xref: /linux/sound/usb/pcm.c (revision 58b3bafff8257c6946df5d6aeb215b8ac839ed2a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/bitrev.h>
8 #include <linux/ratelimit.h>
9 #include <linux/usb.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/pcm_params.h>
16 
17 #include "usbaudio.h"
18 #include "card.h"
19 #include "quirks.h"
20 #include "debug.h"
21 #include "endpoint.h"
22 #include "helper.h"
23 #include "pcm.h"
24 #include "clock.h"
25 #include "power.h"
26 #include "media.h"
27 
28 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
29 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
30 
31 /* return the estimated delay based on USB frame counters */
32 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
33 				    unsigned int rate)
34 {
35 	int current_frame_number;
36 	int frame_diff;
37 	int est_delay;
38 
39 	if (!subs->last_delay)
40 		return 0; /* short path */
41 
42 	current_frame_number = usb_get_current_frame_number(subs->dev);
43 	/*
44 	 * HCD implementations use different widths, use lower 8 bits.
45 	 * The delay will be managed up to 256ms, which is more than
46 	 * enough
47 	 */
48 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
49 
50 	/* Approximation based on number of samples per USB frame (ms),
51 	   some truncation for 44.1 but the estimate is good enough */
52 	est_delay =  frame_diff * rate / 1000;
53 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
54 		est_delay = subs->last_delay - est_delay;
55 	else
56 		est_delay = subs->last_delay + est_delay;
57 
58 	if (est_delay < 0)
59 		est_delay = 0;
60 	return est_delay;
61 }
62 
63 /*
64  * return the current pcm pointer.  just based on the hwptr_done value.
65  */
66 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
67 {
68 	struct snd_usb_substream *subs = substream->runtime->private_data;
69 	unsigned int hwptr_done;
70 
71 	if (atomic_read(&subs->stream->chip->shutdown))
72 		return SNDRV_PCM_POS_XRUN;
73 	spin_lock(&subs->lock);
74 	hwptr_done = subs->hwptr_done;
75 	substream->runtime->delay = snd_usb_pcm_delay(subs,
76 						substream->runtime->rate);
77 	spin_unlock(&subs->lock);
78 	return hwptr_done / (substream->runtime->frame_bits >> 3);
79 }
80 
81 /*
82  * find a matching audio format
83  */
84 static struct audioformat *find_format(struct snd_usb_substream *subs)
85 {
86 	struct audioformat *fp;
87 	struct audioformat *found = NULL;
88 	int cur_attr = 0, attr;
89 
90 	list_for_each_entry(fp, &subs->fmt_list, list) {
91 		if (!(fp->formats & pcm_format_to_bits(subs->pcm_format)))
92 			continue;
93 		if (fp->channels != subs->channels)
94 			continue;
95 		if (subs->cur_rate < fp->rate_min ||
96 		    subs->cur_rate > fp->rate_max)
97 			continue;
98 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
99 			unsigned int i;
100 			for (i = 0; i < fp->nr_rates; i++)
101 				if (fp->rate_table[i] == subs->cur_rate)
102 					break;
103 			if (i >= fp->nr_rates)
104 				continue;
105 		}
106 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
107 		if (! found) {
108 			found = fp;
109 			cur_attr = attr;
110 			continue;
111 		}
112 		/* avoid async out and adaptive in if the other method
113 		 * supports the same format.
114 		 * this is a workaround for the case like
115 		 * M-audio audiophile USB.
116 		 */
117 		if (attr != cur_attr) {
118 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
119 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
120 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
121 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
122 				continue;
123 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
124 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
125 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
126 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
127 				found = fp;
128 				cur_attr = attr;
129 				continue;
130 			}
131 		}
132 		/* find the format with the largest max. packet size */
133 		if (fp->maxpacksize > found->maxpacksize) {
134 			found = fp;
135 			cur_attr = attr;
136 		}
137 	}
138 	return found;
139 }
140 
141 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
142 			 struct usb_host_interface *alts,
143 			 struct audioformat *fmt)
144 {
145 	struct usb_device *dev = chip->dev;
146 	unsigned int ep;
147 	unsigned char data[1];
148 	int err;
149 
150 	if (get_iface_desc(alts)->bNumEndpoints < 1)
151 		return -EINVAL;
152 	ep = get_endpoint(alts, 0)->bEndpointAddress;
153 
154 	data[0] = 1;
155 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
156 			      USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
157 			      UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
158 			      data, sizeof(data));
159 	if (err < 0) {
160 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH\n",
161 			      iface, ep);
162 		return err;
163 	}
164 
165 	return 0;
166 }
167 
168 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
169 			 struct usb_host_interface *alts,
170 			 struct audioformat *fmt)
171 {
172 	struct usb_device *dev = chip->dev;
173 	unsigned char data[1];
174 	int err;
175 
176 	data[0] = 1;
177 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
178 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
179 			      UAC2_EP_CS_PITCH << 8, 0,
180 			      data, sizeof(data));
181 	if (err < 0) {
182 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH (v2)\n",
183 			      iface, fmt->altsetting);
184 		return err;
185 	}
186 
187 	return 0;
188 }
189 
190 /*
191  * initialize the pitch control and sample rate
192  */
193 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
194 		       struct usb_host_interface *alts,
195 		       struct audioformat *fmt)
196 {
197 	/* if endpoint doesn't have pitch control, bail out */
198 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
199 		return 0;
200 
201 	switch (fmt->protocol) {
202 	case UAC_VERSION_1:
203 	default:
204 		return init_pitch_v1(chip, iface, alts, fmt);
205 
206 	case UAC_VERSION_2:
207 		return init_pitch_v2(chip, iface, alts, fmt);
208 	}
209 }
210 
211 static int start_endpoints(struct snd_usb_substream *subs)
212 {
213 	int err;
214 
215 	if (!subs->data_endpoint)
216 		return -EINVAL;
217 
218 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
219 		struct snd_usb_endpoint *ep = subs->data_endpoint;
220 
221 		dev_dbg(&subs->dev->dev, "Starting data EP @%p\n", ep);
222 
223 		ep->data_subs = subs;
224 		err = snd_usb_endpoint_start(ep);
225 		if (err < 0) {
226 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
227 			return err;
228 		}
229 	}
230 
231 	if (subs->sync_endpoint &&
232 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
233 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
234 
235 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
236 		    subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
237 			err = usb_set_interface(subs->dev,
238 						subs->sync_endpoint->iface,
239 						subs->sync_endpoint->altsetting);
240 			if (err < 0) {
241 				clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
242 				dev_err(&subs->dev->dev,
243 					   "%d:%d: cannot set interface (%d)\n",
244 					   subs->sync_endpoint->iface,
245 					   subs->sync_endpoint->altsetting, err);
246 				return -EIO;
247 			}
248 		}
249 
250 		dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
251 
252 		ep->sync_slave = subs->data_endpoint;
253 		err = snd_usb_endpoint_start(ep);
254 		if (err < 0) {
255 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
256 			return err;
257 		}
258 	}
259 
260 	return 0;
261 }
262 
263 static void stop_endpoints(struct snd_usb_substream *subs, bool wait)
264 {
265 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
266 		snd_usb_endpoint_stop(subs->sync_endpoint);
267 
268 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
269 		snd_usb_endpoint_stop(subs->data_endpoint);
270 
271 	if (wait) {
272 		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
273 		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
274 	}
275 }
276 
277 static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
278 				     unsigned int altsetting,
279 				     struct usb_host_interface **alts,
280 				     unsigned int *ep)
281 {
282 	struct usb_interface *iface;
283 	struct usb_interface_descriptor *altsd;
284 	struct usb_endpoint_descriptor *epd;
285 
286 	iface = usb_ifnum_to_if(dev, ifnum);
287 	if (!iface || iface->num_altsetting < altsetting + 1)
288 		return -ENOENT;
289 	*alts = &iface->altsetting[altsetting];
290 	altsd = get_iface_desc(*alts);
291 	if (altsd->bAlternateSetting != altsetting ||
292 	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
293 	    (altsd->bInterfaceSubClass != 2 &&
294 	     altsd->bInterfaceProtocol != 2   ) ||
295 	    altsd->bNumEndpoints < 1)
296 		return -ENOENT;
297 	epd = get_endpoint(*alts, 0);
298 	if (!usb_endpoint_is_isoc_in(epd) ||
299 	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
300 					USB_ENDPOINT_USAGE_IMPLICIT_FB)
301 		return -ENOENT;
302 	*ep = epd->bEndpointAddress;
303 	return 0;
304 }
305 
306 /* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
307  * applies. Returns 1 if a quirk was found.
