xref: /linux/sound/usb/stream.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/usb.h>
9 #include <linux/usb/audio.h>
10 #include <linux/usb/audio-v2.h>
11 #include <linux/usb/audio-v3.h>
12 
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/control.h>
16 #include <sound/tlv.h>
17 
18 #include "usbaudio.h"
19 #include "card.h"
20 #include "proc.h"
21 #include "quirks.h"
22 #include "endpoint.h"
23 #include "pcm.h"
24 #include "helper.h"
25 #include "format.h"
26 #include "clock.h"
27 #include "stream.h"
28 #include "power.h"
29 #include "media.h"
30 
31 static void audioformat_free(struct audioformat *fp)
32 {
33 	list_del(&fp->list); /* unlink for avoiding double-free */
34 	kfree(fp->rate_table);
35 	kfree(fp->chmap);
36 	kfree(fp);
37 }
38 
39 /*
40  * free a substream
41  */
42 static void free_substream(struct snd_usb_substream *subs)
43 {
44 	struct audioformat *fp, *n;
45 
46 	if (!subs->num_formats)
47 		return; /* not initialized */
48 	list_for_each_entry_safe(fp, n, &subs->fmt_list, list)
49 		audioformat_free(fp);
50 	kfree(subs->str_pd);
51 	snd_media_stream_delete(subs);
52 }
53 
54 
55 /*
56  * free a usb stream instance
57  */
58 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
59 {
60 	free_substream(&stream->substream[0]);
61 	free_substream(&stream->substream[1]);
62 	list_del(&stream->list);
63 	kfree(stream);
64 }
65 
66 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
67 {
68 	struct snd_usb_stream *stream = pcm->private_data;
69 	if (stream) {
70 		stream->pcm = NULL;
71 		snd_usb_audio_stream_free(stream);
72 	}
73 }
74 
75 /*
76  * initialize the substream instance.
77  */
78 
79 static void snd_usb_init_substream(struct snd_usb_stream *as,
80 				   int stream,
81 				   struct audioformat *fp,
82 				   struct snd_usb_power_domain *pd)
83 {
84 	struct snd_usb_substream *subs = &as->substream[stream];
85 
86 	INIT_LIST_HEAD(&subs->fmt_list);
87 	spin_lock_init(&subs->lock);
88 
89 	subs->stream = as;
90 	subs->direction = stream;
91 	subs->dev = as->chip->dev;
92 	subs->txfr_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_ALIGN_TRANSFER);
93 	subs->tx_length_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_TX_LENGTH);
94 	subs->speed = snd_usb_get_speed(subs->dev);
95 	subs->pkt_offset_adj = 0;
96 	subs->stream_offset_adj = 0;
97 
98 	snd_usb_set_pcm_ops(as->pcm, stream);
99 
100 	list_add_tail(&fp->list, &subs->fmt_list);
101 	subs->formats |= fp->formats;
102 	subs->num_formats++;
103 	subs->fmt_type = fp->fmt_type;
104 	subs->ep_num = fp->endpoint;
105 	if (fp->channels > subs->channels_max)
106 		subs->channels_max = fp->channels;
107 
108 	if (pd) {
109 		subs->str_pd = pd;
110 		/* Initialize Power Domain to idle status D1 */
111 		snd_usb_power_domain_set(subs->stream->chip, pd,
112 					 UAC3_PD_STATE_D1);
113 	}
114 
115 	snd_usb_preallocate_buffer(subs);
116 }
117 
118 /* kctl callbacks for usb-audio channel maps */
119 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
120 			      struct snd_ctl_elem_info *uinfo)
121 {
122 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
123 	struct snd_usb_substream *subs = info->private_data;
124 
125 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
126 	uinfo->count = subs->channels_max;
127 	uinfo->value.integer.min = 0;
128 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
129 	return 0;
130 }
131 
132 /* check whether a duplicated entry exists in the audiofmt list */
133 static bool have_dup_chmap(struct snd_usb_substream *subs,
134 			   struct audioformat *fp)
135 {
136 	struct audioformat *prev = fp;
137 
138 	list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
139 		if (prev->chmap &&
140 		    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
141 			return true;
142 	}
143 	return false;
144 }
145 
146 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
147 			     unsigned int size, unsigned int __user *tlv)
148 {
149 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
150 	struct snd_usb_substream *subs = info->private_data;
151 	struct audioformat *fp;
152 	unsigned int __user *dst;
153 	int count = 0;
154 
155 	if (size < 8)
156 		return -ENOMEM;
157 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
158 		return -EFAULT;
159 	size -= 8;
160 	dst = tlv + 2;
161 	list_for_each_entry(fp, &subs->fmt_list, list) {
162 		int i, ch_bytes;
163 
164 		if (!fp->chmap)
165 			continue;
166 		if (have_dup_chmap(subs, fp))
167 			continue;
