xref: /freebsd/sys/dev/sound/pcm/channel.c (revision 1323ec57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
5  * Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
6  * Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
7  * Portions Copyright (c) Luigi Rizzo <luigi@FreeBSD.org> - 1997-99
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include "opt_isa.h"
33 
34 #ifdef HAVE_KERNEL_OPTION_HEADERS
35 #include "opt_snd.h"
36 #endif
37 
38 #include <dev/sound/pcm/sound.h>
39 #include <dev/sound/pcm/vchan.h>
40 
41 #include "feeder_if.h"
42 
43 SND_DECLARE_FILE("$FreeBSD$");
44 
45 int report_soft_formats = 1;
46 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_formats, CTLFLAG_RW,
47 	&report_soft_formats, 0, "report software-emulated formats");
48 
49 int report_soft_matrix = 1;
50 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_matrix, CTLFLAG_RW,
51 	&report_soft_matrix, 0, "report software-emulated channel matrixing");
52 
53 int chn_latency = CHN_LATENCY_DEFAULT;
54 
55 static int
56 sysctl_hw_snd_latency(SYSCTL_HANDLER_ARGS)
57 {
58 	int err, val;
59 
60 	val = chn_latency;
61 	err = sysctl_handle_int(oidp, &val, 0, req);
62 	if (err != 0 || req->newptr == NULL)
63 		return err;
64 	if (val < CHN_LATENCY_MIN || val > CHN_LATENCY_MAX)
65 		err = EINVAL;
66 	else
67 		chn_latency = val;
68 
69 	return err;
70 }
71 SYSCTL_PROC(_hw_snd, OID_AUTO, latency,
72     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
73     sysctl_hw_snd_latency, "I",
74     "buffering latency (0=low ... 10=high)");
75 
76 int chn_latency_profile = CHN_LATENCY_PROFILE_DEFAULT;
77 
78 static int
79 sysctl_hw_snd_latency_profile(SYSCTL_HANDLER_ARGS)
80 {
81 	int err, val;
82 
83 	val = chn_latency_profile;
84 	err = sysctl_handle_int(oidp, &val, 0, req);
85 	if (err != 0 || req->newptr == NULL)
86 		return err;
87 	if (val < CHN_LATENCY_PROFILE_MIN || val > CHN_LATENCY_PROFILE_MAX)
88 		err = EINVAL;
89 	else
90 		chn_latency_profile = val;
91 
92 	return err;
93 }
94 SYSCTL_PROC(_hw_snd, OID_AUTO, latency_profile,
95     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
96     sysctl_hw_snd_latency_profile, "I",
97     "buffering latency profile (0=aggressive 1=safe)");
98 
99 static int chn_timeout = CHN_TIMEOUT;
100 
101 static int
102 sysctl_hw_snd_timeout(SYSCTL_HANDLER_ARGS)
103 {
104 	int err, val;
105 
106 	val = chn_timeout;
107 	err = sysctl_handle_int(oidp, &val, 0, req);
108 	if (err != 0 || req->newptr == NULL)
109 		return err;
110 	if (val < CHN_TIMEOUT_MIN || val > CHN_TIMEOUT_MAX)
111 		err = EINVAL;
112 	else
113 		chn_timeout = val;
114 
115 	return err;
116 }
117 SYSCTL_PROC(_hw_snd, OID_AUTO, timeout,
118     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
119     sysctl_hw_snd_timeout, "I",
120     "interrupt timeout (1 - 10) seconds");
121 
122 static int chn_vpc_autoreset = 1;
123 SYSCTL_INT(_hw_snd, OID_AUTO, vpc_autoreset, CTLFLAG_RWTUN,