308  */
309 static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
310 					 struct usb_device *dev,
311 					 struct usb_interface_descriptor *altsd,
312 					 unsigned int attr)
313 {
314 	struct usb_host_interface *alts;
315 	struct usb_interface *iface;
316 	unsigned int ep;
317 	unsigned int ifnum;
318 
319 	/* Implicit feedback sync EPs consumers are always playback EPs */
320 	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
321 		return 0;
322 
323 	switch (subs->stream->chip->usb_id) {
324 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
325 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
326 		ep = 0x81;
327 		ifnum = 3;
328 		goto add_sync_ep_from_ifnum;
329 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
330 	case USB_ID(0x0763, 0x2081):
331 		ep = 0x81;
332 		ifnum = 2;
333 		goto add_sync_ep_from_ifnum;
334 	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
335 		ep = 0x86;
336 		ifnum = 2;
337 		goto add_sync_ep_from_ifnum;
338 	case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx III */
339 		ep = 0x81;
340 		ifnum = 2;
341 		goto add_sync_ep_from_ifnum;
342 	case USB_ID(0x1397, 0x0001): /* Behringer UFX1604 */
343 	case USB_ID(0x1397, 0x0002): /* Behringer UFX1204 */
344 		ep = 0x81;
345 		ifnum = 1;
346 		goto add_sync_ep_from_ifnum;
347 	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */
348 		ep = 0x84;
349 		ifnum = 0;
350 		goto add_sync_ep_from_ifnum;
351 	case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
352 		/* BOSS Katana amplifiers do not need quirks */
353 		return 0;
354 	}
355 
356 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
357 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
358 	    altsd->bInterfaceProtocol == 2 &&
359 	    altsd->bNumEndpoints == 1 &&
360 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
361 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
362 				      altsd->bAlternateSetting,
363 				      &alts, &ep) >= 0) {
364 		goto add_sync_ep;
365 	}
366 
367 	/* No quirk */
368 	return 0;
369 
370 add_sync_ep_from_ifnum:
371 	iface = usb_ifnum_to_if(dev, ifnum);
372 
373 	if (!iface || iface->num_altsetting == 0)
374 		return -EINVAL;
375 
376 	alts = &iface->altsetting[1];
377 
378 add_sync_ep:
379 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
380 						   alts, ep, !subs->direction,
381 						   SND_USB_ENDPOINT_TYPE_DATA);
382 	if (!subs->sync_endpoint)
383 		return -EINVAL;
384 
385 	subs->data_endpoint->sync_master = subs->sync_endpoint;
386 
387 	return 1;
388 }
389 
390 static int set_sync_endpoint(struct snd_usb_substream *subs,
391 			     struct audioformat *fmt,
392 			     struct usb_device *dev,
393 			     struct usb_host_interface *alts,
394 			     struct usb_interface_descriptor *altsd)
395 {
396 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
397 	unsigned int ep, attr;
398 	bool implicit_fb;
399 	int err;
400 
401 	/* we need a sync pipe in async OUT or adaptive IN mode */
402 	/* check the number of EP, since some devices have broken
403 	 * descriptors which fool us.  if it has only one EP,
404 	 * assume it as adaptive-out or sync-in.
405 	 */
406 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
407 
408 	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
409 		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
410 
411 		/*
412 		 * In these modes the notion of sync_endpoint is irrelevant.
413 		 * Reset pointers to avoid using stale data from previously
414 		 * used settings, e.g. when configuration and endpoints were
415 		 * changed
416 		 */
417 
418 		subs->sync_endpoint = NULL;
419 		subs->data_endpoint->sync_master = NULL;
420 	}
421 
422 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
423 	if (err < 0)
424 		return err;
425 
426 	/* endpoint set by quirk */
427 	if (err > 0)
428 		return 0;
429 
430 	if (altsd->bNumEndpoints < 2)
431 		return 0;
432 
433 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
434 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
435 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
436 		return 0;
437 
438 	/*
439 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
440 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
441 	 * error fall back to SYNC mode and don't create sync endpoint
442 	 */
443 
444 	/* check sync-pipe endpoint */
445 	/* ... and check descriptor size before accessing bSynchAddress
446 	   because there is a version of the SB Audigy 2 NX firmware lacking
447 	   the audio fields in the endpoint descriptors */
448 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
449 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
450 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
451 		dev_err(&dev->dev,
452 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
453 			   fmt->iface, fmt->altsetting,
454 			   get_endpoint(alts, 1)->bmAttributes,
455 			   get_endpoint(alts, 1)->bLength,
456 			   get_endpoint(alts, 1)->bSynchAddress);
457 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
458 			return 0;
459 		return -EINVAL;
460 	}
461 	ep = get_endpoint(alts, 1)->bEndpointAddress;
462 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
463 	    get_endpoint(alts, 0)->bSynchAddress != 0 &&
464 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
465 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
466 		dev_err(&dev->dev,
467 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
468 			   fmt->iface, fmt->altsetting,
469 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
470 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
471 			return 0;
472 		return -EINVAL;
473 	}
474 
475 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
476 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
477 
478 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
479 						   alts, ep, !subs->direction,
480 						   implicit_fb ?