168 		/* copy the entry */
169 		ch_bytes = fp->chmap->channels * 4;
170 		if (size < 8 + ch_bytes)
171 			return -ENOMEM;
172 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
173 		    put_user(ch_bytes, dst + 1))
174 			return -EFAULT;
175 		dst += 2;
176 		for (i = 0; i < fp->chmap->channels; i++, dst++) {
177 			if (put_user(fp->chmap->map[i], dst))
178 				return -EFAULT;
179 		}
180 
181 		count += 8 + ch_bytes;
182 		size -= 8 + ch_bytes;
183 	}
184 	if (put_user(count, tlv + 1))
185 		return -EFAULT;
186 	return 0;
187 }
188 
189 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
190 			     struct snd_ctl_elem_value *ucontrol)
191 {
192 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
193 	struct snd_usb_substream *subs = info->private_data;
194 	struct snd_pcm_chmap_elem *chmap = NULL;
195 	int i = 0;
196 
197 	if (subs->cur_audiofmt)
198 		chmap = subs->cur_audiofmt->chmap;
199 	if (chmap) {
200 		for (i = 0; i < chmap->channels; i++)
201 			ucontrol->value.integer.value[i] = chmap->map[i];
202 	}
203 	for (; i < subs->channels_max; i++)
204 		ucontrol->value.integer.value[i] = 0;
205 	return 0;
206 }
207 
208 /* create a chmap kctl assigned to the given USB substream */
209 static int add_chmap(struct snd_pcm *pcm, int stream,
210 		     struct snd_usb_substream *subs)
211 {
212 	struct audioformat *fp;
213 	struct snd_pcm_chmap *chmap;
214 	struct snd_kcontrol *kctl;
215 	int err;
216 
217 	list_for_each_entry(fp, &subs->fmt_list, list)
218 		if (fp->chmap)
219 			goto ok;
220 	/* no chmap is found */
221 	return 0;
222 
223  ok:
224 	err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
225 	if (err < 0)
226 		return err;
227 
228 	/* override handlers */
229 	chmap->private_data = subs;
230 	kctl = chmap->kctl;
231 	kctl->info = usb_chmap_ctl_info;
232 	kctl->get = usb_chmap_ctl_get;
233 	kctl->tlv.c = usb_chmap_ctl_tlv;
234 
235 	return 0;
236 }
237 
238 /* convert from USB ChannelConfig bits to ALSA chmap element */
239 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
240 						int protocol)
241 {
242 	static const unsigned int uac1_maps[] = {
243 		SNDRV_CHMAP_FL,		/* left front */
244 		SNDRV_CHMAP_FR,		/* right front */
245 		SNDRV_CHMAP_FC,		/* center front */
246 		SNDRV_CHMAP_LFE,	/* LFE */
247 		SNDRV_CHMAP_SL,		/* left surround */
248 		SNDRV_CHMAP_SR,		/* right surround */
249 		SNDRV_CHMAP_FLC,	/* left of center */
250 		SNDRV_CHMAP_FRC,	/* right of center */
251 		SNDRV_CHMAP_RC,		/* surround */
252 		SNDRV_CHMAP_SL,		/* side left */
253 		SNDRV_CHMAP_SR,		/* side right */
254 		SNDRV_CHMAP_TC,		/* top */
255 		0 /* terminator */
256 	};
257 	static const unsigned int uac2_maps[] = {
258 		SNDRV_CHMAP_FL,		/* front left */
259 		SNDRV_CHMAP_FR,		/* front right */
260 		SNDRV_CHMAP_FC,		/* front center */
261 		SNDRV_CHMAP_LFE,	/* LFE */
262 		SNDRV_CHMAP_RL,		/* back left */
263 		SNDRV_CHMAP_RR,		/* back right */
264 		SNDRV_CHMAP_FLC,	/* front left of center */
265 		SNDRV_CHMAP_FRC,	/* front right of center */
266 		SNDRV_CHMAP_RC,		/* back center */
267 		SNDRV_CHMAP_SL,		/* side left */
268 		SNDRV_CHMAP_SR,		/* side right */
269 		SNDRV_CHMAP_TC,		/* top center */
270 		SNDRV_CHMAP_TFL,	/* top front left */
271 		SNDRV_CHMAP_TFC,	/* top front center */
272 		SNDRV_CHMAP_TFR,	/* top front right */
273 		SNDRV_CHMAP_TRL,	/* top back left */
274 		SNDRV_CHMAP_TRC,	/* top back center */
275 		SNDRV_CHMAP_TRR,	/* top back right */
276 		SNDRV_CHMAP_TFLC,	/* top front left of center */
277 		SNDRV_CHMAP_TFRC,	/* top front right of center */
278 		SNDRV_CHMAP_LLFE,	/* left LFE */
279 		SNDRV_CHMAP_RLFE,	/* right LFE */
280 		SNDRV_CHMAP_TSL,	/* top side left */
281 		SNDRV_CHMAP_TSR,	/* top side right */
282 		SNDRV_CHMAP_BC,		/* bottom center */
283 		SNDRV_CHMAP_RLC,	/* back left of center */
284 		SNDRV_CHMAP_RRC,	/* back right of center */
285 		0 /* terminator */
286 	};
287 	struct snd_pcm_chmap_elem *chmap;
288 	const unsigned int *maps;
289 	int c;
290 
291 	if (channels > ARRAY_SIZE(chmap->map))
292 		return NULL;
293 
294 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
295 	if (!chmap)
296 		return NULL;
297 
298 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
299 	chmap->channels = channels;
300 	c = 0;
301 
302 	if (bits) {
303 		for (; bits && *maps; maps++, bits >>= 1) {
304 			if (bits & 1)
305 				chmap->map[c++] = *maps;
306 			if (c == chmap->channels)
307 				break;
308 		}
309 	} else {
