longname));
 394                 break;
 395         case USB_SPEED_HIGH:
 396                 strlcat(card->longname, ", high speed", sizeof(card->longname));
 397                 break;
 398         case USB_SPEED_SUPER:
 399                 strlcat(card->longname, ", super speed", sizeof(card->longname));
 400                 break;
 401         default:
 402                 break;
 403         }
 404
 405         snd_usb_audio_create_proc(chip);
 406
 407         *rchip = chip;
 408         return 0;
 409 }
 410
 411 /*
 412  * probe the active usb device
 413  *
 414  * note that this can be called multiple times per a device, when it
 415  * includes multiple audio control interfaces.
 416  *
 417  * thus we check the usb device pointer and creates the card instance
 418  * only at the first time.  the successive calls of this function will
 419  * append the pcm interface to the corresponding card.
 420  */
 421 static void *snd_usb_audio_probe(struct usb_device *dev,
 422                                  struct usb_interface *intf,
 423                                  const struct usb_device_id *usb_id)
 424 {
 425         const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
 426         int i, err;
 427         struct snd_usb_audio *chip;
 428         struct usb_host_interface *alts;
 429         int ifnum;
 430         u32 id;
 431
 432         alts = &intf->altsetting[0];
 433         ifnum = get_iface_desc(alts)->bInterfaceNumber;
 434         id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 435                     le16_to_cpu(dev->descriptor.idProduct));
 436         if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
 437                 goto __err_val;
 438
 439         if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
 440                 goto __err_val;
 441
 442         /*
 443          * found a config.  now register to ALSA
 444          */
 445
 446         /* check whether it's already registered */
 447         chip = NULL;
 448         mutex_lock(&register_mutex);
 449         for (i = 0; i < SNDRV_CARDS; i++) {
 450                 if (usb_chip[i] && usb_chip[i]->dev == dev) {
 451                         if (usb_chip[i]->shutdown) {
 452                                 snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
 453                                 goto __error;
 454                         }
 455                         chip = usb_chip[i];
 456                         chip->probing = 1;
 457                         break;
 458                 }
 459         }
 460         if (! chip) {
 461                 /* it's a fresh one.
 462                  * now look for an empty slot and create a new card instance
 463                  */
 464                 for (i = 0; i < SNDRV_CARDS; i++)
 465                         if (enable[i] && ! usb_chip[i] &&
 466                             (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 467                             (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
 468                                 if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
 469                                         goto __error;
 470                                 }
 471                                 snd_card_set_dev(chip->card, &intf->dev);
 472                                 chip->pm_intf = intf;
 473                                 break;
 474                         }
 475                 if (!chip) {
 476                         printk(KERN_ERR "no available usb audio device\n");
 477                         goto __error;
 478                 }
 479         }
 480
 481         chip->txfr_quirk = 0;
 482         err = 1; /* continue */
 483         if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 484                 /* need some special handlings */
 485                 if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
 486                         goto __error;
 487         }
 488
 489         /*
 490          * For devices with more than one control interface, we assume the
 491          * first contains the audio controls. We might need a more specific
 492          * check here in the future.
 493          */
 494         if (!chip->ctrl_intf)
 495                 chip->ctrl_intf = alts;
 496
 497         if (err > 0) {
 498                 /* create normal USB audio interfaces */
 499                 if (snd_usb_create_streams(chip, ifnum) < 0 ||
 500                     snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
 501                         goto __error;
 502                 }
 503         }
 504
 505         /* we are allowed to call snd_card_register() many times */
 506         if (snd_card_register(chip->card) < 0) {
 507                 goto __error;
 508         }
 509
 510         usb_chip[chip->index] = chip;
 511         chip->num_interfaces++;
 512         chip->probing = 0;
 513         mutex_unlock(&register_mutex);
 514         return chip;
 515
 516  __error:
 517         if (chip && !chip->num_interfaces)
 518                 snd_card_free(chip->card);
 519         mutex_unlock(&register_mutex);
 520  __err_val:
 521         return NULL;
 522 }
 523
 524 /*
 525  * we need to take care of counter, since disconnection can be called also
 526  * many times as well as usb_audio_probe().