481 							SND_USB_ENDPOINT_TYPE_DATA :
482 							SND_USB_ENDPOINT_TYPE_SYNC);
483 	if (!subs->sync_endpoint) {
484 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
485 			return 0;
486 		return -EINVAL;
487 	}
488 
489 	subs->data_endpoint->sync_master = subs->sync_endpoint;
490 
491 	return 0;
492 }
493 
494 /*
495  * find a matching format and set up the interface
496  */
497 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
498 {
499 	struct usb_device *dev = subs->dev;
500 	struct usb_host_interface *alts;
501 	struct usb_interface_descriptor *altsd;
502 	struct usb_interface *iface;
503 	int err;
504 
505 	iface = usb_ifnum_to_if(dev, fmt->iface);
506 	if (WARN_ON(!iface))
507 		return -EINVAL;
508 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
509 	altsd = get_iface_desc(alts);
510 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
511 		return -EINVAL;
512 
513 	if (fmt == subs->cur_audiofmt)
514 		return 0;
515 
516 	/* close the old interface */
517 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
518 		if (!subs->stream->chip->keep_iface) {
519 			err = usb_set_interface(subs->dev, subs->interface, 0);
520 			if (err < 0) {
521 				dev_err(&dev->dev,
522 					"%d:%d: return to setting 0 failed (%d)\n",
523 					fmt->iface, fmt->altsetting, err);
524 				return -EIO;
525 			}
526 		}
527 		subs->interface = -1;
528 		subs->altset_idx = 0;
529 	}
530 
531 	/* set interface */
532 	if (iface->cur_altsetting != alts) {
533 		err = snd_usb_select_mode_quirk(subs, fmt);
534 		if (err < 0)
535 			return -EIO;
536 
537 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
538 		if (err < 0) {
539 			dev_err(&dev->dev,
540 				"%d:%d: usb_set_interface failed (%d)\n",
541 				fmt->iface, fmt->altsetting, err);
542 			return -EIO;
543 		}
544 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
545 			fmt->iface, fmt->altsetting);
546 		snd_usb_set_interface_quirk(dev);
547 	}
548 
549 	subs->interface = fmt->iface;
550 	subs->altset_idx = fmt->altset_idx;
551 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
552 						   alts, fmt->endpoint, subs->direction,
553 						   SND_USB_ENDPOINT_TYPE_DATA);
554 
555 	if (!subs->data_endpoint)
556 		return -EINVAL;
557 
558 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
559 	if (err < 0)
560 		return err;
561 
562 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
563 	if (err < 0)
564 		return err;
565 
566 	subs->cur_audiofmt = fmt;
567 
568 	snd_usb_set_format_quirk(subs, fmt);
569 
570 	return 0;
571 }
572 
573 /*
574  * Return the score of matching two audioformats.
575  * Veto the audioformat if:
576  * - It has no channels for some reason.
577  * - Requested PCM format is not supported.
578  * - Requested sample rate is not supported.
579  */
580 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
581 				       struct audioformat *fp,
582 				       struct audioformat *match, int rate,
583 				       snd_pcm_format_t pcm_format)
584 {
585 	int i;
586 	int score = 0;
587 
588 	if (fp->channels < 1) {
589 		dev_dbg(&subs->dev->dev,
590 			"%s: (fmt @%p) no channels\n", __func__, fp);
591 		return 0;
592 	}
593 
594 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
595 		dev_dbg(&subs->dev->dev,
596 			"%s: (fmt @%p) no match for format %d\n", __func__,
597 			fp, pcm_format);
598 		return 0;
599 	}
600 
601 	for (i = 0; i < fp->nr_rates; i++) {
602 		if (fp->rate_table[i] == rate) {
603 			score++;
604 			break;
605 		}
606 	}
607 	if (!score) {
608 		dev_dbg(&subs->dev->dev,
609 			"%s: (fmt @%p) no match for rate %d\n", __func__,
610 			fp, rate);
611 		return 0;
612 	}
613 
614 	if (fp->channels == match->channels)
615 		score++;
616 
617 	dev_dbg(&subs->dev->dev,
618 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
619 
620 	return score;
621 }
622 
623 /*
624  * Configure the sync ep using the rate and pcm format of the data ep.
625  */
626 static int configure_sync_endpoint(struct snd_usb_substream *subs)
627 {
628 	int ret;
629 	struct audioformat *fp;
630 	struct audioformat *sync_fp = NULL;
631 	int cur_score = 0;
632 	int sync_period_bytes = subs->period_bytes;
633 	struct snd_usb_substream *sync_subs =
634 		&subs->stream->substream[subs->direction ^ 1];
635 
636 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
637 	    !subs->stream)
638 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
639 						   subs->pcm_format,
640 						   subs->channels,
641 						   subs->period_bytes,
642 						   0, 0,
643 						   subs->cur_rate,
644 						   subs->cur_audiofmt,
645 						   NULL);
646 
647 	/* Try to find the best matching audioformat. */
648 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
649 		int score = match_endpoint_audioformats(subs,
650 							fp, subs->cur_audiofmt,
651 			subs->cur_rate, subs->pcm_format);
652 
653 		if (score > cur_score) {
654 			sync_fp = fp;
655 			cur_score = score;
656 		}
657 	}
658 
659 	if (unlikely(sync_fp == NULL)) {
660 		dev_err(&subs->dev->dev,
661 			"%s: no valid audioformat for sync ep %x found\n",
662 			__func__, sync_subs->ep_num);
663 		return -EINVAL;
664 	}
665 
666 	/*
667 	 * Recalculate the period bytes if channel number differ between
668 	 * data and sync ep audioformat.
669 	 */
670 	if (sync_fp->channels != subs->channels) {
671 		sync_period_bytes = (subs->period_bytes / subs->channels) *
672 			sync_fp->channels;
673 		dev_dbg(&subs->dev->dev,
674 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
675 			__func__, subs->period_bytes, sync_period_bytes);
676 	}
677 
678 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
679 					  subs->pcm_format,
680 					  sync_fp->channels,
681 					  sync_period_bytes,
682 					  0, 0,
683 					  subs->cur_rate,
684 					  sync_fp,
685 					  NULL);
686 
687 	return ret;
688 }
689 
690 /*
691  * configure endpoint params
692  *
693  * called  during initial setup and upon resume
694  */
695 static int configure_endpoint(struct snd_usb_substream *subs)
696 {
697 	int ret;
698 
699 	/* format changed */
700 	stop_endpoints(subs, true);
701 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
702 					  subs->pcm_format,
703 					  subs->channels,
704 					  subs->period_bytes,
705 					  subs->period_frames,
706 					  subs->buffer_periods,
707 					  subs->cur_rate,
708 					  subs->cur_audiofmt,
709 					  subs->sync_endpoint);
710 	if (ret < 0)
711 		return ret;
712 
713 	if (subs->sync_endpoint)
714 		ret = configure_sync_endpoint(subs);
715 
716 	return ret;
717 }
718 
719 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
720 {
721 	int ret;
722 
723 	if (!subs->str_pd)
724 		return 0;
725 
726 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
727 	if (ret < 0) {
728 		dev_err(&subs->dev->dev,
729 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
730 			subs->str_pd->pd_id, state, ret);
731 		return ret;
732 	}
733 
734 	return 0;
735 }
736 
737 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
738 {
739 	int ret;
740 
741 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
742 	if (ret < 0)
743 		return ret;
744 
745 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
746 	if (ret < 0)
747 		return ret;
748 
749 	return 0;
750 }
751 
752 int snd_usb_pcm_resume(struct snd_usb_stream *as)
753 {
754 	int ret;
755 
756 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
757 	if (ret < 0)
758 		return ret;
759 
760 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
761 	if (ret < 0)
762 		return ret;
763 
764 	return 0;
765 }
766 
767 /*
768  * hw_params callback
769  *
770  * allocate a buffer and set the given audio format.