310 		/* If we're missing wChannelConfig, then guess something
311 		    to make sure the channel map is not skipped entirely */
312 		if (channels == 1)
313 			chmap->map[c++] = SNDRV_CHMAP_MONO;
314 		else
315 			for (; c < channels && *maps; maps++)
316 				chmap->map[c++] = *maps;
317 	}
318 
319 	for (; c < channels; c++)
320 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
321 
322 	return chmap;
323 }
324 
325 /* UAC3 device stores channels information in Cluster Descriptors */
326 static struct
327 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
328 								*cluster)
329 {
330 	unsigned int channels = cluster->bNrChannels;
331 	struct snd_pcm_chmap_elem *chmap;
332 	void *p = cluster;
333 	int len, c;
334 
335 	if (channels > ARRAY_SIZE(chmap->map))
336 		return NULL;
337 
338 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
339 	if (!chmap)
340 		return NULL;
341 
342 	len = le16_to_cpu(cluster->wLength);
343 	c = 0;
344 	p += sizeof(struct uac3_cluster_header_descriptor);
345 
346 	while (((p - (void *)cluster) < len) && (c < channels)) {
347 		struct uac3_cluster_segment_descriptor *cs_desc = p;
348 		u16 cs_len;
349 		u8 cs_type;
350 
351 		cs_len = le16_to_cpu(cs_desc->wLength);
352 		cs_type = cs_desc->bSegmentType;
353 
354 		if (cs_type == UAC3_CHANNEL_INFORMATION) {
355 			struct uac3_cluster_information_segment_descriptor *is = p;
356 			unsigned char map;
357 
358 			/*
359 			 * TODO: this conversion is not complete, update it
360 			 * after adding UAC3 values to asound.h
361 			 */
362 			switch (is->bChRelationship) {
363 			case UAC3_CH_MONO:
364 				map = SNDRV_CHMAP_MONO;
365 				break;
366 			case UAC3_CH_LEFT:
367 			case UAC3_CH_FRONT_LEFT:
368 			case UAC3_CH_HEADPHONE_LEFT:
369 				map = SNDRV_CHMAP_FL;
370 				break;
371 			case UAC3_CH_RIGHT:
372 			case UAC3_CH_FRONT_RIGHT:
373 			case UAC3_CH_HEADPHONE_RIGHT:
374 				map = SNDRV_CHMAP_FR;
375 				break;
376 			case UAC3_CH_FRONT_CENTER:
377 				map = SNDRV_CHMAP_FC;
378 				break;
379 			case UAC3_CH_FRONT_LEFT_OF_CENTER:
380 				map = SNDRV_CHMAP_FLC;
381 				break;
382 			case UAC3_CH_FRONT_RIGHT_OF_CENTER:
383 				map = SNDRV_CHMAP_FRC;
384 				break;
385 			case UAC3_CH_SIDE_LEFT:
386 				map = SNDRV_CHMAP_SL;
387 				break;
388 			case UAC3_CH_SIDE_RIGHT:
389 				map = SNDRV_CHMAP_SR;
390 				break;
391 			case UAC3_CH_BACK_LEFT:
392 				map = SNDRV_CHMAP_RL;
393 				break;
394 			case UAC3_CH_BACK_RIGHT:
395 				map = SNDRV_CHMAP_RR;
396 				break;
397 			case UAC3_CH_BACK_CENTER:
398 				map = SNDRV_CHMAP_RC;
399 				break;
400 			case UAC3_CH_BACK_LEFT_OF_CENTER:
401 				map = SNDRV_CHMAP_RLC;
402 				break;
403 			case UAC3_CH_BACK_RIGHT_OF_CENTER:
404 				map = SNDRV_CHMAP_RRC;
405 				break;
406 			case UAC3_CH_TOP_CENTER:
407 				map = SNDRV_CHMAP_TC;
408 				break;
409 			case UAC3_CH_TOP_FRONT_LEFT:
410 				map = SNDRV_CHMAP_TFL;
411 				break;
412 			case UAC3_CH_TOP_FRONT_RIGHT:
413 				map = SNDRV_CHMAP_TFR;
414 				break;
415 			case UAC3_CH_TOP_FRONT_CENTER:
416 				map = SNDRV_CHMAP_TFC;
417 				break;
418 			case UAC3_CH_TOP_FRONT_LOC:
419 				map = SNDRV_CHMAP_TFLC;
420 				break;
421 			case UAC3_CH_TOP_FRONT_ROC:
422 				map = SNDRV_CHMAP_TFRC;
423 				break;
424 			case UAC3_CH_TOP_SIDE_LEFT:
425 				map = SNDRV_CHMAP_TSL;
426 				break;
427 			case UAC3_CH_TOP_SIDE_RIGHT:
428 				map = SNDRV_CHMAP_TSR;
429 				break;
430 			case UAC3_CH_TOP_BACK_LEFT:
431 				map = SNDRV_CHMAP_TRL;
432 				break;
433 			case UAC3_CH_TOP_BACK_RIGHT:
434 				map = SNDRV_CHMAP_TRR;
435 				break;
436 			case UAC3_CH_TOP_BACK_CENTER:
437 				map = SNDRV_CHMAP_TRC;
438 				break;
439 			case UAC3_CH_BOTTOM_CENTER:
440 				map = SNDRV_CHMAP_BC;
441 				break;
442 			case UAC3_CH_LOW_FREQUENCY_EFFECTS:
443 				map = SNDRV_CHMAP_LFE;
444 				break;
445 			case UAC3_CH_LFE_LEFT:
446 				map = SNDRV_CHMAP_LLFE;
447 				break;
448 			case UAC3_CH_LFE_RIGHT:
449 				map = SNDRV_CHMAP_RLFE;
450 				break;
451 			case UAC3_CH_RELATIONSHIP_UNDEFINED:
452 			default:
453 				map = SNDRV_CHMAP_UNKNOWN;
454 				break;
455 			}
456 			chmap->map[c++] = map;
457 		}
458 		p += cs_len;
459 	}
460 
461 	if (channels < c)
462 		pr_err("%s: channel number mismatch\n", __func__);
463 
464 	chmap->channels = channels;
465 
466 	for (; c < channels; c++)
467 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
468 
469 	return chmap;
470 }
471 
472 /*
473  * add this endpoint to the chip instance.
