endpoint.c 31 KB
Newer Older
Daniel Mack's avatar
Daniel Mack committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

18
19
#include <linux/gfp.h>
#include <linux/init.h>
20
#include <linux/ratelimit.h>
21
22
#include <linux/usb.h>
#include <linux/usb/audio.h>
23
#include <linux/slab.h>
24
25
26

#include <sound/core.h>
#include <sound/pcm.h>
27
#include <sound/pcm_params.h>
28
29
30
31
32
33

#include "usbaudio.h"
#include "helper.h"
#include "card.h"
#include "endpoint.h"
#include "pcm.h"
34
#include "quirks.h"
35

36
#define EP_FLAG_RUNNING		1
37
#define EP_FLAG_STOPPING	2
38

39
40
41
42
43
/*
 * snd_usb_endpoint is a model that abstracts everything related to an
 * USB endpoint and its streaming.
 *
 * There are functions to activate and deactivate the streaming URBs and
44
 * optional callbacks to let the pcm logic handle the actual content of the
45
46
47
 * packets for playback and record. Thus, the bus streaming and the audio
 * handlers are fully decoupled.
 *
48
 * There are two different types of endpoints in audio applications.
49
50
51
52
 *
 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
 * inbound and outbound traffic.
 *
53
54
55
 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
 * (3 or 4 bytes).
56
 *
57
58
 * Each endpoint has to be configured prior to being used by calling
 * snd_usb_endpoint_set_params().
59
60
61
62
 *
 * The model incorporates a reference counting, so that multiple users
 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
 * only the first user will effectively start the URBs, and only the last
63
 * one to stop it will tear the URBs down again.
64
65
 */

66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
/*
 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 * this will overflow at approx 524 kHz
 */
static inline unsigned get_usb_full_speed_rate(unsigned int rate)
{
	return ((rate << 13) + 62) / 125;
}

/*
 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 * this will overflow at approx 4 MHz
 */
static inline unsigned get_usb_high_speed_rate(unsigned int rate)
{
	return ((rate << 10) + 62) / 125;
}

/*
 * release a urb data
 */
static void release_urb_ctx(struct snd_urb_ctx *u)
{
89
90
91
92
93
94
	if (u->buffer_size)
		usb_free_coherent(u->ep->chip->dev, u->buffer_size,
				  u->urb->transfer_buffer,
				  u->urb->transfer_dma);
	usb_free_urb(u->urb);
	u->urb = NULL;
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
}

static const char *usb_error_string(int err)
{
	switch (err) {
	case -ENODEV:
		return "no device";
	case -ENOENT:
		return "endpoint not enabled";
	case -EPIPE:
		return "endpoint stalled";
	case -ENOSPC:
		return "not enough bandwidth";
	case -ESHUTDOWN:
		return "device disabled";
	case -EHOSTUNREACH:
		return "device suspended";
	case -EINVAL:
	case -EAGAIN:
	case -EFBIG:
	case -EMSGSIZE:
		return "internal error";
	default:
		return "unknown error";
	}
}

122
123
124
/**
 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
 *
125
 * @ep: The snd_usb_endpoint
126
127
128
129
 *
 * Determine whether an endpoint is driven by an implicit feedback
 * data endpoint source.
 */
130
int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
131
132
133
134
135
136
137
{
	return  ep->sync_master &&
		ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA &&
		ep->type == SND_USB_ENDPOINT_TYPE_DATA &&
		usb_pipeout(ep->pipe);
}

138
139
140
141
142
143
144
/*
 * For streaming based on information derived from sync endpoints,
 * prepare_outbound_urb_sizes() will call next_packet_size() to
 * determine the number of samples to be sent in the next packet.
 *
 * For implicit feedback, next_packet_size() is unused.
 */
145
int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
{
	unsigned long flags;
	int ret;

	if (ep->fill_max)
		return ep->maxframesize;

	spin_lock_irqsave(&ep->lock, flags);
	ep->phase = (ep->phase & 0xffff)
		+ (ep->freqm << ep->datainterval);
	ret = min(ep->phase >> 16, ep->maxframesize);
	spin_unlock_irqrestore(&ep->lock, flags);

	return ret;
}

static void retire_outbound_urb(struct snd_usb_endpoint *ep,
				struct snd_urb_ctx *urb_ctx)
{
	if (ep->retire_data_urb)
		ep->retire_data_urb(ep->data_subs, urb_ctx->urb);
}

static void retire_inbound_urb(struct snd_usb_endpoint *ep,
			       struct snd_urb_ctx *urb_ctx)
{
	struct urb *urb = urb_ctx->urb;

