1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * (Tentative) USB Audio Driver for ALSA
7 * Many codes borrowed from audio.c by
15 * - the linked URBs would be preferred but not used so far because of
16 * the instability of unlinking.
17 * - type II is not supported properly. there is no device which supports
18 * this type *correctly*. SB extigy looks as if it supports, but it's
19 * indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
23 #include <linux/bitops.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/slab.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/usb.h>
30 #include <linux/moduleparam.h>
31 #include <linux/mutex.h>
32 #include <linux/usb/audio.h>
33 #include <linux/usb/audio-v2.h>
34 #include <linux/usb/audio-v3.h>
35 #include <linux/module.h>
37 #include <sound/control.h>
38 #include <sound/core.h>
39 #include <sound/info.h>
40 #include <sound/pcm.h>
41 #include <sound/pcm_params.h>
42 #include <sound/initval.h>
60 MODULE_DESCRIPTION("USB Audio");
61 MODULE_LICENSE("GPL");
62 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
65 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
66 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
67 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
68 /* Vendor/product IDs for this card */
69 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
70 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
71 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
72 static bool ignore_ctl_error;
73 static bool autoclock = true;
74 static char *quirk_alias[SNDRV_CARDS];
76 bool snd_usb_use_vmalloc = true;
78 module_param_array(index, int, NULL, 0444);
79 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
80 module_param_array(id, charp, NULL, 0444);
81 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
82 module_param_array(enable, bool, NULL, 0444);
83 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
84 module_param_array(vid, int, NULL, 0444);
85 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
86 module_param_array(pid, int, NULL, 0444);
87 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
88 module_param_array(device_setup, int, NULL, 0444);
89 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
90 module_param(ignore_ctl_error, bool, 0444);
91 MODULE_PARM_DESC(ignore_ctl_error,
92 "Ignore errors from USB controller for mixer interfaces.");
93 module_param(autoclock, bool, 0444);
94 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
95 module_param_array(quirk_alias, charp, NULL, 0444);
96 MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
97 module_param_named(use_vmalloc, snd_usb_use_vmalloc, bool, 0444);
98 MODULE_PARM_DESC(use_vmalloc, "Use vmalloc for PCM intermediate buffers (default: yes).");
101 * we keep the snd_usb_audio_t instances by ourselves for merging
102 * the all interfaces on the same card as one sound device.
105 static DEFINE_MUTEX(register_mutex);
106 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
107 static struct usb_driver usb_audio_driver;
111 * called from usb_audio_disconnect()
113 static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
116 struct snd_usb_substream *subs;
118 for (idx = 0; idx < 2; idx++) {
119 subs = &as->substream[idx];
120 if (!subs->num_formats)
122 subs->interface = -1;
123 subs->data_endpoint = NULL;
124 subs->sync_endpoint = NULL;
128 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
130 struct usb_device *dev = chip->dev;
131 struct usb_host_interface *alts;
132 struct usb_interface_descriptor *altsd;
133 struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
136 dev_err(&dev->dev, "%u:%d : does not exist\n",
141 alts = &iface->altsetting[0];
142 altsd = get_iface_desc(alts);
145 * Android with both accessory and audio interfaces enabled gets the
146 * interface numbers wrong.