474  * if a stream with the same endpoint already exists, append to it.
475  * if not, create a new pcm stream. note, fp is added to the substream
476  * fmt_list and will be freed on the chip instance release. do not free
477  * fp or do remove it from the substream fmt_list to avoid double-free.
478  */
479 static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
480 				      int stream,
481 				      struct audioformat *fp,
482 				      struct snd_usb_power_domain *pd)
483 
484 {
485 	struct snd_usb_stream *as;
486 	struct snd_usb_substream *subs;
487 	struct snd_pcm *pcm;
488 	int err;
489 
490 	list_for_each_entry(as, &chip->pcm_list, list) {
491 		if (as->fmt_type != fp->fmt_type)
492 			continue;
493 		subs = &as->substream[stream];
494 		if (subs->ep_num == fp->endpoint) {
495 			list_add_tail(&fp->list, &subs->fmt_list);
496 			subs->num_formats++;
497 			subs->formats |= fp->formats;
498 			return 0;
499 		}
500 	}
501 
502 	if (chip->card->registered)
503 		chip->need_delayed_register = true;
504 
505 	/* look for an empty stream */
506 	list_for_each_entry(as, &chip->pcm_list, list) {
507 		if (as->fmt_type != fp->fmt_type)
508 			continue;
509 		subs = &as->substream[stream];
510 		if (subs->ep_num)
511 			continue;
512 		err = snd_pcm_new_stream(as->pcm, stream, 1);
513 		if (err < 0)
514 			return err;
515 		snd_usb_init_substream(as, stream, fp, pd);
516 		return add_chmap(as->pcm, stream, subs);
517 	}
518 
519 	/* create a new pcm */
520 	as = kzalloc(sizeof(*as), GFP_KERNEL);
521 	if (!as)
522 		return -ENOMEM;
523 	as->pcm_index = chip->pcm_devs;
524 	as->chip = chip;
525 	as->fmt_type = fp->fmt_type;
526 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
527 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
528 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
529 			  &pcm);
530 	if (err < 0) {
531 		kfree(as);
532 		return err;
533 	}
534 	as->pcm = pcm;
535 	pcm->private_data = as;
536 	pcm->private_free = snd_usb_audio_pcm_free;
537 	pcm->info_flags = 0;
538 	if (chip->pcm_devs > 0)
539 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
540 	else
541 		strcpy(pcm->name, "USB Audio");
542 
543 	snd_usb_init_substream(as, stream, fp, pd);
544 
545 	/*
546 	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
547 	 * fix to swap capture stream order in conf/cards/USB-audio.conf
548 	 */
549 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
550 		list_add(&as->list, &chip->pcm_list);
551 	else
552 		list_add_tail(&as->list, &chip->pcm_list);
553 
554 	chip->pcm_devs++;
555 
556 	snd_usb_proc_pcm_format_add(as);
557 
558 	return add_chmap(pcm, stream, &as->substream[stream]);
559 }
560 
561 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
562 			     int stream,
563 			     struct audioformat *fp)
564 {
565 	return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
566 }
567 
568 static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
569 				       int stream,
570 				       struct audioformat *fp,
571 				       struct snd_usb_power_domain *pd)
572 {
573 	return __snd_usb_add_audio_stream(chip, stream, fp, pd);
574 }
575 
576 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
577 					 struct usb_host_interface *alts,
578 					 int protocol, int iface_no)
579 {
580 	/* parsed with a v1 header here. that's ok as we only look at the
581 	 * header first which is the same for both versions */
582 	struct uac_iso_endpoint_descriptor *csep;
583 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
584 	int attributes = 0;
585 
586 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
587 
588 	/* Creamware Noah has this descriptor after the 2nd endpoint */
589 	if (!csep && altsd->bNumEndpoints >= 2)
590 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
591 
592 	/*
593 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
594 	 * bytes after the first endpoint, go search the entire interface.
