xref: /linux/sound/usb/card.c (revision 3b812ecce736432e6b55e77028ea387eb1517d24)
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  *   - the linked URBs would be preferred but not used so far because of
29  *     the instability of unlinking.
30  *   - type II is not supported properly.  there is no device which supports
31  *     this type *correctly*.  SB extigy looks as if it supports, but it's
32  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
33  */
34 
35 
36 #include <linux/bitops.h>
37 #include <linux/init.h>
38 #include <linux/list.h>
39 #include <linux/slab.h>
40 #include <linux/string.h>
41 #include <linux/ctype.h>
42 #include <linux/usb.h>
43 #include <linux/moduleparam.h>
44 #include <linux/mutex.h>
45 #include <linux/usb/audio.h>
46 #include <linux/usb/audio-v2.h>
47 #include <linux/module.h>
48 
49 #include <sound/control.h>
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 "format.h"
67 #include "power.h"
68 #include "stream.h"
69 #include "media.h"
70 
71 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
72 MODULE_DESCRIPTION("USB Audio");
73 MODULE_LICENSE("GPL");
74 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
75 
76 
77 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
78 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
79 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
80 /* Vendor/product IDs for this card */
81 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
82 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
83 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
84 static bool ignore_ctl_error;
85 static bool autoclock = true;
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_array(device_setup, int, NULL, 0444);
98 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
99 module_param(ignore_ctl_error, bool, 0444);
100 MODULE_PARM_DESC(ignore_ctl_error,
101 		 "Ignore errors from USB controller for mixer interfaces.");
102 module_param(autoclock, bool, 0444);
103 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
104 
105 /*
106  * we keep the snd_usb_audio_t instances by ourselves for merging
107  * the all interfaces on the same card as one sound device.
108  */
109 
110 static DEFINE_MUTEX(register_mutex);
111 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
112 static struct usb_driver usb_audio_driver;
113 
114 /*
115  * disconnect streams
116  * called from usb_audio_disconnect()
117  */
118 static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
119 {
120 	int idx;
121 	struct snd_usb_substream *subs;
122 
123 	for (idx = 0; idx < 2; idx++) {
124 		subs = &as->substream[idx];
125 		if (!subs->num_formats)
126 			continue;
127 		subs->interface = -1;
128 		subs->data_endpoint = NULL;
129 		subs->sync_endpoint = NULL;
130 	}
131 }
132 
133 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
134 {
135 	struct usb_device *dev = chip->dev;
136 	struct usb_host_interface *alts;
137 	struct usb_interface_descriptor *altsd;
138 	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
139 
140 	if (!iface) {
141 		dev_err(&dev->dev, "%u:%d : does not exist\n",
142 			ctrlif, interface);
143 		return -EINVAL;
144 	}
145 
146 	alts = &iface->altsetting[0];
147 	altsd = get_iface_desc(alts);
148 
149 	/*
150 	 * Android with both accessory and audio interfaces enabled gets the
151 	 * interface numbers wrong.