148 if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
149 chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
151 altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
152 altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
154 iface = usb_ifnum_to_if(dev, interface);
157 alts = &iface->altsetting[0];
158 altsd = get_iface_desc(alts);
161 if (usb_interface_claimed(iface)) {
162 dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
167 if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
168 altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
169 altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
170 int err = __snd_usbmidi_create(chip->card, iface,
171 &chip->midi_list, NULL,
175 "%u:%d: cannot create sequencer device\n",
179 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
184 if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
185 altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
186 altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
188 "%u:%d: skipping non-supported interface %d\n",
189 ctrlif, interface, altsd->bInterfaceClass);
190 /* skip non-supported classes */
194 if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
195 dev_err(&dev->dev, "low speed audio streaming not supported\n");
199 if (! snd_usb_parse_audio_interface(chip, interface)) {
200 usb_set_interface(dev, interface, 0); /* reset the current interface */
201 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
208 * parse audio control descriptor and create pcm/midi streams
210 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
212 struct usb_device *dev = chip->dev;
213 struct usb_host_interface *host_iface;
214 struct usb_interface_descriptor *altsd;
217 /* find audiocontrol interface */
218 host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
219 altsd = get_iface_desc(host_iface);
220 protocol = altsd->bInterfaceProtocol;
225 "unknown interface protocol %#02x, assuming v1\n",
229 case UAC_VERSION_1: {
230 struct uac1_ac_header_descriptor *h1;
233 h1 = snd_usb_find_csint_desc(host_iface->extra,
234 host_iface->extralen,
236 if (!h1 || h1->bLength < sizeof(*h1)) {
237 dev_err(&dev->dev, "cannot find UAC_HEADER\n");
241 rest_bytes = (void *)(host_iface->extra +
242 host_iface->extralen) - (void *)h1;
244 /* just to be sure -- this shouldn't hit at all */
245 if (rest_bytes <= 0) {
246 dev_err(&dev->dev, "invalid control header\n");
250 if (rest_bytes < sizeof(*h1)) {
251 dev_err(&dev->dev, "too short v1 buffer descriptor\n");
255 if (!h1->bInCollection) {
256 dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
260 if (rest_bytes < h1->bLength) {
261 dev_err(&dev->dev, "invalid buffer length (v1)\n");
265 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
266 dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
270 for (i = 0; i < h1->bInCollection; i++)
271 snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
277 case UAC_VERSION_3: {
278 struct usb_interface_assoc_descriptor *assoc =
279 usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
283 * Firmware writers cannot count to three. So to find
284 * the IAD on the NuForce UDH-100, also check the next
287 struct usb_interface *iface =
288 usb_ifnum_to_if(dev, ctrlif + 1);
291 iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
292 iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
293 assoc = iface->intf_assoc;
297 dev_err(&dev->dev, "Audio class v2/v3 interfaces need an interface association\n");
301 if (protocol == UAC_VERSION_3) {
302 int badd = assoc->bFunctionSubClass;
304 if (badd != UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0 &&
305 (badd < UAC3_FUNCTION_SUBCLASS_GENERIC_IO ||
306 badd > UAC3_FUNCTION_SUBCLASS_SPEAKERPHONE)) {
308 "Unsupported UAC3 BADD profile\n");
312 chip->badd_profile = badd;
315 for (i = 0; i < assoc->bInterfaceCount; i++) {
316 int intf = assoc->bFirstInterface + i;
319 snd_usb_create_stream(chip, ctrlif, intf);
330 * free the chip instance
332 * here we have to do not much, since pcm and controls are already freed
336 static void snd_usb_audio_free(struct snd_card *card)
338 struct snd_usb_audio *chip = card->private_data;
339 struct snd_usb_endpoint *ep, *n;
341 list_for_each_entry_safe(ep, n, &chip->ep_list, list)
342 snd_usb_endpoint_free(ep);
344 mutex_destroy(&chip->mutex);
345 if (!atomic_read(&chip->shutdown))
346 dev_set_drvdata(&chip->dev->dev, NULL);
349 static void usb_audio_make_shortname(struct usb_device *dev,
350 struct snd_usb_audio *chip,
351 const struct snd_usb_audio_quirk *quirk)
353 struct snd_card *card = chip->card;
355 if (quirk && quirk->product_name && *quirk->product_name) {
356 strlcpy(card->shortname, quirk->product_name,
357 sizeof(card->shortname));
361 /* retrieve the device string as shortname */
362 if (!dev->descriptor.iProduct ||
363 usb_string(dev, dev->descriptor.iProduct,
364 card->shortname, sizeof(card->shortname)) <= 0) {
365 /* no name available from anywhere, so use ID */
366 sprintf(card->shortname, "USB Device %#04x:%#04x",
367 USB_ID_VENDOR(chip->usb_id),
368 USB_ID_PRODUCT(chip->usb_id));
371 strim(card->shortname);
374 static void usb_audio_make_longname(struct usb_device *dev,
375 struct snd_usb_audio *chip,
376 const struct snd_usb_audio_quirk *quirk)
378 struct snd_card *card = chip->card;
381 /* shortcut - if any pre-defined string is given, use it */
382 if (quirk && quirk->profile_name && *quirk->profile_name) {
383 strlcpy(card->longname, quirk->profile_name,
384 sizeof(card->longname));
388 if (quirk && quirk->vendor_name && *quirk->vendor_name) {
389 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
391 /* retrieve the vendor and device strings as longname */
392 if (dev->descriptor.iManufacturer)
393 len = usb_string(dev, dev->descriptor.iManufacturer,
394 card->longname, sizeof(card->longname));
397 /* we don't really care if there isn't any vendor string */
400 strim(card->longname);
402 strlcat(card->longname, " ", sizeof(card->longname));
405 strlcat(card->longname, card->shortname, sizeof(card->longname));
407 len = strlcat(card->longname, " at ", sizeof(card->longname));
409 if (len < sizeof(card->longname))
410 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
412 switch (snd_usb_get_speed(dev)) {
414 strlcat(card->longname, ", low speed", sizeof(card->longname));
417 strlcat(card->longname, ", full speed", sizeof(card->longname));
420 strlcat(card->longname, ", high speed", sizeof(card->longname));
422 case USB_SPEED_SUPER:
423 strlcat(card->longname, ", super speed", sizeof(card->longname));
425 case USB_SPEED_SUPER_PLUS:
426 strlcat(card->longname, ", super speed plus", sizeof(card->longname));
434 * create a chip instance and set its names.