174
175
176
177
178
	if (unlikely(ep->skip_packets > 0)) {
		ep->skip_packets--;
		return;
	}

179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
	if (ep->sync_slave)
		snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);

	if (ep->retire_data_urb)
		ep->retire_data_urb(ep->data_subs, urb);
}

/*
 * Prepare a PLAYBACK urb for submission to the bus.
 */
static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
				 struct snd_urb_ctx *ctx)
{
	int i;
	struct urb *urb = ctx->urb;
	unsigned char *cp = urb->transfer_buffer;

	urb->dev = ep->chip->dev; /* we need to set this at each time */

	switch (ep->type) {
	case SND_USB_ENDPOINT_TYPE_DATA:
		if (ep->prepare_data_urb) {
			ep->prepare_data_urb(ep->data_subs, urb);
		} else {
			/* no data provider, so send silence */
			unsigned int offs = 0;
			for (i = 0; i < ctx->packets; ++i) {
206
207
208
209
210
211
212
				int counts;

				if (ctx->packet_size[i])
					counts = ctx->packet_size[i];
				else
					counts = snd_usb_endpoint_next_packet_size(ep);

213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
				urb->iso_frame_desc[i].offset = offs * ep->stride;
				urb->iso_frame_desc[i].length = counts * ep->stride;
				offs += counts;
			}

			urb->number_of_packets = ctx->packets;
			urb->transfer_buffer_length = offs * ep->stride;
			memset(urb->transfer_buffer, ep->silence_value,
			       offs * ep->stride);
		}
		break;

	case SND_USB_ENDPOINT_TYPE_SYNC:
		if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
			/*
			 * fill the length and offset of each urb descriptor.
			 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
			 */
			urb->iso_frame_desc[0].length = 4;
			urb->iso_frame_desc[0].offset = 0;
			cp[0] = ep->freqn;
			cp[1] = ep->freqn >> 8;
			cp[2] = ep->freqn >> 16;
			cp[3] = ep->freqn >> 24;
		} else {
			/*
			 * fill the length and offset of each urb descriptor.
			 * the fixed 10.14 frequency is passed through the pipe.
			 */
			urb->iso_frame_desc[0].length = 3;
			urb->iso_frame_desc[0].offset = 0;
			cp[0] = ep->freqn >> 2;
			cp[1] = ep->freqn >> 10;
			cp[2] = ep->freqn >> 18;
		}

		break;
	}
}

/*
 * Prepare a CAPTURE or SYNC urb for submission to the bus.
 */
static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
				       struct snd_urb_ctx *urb_ctx)
{
	int i, offs;
	struct urb *urb = urb_ctx->urb;

	urb->dev = ep->chip->dev; /* we need to set this at each time */

	switch (ep->type) {
	case SND_USB_ENDPOINT_TYPE_DATA:
		offs = 0;
		for (i = 0; i < urb_ctx->packets; i++) {
			urb->iso_frame_desc[i].offset = offs;
			urb->iso_frame_desc[i].length = ep->curpacksize;
			offs += ep->curpacksize;
		}

		urb->transfer_buffer_length = offs;
		urb->number_of_packets = urb_ctx->packets;
		break;

	case SND_USB_ENDPOINT_TYPE_SYNC:
		urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
		urb->iso_frame_desc[0].offset = 0;
		break;
	}
}