124 	&chn_vpc_autoreset, 0, "automatically reset channels volume to 0db");
125 
126 static int chn_vol_0db_pcm = SND_VOL_0DB_PCM;
127 
128 static void
129 chn_vpc_proc(int reset, int db)
130 {
131 	struct snddev_info *d;
132 	struct pcm_channel *c;
133 	int i;
134 
135 	for (i = 0; pcm_devclass != NULL &&
136 	    i < devclass_get_maxunit(pcm_devclass); i++) {
137 		d = devclass_get_softc(pcm_devclass, i);
138 		if (!PCM_REGISTERED(d))
139 			continue;
140 		PCM_LOCK(d);
141 		PCM_WAIT(d);
142 		PCM_ACQUIRE(d);
143 		CHN_FOREACH(c, d, channels.pcm) {
144 			CHN_LOCK(c);
145 			CHN_SETVOLUME(c, SND_VOL_C_PCM, SND_CHN_T_VOL_0DB, db);
146 			if (reset != 0)
147 				chn_vpc_reset(c, SND_VOL_C_PCM, 1);
148 			CHN_UNLOCK(c);
149 		}
150 		PCM_RELEASE(d);
151 		PCM_UNLOCK(d);
152 	}
153 }
154 
155 static int
156 sysctl_hw_snd_vpc_0db(SYSCTL_HANDLER_ARGS)
157 {
158 	int err, val;
159 
160 	val = chn_vol_0db_pcm;
161 	err = sysctl_handle_int(oidp, &val, 0, req);
162 	if (err != 0 || req->newptr == NULL)
163 		return (err);
164 	if (val < SND_VOL_0DB_MIN || val > SND_VOL_0DB_MAX)
165 		return (EINVAL);
166 
167 	chn_vol_0db_pcm = val;
168 	chn_vpc_proc(0, val);
169 
170 	return (0);
171 }
172 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_0db,
173     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int),
174     sysctl_hw_snd_vpc_0db, "I",
175     "0db relative level");
176 
177 static int
178 sysctl_hw_snd_vpc_reset(SYSCTL_HANDLER_ARGS)
179 {
180 	int err, val;
181 
182 	val = 0;
183 	err = sysctl_handle_int(oidp, &val, 0, req);
184 	if (err != 0 || req->newptr == NULL || val == 0)
185 		return (err);
186 
187 	chn_vol_0db_pcm = SND_VOL_0DB_PCM;
188 	chn_vpc_proc(1, SND_VOL_0DB_PCM);
189 
190 	return (0);
191 }
192 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_reset,
193     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int),
194     sysctl_hw_snd_vpc_reset, "I",
195     "reset volume on all channels");
196 
197 static int chn_usefrags = 0;
198 static int chn_syncdelay = -1;
199 
200 SYSCTL_INT(_hw_snd, OID_AUTO, usefrags, CTLFLAG_RWTUN,
201 	&chn_usefrags, 0, "prefer setfragments() over setblocksize()");
202 SYSCTL_INT(_hw_snd, OID_AUTO, syncdelay, CTLFLAG_RWTUN,
203 	&chn_syncdelay, 0,
204 	"append (0-1000) millisecond trailing buffer delay on each sync");
205 
206 /**
207  * @brief Channel sync group lock
208  *
209  * Clients should acquire this lock @b without holding any channel locks
210  * before touching syncgroups or the main syncgroup list.
211  */
212 struct mtx snd_pcm_syncgroups_mtx;
213 MTX_SYSINIT(pcm_syncgroup, &snd_pcm_syncgroups_mtx, "PCM channel sync group lock", MTX_DEF);
214 /**
215  * @brief syncgroups' master list
216  *
217  * Each time a channel syncgroup is created, it's added to this list.  This
218  * list should only be accessed with @sa snd_pcm_syncgroups_mtx held.
219  *
220  * See SNDCTL_DSP_SYNCGROUP for more information.