595 	 * Some devices have it directly *before* the standard endpoint.
596 	 */
597 	if (!csep)
598 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
599 
600 	if (!csep || csep->bLength < 7 ||
601 	    csep->bDescriptorSubtype != UAC_EP_GENERAL)
602 		goto error;
603 
604 	if (protocol == UAC_VERSION_1) {
605 		attributes = csep->bmAttributes;
606 	} else if (protocol == UAC_VERSION_2) {
607 		struct uac2_iso_endpoint_descriptor *csep2 =
608 			(struct uac2_iso_endpoint_descriptor *) csep;
609 
610 		if (csep2->bLength < sizeof(*csep2))
611 			goto error;
612 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
613 
614 		/* emulate the endpoint attributes of a v1 device */
615 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
616 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
617 	} else { /* UAC_VERSION_3 */
618 		struct uac3_iso_endpoint_descriptor *csep3 =
619 			(struct uac3_iso_endpoint_descriptor *) csep;
620 
621 		if (csep3->bLength < sizeof(*csep3))
622 			goto error;
623 		/* emulate the endpoint attributes of a v1 device */
624 		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
625 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
626 	}
627 
628 	return attributes;
629 
630  error:
631 	usb_audio_warn(chip,
632 		       "%u:%d : no or invalid class specific endpoint descriptor\n",
633 		       iface_no, altsd->bAlternateSetting);
634 	return 0;
635 }
636 
637 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
638  * terminal id
639  */
640 static void *
641 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
642 				       int terminal_id, int protocol)
643 {
644 	struct uac2_input_terminal_descriptor *term = NULL;
645 
646 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
647 					       ctrl_iface->extralen,
648 					       term, UAC_INPUT_TERMINAL))) {
649 		if (!snd_usb_validate_audio_desc(term, protocol))
650 			continue;
651 		if (term->bTerminalID == terminal_id)
652 			return term;
653 	}
654 
655 	return NULL;
656 }
657 
658 static void *
659 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
660 					int terminal_id, int protocol)
661 {
662 	/* OK to use with both UAC2 and UAC3 */
663 	struct uac2_output_terminal_descriptor *term = NULL;
664 
665 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
666 					       ctrl_iface->extralen,
667 					       term, UAC_OUTPUT_TERMINAL))) {
668 		if (!snd_usb_validate_audio_desc(term, protocol))
669 			continue;
670 		if (term->bTerminalID == terminal_id)
671 			return term;
672 	}
673 
674 	return NULL;
675 }
676 
677 static struct audioformat *
678 audio_format_alloc_init(struct snd_usb_audio *chip,
679 		       struct usb_host_interface *alts,
680 		       int protocol, int iface_no, int altset_idx,
681 		       int altno, int num_channels, int clock)
682 {
683 	struct audioformat *fp;
684 
685 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
686 	if (!fp)
687 		return NULL;
688 
689 	fp->iface = iface_no;
690 	fp->altsetting = altno;
691 	fp->altset_idx = altset_idx;
692 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
693 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
694 	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
695 	fp->protocol = protocol;
696 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
697 	fp->channels = num_channels;
698 	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
699 		fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
700 				* (fp->maxpacksize & 0x7ff);
701 	fp->clock = clock;
702 	INIT_LIST_HEAD(&fp->list);
703 
704 	return fp;
705 }
706 
707 static struct audioformat *
708 snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
709 			      struct usb_host_interface *alts,
710 			      int protocol, int iface_no, int altset_idx,
711 			      int altno, int stream, int bm_quirk)
712 {
713 	struct usb_device *dev = chip->dev;
714 	struct uac_format_type_i_continuous_descriptor *fmt;
715 	unsigned int num_channels = 0, chconfig = 0;
716 	struct audioformat *fp;
717 	int clock = 0;
718 	u64 format;
719 
720 	/* get audio formats */
721 	if (protocol == UAC_VERSION_1) {
722 		struct uac1_as_header_descriptor *as =
723 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
724 						NULL, UAC_AS_GENERAL);
725 		struct uac_input_terminal_descriptor *iterm;
726 
727 		if (!as) {
728 			dev_err(&dev->dev,
729 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
730 				iface_no, altno);
731 			return NULL;
732 		}
733 
734 		if (as->bLength < sizeof(*as)) {
735 			dev_err(&dev->dev,
736 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
737 				iface_no, altno);
738 			return NULL;
739 		}
740 
741 		format = le16_to_cpu(as->wFormatTag); /* remember the format value */
742 
743 		iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
744 							       as->bTerminalLink,
745 							       protocol);
746 		if (iterm) {
747 			num_channels = iterm->bNrChannels;
748 			chconfig = le16_to_cpu(iterm->wChannelConfig);
749 		}
750 	} else { /* UAC_VERSION_2 */
751 		struct uac2_input_terminal_descriptor *input_term;
752 		struct uac2_output_terminal_descriptor *output_term;
753 		struct uac2_as_header_descriptor *as =
754 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
755 						NULL, UAC_AS_GENERAL);
756 
757 		if (!as) {
758 			dev_err(&dev->dev,
759 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