152 	 */
153 	if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
154 	     chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
155 	    interface == 0 &&
156 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
157 	    altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
158 		interface = 2;
159 		iface = usb_ifnum_to_if(dev, interface);
160 		if (!iface)
161 			return -EINVAL;
162 		alts = &iface->altsetting[0];
163 		altsd = get_iface_desc(alts);
164 	}
165 
166 	if (usb_interface_claimed(iface)) {
167 		dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
168 			ctrlif, interface);
169 		return -EINVAL;
170 	}
171 
172 	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
173 	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
174 	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
175 		int err = snd_usbmidi_create(chip->card, iface,
176 					     &chip->midi_list, NULL);
177 		if (err < 0) {
178 			dev_err(&dev->dev,
179 				"%u:%d: cannot create sequencer device\n",
180 				ctrlif, interface);
181 			return -EINVAL;
182 		}
183 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
184 
185 		return 0;
186 	}
187 
188 	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
189 	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
190 	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
191 		dev_dbg(&dev->dev,
192 			"%u:%d: skipping non-supported interface %d\n",
193 			ctrlif, interface, altsd->bInterfaceClass);
194 		/* skip non-supported classes */
195 		return -EINVAL;
196 	}
197 
198 	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
199 		dev_err(&dev->dev, "low speed audio streaming not supported\n");
200 		return -EINVAL;
201 	}
202 
203 	if (! snd_usb_parse_audio_interface(chip, interface)) {
204 		usb_set_interface(dev, interface, 0); /* reset the current interface */
205 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
206 		return -EINVAL;
207 	}
208 
209 	return 0;
210 }
211 
212 /*
213  * parse audio control descriptor and create pcm/midi streams
214  */
215 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
216 {
217 	struct usb_device *dev = chip->dev;
218 	struct usb_host_interface *host_iface;
219 	struct usb_interface_descriptor *altsd;
220 	void *control_header;
221 	int i, protocol;
222 
223 	/* find audiocontrol interface */
224 	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
225 	control_header = snd_usb_find_csint_desc(host_iface->extra,
226 						 host_iface->extralen,
227 						 NULL, UAC_HEADER);
228 	altsd = get_iface_desc(host_iface);
229 	protocol = altsd->bInterfaceProtocol;
230 
231 	if (!control_header) {
232 		dev_err(&dev->dev, "cannot find UAC_HEADER\n");
233 		return -EINVAL;
234 	}
235 
236 	switch (protocol) {
237 	default:
238 		dev_warn(&dev->dev,
239 			 "unknown interface protocol %#02x, assuming v1\n",
240 			 protocol);
241 		/* fall through */
242 
243 	case UAC_VERSION_1: {
244 		struct uac1_ac_header_descriptor *h1 = control_header;
245 
246 		if (!h1->bInCollection) {
247 			dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
248 			return -EINVAL;
249 		}
250 
251 		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
252 			dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
253 			return -EINVAL;
254 		}
255 
256 		for (i = 0; i < h1->bInCollection; i++)
257 			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
258 
259 		break;
260 	}
261 
262 	case UAC_VERSION_2: {
263 		struct usb_interface_assoc_descriptor *assoc =
264 			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
265 
266 		if (!assoc) {
267 			/*
268 			 * Firmware writers cannot count to three.  So to find
269 			 * the IAD on the NuForce UDH-100, also check the next
270 			 * interface.
271 			 */
272 			struct usb_interface *iface =
273 				usb_ifnum_to_if(dev, ctrlif + 1);
274 			if (iface &&
275 			    iface->intf_assoc &&
276 			    iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
277 			    iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
278 				assoc = iface->intf_assoc;
279 		}
280 
281 		if (!assoc) {
282 			dev_err(&dev->dev, "Audio class v2 interfaces need an interface association\n");
283 			return -EINVAL;
284 		}
285 
286 		for (i = 0; i < assoc->bInterfaceCount; i++) {
287 			int intf = assoc->bFirstInterface + i;
288 
289 			if (intf != ctrlif)
290 				snd_usb_create_stream(chip, ctrlif, intf);
291 		}
292 
293 		break;
294 	}
295 	}
296 
297 	return 0;
298 }
299 
300 /*
301  * free the chip instance
302  *
303  * here we have to do not much, since pcm and controls are already freed
304  *
305  */
306 
307 static int snd_usb_audio_free(struct snd_usb_audio *chip)
308 {
309 	struct snd_usb_endpoint *ep, *n;
310 
311 	list_for_each_entry_safe(ep, n, &chip->ep_list, list)
312 		snd_usb_endpoint_free(ep);
313 
314 	mutex_destroy(&chip->mutex);
315 	kfree(chip);
316 	return 0;
317 }
318 
319 static int snd_usb_audio_dev_free(struct snd_device *device)
320 {
321 	struct snd_usb_audio *chip = device->device_data;
322 	return snd_usb_audio_free(chip);
323 }
324 
325 /*
326  * create a chip instance and set its names.