436 static int snd_usb_audio_create(struct usb_interface *intf,
437 struct usb_device *dev, int idx,
438 const struct snd_usb_audio_quirk *quirk,
440 struct snd_usb_audio **rchip)
442 struct snd_card *card;
443 struct snd_usb_audio *chip;
449 switch (snd_usb_get_speed(dev)) {
453 case USB_SPEED_WIRELESS:
454 case USB_SPEED_SUPER:
455 case USB_SPEED_SUPER_PLUS:
458 dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
462 err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
463 sizeof(*chip), &card);
465 dev_err(&dev->dev, "cannot create card instance %d\n", idx);
469 chip = card->private_data;
470 mutex_init(&chip->mutex);
471 init_waitqueue_head(&chip->shutdown_wait);
475 chip->setup = device_setup[idx];
476 chip->autoclock = autoclock;
477 atomic_set(&chip->active, 1); /* avoid autopm during probing */
478 atomic_set(&chip->usage_count, 0);
479 atomic_set(&chip->shutdown, 0);
481 chip->usb_id = usb_id;
482 INIT_LIST_HEAD(&chip->pcm_list);
483 INIT_LIST_HEAD(&chip->ep_list);
484 INIT_LIST_HEAD(&chip->midi_list);
485 INIT_LIST_HEAD(&chip->mixer_list);
487 card->private_free = snd_usb_audio_free;
489 strcpy(card->driver, "USB-Audio");
490 sprintf(component, "USB%04x:%04x",
491 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
492 snd_component_add(card, component);
494 usb_audio_make_shortname(dev, chip, quirk);
495 usb_audio_make_longname(dev, chip, quirk);
497 snd_usb_audio_create_proc(chip);
503 /* look for a matching quirk alias id */
504 static bool get_alias_id(struct usb_device *dev, unsigned int *id)
507 unsigned int src, dst;
509 for (i = 0; i < ARRAY_SIZE(quirk_alias); i++) {
510 if (!quirk_alias[i] ||
511 sscanf(quirk_alias[i], "%x:%x", &src, &dst) != 2 ||
515 "device (%04x:%04x): applying quirk alias %04x:%04x\n",
516 USB_ID_VENDOR(*id), USB_ID_PRODUCT(*id),
517 USB_ID_VENDOR(dst), USB_ID_PRODUCT(dst));
525 static const struct usb_device_id usb_audio_ids[]; /* defined below */
527 /* look for the corresponding quirk */
528 static const struct snd_usb_audio_quirk *
529 get_alias_quirk(struct usb_device *dev, unsigned int id)
531 const struct usb_device_id *p;
533 for (p = usb_audio_ids; p->match_flags; p++) {
534 /* FIXME: this checks only vendor:product pair in the list */
535 if ((p->match_flags & USB_DEVICE_ID_MATCH_DEVICE) ==
536 USB_DEVICE_ID_MATCH_DEVICE &&
537 p->idVendor == USB_ID_VENDOR(id) &&
538 p->idProduct == USB_ID_PRODUCT(id))
539 return (const struct snd_usb_audio_quirk *)p->driver_info;
546 * probe the active usb device
548 * note that this can be called multiple times per a device, when it
549 * includes multiple audio control interfaces.
551 * thus we check the usb device pointer and creates the card instance
552 * only at the first time. the successive calls of this function will
553 * append the pcm interface to the corresponding card.
