Merge tag 'asoc-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / sound / usb / card.c
blob561bb74fd364ae388cb8dc2af548e014b0bb801b
1 /*
2 * (Tentative) USB Audio Driver for ALSA
4 * Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
6 * Many codes borrowed from audio.c by
7 * Alan Cox (alan@lxorguk.ukuu.org.uk)
8 * Thomas Sailer (sailer@ife.ee.ethz.ch)
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.
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.
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
26 * NOTES:
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).
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/ctype.h>
45 #include <linux/usb.h>
46 #include <linux/moduleparam.h>
47 #include <linux/mutex.h>
48 #include <linux/usb/audio.h>
49 #include <linux/usb/audio-v2.h>
50 #include <linux/module.h>
52 #include <sound/control.h>
53 #include <sound/core.h>
54 #include <sound/info.h>
55 #include <sound/pcm.h>
56 #include <sound/pcm_params.h>
57 #include <sound/initval.h>
59 #include "usbaudio.h"
60 #include "card.h"
61 #include "midi.h"
62 #include "mixer.h"
63 #include "proc.h"
64 #include "quirks.h"
65 #include "endpoint.h"
66 #include "helper.h"
67 #include "debug.h"
68 #include "pcm.h"
69 #include "format.h"
70 #include "power.h"
71 #include "stream.h"
73 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
74 MODULE_DESCRIPTION("USB Audio");
75 MODULE_LICENSE("GPL");
76 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
79 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
80 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
81 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
82 /* Vendor/product IDs for this card */
83 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
84 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
85 static int nrpacks = 8; /* max. number of packets per urb */
86 static bool async_unlink = 1;
87 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
88 static bool ignore_ctl_error;
90 module_param_array(index, int, NULL, 0444);
91 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
92 module_param_array(id, charp, NULL, 0444);
93 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
94 module_param_array(enable, bool, NULL, 0444);
95 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
96 module_param_array(vid, int, NULL, 0444);
97 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
98 module_param_array(pid, int, NULL, 0444);
99 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
100 module_param(nrpacks, int, 0644);
101 MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
102 module_param(async_unlink, bool, 0444);
103 MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
104 module_param_array(device_setup, int, NULL, 0444);
105 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
106 module_param(ignore_ctl_error, bool, 0444);
107 MODULE_PARM_DESC(ignore_ctl_error,
108 "Ignore errors from USB controller for mixer interfaces.");
111 * we keep the snd_usb_audio_t instances by ourselves for merging
112 * the all interfaces on the same card as one sound device.
115 static DEFINE_MUTEX(register_mutex);
116 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
117 static struct usb_driver usb_audio_driver;
120 * disconnect streams
121 * called from snd_usb_audio_disconnect()
123 static void snd_usb_stream_disconnect(struct list_head *head)
125 int idx;
126 struct snd_usb_stream *as;
127 struct snd_usb_substream *subs;
129 as = list_entry(head, struct snd_usb_stream, list);
130 for (idx = 0; idx < 2; idx++) {
131 subs = &as->substream[idx];
132 if (!subs->num_formats)
133 continue;
134 subs->interface = -1;
135 subs->data_endpoint = NULL;
136 subs->sync_endpoint = NULL;
140 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
142 struct usb_device *dev = chip->dev;
143 struct usb_host_interface *alts;
144 struct usb_interface_descriptor *altsd;
145 struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
147 if (!iface) {
148 snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
149 dev->devnum, ctrlif, interface);
150 return -EINVAL;
153 if (usb_interface_claimed(iface)) {
154 snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
155 dev->devnum, ctrlif, interface);
156 return -EINVAL;
159 alts = &iface->altsetting[0];
160 altsd = get_iface_desc(alts);
161 if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
162 altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
163 altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
164 int err = snd_usbmidi_create(chip->card, iface,
165 &chip->midi_list, NULL);
166 if (err < 0) {
167 snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
168 dev->devnum, ctrlif, interface);
169 return -EINVAL;
171 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
173 return 0;
176 if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
177 altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
178 altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
179 snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
180 dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
181 /* skip non-supported classes */
182 return -EINVAL;
185 if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
186 snd_printk(KERN_ERR "low speed audio streaming not supported\n");
187 return -EINVAL;
190 if (! snd_usb_parse_audio_interface(chip, interface)) {
191 usb_set_interface(dev, interface, 0); /* reset the current interface */
192 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
193 return -EINVAL;
196 return 0;
200 * parse audio control descriptor and create pcm/midi streams
202 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
204 struct usb_device *dev = chip->dev;
205 struct usb_host_interface *host_iface;
206 struct usb_interface_descriptor *altsd;