327  */
328 static int snd_usb_audio_create(struct usb_interface *intf,
329 				struct usb_device *dev, int idx,
330 				const struct snd_usb_audio_quirk *quirk,
331 				struct snd_usb_audio **rchip)
332 {
333 	struct snd_card *card;
334 	struct snd_usb_audio *chip;
335 	int err, len;
336 	char component[14];
337 	static struct snd_device_ops ops = {
338 		.dev_free =	snd_usb_audio_dev_free,
339 	};
340 
341 	*rchip = NULL;
342 
343 	switch (snd_usb_get_speed(dev)) {
344 	case USB_SPEED_LOW:
345 	case USB_SPEED_FULL:
346 	case USB_SPEED_HIGH:
347 	case USB_SPEED_WIRELESS:
348 	case USB_SPEED_SUPER:
349 		break;
350 	default:
351 		dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
352 		return -ENXIO;
353 	}
354 
355 	err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
356 			   0, &card);
357 	if (err < 0) {
358 		dev_err(&dev->dev, "cannot create card instance %d\n", idx);
359 		return err;
360 	}
361 
362 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
363 	if (! chip) {
364 		snd_card_free(card);
365 		return -ENOMEM;
366 	}
367 
368 	mutex_init(&chip->mutex);
369 	init_waitqueue_head(&chip->shutdown_wait);
370 	chip->index = idx;
371 	chip->dev = dev;
372 	chip->card = card;
373 	chip->setup = device_setup[idx];
374 	chip->autoclock = autoclock;
375 	atomic_set(&chip->active, 1); /* avoid autopm during probing */
376 	atomic_set(&chip->usage_count, 0);
377 	atomic_set(&chip->shutdown, 0);
378 
379 	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
380 			      le16_to_cpu(dev->descriptor.idProduct));
381 	INIT_LIST_HEAD(&chip->pcm_list);
382 	INIT_LIST_HEAD(&chip->ep_list);
383 	INIT_LIST_HEAD(&chip->midi_list);
384 	INIT_LIST_HEAD(&chip->mixer_list);
385 
386 	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
387 		snd_usb_audio_free(chip);
388 		snd_card_free(card);
389 		return err;
390 	}
391 
392 	strcpy(card->driver, "USB-Audio");
393 	sprintf(component, "USB%04x:%04x",
394 		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
395 	snd_component_add(card, component);
396 
397 	/* retrieve the device string as shortname */
398 	if (quirk && quirk->product_name && *quirk->product_name) {
399 		strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
400 	} else {
401 		if (!dev->descriptor.iProduct ||
402 		    usb_string(dev, dev->descriptor.iProduct,
403 		    card->shortname, sizeof(card->shortname)) <= 0) {
404 			/* no name available from anywhere, so use ID */
405 			sprintf(card->shortname, "USB Device %#04x:%#04x",
406 				USB_ID_VENDOR(chip->usb_id),
407 				USB_ID_PRODUCT(chip->usb_id));
408 		}
409 	}
410 	strim(card->shortname);
411 
412 	/* retrieve the vendor and device strings as longname */
413 	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
414 		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
415 	} else {
416 		if (dev->descriptor.iManufacturer)
417 			len = usb_string(dev, dev->descriptor.iManufacturer,
418 					 card->longname, sizeof(card->longname));
419 		else
420 			len = 0;
421 		/* we don't really care if there isn't any vendor string */
422 	}
423 	if (len > 0) {
424 		strim(card->longname);
425 		if (*card->longname)
426 			strlcat(card->longname, " ", sizeof(card->longname));
427 	}
428 
429 	strlcat(card->longname, card->shortname, sizeof(card->longname));
430 
431 	len = strlcat(card->longname, " at ", sizeof(card->longname));
432 
433 	if (len < sizeof(card->longname))
434 		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
435 
436 	switch (snd_usb_get_speed(dev)) {
437 	case USB_SPEED_LOW:
438 		strlcat(card->longname, ", low speed", sizeof(card->longname));
439 		break;
440 	case USB_SPEED_FULL:
441 		strlcat(card->longname, ", full speed", sizeof(card->longname));
442 		break;
443 	case USB_SPEED_HIGH:
444 		strlcat(card->longname, ", high speed", sizeof(card->longname));
445 		break;
446 	case USB_SPEED_SUPER:
447 		strlcat(card->longname, ", super speed", sizeof(card->longname));
448 		break;
449 	default:
450 		break;
451 	}
452 
453 	snd_usb_audio_create_proc(chip);
454 
455 	*rchip = chip;
456 	return 0;
457 }
458 
459 /*
460  * probe the active usb device
461  *
462  * note that this can be called multiple times per a device, when it
463  * includes multiple audio control interfaces.