555 static int usb_audio_probe(struct usb_interface *intf,
556 const struct usb_device_id *usb_id)
558 struct usb_device *dev = interface_to_usbdev(intf);
559 const struct snd_usb_audio_quirk *quirk =
560 (const struct snd_usb_audio_quirk *)usb_id->driver_info;
561 struct snd_usb_audio *chip;
563 struct usb_host_interface *alts;
567 alts = &intf->altsetting[0];
568 ifnum = get_iface_desc(alts)->bInterfaceNumber;
569 id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
570 le16_to_cpu(dev->descriptor.idProduct));
571 if (get_alias_id(dev, &id))
572 quirk = get_alias_quirk(dev, id);
573 if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
576 err = snd_usb_apply_boot_quirk(dev, intf, quirk, id);
581 * found a config. now register to ALSA
584 /* check whether it's already registered */
586 mutex_lock(®ister_mutex);
587 for (i = 0; i < SNDRV_CARDS; i++) {
588 if (usb_chip[i] && usb_chip[i]->dev == dev) {
589 if (atomic_read(&usb_chip[i]->shutdown)) {
590 dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
595 atomic_inc(&chip->active); /* avoid autopm */
601 * now look for an empty slot and create a new card instance
603 for (i = 0; i < SNDRV_CARDS; i++)
605 (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
606 (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
608 err = snd_usb_audio_create(intf, dev, i, quirk,
612 chip->pm_intf = intf;
614 } else if (vid[i] != -1 || pid[i] != -1) {
616 "device (%04x:%04x) is disabled\n",
624 dev_err(&dev->dev, "no available usb audio device\n");
629 dev_set_drvdata(&dev->dev, chip);
632 * For devices with more than one control interface, we assume the
633 * first contains the audio controls. We might need a more specific
634 * check here in the future.
636 if (!chip->ctrl_intf)
637 chip->ctrl_intf = alts;
639 chip->txfr_quirk = 0;
640 err = 1; /* continue */
641 if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
642 /* need some special handlings */
643 err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
649 /* create normal USB audio interfaces */
650 err = snd_usb_create_streams(chip, ifnum);
653 err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
658 /* we are allowed to call snd_card_register() many times */
659 err = snd_card_register(chip->card);
663 if (quirk && quirk->shares_media_device) {
664 /* don't want to fail when snd_media_device_create() fails */
665 snd_media_device_create(chip, intf);
668 usb_chip[chip->index] = chip;
669 chip->num_interfaces++;
670 usb_set_intfdata(intf, chip);
671 atomic_dec(&chip->active);
672 mutex_unlock(®ister_mutex);
677 /* chip->active is inside the chip->card object,
678 * decrement before memory is possibly returned.
680 atomic_dec(&chip->active);
681 if (!chip->num_interfaces)
682 snd_card_free(chip->card);
684 mutex_unlock(®ister_mutex);
689 * we need to take care of counter, since disconnection can be called also
690 * many times as well as usb_audio_probe().
692 static void usb_audio_disconnect(struct usb_interface *intf)
694 struct snd_usb_audio *chip = usb_get_intfdata(intf);
695 struct snd_card *card;
698 if (chip == (void *)-1L)
703 mutex_lock(®ister_mutex);
704 if (atomic_inc_return(&chip->shutdown) == 1) {
705 struct snd_usb_stream *as;
706 struct snd_usb_endpoint *ep;
707 struct usb_mixer_interface *mixer;
709 /* wait until all pending tasks done;
710 * they are protected by snd_usb_lock_shutdown()
712 wait_event(chip->shutdown_wait,
713 !atomic_read(&chip->usage_count));
714 snd_card_disconnect(card);
715 /* release the pcm resources */
716 list_for_each_entry(as, &chip->pcm_list, list) {
717 snd_usb_stream_disconnect(as);
719 /* release the endpoint resources */
720 list_for_each_entry(ep, &chip->ep_list, list) {
721 snd_usb_endpoint_release(ep);
723 /* release the midi resources */
724 list_for_each(p, &chip->midi_list) {
725 snd_usbmidi_disconnect(p);
728 * Nice to check quirk && quirk->shares_media_device and
729 * then call the snd_media_device_delete(). Don't have