760 				iface_no, altno);
761 			return NULL;
762 		}
763 
764 		if (as->bLength < sizeof(*as)) {
765 			dev_err(&dev->dev,
766 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
767 				iface_no, altno);
768 			return NULL;
769 		}
770 
771 		num_channels = as->bNrChannels;
772 		format = le32_to_cpu(as->bmFormats);
773 		chconfig = le32_to_cpu(as->bmChannelConfig);
774 
775 		/*
776 		 * lookup the terminal associated to this interface
777 		 * to extract the clock
778 		 */
779 		input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
780 								    as->bTerminalLink,
781 								    protocol);
782 		if (input_term) {
783 			clock = input_term->bCSourceID;
784 			if (!chconfig && (num_channels == input_term->bNrChannels))
785 				chconfig = le32_to_cpu(input_term->bmChannelConfig);
786 			goto found_clock;
787 		}
788 
789 		output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
790 								      as->bTerminalLink,
791 								      protocol);
792 		if (output_term) {
793 			clock = output_term->bCSourceID;
794 			goto found_clock;
795 		}
796 
797 		dev_err(&dev->dev,
798 			"%u:%d : bogus bTerminalLink %d\n",
799 			iface_no, altno, as->bTerminalLink);
800 		return NULL;
801 	}
802 
803 found_clock:
804 	/* get format type */
805 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
806 				      NULL, UAC_FORMAT_TYPE);
807 	if (!fmt) {
808 		dev_err(&dev->dev,
809 			"%u:%d : no UAC_FORMAT_TYPE desc\n",
810 			iface_no, altno);
811 		return NULL;
812 	}
813 	if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
814 			|| ((protocol == UAC_VERSION_2) &&
815 					(fmt->bLength < 6))) {
816 		dev_err(&dev->dev,
817 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
818 			iface_no, altno);
819 		return NULL;
820 	}
821 
822 	/*
823 	 * Blue Microphones workaround: The last altsetting is
824 	 * identical with the previous one, except for a larger
825 	 * packet size, but is actually a mislabeled two-channel
826 	 * setting; ignore it.
827 	 *
828 	 * Part 2: analyze quirk flag and format
829 	 */
830 	if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
831 		return NULL;
832 
833 	fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
834 				     altset_idx, altno, num_channels, clock);
835 	if (!fp)
836 		return ERR_PTR(-ENOMEM);
837 
838 	fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
839 						       iface_no);
840 
841 	/* some quirks for attributes here */
842 	snd_usb_audioformat_attributes_quirk(chip, fp, stream);
843 
844 	/* ok, let's parse further... */
845 	if (snd_usb_parse_audio_format(chip, fp, format,
846 					fmt, stream) < 0) {
847 		audioformat_free(fp);
848 		return NULL;
849 	}
850 
851 	/* Create chmap */
852 	if (fp->channels != num_channels)
853 		chconfig = 0;
854 
855 	fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
856 
857 	return fp;
858 }
859 
860 static struct audioformat *
861 snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
862 			     struct usb_host_interface *alts,
863 			     struct snd_usb_power_domain **pd_out,
864 			     int iface_no, int altset_idx,
865 			     int altno, int stream)
866 {
867 	struct usb_device *dev = chip->dev;
868 	struct uac3_input_terminal_descriptor *input_term;
869 	struct uac3_output_terminal_descriptor *output_term;
870 	struct uac3_cluster_header_descriptor *cluster;
871 	struct uac3_as_header_descriptor *as = NULL;
872 	struct uac3_hc_descriptor_header hc_header;
873 	struct snd_pcm_chmap_elem *chmap;
874 	struct snd_usb_power_domain *pd;
875 	unsigned char badd_profile;
876 	u64 badd_formats = 0;
877 	unsigned int num_channels;
878 	struct audioformat *fp;
879 	u16 cluster_id, wLength;
880 	int clock = 0;
881 	int err;
882 
883 	badd_profile = chip->badd_profile;
884 
885 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
886 		unsigned int maxpacksize =
887 			le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
888 
889 		switch (maxpacksize) {
890 		default:
891 			dev_err(&dev->dev,
892 				"%u:%d : incorrect wMaxPacketSize for BADD profile\n",
893 				iface_no, altno);
894 			return NULL;
895 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
896 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
897 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
898 			num_channels = 1;
899 			break;
900 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
901 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
902 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
903 			num_channels = 1;
904 			break;
905 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
906 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
907 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
908 			num_channels = 2;
909 			break;
910 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
911 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
912 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
913 			num_channels = 2;
914 			break;
915 		}
916 
917 		chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
918 		if (!chmap)
919 			return ERR_PTR(-ENOMEM);
920 
921 		if (num_channels == 1) {
922 			chmap->map[0] = SNDRV_CHMAP_MONO;
923 		} else {
924 			chmap->map[0] = SNDRV_CHMAP_FL;
925 			chmap->map[1] = SNDRV_CHMAP_FR;
926 		}
927 
928 		chmap->channels = num_channels;
929 		clock = UAC3_BADD_CS_ID9;
930 		goto found_clock;