464  *
465  * thus we check the usb device pointer and creates the card instance
466  * only at the first time.  the successive calls of this function will
467  * append the pcm interface to the corresponding card.
468  */
469 static int usb_audio_probe(struct usb_interface *intf,
470 			   const struct usb_device_id *usb_id)
471 {
472 	struct usb_device *dev = interface_to_usbdev(intf);
473 	const struct snd_usb_audio_quirk *quirk =
474 		(const struct snd_usb_audio_quirk *)usb_id->driver_info;
475 	struct snd_usb_audio *chip;
476 	int i, err;
477 	struct usb_host_interface *alts;
478 	int ifnum;
479 	u32 id;
480 
481 	alts = &intf->altsetting[0];
482 	ifnum = get_iface_desc(alts)->bInterfaceNumber;
483 	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
484 		    le16_to_cpu(dev->descriptor.idProduct));
485 	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
486 		return -ENXIO;
487 
488 	err = snd_usb_apply_boot_quirk(dev, intf, quirk);
489 	if (err < 0)
490 		return err;
491 
492 	/*
493 	 * found a config.  now register to ALSA
494 	 */
495 
496 	/* check whether it's already registered */
497 	chip = NULL;
498 	mutex_lock(&register_mutex);
499 	for (i = 0; i < SNDRV_CARDS; i++) {
500 		if (usb_chip[i] && usb_chip[i]->dev == dev) {
501 			if (atomic_read(&usb_chip[i]->shutdown)) {
502 				dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
503 				err = -EIO;
504 				goto __error;
505 			}
506 			chip = usb_chip[i];
507 			atomic_inc(&chip->active); /* avoid autopm */
508 			break;
509 		}
510 	}
511 	if (! chip) {
512 		/* it's a fresh one.
513 		 * now look for an empty slot and create a new card instance
514 		 */
515 		for (i = 0; i < SNDRV_CARDS; i++)
516 			if (enable[i] && ! usb_chip[i] &&
517 			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
518 			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
519 				err = snd_usb_audio_create(intf, dev, i, quirk,
520 							   &chip);
521 				if (err < 0)
522 					goto __error;
523 				chip->pm_intf = intf;
524 				break;
525 			}
526 		if (!chip) {
527 			dev_err(&dev->dev, "no available usb audio device\n");
528 			err = -ENODEV;
529 			goto __error;
530 		}
531 	}
532 
533 	/*
534 	 * For devices with more than one control interface, we assume the
535 	 * first contains the audio controls. We might need a more specific
536 	 * check here in the future.
