endpoint.c 39.5 KB
Newer Older
1
// SPDX-License-Identifier: GPL-2.0-or-later
Daniel Mack's avatar
Daniel Mack committed
2
3
4
/*
 */

5
6
#include <linux/gfp.h>
#include <linux/init.h>
7
#include <linux/ratelimit.h>
8
9
#include <linux/usb.h>
#include <linux/usb/audio.h>
10
#include <linux/slab.h>
11
12
13

#include <sound/core.h>
#include <sound/pcm.h>
14
#include <sound/pcm_params.h>
15
16
17
18
19
20

#include "usbaudio.h"
#include "helper.h"
#include "card.h"
#include "endpoint.h"
#include "pcm.h"
21
#include "quirks.h"
22

23
#define EP_FLAG_RUNNING		1
24
#define EP_FLAG_STOPPING	2
25

26
27
28
29
30
/*
 * 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
31
 * optional callbacks to let the pcm logic handle the actual content of the
32
33
34
 * packets for playback and record. Thus, the bus streaming and the audio
 * handlers are fully decoupled.
 *
35
 * There are two different types of endpoints in audio applications.
36
37
38
39
 *
 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
 * inbound and outbound traffic.
 *
40
41
42
 * 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).
43
 *
44
45
 * Each endpoint has to be configured prior to being used by calling
 * snd_usb_endpoint_set_params().
46
47
48
49
 *
 * 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
50
 * one to stop it will tear the URBs down again.
51
52
 */

53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
/*
 * 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)
{
76
77
78
79
80
81
	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;
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
}

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";
	}
}

109
110
111
/**
 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
 *
112
 * @ep: The snd_usb_endpoint
113
114
115
116
 *
 * Determine whether an endpoint is driven by an implicit feedback
 * data endpoint source.
 */
117
int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
118
119
120
121
122
123
124
{
	return  ep->sync_master &&
		ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA &&
		ep->type == SND_USB_ENDPOINT_TYPE_DATA &&
		usb_pipeout(ep->pipe);
}

125
126
/*
 * For streaming based on information derived from sync endpoints,
127
 * prepare_outbound_urb_sizes() will call slave_next_packet_size() to
128
129
 * determine the number of samples to be sent in the next packet.
 *
130
 * For implicit feedback, slave_next_packet_size() is unused.
131
 */
132
int snd_usb_endpoint_slave_next_packet_size(struct snd_usb_endpoint *ep)
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
{
	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;
}

149
150
151
152
153
154
155
156
157
158
159
160
161
/*
 * For adaptive and synchronous endpoints, prepare_outbound_urb_sizes()
 * will call next_packet_size() to determine the number of samples to be
 * sent in the next packet.
 */
int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
{
	int ret;

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

	ep->sample_accum += ep->sample_rem;
162
163
164
	if (ep->sample_accum >= ep->pps) {
		ep->sample_accum -= ep->pps;
		ret = ep->packsize[1];
165
	} else {
166
		ret = ep->packsize[0];
167
168
169
170
171
	}

	return ret;
}

172
173
174
175
176
177
178
179
180
181
182
183
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;

184
185
186
187
188
	if (unlikely(ep->skip_packets > 0)) {
		ep->skip_packets--;
		return;
	}

189
190
191
192
193
194
195
	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);
}

196
197
198
199
200
static void prepare_silent_urb(struct snd_usb_endpoint *ep,
			       struct snd_urb_ctx *ctx)
{
	struct urb *urb = ctx->urb;
	unsigned int offs = 0;
201
202
	unsigned int extra = 0;
	__le32 packet_length;
203
204
	int i;

205
206
207
208
	/* For tx_length_quirk, put packet length at start of packet */
	if (ep->chip->tx_length_quirk)
		extra = sizeof(packet_length);

209
	for (i = 0; i < ctx->packets; ++i) {
210
211
		unsigned int offset;
		unsigned int length;
212
213
214
215
		int counts;

		if (ctx->packet_size[i])
			counts = ctx->packet_size[i];
216
217
		else if (ep->sync_master)
			counts = snd_usb_endpoint_slave_next_packet_size(ep);
218
219
220
		else
			counts = snd_usb_endpoint_next_packet_size(ep);

221
222
223
224
225
226
227
228
229
230
231
		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);
232
233
234
235
		offs += counts;
	}

	urb->number_of_packets = ctx->packets;
236
	urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
237
238
}

239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/*
 * 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 */
256
			prepare_silent_urb(ep, ctx);
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
307
308
309
310
311
312
313
314
315
316
317
318
		}
		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;
	}
}