221  */
222 struct pcm_synclist snd_pcm_syncgroups = SLIST_HEAD_INITIALIZER(snd_pcm_syncgroups);
223 
224 static void
225 chn_lockinit(struct pcm_channel *c, int dir)
226 {
227 	switch (dir) {
228 	case PCMDIR_PLAY:
229 		c->lock = snd_mtxcreate(c->name, "pcm play channel");
230 		cv_init(&c->intr_cv, "pcmwr");
231 		break;
232 	case PCMDIR_PLAY_VIRTUAL:
233 		c->lock = snd_mtxcreate(c->name, "pcm virtual play channel");
234 		cv_init(&c->intr_cv, "pcmwrv");
235 		break;
236 	case PCMDIR_REC:
237 		c->lock = snd_mtxcreate(c->name, "pcm record channel");
238 		cv_init(&c->intr_cv, "pcmrd");
239 		break;
240 	case PCMDIR_REC_VIRTUAL:
241 		c->lock = snd_mtxcreate(c->name, "pcm virtual record channel");
242 		cv_init(&c->intr_cv, "pcmrdv");
243 		break;
244 	default:
245 		panic("%s(): Invalid direction=%d", __func__, dir);
246 		break;
247 	}
248 
249 	cv_init(&c->cv, "pcmchn");
250 }
251 
252 static void
253 chn_lockdestroy(struct pcm_channel *c)
254 {
255 	CHN_LOCKASSERT(c);
256 
257 	CHN_BROADCAST(&c->cv);
258 	CHN_BROADCAST(&c->intr_cv);
259 
260 	cv_destroy(&c->cv);
261 	cv_destroy(&c->intr_cv);
262 
263 	snd_mtxfree(c->lock);
264 }
265 
266 /**
267  * @brief Determine channel is ready for I/O
268  *
269  * @retval 1 = ready for I/O
270  * @retval 0 = not ready for I/O
271  */
272 static int
273 chn_polltrigger(struct pcm_channel *c)
274 {
275 	struct snd_dbuf *bs = c->bufsoft;
276 	u_int delta;
277 
278 	CHN_LOCKASSERT(c);
279 
280 	if (c->flags & CHN_F_MMAP) {
281 		if (sndbuf_getprevtotal(bs) < c->lw)
282 			delta = c->lw;
283 		else
284 			delta = sndbuf_gettotal(bs) - sndbuf_getprevtotal(bs);
285 	} else {
286 		if (c->direction == PCMDIR_PLAY)
287 			delta = sndbuf_getfree(bs);
288 		else
289 			delta = sndbuf_getready(bs);
290 	}
291 
292 	return ((delta < c->lw) ? 0 : 1);
293 }
294 
295 static void
296 chn_pollreset(struct pcm_channel *c)
297 {
298 
299 	CHN_LOCKASSERT(c);
300 	sndbuf_updateprevtotal(c->bufsoft);
301 }
302 
303 static void
304 chn_wakeup(struct pcm_channel *c)
305 {
306 	struct snd_dbuf *bs;
307 	struct pcm_channel *ch;
308 
309 	CHN_LOCKASSERT(c);
310 
311 	bs = c->bufsoft;
312 
313 	if (CHN_EMPTY(c, children.busy)) {
314 		if (SEL_WAITING(sndbuf_getsel(bs)) && chn_polltrigger(c))
315 			selwakeuppri(sndbuf_getsel(bs), PRIBIO);
316 		if (c->flags & CHN_F_SLEEPING) {
317 			/*
318 			 * Ok, I can just panic it right here since it is
319 			 * quite obvious that we never allow multiple waiters
320 			 * from userland. I'm too generous...
321 			 */
322 			CHN_BROADCAST(&c->intr_cv);
323 		}
324 	} else {
325 		CHN_FOREACH(ch, c, children.busy) {
326 			CHN_LOCK(ch);
327 			chn_wakeup(ch);
328 			CHN_UNLOCK(ch);
329 		}
330 	}
331 }
332 
333 static int
334 chn_sleep(struct pcm_channel *c, int timeout)
335 {
336 	int ret;
337 
338 	CHN_LOCKASSERT(c);
339 
340 	if (c->flags & CHN_F_DEAD)
341 		return (EINVAL);
342 
343 	c->flags |= CHN_F_SLEEPING;
344 	ret = cv_timedwait_sig(&c->intr_cv, c->lock, timeout);
345 	c->flags &= ~CHN_F_SLEEPING;
346 
347 	return ((c->flags & CHN_F_DEAD) ? EINVAL : ret);
348 }
349 
350 /*
351  * chn_dmaupdate() tracks the status of a dma transfer,
352  * updating pointers.
