aboutsummaryrefslogtreecommitdiffstats
path: root/sound/core/seq/seq_queue.c
blob: 98de2e711fde90b174d6cc87ffde3b00861073d1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
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
76
77
78
79
80
81
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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
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
174
175
176
177
178
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
206
207
208
209
210
211
212
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
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
319
320
321
322
323
324
325
326
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
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
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
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
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
/*
 *   ALSA sequencer Timing queue handling
 *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
 *
 *   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
 *
 * MAJOR CHANGES
 *   Nov. 13, 1999	Takashi Iwai <iwai@ww.uni-erlangen.de>
 *     - Queues are allocated dynamically via ioctl.
 *     - When owner client is deleted, all owned queues are deleted, too.
 *     - Owner of unlocked queue is kept unmodified even if it is
 *	 manipulated by other clients.
 *     - Owner field in SET_QUEUE_OWNER ioctl must be identical with the
 *       caller client.  i.e. Changing owner to a third client is not
 *       allowed.
 *
 *  Aug. 30, 2000	Takashi Iwai
 *     - Queues are managed in static array again, but with better way.
 *       The API itself is identical.
 *     - The queue is locked when queue_t pinter is returned via
 *       queueptr().  This pointer *MUST* be released afterward by
 *       queuefree(ptr).
 *     - Addition of experimental sync support.
 */

#include <sound/driver.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <sound/core.h>

#include "seq_memory.h"
#include "seq_queue.h"
#include "seq_clientmgr.h"
#include "seq_fifo.h"
#include "seq_timer.h"
#include "seq_info.h"

/* list of allocated queues */
static queue_t *queue_list[SNDRV_SEQ_MAX_QUEUES];
static DEFINE_SPINLOCK(queue_list_lock);
/* number of queues allocated */
static int num_queues;

int snd_seq_queue_get_cur_queues(void)
{
	return num_queues;
}

/*----------------------------------------------------------------*/

/* assign queue id and insert to list */
static int queue_list_add(queue_t *q)
{
	int i;
	unsigned long flags;

	spin_lock_irqsave(&queue_list_lock, flags);
	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if (! queue_list[i]) {
			queue_list[i] = q;
			q->queue = i;
			num_queues++;
			spin_unlock_irqrestore(&queue_list_lock, flags);
			return i;
		}
	}
	spin_unlock_irqrestore(&queue_list_lock, flags);
	return -1;
}

static queue_t *queue_list_remove(int id, int client)
{
	queue_t *q;
	unsigned long flags;

	spin_lock_irqsave(&queue_list_lock, flags);
	q = queue_list[id];
	if (q) {
		spin_lock(&q->owner_lock);
		if (q->owner == client) {
			/* found */
			q->klocked = 1;
			spin_unlock(&q->owner_lock);
			queue_list[id] = NULL;
			num_queues--;
			spin_unlock_irqrestore(&queue_list_lock, flags);
			return q;
		}
		spin_unlock(&q->owner_lock);
	}
	spin_unlock_irqrestore(&queue_list_lock, flags);
	return NULL;
}

/*----------------------------------------------------------------*/

/* create new queue (constructor) */
static queue_t *queue_new(int owner, int locked)
{
	queue_t *q;

	q = kcalloc(1, sizeof(*q), GFP_KERNEL);
	if (q == NULL) {
		snd_printd("malloc failed for snd_seq_queue_new()\n");
		return NULL;
	}

	spin_lock_init(&q->owner_lock);
	spin_lock_init(&q->check_lock);
	init_MUTEX(&q->timer_mutex);
	snd_use_lock_init(&q->use_lock);
	q->queue = -1;

	q->tickq = snd_seq_prioq_new();
	q->timeq = snd_seq_prioq_new();
	q->timer = snd_seq_timer_new();
	if (q->tickq == NULL || q->timeq == NULL || q->timer == NULL) {
		snd_seq_prioq_delete(&q->tickq);
		snd_seq_prioq_delete(&q->timeq);
		snd_seq_timer_delete(&q->timer);
		kfree(q);
		return NULL;
	}

	q->owner = owner;
	q->locked = locked;
	q->klocked = 0;

	return q;
}

/* delete queue (destructor) */
static void queue_delete(queue_t *q)
{
	/* stop and release the timer */
	snd_seq_timer_stop(q->timer);
	snd_seq_timer_close(q);
	/* wait until access free */
	snd_use_lock_sync(&q->use_lock);
	/* release resources... */
	snd_seq_prioq_delete(&q->tickq);
	snd_seq_prioq_delete(&q->timeq);
	snd_seq_timer_delete(&q->timer);

	kfree(q);
}


/*----------------------------------------------------------------*/

/* setup queues */
int __init snd_seq_queues_init(void)
{
	/*
	memset(queue_list, 0, sizeof(queue_list));
	num_queues = 0;
	*/
	return 0;
}