319
/*
320
 * Send output urbs that have been prepared previously. URBs are dequeued
321
322
323
324
 * 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.
 *
325
326
327
 * 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.
328
329
 *
 * This function is only used for implicit feedback endpoints. For endpoints
330
331
 * driven by dedicated sync endpoints, URBs are immediately re-submitted
 * from their completion handler.
332
 */
333
334
335
336
337
static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
{
	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {

		unsigned long flags;
338
		struct snd_usb_packet_info *packet;
339
340
341
342
343
344
345
346
347
348
		struct snd_urb_ctx *ctx = NULL;
		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 */
349
			if (!list_empty(&ep->ready_playback_urbs)) {
350
351
				ctx = list_first_entry(&ep->ready_playback_urbs,
					       struct snd_urb_ctx, ready_list);
352
353
				list_del_init(&ctx->ready_list);
			}
354
355
356
357
358
359
360
361
362
363
		}
		spin_unlock_irqrestore(&ep->lock, flags);

		if (ctx == NULL)
			return;

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

364
		/* call the data handler to fill in playback data */
365
366
367
368
		prepare_outbound_urb(ep, ctx);

		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
		if (err < 0)
369
370
371
			usb_audio_err(ep->chip,
				"Unable to submit urb #%d: %d (urb %p)\n",
				ctx->index, err, ctx->urb);
372
373
374
375
376
377
378
379
380
381
382
383
		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;
384
385
	struct snd_pcm_substream *substream;
	unsigned long flags;
386
387
388
389
390
	int err;

	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
		     urb->status == -ENODEV ||		/* device removed */
		     urb->status == -ECONNRESET ||	/* unlinked */
391
392
393
394
		     urb->status == -ESHUTDOWN))	/* device disabled */
		goto exit_clear;
	/* device disconnected */
	if (unlikely(atomic_read(&ep->chip->shutdown)))
395
396
		goto exit_clear;

397
398
399
	if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
		goto exit_clear;

400
401
402
403
404
405
	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;

406
		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
407
408
409
410
411
412
413
414
415
			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);
416
417
418
		/* can be stopped during prepare callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;
419
420
421
422
423
424
425
426
427
428
429
430
431
	} 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;

432
	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
433
434
	if (ep->data_subs && ep->data_subs->pcm_substream) {
		substream = ep->data_subs->pcm_substream;
435
		snd_pcm_stop_xrun(substream);
436
	}
437
438
439
440
441

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

442
/**
443
 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
444
445
446
447
448
449
450
451
452
453
454
455
456
 *
 * @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().
457
458
459
 *
 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
 * bNumEndpoints > 1 beforehand.
460
 */
461
462
463
464
465
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;
466
	int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
467

468
469
470
	if (WARN_ON(!alts))
		return NULL;

471
472
	mutex_lock(&chip->mutex);

473
	list_for_each_entry(ep, &chip->ep_list, list) {
474
475
		if (ep->ep_num == ep_num &&
		    ep->iface == alts->desc.bInterfaceNumber &&
476
		    ep->altsetting == alts->desc.bAlternateSetting) {
477
478
			usb_audio_dbg(ep->chip,
				      "Re-using EP %x in iface %d,%d @%p\n",
479
					ep_num, ep->iface, ep->altsetting, ep);
480
481
482
483
			goto __exit_unlock;
		}
	}

484
	usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
485
486
487
488
489
490
491
492
493
494
495
496
497
		    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;
498
	ep->altsetting = alts->desc.bAlternateSetting;
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
	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);

525
526
	ep->is_implicit_feedback = 0;

527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
__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 {
542
		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
543
544
545
546
547
548
549
		if (!alive)
			break;

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

	if (alive)
550
551
552
		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
553
	clear_bit(EP_FLAG_STOPPING, &ep->flags);
554

555
556
557
558
559
	ep->data_subs = NULL;
	ep->sync_slave = NULL;
	ep->retire_data_urb = NULL;
	ep->prepare_data_urb = NULL;

560
561
562
	return 0;
}

563
564
565
566
567
568
569
570
571
/* 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);
}

572
573
574
/*
 * unlink active urbs.
 */
575
static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
576
577
578
{
	unsigned int i;

579
	if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
580
581
582
583
584
585
586
587
588
589
590
591
		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;
592
				usb_unlink_urb(u);
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
			}
		}
	}

	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 */
612
	deactivate_urbs(ep, force);
613
614
615
616
617
	wait_clear_urbs(ep);

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

618
619
	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
			  ep->syncbuf, ep->sync_dma);
620
621
622
623
624