284
/*
285
 * Send output urbs that have been prepared previously. URBs are dequeued
286
287
288
289
 * from ep->ready_playback_urbs and in case there there aren't any available
 * or there are no packets that have been prepared, this function does
 * nothing.
 *
290
291
292
 * The reason why the functionality of sending and preparing URBs is separated
 * is that host controllers don't guarantee the order in which they return
 * inbound and outbound packets to their submitters.
293
294
 *
 * This function is only used for implicit feedback endpoints. For endpoints
295
296
 * driven by dedicated sync endpoints, URBs are immediately re-submitted
 * from their completion handler.
297
 */
298
299
300
301
302
static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
{
	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {

		unsigned long flags;
303
		struct snd_usb_packet_info *uninitialized_var(packet);
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
		struct snd_urb_ctx *ctx = NULL;
		struct urb *urb;
		int err, i;

		spin_lock_irqsave(&ep->lock, flags);
		if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
			packet = ep->next_packet + ep->next_packet_read_pos;
			ep->next_packet_read_pos++;
			ep->next_packet_read_pos %= MAX_URBS;

			/* take URB out of FIFO */
			if (!list_empty(&ep->ready_playback_urbs))
				ctx = list_first_entry(&ep->ready_playback_urbs,
					       struct snd_urb_ctx, ready_list);
		}
		spin_unlock_irqrestore(&ep->lock, flags);

		if (ctx == NULL)
			return;

		list_del_init(&ctx->ready_list);
		urb = ctx->urb;

		/* copy over the length information */
		for (i = 0; i < packet->packets; i++)
			ctx->packet_size[i] = packet->packet_size[i];

331
		/* call the data handler to fill in playback data */
332
333
334
335
		prepare_outbound_urb(ep, ctx);

		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
		if (err < 0)
336
337
338
			usb_audio_err(ep->chip,
				"Unable to submit urb #%d: %d (urb %p)\n",
				ctx->index, err, ctx->urb);
339
340
341
342
343
344
345
346
347
348
349
350
		else
			set_bit(ctx->index, &ep->active_mask);
	}
}

/*
 * complete callback for urbs
 */
static void snd_complete_urb(struct urb *urb)
{
	struct snd_urb_ctx *ctx = urb->context;
	struct snd_usb_endpoint *ep = ctx->ep;
351
352
	struct snd_pcm_substream *substream;
	unsigned long flags;
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
	int err;

	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
		     urb->status == -ENODEV ||		/* device removed */
		     urb->status == -ECONNRESET ||	/* unlinked */
		     urb->status == -ESHUTDOWN ||	/* device disabled */
		     ep->chip->shutdown))		/* device disconnected */
		goto exit_clear;

	if (usb_pipeout(ep->pipe)) {
		retire_outbound_urb(ep, ctx);
		/* can be stopped during retire callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;

368
		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
			spin_lock_irqsave(&ep->lock, flags);
			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
			spin_unlock_irqrestore(&ep->lock, flags);
			queue_pending_output_urbs(ep);

			goto exit_clear;
		}

		prepare_outbound_urb(ep, ctx);
	} else {
		retire_inbound_urb(ep, ctx);
		/* can be stopped during retire callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;

		prepare_inbound_urb(ep, ctx);
	}

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err == 0)
		return;

391
	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
392
393
	if (ep->data_subs && ep->data_subs->pcm_substream) {
		substream = ep->data_subs->pcm_substream;
394
		snd_pcm_stop_xrun(substream);
395
	}
396
397
398
399
400

exit_clear:
	clear_bit(ctx->index, &ep->active_mask);
}

401
/**
402
 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
403
404
405
406
407
408
409
410
411
412
413
414
415
416
 *
 * @chip: The chip
 * @alts: The USB host interface
 * @ep_num: The number of the endpoint to use
 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
 *
 * If the requested endpoint has not been added to the given chip before,
 * a new instance is created. Otherwise, a pointer to the previoulsy
 * created instance is returned. In case of any error, NULL is returned.
 *
 * New endpoints will be added to chip->ep_list and must be freed by
 * calling snd_usb_endpoint_free().
 */
417
418
419
420
421
struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
					      struct usb_host_interface *alts,
					      int ep_num, int direction, int type)
{
	struct snd_usb_endpoint *ep;
422
	int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
423

424
425
426
	if (WARN_ON(!alts))
		return NULL;

427
428
	mutex_lock(&chip->mutex);

