endpoint.c 33 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
	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);
}

186
187
188
189
190
static void prepare_silent_urb(struct snd_usb_endpoint *ep,
			       struct snd_urb_ctx *ctx)
{
	struct urb *urb = ctx->urb;
	unsigned int offs = 0;
191
192
	unsigned int extra = 0;
	__le32 packet_length;
193
194
	int i;

195
196
197
198
	/* For tx_length_quirk, put packet length at start of packet */
	if (ep->chip->tx_length_quirk)
		extra = sizeof(packet_length);

199
	for (i = 0; i < ctx->packets; ++i) {
200
201
		unsigned int offset;
		unsigned int length;
202
203
204
205
206
207
208
		int counts;

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

209
210
211
212
213
214
215
216
217
218
219
		length = counts * ep->stride; /* number of silent bytes */
		offset = offs * ep->stride + extra * i;
		urb->iso_frame_desc[i].offset = offset;
		urb->iso_frame_desc[i].length = length + extra;
		if (extra) {
			packet_length = cpu_to_le32(length);
			memcpy(urb->transfer_buffer + offset,
			       &packet_length, sizeof(packet_length));
		}
		memset(urb->transfer_buffer + offset + extra,
		       ep->silence_value, length);
220
221
222
223
		offs += counts;
	}

	urb->number_of_packets = ctx->packets;
224
	urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
225
226
}

227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/*
 * Prepare a PLAYBACK urb for submission to the bus.
 */
static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
				 struct snd_urb_ctx *ctx)
{
	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 */
244
			prepare_silent_urb(ep, ctx);
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
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
		}
		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;
	}
}

307
/*
308
 * Send output urbs that have been prepared previously. URBs are dequeued
309
310
311
312
 * 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.
 *
313
314
315
 * 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.
316
317
 *
 * This function is only used for implicit feedback endpoints. For endpoints
318
319
 * driven by dedicated sync endpoints, URBs are immediately re-submitted
 * from their completion handler.
320
 */
321
322
323
324
325
static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
{
	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {

		unsigned long flags;
326
		struct snd_usb_packet_info *uninitialized_var(packet);
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
		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];

354
		/* call the data handler to fill in playback data */
355
356
357
358
		prepare_outbound_urb(ep, ctx);

		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
		if (err < 0)
359
360
361
			usb_audio_err(ep->chip,
				"Unable to submit urb #%d: %d (urb %p)\n",
				ctx->index, err, ctx->urb);
362
363
364
365
366
367
368
369
370
371
372
373
		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;
374
375
	struct snd_pcm_substream *substream;
	unsigned long flags;
376
377
378
379
380
	int err;

	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
		     urb->status == -ENODEV ||		/* device removed */
		     urb->status == -ECONNRESET ||	/* unlinked */
381
382
383
384
		     urb->status == -ESHUTDOWN))	/* device disabled */
		goto exit_clear;
	/* device disconnected */
	if (unlikely(atomic_read(&ep->chip->shutdown)))
385
386
		goto exit_clear;

387
388
389
	if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
		goto exit_clear;

390
391
392
393
394
395
	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;

396
		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
			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;

419
	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
420
421
	if (ep->data_subs && ep->data_subs->pcm_substream) {
		substream = ep->data_subs->pcm_substream;
422
		snd_pcm_stop_xrun(substream);
423
	}
424
425
426
427
428

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

429
/**
430
 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
431
432
433
434
435
436
437
438
439
440
441
442
443
 *
 * @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().
444
445
446
 *
 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
 * bNumEndpoints > 1 beforehand.
447
 */
448
449
450
451
452
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;
453
	int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
454

455
456
457
	if (WARN_ON(!alts))
		return NULL;

458
459
	mutex_lock(&chip->mutex);

460
	list_for_each_entry(ep, &chip->ep_list, list) {
461
462
		if (ep->ep_num == ep_num &&
		    ep->iface == alts->desc.bInterfaceNumber &&
463
		    ep->altsetting == alts->desc.bAlternateSetting) {
464
465
			usb_audio_dbg(ep->chip,
				      "Re-using EP %x in iface %d,%d @%p\n",
466
					ep_num, ep->iface, ep->altsetting, ep);
467
468
469
470
			goto __exit_unlock;
		}
	}

471
	usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
472
473
474
475
476
477
478
479
480
481
482
483
484
		    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;
485
	ep->altsetting = alts->desc.bAlternateSetting;
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
	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);
	}