207 void *control_header;
208 int i, protocol;
210 /* find audiocontrol interface */
211 host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
212 control_header = snd_usb_find_csint_desc(host_iface->extra,
213 host_iface->extralen,
214 NULL, UAC_HEADER);
215 altsd = get_iface_desc(host_iface);
216 protocol = altsd->bInterfaceProtocol;
218 if (!control_header) {
219 snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
220 return -EINVAL;
223 switch (protocol) {
224 default:
225 snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
226 protocol);
227 /* fall through */
229 case UAC_VERSION_1: {
230 struct uac1_ac_header_descriptor *h1 = control_header;
232 if (!h1->bInCollection) {
233 snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
234 return -EINVAL;
237 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
238 snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
239 return -EINVAL;
242 for (i = 0; i < h1->bInCollection; i++)
243 snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
245 break;
248 case UAC_VERSION_2: {
249 struct usb_interface_assoc_descriptor *assoc =
250 usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
252 if (!assoc) {
253 snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
254 return -EINVAL;
257 for (i = 0; i < assoc->bInterfaceCount; i++) {
258 int intf = assoc->bFirstInterface + i;
260 if (intf != ctrlif)
261 snd_usb_create_stream(chip, ctrlif, intf);
264 break;
268 return 0;
272 * free the chip instance
274 * here we have to do not much, since pcm and controls are already freed
278 static int snd_usb_audio_free(struct snd_usb_audio *chip)
280 mutex_destroy(&chip->mutex);
281 kfree(chip);
282 return 0;
285 static int snd_usb_audio_dev_free(struct snd_device *device)
287 struct snd_usb_audio *chip = device->device_data;
288 return snd_usb_audio_free(chip);
291 static void remove_trailing_spaces(char *str)
293 char *p;
295 if (!*str)
296 return;
297 for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
298 *p = 0;
302 * create a chip instance and set its names.
304 static int snd_usb_audio_create(struct usb_device *dev, int idx,
305 const struct snd_usb_audio_quirk *quirk,
306 struct snd_usb_audio **rchip)
308 struct snd_card *card;
309 struct snd_usb_audio *chip;
310 int err, len;
311 char component[14];
312 static struct snd_device_ops ops = {
313 .dev_free = snd_usb_audio_dev_free,
316 *rchip = NULL;
318 switch (snd_usb_get_speed(dev)) {
319 case USB_SPEED_LOW:
320 case USB_SPEED_FULL:
321 case USB_SPEED_HIGH:
322 case USB_SPEED_SUPER:
323 break;
324 default:
325 snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
326 return -ENXIO;
329 err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
330 if (err < 0) {
331 snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
332 return err;
335 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
336 if (! chip) {
337 snd_card_free(card);
338 return -ENOMEM;
341 mutex_init(&chip->mutex);
342 mutex_init(&chip->shutdown_mutex);
343 chip->index = idx;
344 chip->dev = dev;
345 chip->card = card;
346 chip->setup = device_setup[idx];
347 chip->nrpacks = nrpacks;
348 chip->async_unlink = async_unlink;
349 chip->probing = 1;
351 chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
352 le16_to_cpu(dev->descriptor.idProduct));
353 INIT_LIST_HEAD(&chip->pcm_list);
354 INIT_LIST_HEAD(&chip->ep_list);
355 INIT_LIST_HEAD(&chip->midi_list);
356 INIT_LIST_HEAD(&chip->mixer_list);
358 if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
359 snd_usb_audio_free(chip);
360 snd_card_free(card);
361 return err;
364 strcpy(card->driver, "USB-Audio");
365 sprintf(component, "USB%04x:%04x",
366 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
367 snd_component_add(card, component);
369 /* retrieve the device string as shortname */
370 if (quirk && quirk->product_name && *quirk->product_name) {
371 strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
372 } else {
373 if (!dev->descriptor.iProduct ||
374 usb_string(dev, dev->descriptor.iProduct,
375 card->shortname, sizeof(card->shortname)) <= 0) {
376 /* no name available from anywhere, so use ID */
377 sprintf(card->shortname, "USB Device %#04x:%#04x",
378 USB_ID_VENDOR(chip->usb_id),
379 USB_ID_PRODUCT(chip->usb_id));
382 remove_trailing_spaces(card->shortname);
384 /* retrieve the vendor and device strings as longname */
385 if (quirk && quirk->vendor_name && *quirk->vendor_name) {
386 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
387 } else {
388 if (dev->descriptor.iManufacturer)
389 len = usb_string(dev, dev->descriptor.iManufacturer,
390 card->longname, sizeof(card->longname));
391 else
392 len = 0;
393 /* we don't really care if there isn't any vendor string */
395 if (len > 0) {
396 remove_trailing_spaces(card->longname);
397 if (*card->longname)
398 strlcat(card->longname, " ", sizeof(card->longname));
401 strlcat(card->longname, card->shortname, sizeof(card->longname));
403 len = strlcat(card->longname, " at ", sizeof(card->longname));
405 if (len < sizeof(card->longname))
406 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
408 switch (snd_usb_get_speed(dev)) {
409 case USB_SPEED_LOW:
410 strlcat(card->longname, ", low speed", sizeof(card->longname));
411 break;
412 case USB_SPEED_FULL:
413 strlcat(card->longname, ", full speed", sizeof(card->longname));
414 break;
415 case USB_SPEED_HIGH:
416 strlcat(card->longname, ", high speed", sizeof(card->longname));
417 break;
418 case USB_SPEED_SUPER:
419 strlcat(card->longname, ", super speed", sizeof(card->longname));
420 break;
421 default:
422 break;
425 snd_usb_audio_create_proc(chip);
427 *rchip = chip;
428 return 0;
432 * probe the active usb device
434 * note that this can be called multiple times per a device, when it
435 * includes multiple audio control interfaces.