429
	list_for_each_entry(ep, &chip->ep_list, list) {
430
431
		if (ep->ep_num == ep_num &&
		    ep->iface == alts->desc.bInterfaceNumber &&
432
		    ep->altsetting == alts->desc.bAlternateSetting) {
433
434
			usb_audio_dbg(ep->chip,
				      "Re-using EP %x in iface %d,%d @%p\n",
435
					ep_num, ep->iface, ep->altsetting, ep);
436
437
438
439
			goto __exit_unlock;
		}
	}

440
	usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
441
442
443
444
445
446
447
448
449
450
451
452
453
		    is_playback ? "playback" : "capture",
		    type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
		    ep_num);

	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
	if (!ep)
		goto __exit_unlock;

	ep->chip = chip;
	spin_lock_init(&ep->lock);
	ep->type = type;
	ep->ep_num = ep_num;
	ep->iface = alts->desc.bInterfaceNumber;
454
	ep->altsetting = alts->desc.bAlternateSetting;
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
	INIT_LIST_HEAD(&ep->ready_playback_urbs);
	ep_num &= USB_ENDPOINT_NUMBER_MASK;

	if (is_playback)
		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
	else
		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);

	if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
		    get_endpoint(alts, 1)->bRefresh >= 1 &&
		    get_endpoint(alts, 1)->bRefresh <= 9)
			ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
		else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
			ep->syncinterval = 1;
		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
			 get_endpoint(alts, 1)->bInterval <= 16)
			ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
		else
			ep->syncinterval = 3;

		ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
477
478
479
480

		if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
		    ep->syncmaxsize == 4)
			ep->udh01_fb_quirk = 1;
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
	}

	list_add_tail(&ep->list, &chip->ep_list);

__exit_unlock:
	mutex_unlock(&chip->mutex);

	return ep;
}

/*
 *  wait until all urbs are processed.
 */
static int wait_clear_urbs(struct snd_usb_endpoint *ep)
{
	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
	int alive;

	do {
500
		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
501
502
503
504
505
506
507
		if (!alive)
			break;

		schedule_timeout_uninterruptible(1);
	} while (time_before(jiffies, end_time));

	if (alive)
508
509
510
		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
511
	clear_bit(EP_FLAG_STOPPING, &ep->flags);
512
513
514
515

	return 0;
}

516
517
518
519
520
521
522
523
524
/* sync the pending stop operation;
 * this function itself doesn't trigger the stop operation
 */
void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
{
	if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
		wait_clear_urbs(ep);
}

525
526
527
/*
 * unlink active urbs.
 */
528
static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
{
	unsigned int i;

	if (!force && ep->chip->shutdown) /* to be sure... */
		return -EBADFD;

	clear_bit(EP_FLAG_RUNNING, &ep->flags);

	INIT_LIST_HEAD(&ep->ready_playback_urbs);
	ep->next_packet_read_pos = 0;
	ep->next_packet_write_pos = 0;

	for (i = 0; i < ep->nurbs; i++) {
		if (test_bit(i, &ep->active_mask)) {
			if (!test_and_set_bit(i, &ep->unlink_mask)) {
				struct urb *u = ep->urb[i].urb;
545
				usb_unlink_urb(u);
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
			}
		}
	}

	return 0;
}

/*
 * release an endpoint's urbs
 */
static void release_urbs(struct snd_usb_endpoint *ep, int force)
{
	int i;

	/* route incoming urbs to nirvana */
	ep->retire_data_urb = NULL;
	ep->prepare_data_urb = NULL;

	/* stop urbs */
565
	deactivate_urbs(ep, force);
566
567
568
569
570
571
572
573
574
575
576
577
578
	wait_clear_urbs(ep);

	for (i = 0; i < ep->nurbs; i++)
		release_urb_ctx(&ep->urb[i]);

	if (ep->syncbuf)
		usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
				  ep->syncbuf, ep->sync_dma);

	ep->syncbuf = NULL;
	ep->nurbs = 0;
}

579
580
581
/*
 * configure a data endpoint
 */
582
static int data_ep_set_params(struct snd_usb_endpoint *ep,
583
584
585
			      snd_pcm_format_t pcm_format,
			      unsigned int channels,
			      unsigned int period_bytes,
586
587
			      unsigned int frames_per_period,
			      unsigned int periods_per_buffer,
588
589
590
			      struct audioformat *fmt,
			      struct snd_usb_endpoint *sync_ep)
{
591
592
593
	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
	unsigned int max_packs_per_period, urbs_per_period, urb_packs;
	unsigned int max_urbs, i;
594
	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
595