771  *
772  * so far we use a physically linear buffer although packetize transfer
773  * doesn't need a continuous area.
774  * if sg buffer is supported on the later version of alsa, we'll follow
775  * that.
776  */
777 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
778 			     struct snd_pcm_hw_params *hw_params)
779 {
780 	struct snd_usb_substream *subs = substream->runtime->private_data;
781 	struct audioformat *fmt;
782 	int ret;
783 
784 	ret = snd_media_start_pipeline(subs);
785 	if (ret)
786 		return ret;
787 
788 	ret = snd_pcm_lib_malloc_pages(substream,
789 				       params_buffer_bytes(hw_params));
790 	if (ret < 0)
791 		goto stop_pipeline;
792 
793 	subs->pcm_format = params_format(hw_params);
794 	subs->period_bytes = params_period_bytes(hw_params);
795 	subs->period_frames = params_period_size(hw_params);
796 	subs->buffer_periods = params_periods(hw_params);
797 	subs->channels = params_channels(hw_params);
798 	subs->cur_rate = params_rate(hw_params);
799 
800 	fmt = find_format(subs);
801 	if (!fmt) {
802 		dev_dbg(&subs->dev->dev,
803 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
804 			   subs->pcm_format, subs->cur_rate, subs->channels);
805 		ret = -EINVAL;
806 		goto stop_pipeline;
807 	}
808 
809 	ret = snd_usb_lock_shutdown(subs->stream->chip);
810 	if (ret < 0)
811 		goto stop_pipeline;
812 
813 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
814 	if (ret < 0)
815 		goto unlock;
816 
817 	ret = set_format(subs, fmt);
818 	if (ret < 0)
819 		goto unlock;
820 
821 	subs->interface = fmt->iface;
822 	subs->altset_idx = fmt->altset_idx;
823 	subs->need_setup_ep = true;
824 
825  unlock:
826 	snd_usb_unlock_shutdown(subs->stream->chip);
827 	if (ret < 0)
828 		goto stop_pipeline;
829 	return ret;
830 
831  stop_pipeline:
832 	snd_media_stop_pipeline(subs);
833 	return ret;
834 }
835 
836 /*
837  * hw_free callback
838  *
839  * reset the audio format and release the buffer
840  */
841 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
842 {
843 	struct snd_usb_substream *subs = substream->runtime->private_data;
844 
845 	snd_media_stop_pipeline(subs);
846 	subs->cur_audiofmt = NULL;
847 	subs->cur_rate = 0;
848 	subs->period_bytes = 0;
849 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
850 		stop_endpoints(subs, true);
851 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
852 		snd_usb_endpoint_deactivate(subs->data_endpoint);
853 		snd_usb_unlock_shutdown(subs->stream->chip);
854 	}
855 
856 	return snd_pcm_lib_free_pages(substream);
857 }
858 
859 /*
860  * prepare callback
861  *
862  * only a few subtle things...
863  */
864 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
865 {
866 	struct snd_pcm_runtime *runtime = substream->runtime;
867 	struct snd_usb_substream *subs = runtime->private_data;
868 	struct usb_host_interface *alts;
869 	struct usb_interface *iface;
870 	int ret;
871 
872 	if (! subs->cur_audiofmt) {
873 		dev_err(&subs->dev->dev, "no format is specified!\n");
874 		return -ENXIO;
875 	}
876 
877 	ret = snd_usb_lock_shutdown(subs->stream->chip);
878 	if (ret < 0)
879 		return ret;
880 	if (snd_BUG_ON(!subs->data_endpoint)) {
881 		ret = -EIO;
882 		goto unlock;
883 	}
884 
885 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
886 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
887 
888 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
889 	if (ret < 0)
890 		goto unlock;
891 
892 	ret = set_format(subs, subs->cur_audiofmt);
893 	if (ret < 0)
894 		goto unlock;
895 
896 	if (subs->need_setup_ep) {
897 
898 		iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
899 		alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
900 		ret = snd_usb_init_sample_rate(subs->stream->chip,
901 					       subs->cur_audiofmt->iface,
902 					       alts,
903 					       subs->cur_audiofmt,
904 					       subs->cur_rate);
905 		if (ret < 0)
906 			goto unlock;
907 
908 		ret = configure_endpoint(subs);
909 		if (ret < 0)
910 			goto unlock;
911 		subs->need_setup_ep = false;
912 	}
913 
914 	/* some unit conversions in runtime */
915 	subs->data_endpoint->maxframesize =
916 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
917 	subs->data_endpoint->curframesize =
918 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
919 
920 	/* reset the pointer */
921 	subs->hwptr_done = 0;
922 	subs->transfer_done = 0;
923 	subs->last_delay = 0;
924 	subs->last_frame_number = 0;
925 	runtime->delay = 0;
926 
927 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
928 	 * updates for all URBs would happen at the same time when starting */
929 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
930 		ret = start_endpoints(subs);
931 
932  unlock:
933 	snd_usb_unlock_shutdown(subs->stream->chip);
934 	return ret;
935 }
936 
937 static const struct snd_pcm_hardware snd_usb_hardware =
938 {
939 	.info =			SNDRV_PCM_INFO_MMAP |
940 				SNDRV_PCM_INFO_MMAP_VALID |
941 				SNDRV_PCM_INFO_BATCH |
942 				SNDRV_PCM_INFO_INTERLEAVED |
943 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
944 				SNDRV_PCM_INFO_PAUSE,
945 	.buffer_bytes_max =	1024 * 1024,
946 	.period_bytes_min =	64,
947 	.period_bytes_max =	512 * 1024,
948 	.periods_min =		2,
949 	.periods_max =		1024,
950 };
951 
952 static int hw_check_valid_format(struct snd_usb_substream *subs,
953 				 struct snd_pcm_hw_params *params,
954 				 struct audioformat *fp)
955 {
956 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
957 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
958 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
959 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
960 	struct snd_mask check_fmts;
961 	unsigned int ptime;
962 
963 	/* check the format */
964 	snd_mask_none(&check_fmts);
965 	check_fmts.bits[0] = (u32)fp->formats;
966 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
967 	snd_mask_intersect(&check_fmts, fmts);
968 	if (snd_mask_empty(&check_fmts)) {
969 		hwc_debug("   > check: no supported format %d\n", fp->format);
970 		return 0;
971 	}
972 	/* check the channels */
973 	if (fp->channels < ct->min || fp->channels > ct->max) {
974 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
975 		return 0;
976 	}
977 	/* check the rate is within the range */
978 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
979 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
980 		return 0;
981 	}
982 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