437 * thus we check the usb device pointer and creates the card instance
438 * only at the first time. the successive calls of this function will
439 * append the pcm interface to the corresponding card.
441 static struct snd_usb_audio *
442 snd_usb_audio_probe(struct usb_device *dev,
443 struct usb_interface *intf,
444 const struct usb_device_id *usb_id)
446 const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
447 int i, err;
448 struct snd_usb_audio *chip;
449 struct usb_host_interface *alts;
450 int ifnum;
451 u32 id;
453 alts = &intf->altsetting[0];
454 ifnum = get_iface_desc(alts)->bInterfaceNumber;
455 id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
456 le16_to_cpu(dev->descriptor.idProduct));
457 if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
458 goto __err_val;
460 if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
461 goto __err_val;
464 * found a config. now register to ALSA
467 /* check whether it's already registered */
468 chip = NULL;
469 mutex_lock(&register_mutex);
470 for (i = 0; i < SNDRV_CARDS; i++) {
471 if (usb_chip[i] && usb_chip[i]->dev == dev) {
472 if (usb_chip[i]->shutdown) {
473 snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
474 goto __error;
476 chip = usb_chip[i];
477 chip->probing = 1;
478 break;
481 if (! chip) {
482 /* it's a fresh one.
483 * now look for an empty slot and create a new card instance
485 for (i = 0; i < SNDRV_CARDS; i++)
486 if (enable[i] && ! usb_chip[i] &&
487 (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
488 (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
489 if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
490 goto __error;
492 snd_card_set_dev(chip->card, &intf->dev);
493 chip->pm_intf = intf;
494 break;
496 if (!chip) {
497 printk(KERN_ERR "no available usb audio device\n");
498 goto __error;
503 * For devices with more than one control interface, we assume the
504 * first contains the audio controls. We might need a more specific
505 * check here in the future.
507 if (!chip->ctrl_intf)
508 chip->ctrl_intf = alts;
510 chip->txfr_quirk = 0;
511 err = 1; /* continue */
512 if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
513 /* need some special handlings */
514 if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
515 goto __error;
518 if (err > 0) {
519 /* create normal USB audio interfaces */
520 if (snd_usb_create_streams(chip, ifnum) < 0 ||
521 snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
522 goto __error;
526 /* we are allowed to call snd_card_register() many times */
527 if (snd_card_register(chip->card) < 0) {
528 goto __error;
531 usb_chip[chip->index] = chip;
532 chip->num_interfaces++;
533 chip->probing = 0;
534 mutex_unlock(&register_mutex);
535 return chip;
537 __error:
538 if (chip) {
539 if (!chip->num_interfaces)
540 snd_card_free(chip->card);
541 chip->probing = 0;
543 mutex_unlock(&register_mutex);
544 __err_val:
545 return NULL;
549 * we need to take care of counter, since disconnection can be called also
550 * many times as well as usb_audio_probe().