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

625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
/*
 * Check data endpoint for format differences
 */
static bool check_ep_params(struct snd_usb_endpoint *ep,
			      snd_pcm_format_t pcm_format,
			      unsigned int channels,
			      unsigned int period_bytes,
			      unsigned int frames_per_period,
			      unsigned int periods_per_buffer,
			      struct audioformat *fmt,
			      struct snd_usb_endpoint *sync_ep)
{
	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;
	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
	int tx_length_quirk = (ep->chip->tx_length_quirk &&
			       usb_pipeout(ep->pipe));
	bool ret = 1;

	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;
	}

	ret = ret && (ep->datainterval == fmt->datainterval);
	ret = ret && (ep->stride == frame_bits >> 3);

	switch (pcm_format) {
	case SNDRV_PCM_FORMAT_U8:
		ret = ret && (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:
		ret = ret && (ep->silence_value == 0x69);
		break;
	default:
		ret = ret && (ep->silence_value == 0);
	}

	/* assume max. frequency is 50% higher than nominal */
	ret = ret && (ep->freqmax == ep->freqn + (ep->freqn >> 1));
	/* 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);
	if (tx_length_quirk)
		maxsize += sizeof(__le32); /* Space for length descriptor */
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
		/* whatever fits into a max. size packet */
		unsigned int data_maxsize = maxsize = ep->maxpacksize;

		if (tx_length_quirk)
			/* Need to remove the length descriptor to calc freq */
			data_maxsize -= sizeof(__le32);
		ret = ret && (ep->freqmax == (data_maxsize / (frame_bits >> 3))
				<< (16 - ep->datainterval));
	}

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

	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
		packs_per_ms = 8 >> ep->datainterval;
		max_packs_per_urb = MAX_PACKS_HS;
	} else {
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
	}
	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
		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)) {

		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;
			}
		}
		/* make capture URBs <= 1 ms and smaller than a period */
		urb_packs = min(max_packs_per_urb, urb_packs);
		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
			urb_packs >>= 1;
		ret = ret && (ep->nurbs == MAX_URBS);

	/*
	 * 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 {
		/* determine how small a packet can be */
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
		/* with sync from device, assume it can be 12% lower */
		if (sync_ep)
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

		/* 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 */
		ret = ret && (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);
		ret = ret && (ep->nurbs == min(max_urbs,
				urbs_per_period * periods_per_buffer));
	}

	ret = ret && (ep->datainterval == fmt->datainterval);
	ret = ret && (ep->maxpacksize == fmt->maxpacksize);
	ret = ret &&
		(ep->fill_max == !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX));

	return ret;
}

797
798
799
/*
 * configure a data endpoint
 */
800
static int data_ep_set_params(struct snd_usb_endpoint *ep,
801
802
803
			      snd_pcm_format_t pcm_format,
			      unsigned int channels,
			      unsigned int period_bytes,
804
805
			      unsigned int frames_per_period,
			      unsigned int periods_per_buffer,
806
807
808
			      struct audioformat *fmt,
			      struct snd_usb_endpoint *sync_ep)
{
809
810
811
	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;
812
	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
813
814
	int tx_length_quirk = (ep->chip->tx_length_quirk &&
			       usb_pipeout(ep->pipe));
815

816
817
818
819
820
821
822
823
824
	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;
	}

825
826
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841

	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;
	}
842

843
844
	/* assume max. frequency is 50% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 1);
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
	/* 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);
862
863
	if (tx_length_quirk)
		maxsize += sizeof(__le32); /* Space for length descriptor */
864
865
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
866
		/* whatever fits into a max. size packet */
867
868
869
870
871
872
		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))
873
874
875
876
877
878
879
880
				<< (16 - ep->datainterval);
	}

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

881
	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
882
		packs_per_ms = 8 >> ep->datainterval;
883
		max_packs_per_urb = MAX_PACKS_HS;
884
	} else {
885
886
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
887
	}
888
	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
		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)) {

904
905
906
907
908
909
910
911
912
913
914
915
916
917
		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;
			}
		}
918
		/* make capture URBs <= 1 ms and smaller than a period */
919
		urb_packs = min(max_packs_per_urb, urb_packs);
920
921
922
		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
			urb_packs >>= 1;
		ep->nurbs = MAX_URBS;
923

924
925
926
927
928
929
930
	/*
	 * 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 {
931
		/* determine how small a packet can be */
932
933
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
934
935
936
937
938
		/* with sync from device, assume it can be 12% lower */
		if (sync_ep)
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
		/* 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);
956
957
958
959
960
961
962
	}

	/* 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;
963
		u->packets = urb_packs;
964
965
966
967
968
969
970
971
972
973
974
975
976
977
		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;
978
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
979
980
981
982
983
984
985
986
987
988
989
990
991
		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;
}

992
993
994
/*
 * configure a sync endpoint
 */
995
static int sync_ep_set_params(struct snd_usb_endpoint *ep)
996
997
998
999
1000
{
	int i;

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