983 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
984 		return 0;
985 	}
986 	/* check whether the period time is >= the data packet interval */
987 	if (subs->speed != USB_SPEED_FULL) {
988 		ptime = 125 * (1 << fp->datainterval);
989 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
990 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
991 			return 0;
992 		}
993 	}
994 	return 1;
995 }
996 
997 static int hw_rule_rate(struct snd_pcm_hw_params *params,
998 			struct snd_pcm_hw_rule *rule)
999 {
1000 	struct snd_usb_substream *subs = rule->private;
1001 	struct audioformat *fp;
1002 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1003 	unsigned int rmin, rmax;
1004 	int changed;
1005 
1006 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
1007 	changed = 0;
1008 	rmin = rmax = 0;
1009 	list_for_each_entry(fp, &subs->fmt_list, list) {
1010 		if (!hw_check_valid_format(subs, params, fp))
1011 			continue;
1012 		if (changed++) {
1013 			if (rmin > fp->rate_min)
1014 				rmin = fp->rate_min;
1015 			if (rmax < fp->rate_max)
1016 				rmax = fp->rate_max;
1017 		} else {
1018 			rmin = fp->rate_min;
1019 			rmax = fp->rate_max;
1020 		}
1021 	}
1022 
1023 	if (!changed) {
1024 		hwc_debug("  --> get empty\n");
1025 		it->empty = 1;
1026 		return -EINVAL;
1027 	}
1028 
1029 	changed = 0;
1030 	if (it->min < rmin) {
1031 		it->min = rmin;
1032 		it->openmin = 0;
1033 		changed = 1;
1034 	}
1035 	if (it->max > rmax) {
1036 		it->max = rmax;
1037 		it->openmax = 0;
1038 		changed = 1;
1039 	}
1040 	if (snd_interval_checkempty(it)) {
1041 		it->empty = 1;
1042 		return -EINVAL;
1043 	}
1044 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1045 	return changed;
1046 }
1047 
1048 
1049 static int hw_rule_channels(struct snd_pcm_hw_params *params,
1050 			    struct snd_pcm_hw_rule *rule)
1051 {
1052 	struct snd_usb_substream *subs = rule->private;
1053 	struct audioformat *fp;
1054 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
1055 	unsigned int rmin, rmax;
1056 	int changed;
1057 
1058 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
1059 	changed = 0;
1060 	rmin = rmax = 0;
1061 	list_for_each_entry(fp, &subs->fmt_list, list) {
1062 		if (!hw_check_valid_format(subs, params, fp))
1063 			continue;
1064 		if (changed++) {
1065 			if (rmin > fp->channels)
1066 				rmin = fp->channels;
1067 			if (rmax < fp->channels)
1068 				rmax = fp->channels;
1069 		} else {
1070 			rmin = fp->channels;
1071 			rmax = fp->channels;
1072 		}
1073 	}
1074 
1075 	if (!changed) {
1076 		hwc_debug("  --> get empty\n");
1077 		it->empty = 1;
1078 		return -EINVAL;
1079 	}
1080 
1081 	changed = 0;
1082 	if (it->min < rmin) {
1083 		it->min = rmin;
1084 		it->openmin = 0;
1085 		changed = 1;
1086 	}
1087 	if (it->max > rmax) {
1088 		it->max = rmax;
1089 		it->openmax = 0;
1090 		changed = 1;
1091 	}
1092 	if (snd_interval_checkempty(it)) {
1093 		it->empty = 1;
1094 		return -EINVAL;
1095 	}
1096 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1097 	return changed;
1098 }
1099 
1100 static int hw_rule_format(struct snd_pcm_hw_params *params,
1101 			  struct snd_pcm_hw_rule *rule)
1102 {
1103 	struct snd_usb_substream *subs = rule->private;
1104 	struct audioformat *fp;
1105 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
1106 	u64 fbits;
1107 	u32 oldbits[2];
1108 	int changed;
1109 
1110 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
1111 	fbits = 0;
1112 	list_for_each_entry(fp, &subs->fmt_list, list) {
1113 		if (!hw_check_valid_format(subs, params, fp))
1114 			continue;
1115 		fbits |= fp->formats;
1116 	}
1117 
1118 	oldbits[0] = fmt->bits[0];
1119 	oldbits[1] = fmt->bits[1];
1120 	fmt->bits[0] &= (u32)fbits;
1121 	fmt->bits[1] &= (u32)(fbits >> 32);
1122 	if (!fmt->bits[0] && !fmt->bits[1]) {
1123 		hwc_debug("  --> get empty\n");
1124 		return -EINVAL;
1125 	}
1126 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1127 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1128 	return changed;
1129 }
1130 
1131 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1132 			       struct snd_pcm_hw_rule *rule)
1133 {
1134 	struct snd_usb_substream *subs = rule->private;
1135 	struct audioformat *fp;
1136 	struct snd_interval *it;
1137 	unsigned char min_datainterval;
1138 	unsigned int pmin;
1139 	int changed;
1140 
1141 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1142 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1143 	min_datainterval = 0xff;
1144 	list_for_each_entry(fp, &subs->fmt_list, list) {
1145 		if (!hw_check_valid_format(subs, params, fp))
1146 			continue;
1147 		min_datainterval = min(min_datainterval, fp->datainterval);
1148 	}
1149 	if (min_datainterval == 0xff) {
1150 		hwc_debug("  --> get empty\n");
1151 		it->empty = 1;
1152 		return -EINVAL;
1153 	}
1154 	pmin = 125 * (1 << min_datainterval);
1155 	changed = 0;
1156 	if (it->min < pmin) {
1157 		it->min = pmin;
1158 		it->openmin = 0;
1159 		changed = 1;
1160 	}
1161 	if (snd_interval_checkempty(it)) {
1162 		it->empty = 1;
1163 		return -EINVAL;
1164 	}
1165 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1166 	return changed;
1167 }
1168 
1169 /*
1170  *  If the device supports unusual bit rates, does the request meet these?
1171  */
1172 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1173 				  struct snd_usb_substream *subs)
1174 {
1175 	struct audioformat *fp;
1176 	int *rate_list;
1177 	int count = 0, needs_knot = 0;
1178 	int err;
1179 
1180 	kfree(subs->rate_list.list);
1181 	subs->rate_list.list = NULL;
1182 
1183 	list_for_each_entry(fp, &subs->fmt_list, list) {
1184 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1185 			return 0;
1186 		count += fp->nr_rates;
1187 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1188 			needs_knot = 1;
1189 	}
1190 	if (!needs_knot)
1191 		return 0;
1192 
1193 	subs->rate_list.list = rate_list =
1194 		kmalloc_array(count, sizeof(int), GFP_KERNEL);
1195 	if (!subs->rate_list.list)
1196 		return -ENOMEM;
1197 	subs->rate_list.count = count;
1198 	subs->rate_list.mask = 0;
1199 	count = 0;
1200 	list_for_each_entry(fp, &subs->fmt_list, list) {
1201 		int i;
1202 		for (i = 0; i < fp->nr_rates; i++)
1203 			rate_list[count++] = fp->rate_table[i];
1204 	}
1205 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1206 					 &subs->rate_list);
1207 	if (err < 0)
1208 		return err;
1209 
1210 	return 0;
1211 }
1212 
1213 
1214 /*
1215  * set up the runtime hardware information.