931 	}
932 
933 	as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
934 				     NULL, UAC_AS_GENERAL);
935 	if (!as) {
936 		dev_err(&dev->dev,
937 			"%u:%d : UAC_AS_GENERAL descriptor not found\n",
938 			iface_no, altno);
939 		return NULL;
940 	}
941 
942 	if (as->bLength < sizeof(*as)) {
943 		dev_err(&dev->dev,
944 			"%u:%d : invalid UAC_AS_GENERAL desc\n",
945 			iface_no, altno);
946 		return NULL;
947 	}
948 
949 	cluster_id = le16_to_cpu(as->wClusterDescrID);
950 	if (!cluster_id) {
951 		dev_err(&dev->dev,
952 			"%u:%d : no cluster descriptor\n",
953 			iface_no, altno);
954 		return NULL;
955 	}
956 
957 	/*
958 	 * Get number of channels and channel map through
959 	 * High Capability Cluster Descriptor
960 	 *
961 	 * First step: get High Capability header and
962 	 * read size of Cluster Descriptor
963 	 */
964 	err = snd_usb_ctl_msg(chip->dev,
965 			usb_rcvctrlpipe(chip->dev, 0),
966 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
967 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
968 			cluster_id,
969 			snd_usb_ctrl_intf(chip),
970 			&hc_header, sizeof(hc_header));
971 	if (err < 0)
972 		return ERR_PTR(err);
973 	else if (err != sizeof(hc_header)) {
974 		dev_err(&dev->dev,
975 			"%u:%d : can't get High Capability descriptor\n",
976 			iface_no, altno);
977 		return ERR_PTR(-EIO);
978 	}
979 
980 	/*
981 	 * Second step: allocate needed amount of memory
982 	 * and request Cluster Descriptor
983 	 */
984 	wLength = le16_to_cpu(hc_header.wLength);
985 	cluster = kzalloc(wLength, GFP_KERNEL);
986 	if (!cluster)
987 		return ERR_PTR(-ENOMEM);
988 	err = snd_usb_ctl_msg(chip->dev,
989 			usb_rcvctrlpipe(chip->dev, 0),
990 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
991 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
992 			cluster_id,
993 			snd_usb_ctrl_intf(chip),
994 			cluster, wLength);
995 	if (err < 0) {
996 		kfree(cluster);
997 		return ERR_PTR(err);
998 	} else if (err != wLength) {
999 		dev_err(&dev->dev,
1000 			"%u:%d : can't get Cluster Descriptor\n",
1001 			iface_no, altno);
1002 		kfree(cluster);
1003 		return ERR_PTR(-EIO);
1004 	}
1005 
1006 	num_channels = cluster->bNrChannels;
1007 	chmap = convert_chmap_v3(cluster);
1008 	kfree(cluster);
1009 
1010 	/*
1011 	 * lookup the terminal associated to this interface
1012 	 * to extract the clock
1013 	 */
1014 	input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1015 							    as->bTerminalLink,
1016 							    UAC_VERSION_3);
1017 	if (input_term) {
1018 		clock = input_term->bCSourceID;
1019 		goto found_clock;
1020 	}
1021 
1022 	output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1023 							      as->bTerminalLink,
1024 							      UAC_VERSION_3);
1025 	if (output_term) {
1026 		clock = output_term->bCSourceID;
1027 		goto found_clock;
1028 	}
1029 
1030 	dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1031 			iface_no, altno, as->bTerminalLink);
1032 	kfree(chmap);
1033 	return NULL;
1034 
1035 found_clock:
1036 	fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1037 				     altset_idx, altno, num_channels, clock);
1038 	if (!fp) {
1039 		kfree(chmap);
1040 		return ERR_PTR(-ENOMEM);
1041 	}
1042 
1043 	fp->chmap = chmap;
1044 
1045 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1046 		fp->attributes = 0; /* No attributes */
1047 
1048 		fp->fmt_type = UAC_FORMAT_TYPE_I;
1049 		fp->formats = badd_formats;
1050 
1051 		fp->nr_rates = 0;	/* SNDRV_PCM_RATE_CONTINUOUS */
1052 		fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1053 		fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1054 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1055 
1056 		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1057 		if (!pd) {
1058 			audioformat_free(fp);
1059 			return NULL;
1060 		}
1061 		pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1062 					UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1063 		pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1064 		pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1065 
1066 	} else {
1067 		fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1068 							       UAC_VERSION_3,
1069 							       iface_no);
1070 
1071 		pd = snd_usb_find_power_domain(chip->ctrl_intf,
1072 					       as->bTerminalLink);
1073 
1074 		/* ok, let's parse further... */
1075 		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1076 			kfree(pd);
1077 			audioformat_free(fp);
1078 			return NULL;
1079 		}
1080 	}
1081 
1082 	if (pd)
1083 		*pd_out = pd;
1084 
1085 	return fp;
1086 }
1087 
1088 static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1089 					   int iface_no,
1090 					   bool *has_non_pcm, bool non_pcm)
1091 {
1092 	struct usb_device *dev;
1093 	struct usb_interface *iface;
1094 	struct usb_host_interface *alts;
1095 	struct usb_interface_descriptor *altsd;
1096 	int i, altno, err, stream;
1097 	struct audioformat *fp = NULL;
1098 	struct snd_usb_power_domain *pd = NULL;
1099 	bool set_iface_first;
1100 	int num, protocol;
1101 
1102 	dev = chip->dev;
1103 
1104 	/* parse the interface's altsettings */
1105 	iface = usb_ifnum_to_if(dev, iface_no);
1106 
1107 	num = iface->num_altsetting;
1108 
1109 	/*
1110 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1111 	 * one misses syncpipe, and does not produce any sound.