596
597
598
599
600
601
602
603
604
	if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
		/*
		 * When operating in DSD DOP mode, the size of a sample frame
		 * in hardware differs from the actual physical format width
		 * because we need to make room for the DOP markers.
		 */
		frame_bits += channels << 3;
	}

605
606
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
607
	ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
608

609
610
611
612
613
614
	/* assume max. frequency is 25% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 2);
	maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3))
				>> (16 - ep->datainterval);
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
615
616
617
618
619
620
621
622
623
624
625
		/* whatever fits into a max. size packet */
		maxsize = ep->maxpacksize;
		ep->freqmax = (maxsize / (frame_bits >> 3))
				<< (16 - ep->datainterval);
	}

	if (ep->fill_max)
		ep->curpacksize = ep->maxpacksize;
	else
		ep->curpacksize = maxsize;

626
	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
627
		packs_per_ms = 8 >> ep->datainterval;
628
		max_packs_per_urb = MAX_PACKS_HS;
629
	} else {
630
631
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
632
	}
633
	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
		max_packs_per_urb = min(max_packs_per_urb,
					1U << sync_ep->syncinterval);
	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);

	/*
	 * Capture endpoints need to use small URBs because there's no way
	 * to tell in advance where the next period will end, and we don't
	 * want the next URB to complete much after the period ends.
	 *
	 * Playback endpoints with implicit sync much use the same parameters
	 * as their corresponding capture endpoint.
	 */
	if (usb_pipein(ep->pipe) ||
			snd_usb_endpoint_implicit_feedback_sink(ep)) {

649
650
651
652
653
654
655
656
657
658
659
660
661
662
		urb_packs = packs_per_ms;
		/*
		 * Wireless devices can poll at a max rate of once per 4ms.
		 * For dataintervals less than 5, increase the packet count to
		 * allow the host controller to use bursting to fill in the
		 * gaps.
		 */
		if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
			int interval = ep->datainterval;
			while (interval < 5) {
				urb_packs <<= 1;
				++interval;
			}
		}
663
		/* make capture URBs <= 1 ms and smaller than a period */
664
		urb_packs = min(max_packs_per_urb, urb_packs);
665
666
667
		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
			urb_packs >>= 1;
		ep->nurbs = MAX_URBS;
668

669
670
671
672
673
674
675
	/*
	 * Playback endpoints without implicit sync are adjusted so that
	 * a period fits as evenly as possible in the smallest number of
	 * URBs.  The total number of URBs is adjusted to the size of the
	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
	 */
	} else {
676
		/* determine how small a packet can be */
677
678
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
679
680
681
682
683
		/* with sync from device, assume it can be 12% lower */
		if (sync_ep)
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
		/* how many packets will contain an entire ALSA period? */
		max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);

		/* how many URBs will contain a period? */
		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
				max_packs_per_urb);
		/* how many packets are needed in each URB? */
		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);

		/* limit the number of frames in a single URB */
		ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
					urbs_per_period);

		/* try to use enough URBs to contain an entire ALSA buffer */
		max_urbs = min((unsigned) MAX_URBS,
				MAX_QUEUE * packs_per_ms / urb_packs);
		ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
701
702
703
704
705
706
707
	}

	/* allocate and initialize data urbs */
	for (i = 0; i < ep->nurbs; i++) {
		struct snd_urb_ctx *u = &ep->urb[i];
		u->index = i;
		u->ep = ep;
708
		u->packets = urb_packs;
709
710
711
712
713
714
715
716
717
718
719
720
721
722
		u->buffer_size = maxsize * u->packets;

		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
			u->packets++; /* for transfer delimiter */
		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
		if (!u->urb)
			goto out_of_memory;

		u->urb->transfer_buffer =
			usb_alloc_coherent(ep->chip->dev, u->buffer_size,
					   GFP_KERNEL, &u->urb->transfer_dma);
		if (!u->urb->transfer_buffer)
			goto out_of_memory;
		u->urb->pipe = ep->pipe;
723
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
724
725
726
727
728
729
730
731
732
733
734
735
736
		u->urb->interval = 1 << ep->datainterval;
		u->urb->context = u;
		u->urb->complete = snd_complete_urb;
		INIT_LIST_HEAD(&u->ready_list);
	}

	return 0;

out_of_memory:
	release_urbs(ep, 0);
	return -ENOMEM;
}

737
738
739
/*
 * configure a sync endpoint
 */
740
static int sync_ep_set_params(struct snd_usb_endpoint *ep)
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
{
	int i;

	ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
					 GFP_KERNEL, &ep->sync_dma);
	if (!ep->syncbuf)
		return -ENOMEM;

	for (i = 0; i < SYNC_URBS; i++) {
		struct snd_urb_ctx *u = &ep->urb[i];
		u->index = i;
		u->ep = ep;
		u->packets = 1;
		u->urb = usb_alloc_urb(1, GFP_KERNEL);
		if (!u->urb)
			goto out_of_memory;
		u->urb->transfer_buffer = ep->syncbuf + i * 4;
		u->urb->transfer_dma = ep->sync_dma + i * 4;
		u->urb->transfer_buffer_length = 4;
		u->urb->pipe = ep->pipe;
761
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
		u->urb->number_of_packets = 1;
		u->urb->interval = 1 << ep->syncinterval;
		u->urb->context = u;
		u->urb->complete = snd_complete_urb;
	}

	ep->nurbs = SYNC_URBS;

	return 0;

out_of_memory:
	release_urbs(ep, 0);
	return -ENOMEM;
}

777
/**
778
 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
779
 *
780
 * @ep: the snd_usb_endpoint to configure
781
782
783
 * @pcm_format: the audio fomat.
 * @channels: the number of audio channels.
 * @period_bytes: the number of bytes in one alsa period.
784
785
 * @period_frames: the number of frames in one alsa period.
 * @buffer_periods: the number of periods in one alsa buffer.
786
 * @rate: the frame rate.
787
788
 * @fmt: the USB audio format information
 * @sync_ep: the sync endpoint to use, if any
789
 *
790
 * Determine the number of URBs to be used on this endpoint.
791
792
793
 * An endpoint must be configured before it can be started.
 * An endpoint that is already running can not be reconfigured.
 */
794
int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
795
796
797
				snd_pcm_format_t pcm_format,
				unsigned int channels,
				unsigned int period_bytes,
798
799
				unsigned int period_frames,
				unsigned int buffer_periods,
800
				unsigned int rate,
801
802
803
804
805
806
				struct audioformat *fmt,
				struct snd_usb_endpoint *sync_ep)
{
	int err;

	if (ep->use_count != 0) {
807
808
809
		usb_audio_warn(ep->chip,
			 "Unable to change format on ep #%x: already in use\n",
			 ep->ep_num);
810
811
812
813
814
815
816
817
		return -EBUSY;
	}

	/* release old buffers, if any */
	release_urbs(ep, 0);

	ep->datainterval = fmt->datainterval;
	ep->maxpacksize = fmt->maxpacksize;
818
	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
819
820

	if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
821
		ep->freqn = get_usb_full_speed_rate(rate);
822
	else
823
		ep->freqn = get_usb_high_speed_rate(rate);
824
825
826
827
828
829
830
831
832

	/* calculate the frequency in 16.16 format */
	ep->freqm = ep->freqn;
	ep->freqshift = INT_MIN;

	ep->phase = 0;

	switch (ep->type) {
	case  SND_USB_ENDPOINT_TYPE_DATA:
833
		err = data_ep_set_params(ep, pcm_format, channels,
834
835
					 period_bytes, period_frames,
					 buffer_periods, fmt, sync_ep);
836
837
		break;
	case  SND_USB_ENDPOINT_TYPE_SYNC:
838
		err = sync_ep_set_params(ep);
839
840
841
842
843
		break;
	default:
		err = -EINVAL;
	}