1216  */
1217 
1218 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1219 {
1220 	struct audioformat *fp;
1221 	unsigned int pt, ptmin;
1222 	int param_period_time_if_needed;
1223 	int err;
1224 
1225 	runtime->hw.formats = subs->formats;
1226 
1227 	runtime->hw.rate_min = 0x7fffffff;
1228 	runtime->hw.rate_max = 0;
1229 	runtime->hw.channels_min = 256;
1230 	runtime->hw.channels_max = 0;
1231 	runtime->hw.rates = 0;
1232 	ptmin = UINT_MAX;
1233 	/* check min/max rates and channels */
1234 	list_for_each_entry(fp, &subs->fmt_list, list) {
1235 		runtime->hw.rates |= fp->rates;
1236 		if (runtime->hw.rate_min > fp->rate_min)
1237 			runtime->hw.rate_min = fp->rate_min;
1238 		if (runtime->hw.rate_max < fp->rate_max)
1239 			runtime->hw.rate_max = fp->rate_max;
1240 		if (runtime->hw.channels_min > fp->channels)
1241 			runtime->hw.channels_min = fp->channels;
1242 		if (runtime->hw.channels_max < fp->channels)
1243 			runtime->hw.channels_max = fp->channels;
1244 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1245 			/* FIXME: there might be more than one audio formats... */
1246 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1247 				fp->frame_size;
1248 		}
1249 		pt = 125 * (1 << fp->datainterval);
1250 		ptmin = min(ptmin, pt);
1251 	}
1252 
1253 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1254 	if (subs->speed == USB_SPEED_FULL)
1255 		/* full speed devices have fixed data packet interval */
1256 		ptmin = 1000;
1257 	if (ptmin == 1000)
1258 		/* if period time doesn't go below 1 ms, no rules needed */
1259 		param_period_time_if_needed = -1;
1260 
1261 	err = snd_pcm_hw_constraint_minmax(runtime,
1262 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1263 					   ptmin, UINT_MAX);
1264 	if (err < 0)
1265 		return err;
1266 
1267 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1268 				  hw_rule_rate, subs,
1269 				  SNDRV_PCM_HW_PARAM_FORMAT,
1270 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1271 				  param_period_time_if_needed,
1272 				  -1);
1273 	if (err < 0)
1274 		return err;
1275 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1276 				  hw_rule_channels, subs,
1277 				  SNDRV_PCM_HW_PARAM_FORMAT,
1278 				  SNDRV_PCM_HW_PARAM_RATE,
1279 				  param_period_time_if_needed,
1280 				  -1);
1281 	if (err < 0)
1282 		return err;
1283 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1284 				  hw_rule_format, subs,
1285 				  SNDRV_PCM_HW_PARAM_RATE,
1286 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1287 				  param_period_time_if_needed,
1288 				  -1);
1289 	if (err < 0)
1290 		return err;
1291 	if (param_period_time_if_needed >= 0) {
1292 		err = snd_pcm_hw_rule_add(runtime, 0,
1293 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1294 					  hw_rule_period_time, subs,
1295 					  SNDRV_PCM_HW_PARAM_FORMAT,
1296 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1297 					  SNDRV_PCM_HW_PARAM_RATE,
1298 					  -1);
1299 		if (err < 0)
1300 			return err;
1301 	}
1302 	err = snd_usb_pcm_check_knot(runtime, subs);
1303 	if (err < 0)
1304 		return err;
1305 
1306 	return snd_usb_autoresume(subs->stream->chip);
1307 }
1308 
1309 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1310 {
1311 	int direction = substream->stream;
1312 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1313 	struct snd_pcm_runtime *runtime = substream->runtime;
1314 	struct snd_usb_substream *subs = &as->substream[direction];
1315 	int ret;
1316 
1317 	subs->interface = -1;
1318 	subs->altset_idx = 0;
1319 	runtime->hw = snd_usb_hardware;
1320 	runtime->private_data = subs;
1321 	subs->pcm_substream = substream;
1322 	/* runtime PM is also done there */
1323 
1324 	/* initialize DSD/DOP context */
1325 	subs->dsd_dop.byte_idx = 0;
1326 	subs->dsd_dop.channel = 0;
1327 	subs->dsd_dop.marker = 1;
1328 
1329 	ret = setup_hw_info(runtime, subs);
1330 	if (ret == 0) {
1331 		ret = snd_media_stream_init(subs, as->pcm, direction);
1332 		if (ret)
1333 			snd_usb_autosuspend(subs->stream->chip);
1334 	}
1335 	return ret;
1336 }
1337 
1338 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1339 {
1340 	int direction = substream->stream;
1341 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1342 	struct snd_usb_substream *subs = &as->substream[direction];
1343 	int ret;
1344 
1345 	stop_endpoints(subs, true);
1346 	snd_media_stop_pipeline(subs);
1347 
1348 	if (!as->chip->keep_iface &&
1349 	    subs->interface >= 0 &&
1350 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
1351 		usb_set_interface(subs->dev, subs->interface, 0);
1352 		subs->interface = -1;
1353 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1354 		snd_usb_unlock_shutdown(subs->stream->chip);
1355 		if (ret < 0)
1356 			return ret;
1357 	}
1358 
1359 	subs->pcm_substream = NULL;
1360 	snd_usb_autosuspend(subs->stream->chip);
1361 
1362 	return 0;
1363 }
1364 
1365 /* Since a URB can handle only a single linear buffer, we must use double
1366  * buffering when the data to be transferred overflows the buffer boundary.
1367  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1368  * for all URBs.