1112 	 */
1113 	if (chip->usb_id == USB_ID(0x04fa, 0x4201) && num >= 4)
1114 		num = 4;
1115 
1116 	for (i = 0; i < num; i++) {
1117 		alts = &iface->altsetting[i];
1118 		altsd = get_iface_desc(alts);
1119 		protocol = altsd->bInterfaceProtocol;
1120 		/* skip invalid one */
1121 		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1122 		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1123 		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1124 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1125 		    altsd->bNumEndpoints < 1 ||
1126 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1127 			continue;
1128 		/* must be isochronous */
1129 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1130 		    USB_ENDPOINT_XFER_ISOC)
1131 			continue;
1132 		/* check direction */
1133 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1134 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1135 		altno = altsd->bAlternateSetting;
1136 
1137 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1138 			continue;
1139 
1140 		/*
1141 		 * Roland audio streaming interfaces are marked with protocols
1142 		 * 0/1/2, but are UAC 1 compatible.
1143 		 */
1144 		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1145 		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1146 		    protocol <= 2)
1147 			protocol = UAC_VERSION_1;
1148 
1149 		switch (protocol) {
1150 		default:
1151 			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1152 				iface_no, altno, protocol);
1153 			protocol = UAC_VERSION_1;
1154 			fallthrough;
1155 		case UAC_VERSION_1:
1156 		case UAC_VERSION_2: {
1157 			int bm_quirk = 0;
1158 
1159 			/*
1160 			 * Blue Microphones workaround: The last altsetting is
1161 			 * identical with the previous one, except for a larger
1162 			 * packet size, but is actually a mislabeled two-channel
1163 			 * setting; ignore it.
1164 			 *
1165 			 * Part 1: prepare quirk flag
1166 			 */
1167 			if (altno == 2 && num == 3 &&
1168 			    fp && fp->altsetting == 1 && fp->channels == 1 &&
1169 			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1170 			    protocol == UAC_VERSION_1 &&
1171 			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1172 							fp->maxpacksize * 2)
1173 				bm_quirk = 1;
1174 
1175 			fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1176 							   iface_no, i, altno,
1177 							   stream, bm_quirk);
1178 			break;
1179 		}
1180 		case UAC_VERSION_3:
1181 			fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1182 						iface_no, i, altno, stream);
1183 			break;
1184 		}
1185 
1186 		if (!fp)
1187 			continue;
1188 		else if (IS_ERR(fp))
1189 			return PTR_ERR(fp);
1190 
1191 		if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1192 			*has_non_pcm = true;
1193 		if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1194 			audioformat_free(fp);
1195 			kfree(pd);
1196 			fp = NULL;
1197 			pd = NULL;
1198 			continue;
1199 		}
1200 
1201 		snd_usb_audioformat_set_sync_ep(chip, fp);
1202 
1203 		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1204 		if (protocol == UAC_VERSION_3)
1205 			err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1206 		else
1207 			err = snd_usb_add_audio_stream(chip, stream, fp);
1208 
1209 		if (err < 0) {
1210 			audioformat_free(fp);
1211 			kfree(pd);
1212 			return err;
1213 		}
1214 
1215 		/* add endpoints */
1216 		err = snd_usb_add_endpoint(chip, fp->endpoint,
1217 					   SND_USB_ENDPOINT_TYPE_DATA);
1218 		if (err < 0)
1219 			return err;
1220 
1221 		if (fp->sync_ep) {
1222 			err = snd_usb_add_endpoint(chip, fp->sync_ep,
1223 						   fp->implicit_fb ?
1224 						   SND_USB_ENDPOINT_TYPE_DATA :
1225 						   SND_USB_ENDPOINT_TYPE_SYNC);
1226 			if (err < 0)
1227 				return err;
1228 		}
1229 
1230 		set_iface_first = false;
1231 		if (protocol == UAC_VERSION_1 ||
1232 		    (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST))
1233 			set_iface_first = true;
1234 
1235 		/* try to set the interface... */
1236 		usb_set_interface(chip->dev, iface_no, 0);
1237 		if (set_iface_first)
1238 			usb_set_interface(chip->dev, iface_no, altno);
1239 		snd_usb_init_pitch(chip, fp);
1240 		snd_usb_init_sample_rate(chip, fp, fp->rate_max);
1241 		if (!set_iface_first)
1242 			usb_set_interface(chip->dev, iface_no, altno);
1243 	}
1244 	return 0;
1245 }
1246 
1247 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1248 {
1249 	int err;
1250 	bool has_non_pcm = false;
1251 
1252 	/* parse PCM formats */
1253 	err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1254 	if (err < 0)
1255 		return err;
1256 
1257 	if (has_non_pcm) {
1258 		/* parse non-PCM formats */
1259 		err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1260 		if (err < 0)
1261 			return err;
1262 	}
1263 
1264 	return 0;
1265 }
1266 
1267