/* delete all existing queues */
void __exit snd_seq_queues_delete(void)
{
	int i;

	/* clear list */
	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if (queue_list[i])
			queue_delete(queue_list[i]);
	}
}

/* allocate a new queue -
 * return queue index value or negative value for error
 */
int snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
{
	queue_t *q;

	q = queue_new(client, locked);
	if (q == NULL)
		return -ENOMEM;
	q->info_flags = info_flags;
	if (queue_list_add(q) < 0) {
		queue_delete(q);
		return -ENOMEM;
	}
	snd_seq_queue_use(q->queue, client, 1); /* use this queue */
	return q->queue;
}

/* delete a queue - queue must be owned by the client */
int snd_seq_queue_delete(int client, int queueid)
{
	queue_t *q;

	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
		return -EINVAL;
	q = queue_list_remove(queueid, client);
	if (q == NULL)
		return -EINVAL;
	queue_delete(q);

	return 0;
}


/* return pointer to queue structure for specified id */
queue_t *queueptr(int queueid)
{
	queue_t *q;
	unsigned long flags;

	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
		return NULL;
	spin_lock_irqsave(&queue_list_lock, flags);
	q = queue_list[queueid];
	if (q)
		snd_use_lock_use(&q->use_lock);
	spin_unlock_irqrestore(&queue_list_lock, flags);
	return q;
}

/* return the (first) queue matching with the specified name */
queue_t *snd_seq_queue_find_name(char *name)
{
	int i;
	queue_t *q;

	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) != NULL) {
			if (strncmp(q->name, name, sizeof(q->name)) == 0)
				return q;
			queuefree(q);
		}
	}
	return NULL;
}


/* -------------------------------------------------------- */

void snd_seq_check_queue(queue_t *q, int atomic, int hop)
{
	unsigned long flags;
	snd_seq_event_cell_t *cell;

	if (q == NULL)
		return;

	/* make this function non-reentrant */
	spin_lock_irqsave(&q->check_lock, flags);
	if (q->check_blocked) {
		q->check_again = 1;
		spin_unlock_irqrestore(&q->check_lock, flags);
		return;		/* other thread is already checking queues */
	}
	q->check_blocked = 1;
	spin_unlock_irqrestore(&q->check_lock, flags);

      __again:
	/* Process tick queue... */
	while ((cell = snd_seq_prioq_cell_peek(q->tickq)) != NULL) {
		if (snd_seq_compare_tick_time(&q->timer->tick.cur_tick, &cell->event.time.tick)) {
			cell = snd_seq_prioq_cell_out(q->tickq);
			if (cell)
				snd_seq_dispatch_event(cell, atomic, hop);
		} else {
			/* event remains in the queue */
			break;
		}
	}


	/* Process time queue... */
	while ((cell = snd_seq_prioq_cell_peek(q->timeq)) != NULL) {
		if (snd_seq_compare_real_time(&q->timer->cur_time, &cell->event.time.time)) {
			cell = snd_seq_prioq_cell_out(q->timeq);
			if (cell)
				snd_seq_dispatch_event(cell, atomic, hop);
		} else {
			/* event remains in the queue */
			break;
		}
	}

	/* free lock */
	spin_lock_irqsave(&q->check_lock, flags);
	if (q->check_again) {
		q->check_again = 0;
		spin_unlock_irqrestore(&q->check_lock, flags);
		goto __again;
	}
	q->check_blocked = 0;
	spin_unlock_irqrestore(&q->check_lock, flags);
}