537 	 */
538 	if (!chip->ctrl_intf)
539 		chip->ctrl_intf = alts;
540 
541 	chip->txfr_quirk = 0;
542 	err = 1; /* continue */
543 	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
544 		/* need some special handlings */
545 		err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
546 		if (err < 0)
547 			goto __error;
548 	}
549 
550 	if (err > 0) {
551 		/* create normal USB audio interfaces */
552 		err = snd_usb_create_streams(chip, ifnum);
553 		if (err < 0)
554 			goto __error;
555 		err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
556 		if (err < 0)
557 			goto __error;
558 	}
559 
560 	/* we are allowed to call snd_card_register() many times */
561 	err = snd_card_register(chip->card);
562 	if (err < 0)
563 		goto __error;
564 
565 	if (quirk->media_device) {
566 		/* don't want to fail when media_snd_device_create() fails */
567 		media_snd_device_create(chip, intf);
568 	}
569 
570 	usb_chip[chip->index] = chip;
571 	chip->num_interfaces++;
572 	usb_set_intfdata(intf, chip);
573 	atomic_dec(&chip->active);
574 	mutex_unlock(&register_mutex);
575 	return 0;
576 
577  __error:
578 	if (chip) {
579 		if (!chip->num_interfaces)
580 			snd_card_free(chip->card);
581 		atomic_dec(&chip->active);
582 	}
583 	mutex_unlock(&register_mutex);
584 	return err;
585 }
586 
587 /*
588  * we need to take care of counter, since disconnection can be called also
589  * many times as well as usb_audio_probe().
590  */
591 static void usb_audio_disconnect(struct usb_interface *intf)
592 {
593 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
594 	struct snd_card *card;
595 	struct list_head *p;
596 
597 	if (chip == (void *)-1L)
598 		return;
599 
600 	card = chip->card;
601 
602 	mutex_lock(&register_mutex);
603 	if (atomic_inc_return(&chip->shutdown) == 1) {
604 		struct snd_usb_stream *as;
605 		struct snd_usb_endpoint *ep;
606 		struct usb_mixer_interface *mixer;
607 
608 		/* wait until all pending tasks done;
609 		 * they are protected by snd_usb_lock_shutdown()
610 		 */
611 		wait_event(chip->shutdown_wait,
612 			   !atomic_read(&chip->usage_count));
613 		snd_card_disconnect(card);
614 		/* release the pcm resources */
615 		list_for_each_entry(as, &chip->pcm_list, list) {
616 			snd_usb_stream_disconnect(as);
617 		}
618 		/* release the endpoint resources */
619 		list_for_each_entry(ep, &chip->ep_list, list) {
620 			snd_usb_endpoint_release(ep);
621 		}
622 		/* release the midi resources */
623 		list_for_each(p, &chip->midi_list) {
624 			snd_usbmidi_disconnect(p);
625 		}
626 		/*
627 		 * Nice to check quirk && quirk->media_device
628 		 * need some special handlings. Doesn't look like
629 		 * we have access to quirk here
630 		 * Acceses mixer_list
631 		*/
632 		media_snd_device_delete(chip);
633 
634 		/* release mixer resources */
635 		list_for_each_entry(mixer, &chip->mixer_list, list) {
636 			snd_usb_mixer_disconnect(mixer);
637 		}
638 	}
639 
640 	chip->num_interfaces--;
641 	if (chip->num_interfaces <= 0) {
642 		usb_chip[chip->index] = NULL;
643 		mutex_unlock(&register_mutex);
644 		snd_card_free_when_closed(card);
645 	} else {
646 		mutex_unlock(&register_mutex);
647 	}
648 }
649 
650 /* lock the shutdown (disconnect) task and autoresume */
651 int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
652 {
653 	int err;
654 
655 	atomic_inc(&chip->usage_count);
656 	if (atomic_read(&chip->shutdown)) {
657 		err = -EIO;
658 		goto error;
659 	}
660 	err = snd_usb_autoresume(chip);
661 	if (err < 0)
662 		goto error;
663 	return 0;
664 
665  error:
666 	if (atomic_dec_and_test(&chip->usage_count))
667 		wake_up(&chip->shutdown_wait);
668 	return err;
669 }
670 
671 /* autosuspend and unlock the shutdown */