1369  */
1370 static void retire_capture_urb(struct snd_usb_substream *subs,
1371 			       struct urb *urb)
1372 {
1373 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1374 	unsigned int stride, frames, bytes, oldptr;
1375 	int i, period_elapsed = 0;
1376 	unsigned long flags;
1377 	unsigned char *cp;
1378 	int current_frame_number;
1379 
1380 	/* read frame number here, update pointer in critical section */
1381 	current_frame_number = usb_get_current_frame_number(subs->dev);
1382 
1383 	stride = runtime->frame_bits >> 3;
1384 
1385 	for (i = 0; i < urb->number_of_packets; i++) {
1386 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1387 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1388 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1389 				i, urb->iso_frame_desc[i].status);
1390 			// continue;
1391 		}
1392 		bytes = urb->iso_frame_desc[i].actual_length;
1393 		frames = bytes / stride;
1394 		if (!subs->txfr_quirk)
1395 			bytes = frames * stride;
1396 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1397 			int oldbytes = bytes;
1398 			bytes = frames * stride;
1399 			dev_warn_ratelimited(&subs->dev->dev,
1400 				 "Corrected urb data len. %d->%d\n",
1401 							oldbytes, bytes);
1402 		}
1403 		/* update the current pointer */
1404 		spin_lock_irqsave(&subs->lock, flags);
1405 		oldptr = subs->hwptr_done;
1406 		subs->hwptr_done += bytes;
1407 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1408 			subs->hwptr_done -= runtime->buffer_size * stride;
1409 		frames = (bytes + (oldptr % stride)) / stride;
1410 		subs->transfer_done += frames;
1411 		if (subs->transfer_done >= runtime->period_size) {
1412 			subs->transfer_done -= runtime->period_size;
1413 			period_elapsed = 1;
1414 		}
1415 		/* capture delay is by construction limited to one URB,
1416 		 * reset delays here
1417 		 */
1418 		runtime->delay = subs->last_delay = 0;
1419 
1420 		/* realign last_frame_number */
1421 		subs->last_frame_number = current_frame_number;
1422 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1423 
1424 		spin_unlock_irqrestore(&subs->lock, flags);
1425 		/* copy a data chunk */
1426 		if (oldptr + bytes > runtime->buffer_size * stride) {
1427 			unsigned int bytes1 =
1428 					runtime->buffer_size * stride - oldptr;
1429 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1430 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1431 		} else {
1432 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1433 		}
1434 	}
1435 
1436 	if (period_elapsed)
1437 		snd_pcm_period_elapsed(subs->pcm_substream);
1438 }
1439 
1440 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1441 					     struct urb *urb, unsigned int bytes)
1442 {
1443 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1444 	unsigned int stride = runtime->frame_bits >> 3;
1445 	unsigned int dst_idx = 0;
1446 	unsigned int src_idx = subs->hwptr_done;
1447 	unsigned int wrap = runtime->buffer_size * stride;
1448 	u8 *dst = urb->transfer_buffer;
1449 	u8 *src = runtime->dma_area;
1450 	u8 marker[] = { 0x05, 0xfa };
1451 
1452 	/*
1453 	 * The DSP DOP format defines a way to transport DSD samples over
1454 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1455 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1456 	 * 2 additional bytes of actual payload. The whole frame is stored
1457 	 * LSB.
1458 	 *
1459 	 * Hence, for a stereo transport, the buffer layout looks like this,
1460 	 * where L refers to left channel samples and R to right.
1461 	 *
1462 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1463 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1464 	 *   .....
1465 	 *
1466 	 */
1467 
1468 	while (bytes--) {
1469 		if (++subs->dsd_dop.byte_idx == 3) {
1470 			/* frame boundary? */
1471 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1472 			src_idx += 2;
1473 			subs->dsd_dop.byte_idx = 0;
1474 
1475 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1476 				/* alternate the marker */
1477 				subs->dsd_dop.marker++;
1478 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1479 				subs->dsd_dop.channel = 0;
1480 			}
1481 		} else {
1482 			/* stuff the DSD payload */
1483 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1484 
1485 			if (subs->cur_audiofmt->dsd_bitrev)
1486 				dst[dst_idx++] = bitrev8(src[idx]);
1487 			else
1488 				dst[dst_idx++] = src[idx];
1489 
1490 			subs->hwptr_done++;
1491 		}
1492 	}
1493 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1494 		subs->hwptr_done -= runtime->buffer_size * stride;
1495 }
1496 
1497 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1498 			int offset, int stride, unsigned int bytes)
1499 {
1500 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1501 
1502 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1503 		/* err, the transferred area goes over buffer boundary. */
1504 		unsigned int bytes1 =
1505 			runtime->buffer_size * stride - subs->hwptr_done;
1506 		memcpy(urb->transfer_buffer + offset,
1507 		       runtime->dma_area + subs->hwptr_done, bytes1);
1508 		memcpy(urb->transfer_buffer + offset + bytes1,
1509 		       runtime->dma_area, bytes - bytes1);
1510 	} else {
1511 		memcpy(urb->transfer_buffer + offset,
1512 		       runtime->dma_area + subs->hwptr_done, bytes);
1513 	}
1514 	subs->hwptr_done += bytes;
1515 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1516 		subs->hwptr_done -= runtime->buffer_size * stride;
1517 }
1518 
1519 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1520 				      struct urb *urb, int stride,
1521 				      unsigned int bytes)
1522 {
1523 	__le32 packet_length;
1524 	int i;
1525 
1526 	/* Put __le32 length descriptor at start of each packet. */
1527 	for (i = 0; i < urb->number_of_packets; i++) {
1528 		unsigned int length = urb->iso_frame_desc[i].length;
1529 		unsigned int offset = urb->iso_frame_desc[i].offset;
1530 
1531 		packet_length = cpu_to_le32(length);
1532 		offset += i * sizeof(packet_length);
1533 		urb->iso_frame_desc[i].offset = offset;
1534 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1535 		memcpy(urb->transfer_buffer + offset,
1536 		       &packet_length, sizeof(packet_length));
1537 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1538 			    stride, length);
1539 	}
1540 	/* Adjust transfer size accordingly. */
1541 	bytes += urb->number_of_packets * sizeof(packet_length);
1542 	return bytes;
1543 }
1544 
1545 static void prepare_playback_urb(struct snd_usb_substream *subs,
1546 				 struct urb *urb)
1547 {
1548 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1549 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1550 	struct snd_urb_ctx *ctx = urb->context;
1551 	unsigned int counts, frames, bytes;
1552 	int i, stride, period_elapsed = 0;
1553 	unsigned long flags;
1554 
1555 	stride = runtime->frame_bits >> 3;
1556 
1557 	frames = 0;
1558 	urb->number_of_packets = 0;
1559 	spin_lock_irqsave(&subs->lock, flags);
1560 	subs->frame_limit += ep->max_urb_frames;
1561 	for (i = 0; i < ctx->packets; i++) {
1562 		if (ctx->packet_size[i])
1563 			counts = ctx->packet_size[i];
1564 		else
1565 			counts = snd_usb_endpoint_next_packet_size(ep);
1566 
1567 		/* set up descriptor */
1568 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1569 		urb->iso_frame_desc[i].length = counts * ep->stride;
1570 		frames += counts;
1571 		urb->number_of_packets++;
1572 		subs->transfer_done += counts;
1573 		if (subs->transfer_done >= runtime->period_size) {
1574 			subs->transfer_done -= runtime->period_size;
1575 			subs->frame_limit = 0;
1576 			period_elapsed = 1;
1577 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1578 				if (subs->transfer_done > 0) {
1579 					/* FIXME: fill-max mode is not
1580 					 * supported yet */
1581 					frames -= subs->transfer_done;
1582 					counts -= subs->transfer_done;
1583 					urb->iso_frame_desc[i].length =
1584 						counts * ep->stride;
1585 					subs->transfer_done = 0;
1586 				}
1587 				i++;
1588 				if (i < ctx->packets) {
1589 					/* add a transfer delimiter */
1590 					urb->iso_frame_desc[i].offset =
1591 						frames * ep->stride;
1592 					urb->iso_frame_desc[i].length = 0;
1593 					urb->number_of_packets++;
1594 				}
1595 				break;
1596 			}
1597 		}
1598 		/* finish at the period boundary or after enough frames */
1599 		if ((period_elapsed ||
1600 				subs->transfer_done >= subs->frame_limit) &&
1601 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1602 			break;
1603 	}
1604 	bytes = frames * ep->stride;
1605 
1606 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1607 		     subs->cur_audiofmt->dsd_dop)) {
1608 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1609 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1610 			   subs->cur_audiofmt->dsd_bitrev)) {
1611 		/* bit-reverse the bytes */
1612 		u8 *buf = urb->transfer_buffer;
1613 		for (i = 0; i < bytes; i++) {
1614 			int idx = (subs->hwptr_done + i)
1615 				% (runtime->buffer_size * stride);
1616 			buf[i] = bitrev8(runtime->dma_area[idx]);
1617 		}
1618 
1619 		subs->hwptr_done += bytes;
1620 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1621 			subs->hwptr_done -= runtime->buffer_size * stride;
1622 	} else {
1623 		/* usual PCM */
1624 		if (!subs->tx_length_quirk)
1625 			copy_to_urb(subs, urb, 0, stride, bytes);
1626 		else
1627 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1628 			/* bytes is now amount of outgoing data */
1629 	}
1630 
1631 	/* update delay with exact number of samples queued */
1632 	runtime->delay = subs->last_delay;
1633 	runtime->delay += frames;
1634 	subs->last_delay = runtime->delay;
1635 
1636 	/* realign last_frame_number */
1637 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1638 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1639 
1640 	if (subs->trigger_tstamp_pending_update) {
1641 		/* this is the first actual URB submitted,
1642 		 * update trigger timestamp to reflect actual start time
1643 		 */
1644 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1645 		subs->trigger_tstamp_pending_update = false;
1646 	}
1647 
1648 	spin_unlock_irqrestore(&subs->lock, flags);
1649 	urb->transfer_buffer_length = bytes;
1650 	if (period_elapsed)
1651 		snd_pcm_period_elapsed(subs->pcm_substream);
1652 }
1653 
1654 /*
1655  * process after playback data complete
1656  * - decrease the delay count again
1657  */
1658 static void retire_playback_urb(struct snd_usb_substream *subs,
1659 			       struct urb *urb)
1660 {
1661 	unsigned long flags;
1662 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1663 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1664 	int processed = urb->transfer_buffer_length / ep->stride;
1665 	int est_delay;
1666 
1667 	/* ignore the delay accounting when procssed=0 is given, i.e.