/* enqueue a event to singe queue */
int snd_seq_enqueue_event(snd_seq_event_cell_t *cell, int atomic, int hop)
{
	int dest, err;
	queue_t *q;

	snd_assert(cell != NULL, return -EINVAL);
	dest = cell->event.queue;	/* destination queue */
	q = queueptr(dest);
	if (q == NULL)
		return -EINVAL;
	/* handle relative time stamps, convert them into absolute */
	if ((cell->event.flags & SNDRV_SEQ_TIME_MODE_MASK) == SNDRV_SEQ_TIME_MODE_REL) {
		switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
		case SNDRV_SEQ_TIME_STAMP_TICK:
			cell->event.time.tick += q->timer->tick.cur_tick;
			break;

		case SNDRV_SEQ_TIME_STAMP_REAL:
			snd_seq_inc_real_time(&cell->event.time.time, &q->timer->cur_time);
			break;
		}
		cell->event.flags &= ~SNDRV_SEQ_TIME_MODE_MASK;
		cell->event.flags |= SNDRV_SEQ_TIME_MODE_ABS;
	}
	/* enqueue event in the real-time or midi queue */
	switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
	case SNDRV_SEQ_TIME_STAMP_TICK:
		err = snd_seq_prioq_cell_in(q->tickq, cell);
		break;

	case SNDRV_SEQ_TIME_STAMP_REAL:
	default:
		err = snd_seq_prioq_cell_in(q->timeq, cell);
		break;
	}

	if (err < 0) {
		queuefree(q); /* unlock */
		return err;
	}

	/* trigger dispatching */
	snd_seq_check_queue(q, atomic, hop);

	queuefree(q); /* unlock */

	return 0;
}


/*----------------------------------------------------------------*/

static inline int check_access(queue_t *q, int client)
{
	return (q->owner == client) || (!q->locked && !q->klocked);
}

/* check if the client has permission to modify queue parameters.
 * if it does, lock the queue
 */
static int queue_access_lock(queue_t *q, int client)
{
	unsigned long flags;
	int access_ok;
	
	spin_lock_irqsave(&q->owner_lock, flags);
	access_ok = check_access(q, client);
	if (access_ok)
		q->klocked = 1;
	spin_unlock_irqrestore(&q->owner_lock, flags);
	return access_ok;
}

/* unlock the queue */
static inline void queue_access_unlock(queue_t *q)
{
	unsigned long flags;

	spin_lock_irqsave(&q->owner_lock, flags);
	q->klocked = 0;
	spin_unlock_irqrestore(&q->owner_lock, flags);
}

/* exported - only checking permission */
int snd_seq_queue_check_access(int queueid, int client)
{
	queue_t *q = queueptr(queueid);
	int access_ok;
	unsigned long flags;

	if (! q)
		return 0;
	spin_lock_irqsave(&q->owner_lock, flags);
	access_ok = check_access(q, client);
	spin_unlock_irqrestore(&q->owner_lock, flags);
	queuefree(q);
	return access_ok;
}

/*----------------------------------------------------------------*/

/*
 * change queue's owner and permission
 */
int snd_seq_queue_set_owner(int queueid, int client, int locked)
{
	queue_t *q = queueptr(queueid);

	if (q == NULL)
		return -EINVAL;

	if (! queue_access_lock(q, client)) {
		queuefree(q);
		return -EPERM;
	}

	q->locked = locked ? 1 : 0;
	q->owner = client;
	queue_access_unlock(q);
	queuefree(q);

	return 0;
}


/*----------------------------------------------------------------*/

/* open timer -
 * q->use mutex should be down before calling this function to avoid
 * confliction with snd_seq_queue_use()
 */
int snd_seq_queue_timer_open(int queueid)
{
	int result = 0;
	queue_t *queue;
	seq_timer_t *tmr;

	queue = queueptr(queueid);
	if (queue == NULL)
		return -EINVAL;
	tmr = queue->timer;
	if ((result = snd_seq_timer_open(queue)) < 0) {
		snd_seq_timer_defaults(tmr);
		result = snd_seq_timer_open(queue);
	}
	queuefree(queue);
	return result;
}

/* close timer -
 * q->use mutex should be down before calling this function
 */
int snd_seq_queue_timer_close(int queueid)
{
	queue_t *queue;
	seq_timer_t *tmr;
	int result = 0;

	queue = queueptr(queueid);
	if (queue == NULL)
		return -EINVAL;
	tmr = queue->timer;
	snd_seq_timer_close(queue);
	queuefree(queue);
	return result;
}

/* change queue tempo and ppq */
int snd_seq_queue_timer_set_tempo(int queueid, int client, snd_seq_queue_tempo_t *info)
{
	queue_t *q = queueptr(queueid);
	int result;

	if (q == NULL)
		return -EINVAL;
	if (! queue_access_lock(q, client)) {
		queuefree(q);
		return -EPERM;
	}

	result = snd_seq_timer_set_tempo(q->timer, info->tempo);
	if (result >= 0)
		result = snd_seq_timer_set_ppq(q->timer, info->ppq);
	if (result >= 0 && info->skew_base > 0)
		result = snd_seq_timer_set_skew(q->timer, info->skew_value, info->skew_base);
	queue_access_unlock(q);
	queuefree(q);
	return result;
}