844
845
846
	usb_audio_dbg(ep->chip,
		"Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
		ep->ep_num, ep->type, ep->nurbs, err);
847
848
849
850

	return err;
}

851
852
853
/**
 * snd_usb_endpoint_start: start an snd_usb_endpoint
 *
854
855
856
 * @ep:		the endpoint to start
 * @can_sleep:	flag indicating whether the operation is executed in
 * 		non-atomic context
857
858
 *
 * A call to this function will increment the use count of the endpoint.
859
 * In case it is not already running, the URBs for this endpoint will be
860
861
862
863
864
865
 * submitted. Otherwise, this function does nothing.
 *
 * Must be balanced to calls of snd_usb_endpoint_stop().
 *
 * Returns an error if the URB submission failed, 0 in all other cases.
 */
866
int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
867
868
869
870
871
872
873
874
875
876
877
{
	int err;
	unsigned int i;

	if (ep->chip->shutdown)
		return -EBADFD;

	/* already running? */
	if (++ep->use_count != 1)
		return 0;

878
	/* just to be sure */
879
	deactivate_urbs(ep, false);
880
881
882
	if (can_sleep)
		wait_clear_urbs(ep);

883
884
885
886
	ep->active_mask = 0;
	ep->unlink_mask = 0;
	ep->phase = 0;

887
888
	snd_usb_endpoint_start_quirk(ep);

889
890
891
	/*
	 * If this endpoint has a data endpoint as implicit feedback source,
	 * don't start the urbs here. Instead, mark them all as available,
892
893
	 * wait for the record urbs to return and queue the playback urbs
	 * from that context.
894
895
896
897
	 */

	set_bit(EP_FLAG_RUNNING, &ep->flags);

898
	if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
		for (i = 0; i < ep->nurbs; i++) {
			struct snd_urb_ctx *ctx = ep->urb + i;
			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
		}

		return 0;
	}

	for (i = 0; i < ep->nurbs; i++) {
		struct urb *urb = ep->urb[i].urb;

		if (snd_BUG_ON(!urb))
			goto __error;

		if (usb_pipeout(ep->pipe)) {
			prepare_outbound_urb(ep, urb->context);
		} else {
			prepare_inbound_urb(ep, urb->context);
		}

		err = usb_submit_urb(urb, GFP_ATOMIC);
		if (err < 0) {
921
922
923
			usb_audio_err(ep->chip,
				"cannot submit urb %d, error %d: %s\n",
				i, err, usb_error_string(err));
924
925
926
927
928
929
930
931
932
933
			goto __error;
		}
		set_bit(i, &ep->active_mask);
	}

	return 0;

__error:
	clear_bit(EP_FLAG_RUNNING, &ep->flags);
	ep->use_count--;
934
	deactivate_urbs(ep, false);
935
936
937
	return -EPIPE;
}

938
939
940
941
942
943
944
/**
 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
 *
 * @ep: the endpoint to stop (may be NULL)
 *
 * A call to this function will decrement the use count of the endpoint.
 * In case the last user has requested the endpoint stop, the URBs will
945
 * actually be deactivated.
946
947
 *
 * Must be balanced to calls of snd_usb_endpoint_start().
948
949
950
 *
 * The caller needs to synchronize the pending stop operation via
 * snd_usb_endpoint_sync_pending_stop().
951
 */
952
void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
953
954
955
956
957
958
959
960
{
	if (!ep)
		return;

	if (snd_BUG_ON(ep->use_count == 0))
		return;

	if (--ep->use_count == 0) {
961
		deactivate_urbs(ep, false);
962
963
964
965
		ep->data_subs = NULL;
		ep->sync_slave = NULL;
		ep->retire_data_urb = NULL;
		ep->prepare_data_urb = NULL;
966
		set_bit(EP_FLAG_STOPPING, &ep->flags);
967
968
969
	}
}

970
971
972
973
974
/**
 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
 *
 * @ep: the endpoint to deactivate
 *
975
976
 * If the endpoint is not currently in use, this functions will
 * deactivate its associated URBs.
977
978
979
 *
 * In case of any active users, this functions does nothing.
 */
980
void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
981
982
{
	if (!ep)
983
		return;
984
985

	if (ep->use_count != 0)
986
		return;
987

988
989
	deactivate_urbs(ep, true);
	wait_clear_urbs(ep);
990
991
}

992
993
994
995
996
997
998
999
1000
/**
 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
 *
 * @ep: the endpoint to release
 *
 * This function does not care for the endpoint's use count but will tear
 * down all the streaming URBs immediately.
 */
void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)