730 * access to the quirk here. snd_media_device_delete()
731 * accesses mixer_list
733 snd_media_device_delete(chip);
735 /* release mixer resources */
736 list_for_each_entry(mixer, &chip->mixer_list, list) {
737 snd_usb_mixer_disconnect(mixer);
741 chip->num_interfaces--;
742 if (chip->num_interfaces <= 0) {
743 usb_chip[chip->index] = NULL;
744 mutex_unlock(®ister_mutex);
745 snd_card_free_when_closed(card);
747 mutex_unlock(®ister_mutex);
751 /* lock the shutdown (disconnect) task and autoresume */
752 int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
756 atomic_inc(&chip->usage_count);
757 if (atomic_read(&chip->shutdown)) {
761 err = snd_usb_autoresume(chip);
767 if (atomic_dec_and_test(&chip->usage_count))
768 wake_up(&chip->shutdown_wait);
772 /* autosuspend and unlock the shutdown */
773 void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
775 snd_usb_autosuspend(chip);
776 if (atomic_dec_and_test(&chip->usage_count))
777 wake_up(&chip->shutdown_wait);
782 int snd_usb_autoresume(struct snd_usb_audio *chip)
784 if (atomic_read(&chip->shutdown))
786 if (atomic_inc_return(&chip->active) == 1)
787 return usb_autopm_get_interface(chip->pm_intf);
791 void snd_usb_autosuspend(struct snd_usb_audio *chip)
793 if (atomic_read(&chip->shutdown))
795 if (atomic_dec_and_test(&chip->active))
796 usb_autopm_put_interface(chip->pm_intf);
799 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
801 struct snd_usb_audio *chip = usb_get_intfdata(intf);
802 struct snd_usb_stream *as;
803 struct usb_mixer_interface *mixer;
806 if (chip == (void *)-1L)
809 chip->autosuspended = !!PMSG_IS_AUTO(message);
810 if (!chip->autosuspended)
811 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
812 if (!chip->num_suspended_intf++) {
813 list_for_each_entry(as, &chip->pcm_list, list) {
814 snd_usb_pcm_suspend(as);
815 as->substream[0].need_setup_ep =
816 as->substream[1].need_setup_ep = true;
818 list_for_each(p, &chip->midi_list)
819 snd_usbmidi_suspend(p);
820 list_for_each_entry(mixer, &chip->mixer_list, list)
821 snd_usb_mixer_suspend(mixer);
827 static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
829 struct snd_usb_audio *chip = usb_get_intfdata(intf);
830 struct snd_usb_stream *as;
831 struct usb_mixer_interface *mixer;
835 if (chip == (void *)-1L)
837 if (--chip->num_suspended_intf)
840 atomic_inc(&chip->active); /* avoid autopm */
842 list_for_each_entry(as, &chip->pcm_list, list) {
843 err = snd_usb_pcm_resume(as);
849 * ALSA leaves material resumption to user space
850 * we just notify and restart the mixers
852 list_for_each_entry(mixer, &chip->mixer_list, list) {
853 err = snd_usb_mixer_resume(mixer, reset_resume);
858 list_for_each(p, &chip->midi_list) {
859 snd_usbmidi_resume(p);
862 if (!chip->autosuspended)
863 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
864 chip->autosuspended = 0;
867 atomic_dec(&chip->active); /* allow autopm after this point */
871 static int usb_audio_resume(struct usb_interface *intf)
873 return __usb_audio_resume(intf, false);
876 static int usb_audio_reset_resume(struct usb_interface *intf)
878 return __usb_audio_resume(intf, true);
881 #define usb_audio_suspend NULL
882 #define usb_audio_resume NULL
883 #define usb_audio_reset_resume NULL
884 #endif /* CONFIG_PM */
886 static const struct usb_device_id usb_audio_ids [] = {
887 #include "quirks-table.h"
888 { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
889 .bInterfaceClass = USB_CLASS_AUDIO,
890 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
891 { } /* Terminating entry */
893 MODULE_DEVICE_TABLE(usb, usb_audio_ids);
896 * entry point for linux usb interface
899 static struct usb_driver usb_audio_driver = {
900 .name = "snd-usb-audio",
901 .probe = usb_audio_probe,
902 .disconnect = usb_audio_disconnect,
903 .suspend = usb_audio_suspend,
904 .resume = usb_audio_resume,
905 .reset_resume = usb_audio_reset_resume,
906 .id_table = usb_audio_ids,
907 .supports_autosuspend = 1,
910 module_usb_driver(usb_audio_driver);