/* use or unuse this queue -
 * if it is the first client, starts the timer.
 * if it is not longer used by any clients, stop the timer.
 */
int snd_seq_queue_use(int queueid, int client, int use)
{
	queue_t *queue;

	queue = queueptr(queueid);
	if (queue == NULL)
		return -EINVAL;
	down(&queue->timer_mutex);
	if (use) {
		if (!test_and_set_bit(client, queue->clients_bitmap))
			queue->clients++;
	} else {
		if (test_and_clear_bit(client, queue->clients_bitmap))
			queue->clients--;
	}
	if (queue->clients) {
		if (use && queue->clients == 1)
			snd_seq_timer_defaults(queue->timer);
		snd_seq_timer_open(queue);
	} else {
		snd_seq_timer_close(queue);
	}
	up(&queue->timer_mutex);
	queuefree(queue);
	return 0;
}

/*
 * check if queue is used by the client
 * return negative value if the queue is invalid.
 * return 0 if not used, 1 if used.
 */
int snd_seq_queue_is_used(int queueid, int client)
{
	queue_t *q;
	int result;

	q = queueptr(queueid);
	if (q == NULL)
		return -EINVAL; /* invalid queue */
	result = test_bit(client, q->clients_bitmap) ? 1 : 0;
	queuefree(q);
	return result;
}


/*----------------------------------------------------------------*/

/* notification that client has left the system -
 * stop the timer on all queues owned by this client
 */
void snd_seq_queue_client_termination(int client)
{
	unsigned long flags;
	int i;
	queue_t *q;

	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) == NULL)
			continue;
		spin_lock_irqsave(&q->owner_lock, flags);
		if (q->owner == client)
			q->klocked = 1;
		spin_unlock_irqrestore(&q->owner_lock, flags);
		if (q->owner == client) {
			if (q->timer->running)
				snd_seq_timer_stop(q->timer);
			snd_seq_timer_reset(q->timer);
		}
		queuefree(q);
	}
}

/* final stage notification -
 * remove cells for no longer exist client (for non-owned queue)
 * or delete this queue (for owned queue)
 */
void snd_seq_queue_client_leave(int client)
{
	int i;
	queue_t *q;

	/* delete own queues from queue list */
	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queue_list_remove(i, client)) != NULL)
			queue_delete(q);
	}

	/* remove cells from existing queues -
	 * they are not owned by this client
	 */
	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) == NULL)
			continue;
		if (test_bit(client, q->clients_bitmap)) {
			snd_seq_prioq_leave(q->tickq, client, 0);
			snd_seq_prioq_leave(q->timeq, client, 0);
			snd_seq_queue_use(q->queue, client, 0);
		}
		queuefree(q);
	}
}



/*----------------------------------------------------------------*/

/* remove cells from all queues */
void snd_seq_queue_client_leave_cells(int client)
{
	int i;
	queue_t *q;

	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) == NULL)
			continue;
		snd_seq_prioq_leave(q->tickq, client, 0);
		snd_seq_prioq_leave(q->timeq, client, 0);
		queuefree(q);
	}
}

/* remove cells based on flush criteria */
void snd_seq_queue_remove_cells(int client, snd_seq_remove_events_t *info)
{
	int i;
	queue_t *q;

	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) == NULL)
			continue;
		if (test_bit(client, q->clients_bitmap) &&
		    (! (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) ||
		     q->queue == info->queue)) {
			snd_seq_prioq_remove_events(q->tickq, client, info);
			snd_seq_prioq_remove_events(q->timeq, client, info);
		}
		queuefree(q);
	}
}

/*----------------------------------------------------------------*/

/*
 * send events to all subscribed ports
 */
static void queue_broadcast_event(queue_t *q, snd_seq_event_t *ev, int atomic, int hop)
{
	snd_seq_event_t sev;

	sev = *ev;
	
	sev.flags = SNDRV_SEQ_TIME_STAMP_TICK|SNDRV_SEQ_TIME_MODE_ABS;
	sev.time.tick = q->timer->tick.cur_tick;
	sev.queue = q->queue;
	sev.data.queue.queue = q->queue;