	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 {
527
		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
528
529
530
531
532
533
534
		if (!alive)
			break;

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

	if (alive)
535
536
537
		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
538
	clear_bit(EP_FLAG_STOPPING, &ep->flags);
539

540
541
542
543
544
	ep->data_subs = NULL;
	ep->sync_slave = NULL;
	ep->retire_data_urb = NULL;
	ep->prepare_data_urb = NULL;

545
546
547
	return 0;
}

548
549
550
551
552
553
554
555
556
/* 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);
}

557
558
559
/*
 * unlink active urbs.
 */
560
static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
561
562
563
{
	unsigned int i;

564
	if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
565
566
567
568
569
570
571
572
573
574
575
576
		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;
577
				usb_unlink_urb(u);
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
			}
		}
	}

	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 */
597
	deactivate_urbs(ep, force);
598
599
600
601
602
603
604
605
606
607
608
609
610
	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;
}

611
612
613
/*
 * configure a data endpoint
 */
614
static int data_ep_set_params(struct snd_usb_endpoint *ep,
615
616
617
			      snd_pcm_format_t pcm_format,
			      unsigned int channels,
			      unsigned int period_bytes,
618
619
			      unsigned int frames_per_period,
			      unsigned int periods_per_buffer,
620
621
622
			      struct audioformat *fmt,
			      struct snd_usb_endpoint *sync_ep)
{
623
624
625
	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;
626
	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
627
628
	int tx_length_quirk = (ep->chip->tx_length_quirk &&
			       usb_pipeout(ep->pipe));
629

630
631
632
633
634
635
636
637
638
	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;
	}

639
640
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655

	switch (pcm_format) {
	case SNDRV_PCM_FORMAT_U8:
		ep->silence_value = 0x80;
		break;
	case SNDRV_PCM_FORMAT_DSD_U8:
	case SNDRV_PCM_FORMAT_DSD_U16_LE:
	case SNDRV_PCM_FORMAT_DSD_U32_LE:
	case SNDRV_PCM_FORMAT_DSD_U16_BE:
	case SNDRV_PCM_FORMAT_DSD_U32_BE:
		ep->silence_value = 0x69;
		break;
	default:
		ep->silence_value = 0;
	}
656

657
658
	/* assume max. frequency is 50% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 1);
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
	/* Round up freqmax to nearest integer in order to calculate maximum
	 * packet size, which must represent a whole number of frames.
	 * This is accomplished by adding 0x0.ffff before converting the
	 * Q16.16 format into integer.
	 * In order to accurately calculate the maximum packet size when
	 * the data interval is more than 1 (i.e. ep->datainterval > 0),
	 * multiply by the data interval prior to rounding. For instance,
	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
	 * frames with a data interval of 1, but 11 (10.25) frames with a
	 * data interval of 2.
	 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
	 * maximum datainterval value of 3, at USB full speed, higher for
	 * USB high speed, noting that ep->freqmax is in units of
	 * frames per packet in Q16.16 format.)
	 */
	maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
			 (frame_bits >> 3);
676
677
	if (tx_length_quirk)
		maxsize += sizeof(__le32); /* Space for length descriptor */
678
679
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
680
		/* whatever fits into a max. size packet */
681
682
683
684
685
686
		unsigned int data_maxsize = maxsize = ep->maxpacksize;

		if (tx_length_quirk)
			/* Need to remove the length descriptor to calc freq */
			data_maxsize -= sizeof(__le32);
		ep->freqmax = (data_maxsize / (frame_bits >> 3))
687
688
689
690
691
692
693
694
				<< (16 - ep->datainterval);
	}

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

695
	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
696
		packs_per_ms = 8 >> ep->datainterval;
697
		max_packs_per_urb = MAX_PACKS_HS;
698
	} else {
699
700
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
701
	}
702
	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
		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)) {

718
719
720
721
722
723
724
725
726
727
728
729
730
731
		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;
			}
		}
732
		/* make capture URBs <= 1 ms and smaller than a period */
733
		urb_packs = min(max_packs_per_urb, urb_packs);
734
735
736
		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
			urb_packs >>= 1;
		ep->nurbs = MAX_URBS;
737