672 void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
673 {
674 	snd_usb_autosuspend(chip);
675 	if (atomic_dec_and_test(&chip->usage_count))
676 		wake_up(&chip->shutdown_wait);
677 }
678 
679 #ifdef CONFIG_PM
680 
681 int snd_usb_autoresume(struct snd_usb_audio *chip)
682 {
683 	if (atomic_read(&chip->shutdown))
684 		return -EIO;
685 	if (atomic_inc_return(&chip->active) == 1)
686 		return usb_autopm_get_interface(chip->pm_intf);
687 	return 0;
688 }
689 
690 void snd_usb_autosuspend(struct snd_usb_audio *chip)
691 {
692 	if (atomic_read(&chip->shutdown))
693 		return;
694 	if (atomic_dec_and_test(&chip->active))
695 		usb_autopm_put_interface(chip->pm_intf);
696 }
697 
698 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
699 {
700 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
701 	struct snd_usb_stream *as;
702 	struct usb_mixer_interface *mixer;
703 	struct list_head *p;
704 
705 	if (chip == (void *)-1L)
706 		return 0;
707 
708 	chip->autosuspended = !!PMSG_IS_AUTO(message);
709 	if (!chip->autosuspended)
710 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
711 	if (!chip->num_suspended_intf++) {
712 		list_for_each_entry(as, &chip->pcm_list, list) {
713 			snd_pcm_suspend_all(as->pcm);
714 			as->substream[0].need_setup_ep =
715 				as->substream[1].need_setup_ep = true;
716 		}
717 		list_for_each(p, &chip->midi_list)
718 			snd_usbmidi_suspend(p);
719 		list_for_each_entry(mixer, &chip->mixer_list, list)
720 			snd_usb_mixer_suspend(mixer);
721 	}
722 
723 	return 0;
724 }
725 
726 static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
727 {
728 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
729 	struct usb_mixer_interface *mixer;
730 	struct list_head *p;
731 	int err = 0;
732 
733 	if (chip == (void *)-1L)
734 		return 0;
735 	if (--chip->num_suspended_intf)
736 		return 0;
737 
738 	atomic_inc(&chip->active); /* avoid autopm */
739 	/*
740 	 * ALSA leaves material resumption to user space
741 	 * we just notify and restart the mixers
742 	 */
743 	list_for_each_entry(mixer, &chip->mixer_list, list) {
744 		err = snd_usb_mixer_resume(mixer, reset_resume);
745 		if (err < 0)
746 			goto err_out;
747 	}
748 
749 	list_for_each(p, &chip->midi_list) {
750 		snd_usbmidi_resume(p);
751 	}
752 
753 	if (!chip->autosuspended)
754 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
755 	chip->autosuspended = 0;
756 
757 err_out:
758 	atomic_dec(&chip->active); /* allow autopm after this point */
759 	return err;
760 }
761 
762 static int usb_audio_resume(struct usb_interface *intf)
763 {
764 	return __usb_audio_resume(intf, false);
765 }
766 
767 static int usb_audio_reset_resume(struct usb_interface *intf)
768 {
769 	return __usb_audio_resume(intf, true);
770 }
771 #else
772 #define usb_audio_suspend	NULL
773 #define usb_audio_resume	NULL
774 #define usb_audio_reset_resume	NULL
775 #endif		/* CONFIG_PM */
776 
777 static struct usb_device_id usb_audio_ids [] = {
778 #include "quirks-table.h"
779     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
780       .bInterfaceClass = USB_CLASS_AUDIO,
781       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
782     { }						/* Terminating entry */
783 };
784 MODULE_DEVICE_TABLE(usb, usb_audio_ids);
785 
786 /*
787  * entry point for linux usb interface
788  */
789 
790 static struct usb_driver usb_audio_driver = {
791 	.name =		"snd-usb-audio",
792 	.probe =	usb_audio_probe,
793 	.disconnect =	usb_audio_disconnect,
794 	.suspend =	usb_audio_suspend,
795 	.resume =	usb_audio_resume,
796 	.reset_resume =	usb_audio_reset_resume,
797 	.id_table =	usb_audio_ids,
798 	.supports_autosuspend = 1,
799 };
800 
801 module_usb_driver(usb_audio_driver);
802