	/* broadcast events from Timer port */
	sev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
	sev.source.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
	sev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
	snd_seq_kernel_client_dispatch(SNDRV_SEQ_CLIENT_SYSTEM, &sev, atomic, hop);
}

/*
 * process a received queue-control event.
 * this function is exported for seq_sync.c.
 */
static void snd_seq_queue_process_event(queue_t *q, snd_seq_event_t *ev,
					int atomic, int hop)
{
	switch (ev->type) {
	case SNDRV_SEQ_EVENT_START:
		snd_seq_prioq_leave(q->tickq, ev->source.client, 1);
		snd_seq_prioq_leave(q->timeq, ev->source.client, 1);
		if (! snd_seq_timer_start(q->timer))
			queue_broadcast_event(q, ev, atomic, hop);
		break;

	case SNDRV_SEQ_EVENT_CONTINUE:
		if (! snd_seq_timer_continue(q->timer))
			queue_broadcast_event(q, ev, atomic, hop);
		break;

	case SNDRV_SEQ_EVENT_STOP:
		snd_seq_timer_stop(q->timer);
		queue_broadcast_event(q, ev, atomic, hop);
		break;

	case SNDRV_SEQ_EVENT_TEMPO:
		snd_seq_timer_set_tempo(q->timer, ev->data.queue.param.value);
		queue_broadcast_event(q, ev, atomic, hop);
		break;

	case SNDRV_SEQ_EVENT_SETPOS_TICK:
		if (snd_seq_timer_set_position_tick(q->timer, ev->data.queue.param.time.tick) == 0) {
			queue_broadcast_event(q, ev, atomic, hop);
		}
		break;

	case SNDRV_SEQ_EVENT_SETPOS_TIME:
		if (snd_seq_timer_set_position_time(q->timer, ev->data.queue.param.time.time) == 0) {
			queue_broadcast_event(q, ev, atomic, hop);
		}
		break;
	case SNDRV_SEQ_EVENT_QUEUE_SKEW:
		if (snd_seq_timer_set_skew(q->timer,
					   ev->data.queue.param.skew.value,
					   ev->data.queue.param.skew.base) == 0) {
			queue_broadcast_event(q, ev, atomic, hop);
		}
		break;
	}
}


/*
 * Queue control via timer control port:
 * this function is exported as a callback of timer port.
 */
int snd_seq_control_queue(snd_seq_event_t *ev, int atomic, int hop)
{
	queue_t *q;

	snd_assert(ev != NULL, return -EINVAL);
	q = queueptr(ev->data.queue.queue);

	if (q == NULL)
		return -EINVAL;

	if (! queue_access_lock(q, ev->source.client)) {
		queuefree(q);
		return -EPERM;
	}

	snd_seq_queue_process_event(q, ev, atomic, hop);

	queue_access_unlock(q);
	queuefree(q);
	return 0;
}


/*----------------------------------------------------------------*/

/* exported to seq_info.c */
void snd_seq_info_queues_read(snd_info_entry_t *entry, 
			      snd_info_buffer_t * buffer)
{
	int i, bpm;
	queue_t *q;
	seq_timer_t *tmr;

	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
		if ((q = queueptr(i)) == NULL)
			continue;

		tmr = q->timer;
		if (tmr->tempo)
			bpm = 60000000 / tmr->tempo;
		else
			bpm = 0;

		snd_iprintf(buffer, "queue %d: [%s]\n", q->queue, q->name);
		snd_iprintf(buffer, "owned by client    : %d\n", q->owner);
		snd_iprintf(buffer, "lock status        : %s\n", q->locked ? "Locked" : "Free");
		snd_iprintf(buffer, "queued time events : %d\n", snd_seq_prioq_avail(q->timeq));
		snd_iprintf(buffer, "queued tick events : %d\n", snd_seq_prioq_avail(q->tickq));
		snd_iprintf(buffer, "timer state        : %s\n", tmr->running ? "Running" : "Stopped");
		snd_iprintf(buffer, "timer PPQ          : %d\n", tmr->ppq);
		snd_iprintf(buffer, "current tempo      : %d\n", tmr->tempo);
		snd_iprintf(buffer, "current BPM        : %d\n", bpm);
		snd_iprintf(buffer, "current time       : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
		snd_iprintf(buffer, "current tick       : %d\n", tmr->tick.cur_tick);
		snd_iprintf(buffer, "\n");
		queuefree(q);
	}
}