738
739
740
741
742
743
744
	/*
	 * 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 {
745
		/* determine how small a packet can be */
746
747
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
748
749
750
751
752
		/* with sync from device, assume it can be 12% lower */
		if (sync_ep)
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
		/* 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);
770
771
772
773
774
775
776
	}

	/* 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;
777
		u->packets = urb_packs;
778
779
780
781
782
783
784
785
786
787
788
789
790
791
		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;
792
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
793
794
795
796
797
798
799
800
801
802
803
804
805
		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;
}

806
807
808
/*
 * configure a sync endpoint
 */
809
static int sync_ep_set_params(struct snd_usb_endpoint *ep)
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
{
	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;
830
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
		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;
}

846
/**
847
 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
848
 *
849
 * @ep: the snd_usb_endpoint to configure
850
851
852
 * @pcm_format: the audio fomat.
 * @channels: the number of audio channels.
 * @period_bytes: the number of bytes in one alsa period.
853
854
 * @period_frames: the number of frames in one alsa period.
 * @buffer_periods: the number of periods in one alsa buffer.
855
 * @rate: the frame rate.
856
857
 * @fmt: the USB audio format information
 * @sync_ep: the sync endpoint to use, if any
858
 *
859
 * Determine the number of URBs to be used on this endpoint.
860
861
862
 * An endpoint must be configured before it can be started.
 * An endpoint that is already running can not be reconfigured.
 */
863
int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
864
865
866
				snd_pcm_format_t pcm_format,
				unsigned int channels,
				unsigned int period_bytes,
867
868
				unsigned int period_frames,
				unsigned int buffer_periods,
869
				unsigned int rate,
870
871
872
873
874
875
				struct audioformat *fmt,
				struct snd_usb_endpoint *sync_ep)
{
	int err;

	if (ep->use_count != 0) {
876
877
878
		usb_audio_warn(ep->chip,
			 "Unable to change format on ep #%x: already in use\n",
			 ep->ep_num);
879
880
881
882
883
884
885
886
		return -EBUSY;
	}

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

	ep->datainterval = fmt->datainterval;
	ep->maxpacksize = fmt->maxpacksize;
887
	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
888
889

	if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
890
		ep->freqn = get_usb_full_speed_rate(rate);
891
	else
892
		ep->freqn = get_usb_high_speed_rate(rate);
893
894
895
896
897
898
899
900
901

	/* 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:
902
		err = data_ep_set_params(ep, pcm_format, channels,
903
904
					 period_bytes, period_frames,
					 buffer_periods, fmt, sync_ep);
905
906
		break;
	case  SND_USB_ENDPOINT_TYPE_SYNC:
907
		err = sync_ep_set_params(ep);
908
909
910
911
912
		break;
	default:
		err = -EINVAL;
	}

913
914
915
	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);
916
917
918
919

	return err;
}

920
921
922
/**
 * snd_usb_endpoint_start: start an snd_usb_endpoint
 *
923
 * @ep: the endpoint to start
924
925
 *
 * A call to this function will increment the use count of the endpoint.
926
 * In case it is not already running, the URBs for this endpoint will be
927
928
929
930
931
932
 * 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.
 */
933
int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
934
935
936
937
{
	int err;
	unsigned int i;

938
	if (atomic_read(&ep->chip->shutdown))
939
940
941
942
943
944
		return -EBADFD;

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

945
	/* just to be sure */
946
	deactivate_urbs(ep, false);
947

948
949
950
951
	ep->active_mask = 0;
	ep->unlink_mask = 0;
	ep->phase = 0;

952
953
	snd_usb_endpoint_start_quirk(ep);

954
955
956
	/*
	 * If this endpoint has a data endpoint as implicit feedback source,
	 * don't start the urbs here. Instead, mark them all as available,
957
958
	 * wait for the record urbs to return and queue the playback urbs
	 * from that context.
959
960
961
962
	 */

	set_bit(EP_FLAG_RUNNING, &ep->flags);

963
	if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
		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) {
986
987
988
			usb_audio_err(ep->chip,
				"cannot submit urb %d, error %d: %s\n",
				i, err, usb_error_string(err));
989
990
991
992
993
994
995
996
997
998
			goto __error;
		}
		set_bit(i, &ep->active_mask);
	}

	return 0;

__error:
	clear_bit(EP_FLAG_RUNNING, &ep->flags);
	ep->use_count--;
999
	deactivate_urbs(ep, false);
1000
	return -EPIPE;
For faster browsing, not all history is shown. View entire blame