1668 	 * silent payloads are procssed before handling the actual data
1669 	 */
1670 	if (!processed)
1671 		return;
1672 
1673 	spin_lock_irqsave(&subs->lock, flags);
1674 	if (!subs->last_delay)
1675 		goto out; /* short path */
1676 
1677 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1678 	/* update delay with exact number of samples played */
1679 	if (processed > subs->last_delay)
1680 		subs->last_delay = 0;
1681 	else
1682 		subs->last_delay -= processed;
1683 	runtime->delay = subs->last_delay;
1684 
1685 	/*
1686 	 * Report when delay estimate is off by more than 2ms.
1687 	 * The error should be lower than 2ms since the estimate relies
1688 	 * on two reads of a counter updated every ms.
1689 	 */
1690 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1691 		dev_dbg_ratelimited(&subs->dev->dev,
1692 			"delay: estimated %d, actual %d\n",
1693 			est_delay, subs->last_delay);
1694 
1695 	if (!subs->running) {
1696 		/* update last_frame_number for delay counting here since
1697 		 * prepare_playback_urb won't be called during pause
1698 		 */
1699 		subs->last_frame_number =
1700 			usb_get_current_frame_number(subs->dev) & 0xff;
1701 	}
1702 
1703  out:
1704 	spin_unlock_irqrestore(&subs->lock, flags);
1705 }
1706 
1707 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1708 					      int cmd)
1709 {
1710 	struct snd_usb_substream *subs = substream->runtime->private_data;
1711 
1712 	switch (cmd) {
1713 	case SNDRV_PCM_TRIGGER_START:
1714 		subs->trigger_tstamp_pending_update = true;
1715 		/* fall through */
1716 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1717 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1718 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1719 		subs->running = 1;
1720 		return 0;
1721 	case SNDRV_PCM_TRIGGER_STOP:
1722 		stop_endpoints(subs, false);
1723 		subs->running = 0;
1724 		return 0;
1725 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1726 		subs->data_endpoint->prepare_data_urb = NULL;
1727 		/* keep retire_data_urb for delay calculation */
1728 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1729 		subs->running = 0;
1730 		return 0;
1731 	}
1732 
1733 	return -EINVAL;
1734 }
1735 
1736 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1737 					     int cmd)
1738 {
1739 	int err;
1740 	struct snd_usb_substream *subs = substream->runtime->private_data;
1741 
1742 	switch (cmd) {
1743 	case SNDRV_PCM_TRIGGER_START:
1744 		err = start_endpoints(subs);
1745 		if (err < 0)
1746 			return err;
1747 
1748 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1749 		subs->running = 1;
1750 		return 0;
1751 	case SNDRV_PCM_TRIGGER_STOP:
1752 		stop_endpoints(subs, false);
1753 		subs->running = 0;
1754 		return 0;
1755 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1756 		subs->data_endpoint->retire_data_urb = NULL;
1757 		subs->running = 0;
1758 		return 0;
1759 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1760 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1761 		subs->running = 1;
1762 		return 0;
1763 	}
1764 
1765 	return -EINVAL;
1766 }
1767 
1768 static const struct snd_pcm_ops snd_usb_playback_ops = {
1769 	.open =		snd_usb_pcm_open,
1770 	.close =	snd_usb_pcm_close,
1771 	.ioctl =	snd_pcm_lib_ioctl,
1772 	.hw_params =	snd_usb_hw_params,
1773 	.hw_free =	snd_usb_hw_free,
1774 	.prepare =	snd_usb_pcm_prepare,
1775 	.trigger =	snd_usb_substream_playback_trigger,
1776 	.pointer =	snd_usb_pcm_pointer,
1777 };
1778 
1779 static const struct snd_pcm_ops snd_usb_capture_ops = {
1780 	.open =		snd_usb_pcm_open,
1781 	.close =	snd_usb_pcm_close,
1782 	.ioctl =	snd_pcm_lib_ioctl,
1783 	.hw_params =	snd_usb_hw_params,
1784 	.hw_free =	snd_usb_hw_free,
1785 	.prepare =	snd_usb_pcm_prepare,
1786 	.trigger =	snd_usb_substream_capture_trigger,
1787 	.pointer =	snd_usb_pcm_pointer,
1788 };
1789 
1790 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1791 {
1792 	const struct snd_pcm_ops *ops;
1793 
1794 	ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1795 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1796 	snd_pcm_set_ops(pcm, stream, ops);
1797 }
1798 
1799 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1800 {
1801 	struct snd_pcm *pcm = subs->stream->pcm;
1802 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1803 	struct device *dev = subs->dev->bus->controller;
1804 
1805 	if (snd_usb_use_vmalloc)
1806 		snd_pcm_lib_preallocate_pages(s, SNDRV_DMA_TYPE_VMALLOC,
1807 					      NULL, 0, 0);
1808 	else
1809 		snd_pcm_lib_preallocate_pages(s, SNDRV_DMA_TYPE_DEV_SG,
1810 					      dev, 64*1024, 512*1024);
1811 }
1812