552 static void snd_usb_audio_disconnect(struct usb_device *dev,
553 struct snd_usb_audio *chip)
555 struct snd_card *card;
556 struct list_head *p, *n;
558 if (chip == (void *)-1L)
559 return;
561 card = chip->card;
562 mutex_lock(&register_mutex);
563 mutex_lock(&chip->shutdown_mutex);
564 chip->shutdown = 1;
565 chip->num_interfaces--;
566 if (chip->num_interfaces <= 0) {
567 snd_card_disconnect(card);
568 /* release the pcm resources */
569 list_for_each(p, &chip->pcm_list) {
570 snd_usb_stream_disconnect(p);
572 /* release the endpoint resources */
573 list_for_each_safe(p, n, &chip->ep_list) {
574 snd_usb_endpoint_free(p);
576 /* release the midi resources */
577 list_for_each(p, &chip->midi_list) {
578 snd_usbmidi_disconnect(p);
580 /* release mixer resources */
581 list_for_each(p, &chip->mixer_list) {
582 snd_usb_mixer_disconnect(p);
584 usb_chip[chip->index] = NULL;
585 mutex_unlock(&chip->shutdown_mutex);
586 mutex_unlock(&register_mutex);
587 snd_card_free_when_closed(card);
588 } else {
589 mutex_unlock(&chip->shutdown_mutex);
590 mutex_unlock(&register_mutex);
595 * new 2.5 USB kernel API
597 static int usb_audio_probe(struct usb_interface *intf,
598 const struct usb_device_id *id)
600 struct snd_usb_audio *chip;
601 chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
602 if (chip) {
603 usb_set_intfdata(intf, chip);
604 return 0;
605 } else
606 return -EIO;
609 static void usb_audio_disconnect(struct usb_interface *intf)
611 snd_usb_audio_disconnect(interface_to_usbdev(intf),
612 usb_get_intfdata(intf));
615 #ifdef CONFIG_PM
617 int snd_usb_autoresume(struct snd_usb_audio *chip)
619 int err = -ENODEV;
621 if (!chip->shutdown && !chip->probing)
622 err = usb_autopm_get_interface(chip->pm_intf);
624 return err;
627 void snd_usb_autosuspend(struct snd_usb_audio *chip)
629 if (!chip->shutdown && !chip->probing)
630 usb_autopm_put_interface(chip->pm_intf);
633 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
635 struct snd_usb_audio *chip = usb_get_intfdata(intf);
636 struct list_head *p;
637 struct snd_usb_stream *as;
638 struct usb_mixer_interface *mixer;
640 if (chip == (void *)-1L)
641 return 0;
643 if (!PMSG_IS_AUTO(message)) {
644 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
645 if (!chip->num_suspended_intf++) {
646 list_for_each(p, &chip->pcm_list) {
647 as = list_entry(p, struct snd_usb_stream, list);
648 snd_pcm_suspend_all(as->pcm);
649 as->substream[0].need_setup_ep =
650 as->substream[1].need_setup_ep = true;
653 } else {
655 * otherwise we keep the rest of the system in the dark
656 * to keep this transparent
658 if (!chip->num_suspended_intf++)
659 chip->autosuspended = 1;
662 list_for_each_entry(mixer, &chip->mixer_list, list)
663 snd_usb_mixer_inactivate(mixer);
665 return 0;
668 static int usb_audio_resume(struct usb_interface *intf)
670 struct snd_usb_audio *chip = usb_get_intfdata(intf);
671 struct usb_mixer_interface *mixer;
672 int err = 0;
674 if (chip == (void *)-1L)
675 return 0;
676 if (--chip->num_suspended_intf)
677 return 0;
679 * ALSA leaves material resumption to user space
680 * we just notify and restart the mixers
682 list_for_each_entry(mixer, &chip->mixer_list, list) {
683 err = snd_usb_mixer_activate(mixer);
684 if (err < 0)
685 goto err_out;
688 if (!chip->autosuspended)
689 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
690 chip->autosuspended = 0;
692 err_out:
693 return err;
695 #else
696 #define usb_audio_suspend NULL
697 #define usb_audio_resume NULL
698 #endif /* CONFIG_PM */
700 static struct usb_device_id usb_audio_ids [] = {
701 #include "quirks-table.h"
702 { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
703 .bInterfaceClass = USB_CLASS_AUDIO,
704 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
705 { } /* Terminating entry */
708 MODULE_DEVICE_TABLE (usb, usb_audio_ids);
711 * entry point for linux usb interface
714 static struct usb_driver usb_audio_driver = {
715 .name = "snd-usb-audio",
716 .probe = usb_audio_probe,
717 .disconnect = usb_audio_disconnect,
718 .suspend = usb_audio_suspend,
719 .resume = usb_audio_resume,
720 .id_table = usb_audio_ids,
721 .supports_autosuspend = 1,
724 static int __init snd_usb_audio_init(void)
726 if (nrpacks < 1 || nrpacks > MAX_PACKS) {
727 printk(KERN_WARNING "invalid nrpacks value.\n");
728 return -EINVAL;
730 return usb_register(&usb_audio_driver);
733 static void __exit snd_usb_audio_cleanup(void)
735 usb_deregister(&usb_audio_driver);
738 module_init(snd_usb_audio_init);
739 module_exit(snd_usb_audio_cleanup);