 527  */
 528 static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr)
 529 {
 530         struct snd_usb_audio *chip;
 531         struct snd_card *card;
 532         struct list_head *p;
 533
 534         if (ptr == (void *)-1L)
 535                 return;
 536
 537         chip = ptr;
 538         card = chip->card;
 539         mutex_lock(&register_mutex);
 540         mutex_lock(&chip->shutdown_mutex);
 541         chip->shutdown = 1;
 542         chip->num_interfaces--;
 543         if (chip->num_interfaces <= 0) {
 544                 snd_card_disconnect(card);
 545                 /* release the pcm resources */
 546                 list_for_each(p, &chip->pcm_list) {
 547                         snd_usb_stream_disconnect(p);
 548                 }
 549                 /* release the midi resources */
 550                 list_for_each(p, &chip->midi_list) {
 551                         snd_usbmidi_disconnect(p);
 552                 }
 553                 /* release mixer resources */
 554                 list_for_each(p, &chip->mixer_list) {
 555                         snd_usb_mixer_disconnect(p);
 556                 }
 557                 usb_chip[chip->index] = NULL;
 558                 mutex_unlock(&chip->shutdown_mutex);
 559                 mutex_unlock(&register_mutex);
 560                 snd_card_free_when_closed(card);
 561         } else {
 562                 mutex_unlock(&chip->shutdown_mutex);
 563                 mutex_unlock(&register_mutex);
 564         }
 565 }
 566
 567 /*
 568  * new 2.5 USB kernel API
 569  */
 570 static int usb_audio_probe(struct usb_interface *intf,
 571                            const struct usb_device_id *id)
 572 {
 573         void *chip;
 574         chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
 575         if (chip) {
 576                 usb_set_intfdata(intf, chip);
 577                 return 0;
 578         } else
 579                 return -EIO;
 580 }
 581
 582 static void usb_audio_disconnect(struct usb_interface *intf)
 583 {
 584         snd_usb_audio_disconnect(interface_to_usbdev(intf),
 585                                  usb_get_intfdata(intf));
 586 }
 587
 588 #ifdef CONFIG_PM
 589
 590 int snd_usb_autoresume(struct snd_usb_audio *chip)
 591 {
 592         int err = -ENODEV;
 593
 594         if (!chip->shutdown && !chip->probing)
 595                 err = usb_autopm_get_interface(chip->pm_intf);
 596
 597         return err;
 598 }
 599
 600 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 601 {
 602         if (!chip->shutdown && !chip->probing)
 603                 usb_autopm_put_interface(chip->pm_intf);
 604 }
 605
 606 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 607 {
 608         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 609         struct list_head *p;
 610         struct snd_usb_stream *as;
 611         struct usb_mixer_interface *mixer;
 612
 613         if (chip == (void *)-1L)
 614                 return 0;
 615
 616         if (!(message.event & PM_EVENT_AUTO)) {
 617                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 618                 if (!chip->num_suspended_intf++) {
 619                         list_for_each(p, &chip->pcm_list) {
 620                                 as = list_entry(p, struct snd_usb_stream, list);
 621                                 snd_pcm_suspend_all(as->pcm);
 622                         }
 623                 }
 624         } else {
 625                 /*
 626                  * otherwise we keep the rest of the system in the dark
 627                  * to keep this transparent
 628                  */
 629                 if (!chip->num_suspended_intf++)
 630                         chip->autosuspended = 1;
 631         }
 632
 633         list_for_each_entry(mixer, &chip->mixer_list, list)
 634                 snd_usb_mixer_inactivate(mixer);
 635
 636         return 0;
 637 }
 638
 639 static int usb_audio_resume(struct usb_interface *intf)
 640 {
 641         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 642         struct usb_mixer_interface *mixer;
 643         int err = 0;
 644
 645         if (chip == (void *)-1L)
 646                 return 0;
 647         if (--chip->num_suspended_intf)
 648                 return 0;
 649         /*
 650          * ALSA leaves material resumption to user space
 651          * we just notify and restart the mixers
 652          */
 653         list_for_each_entry(mixer, &chip->mixer_list, list) {
 654                 err = snd_usb_mixer_activate(mixer);
 655                 if (err < 0)
 656                         goto err_out;
 657         }
 658
 659         if (!chip->autosuspended)
 660                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 661         chip->autosuspended = 0;
 662
 663 err_out:
 664         return err;
 665 }
 666 #else
 667 #define usb_audio_suspend       NULL
 668 #define usb_audio_resume        NULL
 669 #endif          /* CONFIG_PM */
 670
 671 static struct usb_device_id usb_audio_ids [] = {
 672 #include "quirks-table.h"
 673     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
 674       .bInterfaceClass = USB_CLASS_AUDIO,
 675       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
 676     { }                                         /* Terminating entry */
 677 };
 678
 679 MODULE_DEVICE_TABLE (usb, usb_audio_ids);
 680
 681 /*
 682  * entry point for linux usb interface
 683  */
 684
 685 static struct usb_driver usb_audio_driver = {
 686         .name =         "snd-usb-audio",
 687         .probe =        usb_audio_probe,
 688         .disconnect =   usb_audio_disconnect,
 689         .suspend =      usb_audio_suspend,
 690         .resume =       usb_audio_resume,
 691         .id_table =     usb_audio_ids,
 692         .supports_autosuspend = 1,
 693 };
 694
 695 static int __init snd_usb_audio_init(void)
 696 {
 697         if (nrpacks < 1 || nrpacks > MAX_PACKS) {
 698                 printk(KERN_WARNING "invalid nrpacks value.\n");
 699                 return -EINVAL;
 700         }
 701         return usb_register(&usb_audio_driver);
 702 }
 703
 704 static void __exit snd_usb_audio_cleanup(void)
 705 {
 706         usb_deregister(&usb_audio_driver);
 707 }
 708
 709 module_init(snd_usb_audio_init);
 710 module_exit(snd_usb_audio_cleanup);