353  */
354 
355 static unsigned int
356 chn_dmaupdate(struct pcm_channel *c)
357 {
358 	struct snd_dbuf *b = c->bufhard;
359 	unsigned int delta, old, hwptr, amt;
360 
361 	KASSERT(sndbuf_getsize(b) > 0, ("bufsize == 0"));
362 	CHN_LOCKASSERT(c);
363 
364 	old = sndbuf_gethwptr(b);
365 	hwptr = chn_getptr(c);
366 	delta = (sndbuf_getsize(b) + hwptr - old) % sndbuf_getsize(b);
367 	sndbuf_sethwptr(b, hwptr);
368 
369 	if (c->direction == PCMDIR_PLAY) {
370 		amt = min(delta, sndbuf_getready(b));
371 		amt -= amt % sndbuf_getalign(b);
372 		if (amt > 0)
373 			sndbuf_dispose(b, NULL, amt);
374 	} else {
375 		amt = min(delta, sndbuf_getfree(b));
376 		amt -= amt % sndbuf_getalign(b);
377 		if (amt > 0)
378 		       sndbuf_acquire(b, NULL, amt);
379 	}
380 	if (snd_verbose > 3 && CHN_STARTED(c) && delta == 0) {
381 		device_printf(c->dev, "WARNING: %s DMA completion "
382 			"too fast/slow ! hwptr=%u, old=%u "
383 			"delta=%u amt=%u ready=%u free=%u\n",
384 			CHN_DIRSTR(c), hwptr, old, delta, amt,
385 			sndbuf_getready(b), sndbuf_getfree(b));
386 	}
387 
388 	return delta;
389 }
390 
391 static void
392 chn_wrfeed(struct pcm_channel *c)
393 {
394     	struct snd_dbuf *b = c->bufhard;
395     	struct snd_dbuf *bs = c->bufsoft;
396 	unsigned int amt, want, wasfree;
397 
398 	CHN_LOCKASSERT(c);
399 
400 	if ((c->flags & CHN_F_MMAP) && !(c->flags & CHN_F_CLOSING))
401 		sndbuf_acquire(bs, NULL, sndbuf_getfree(bs));
402 
403 	wasfree = sndbuf_getfree(b);
404 	want = min(sndbuf_getsize(b),
405 	    imax(0, sndbuf_xbytes(sndbuf_getsize(bs), bs, b) -
406 	     sndbuf_getready(b)));
407 	amt = min(wasfree, want);
408 	if (amt > 0)
409 		sndbuf_feed(bs, b, c, c->feeder, amt);
410 
411 	/*
412 	 * Possible xruns. There should be no empty space left in buffer.
413 	 */
414 	if (sndbuf_getready(b) < want)
415 		c->xruns++;
416 
417 	if (sndbuf_getfree(b) < wasfree)
418 		chn_wakeup(c);
419 }
420 
421 #if 0
422 static void
423 chn_wrupdate(struct pcm_channel *c)
424 {
425 
426 	CHN_LOCKASSERT(c);
427 	KASSERT(c->direction == PCMDIR_PLAY, ("%s(): bad channel", __func__));
428 
429 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
430 		return;
431 	chn_dmaupdate(c);
432 	chn_wrfeed(c);
433 	/* tell the driver we've updated the primary buffer */
434 	chn_trigger(c, PCMTRIG_EMLDMAWR);
435 }
436 #endif
437 
438 static void
439 chn_wrintr(struct pcm_channel *c)
440 {
441 
442 	CHN_LOCKASSERT(c);
443 	/* update pointers in primary buffer */
444 	chn_dmaupdate(c);
445 	/* ...and feed from secondary to primary */
446 	chn_wrfeed(c);
447 	/* tell the driver we've updated the primary buffer */
448 	chn_trigger(c, PCMTRIG_EMLDMAWR);
449 }
450 
451 /*
452  * user write routine - uiomove data into secondary buffer, trigger if necessary
453  * if blocking, sleep, rinse and repeat.
454  *
455  * called externally, so must handle locking
456  */
457 
458 int
459 chn_write(struct pcm_channel *c, struct uio *buf)
460 {
461 	struct snd_dbuf *bs = c->bufsoft;
462 	void *off;
463 	int ret, timeout, sz, t, p;
464 
465 	CHN_LOCKASSERT(c);
466 
467 	ret = 0;
468 	timeout = chn_timeout * hz;
469 
470 	while (ret == 0 && buf->uio_resid > 0) {
471 		sz = min(buf->uio_resid, sndbuf_getfree(bs));
472 		if (sz > 0) {
473 			/*
474 			 * The following assumes that the free space in
475 			 * the buffer can never be less around the
476 			 * unlock-uiomove-lock sequence.
477 			 */
478 			while (ret == 0 && sz > 0) {
479 				p = sndbuf_getfreeptr(bs);
480 				t = min(sz, sndbuf_getsize(bs) - p);
481 				off = sndbuf_getbufofs(bs, p);
482 				CHN_UNLOCK(c);
483 				ret = uiomove(off, t, buf);
484 				CHN_LOCK(c);
485 				sz -= t;
486 				sndbuf_acquire(bs, NULL, t);
487 			}
488 			ret = 0;
489 			if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
490 				ret = chn_start(c, 0);
491 				if (ret != 0)
492 					c->flags |= CHN_F_DEAD;
493 			}
494 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER)) {
495 			/**
496 			 * @todo Evaluate whether EAGAIN is truly desirable.
497 			 * 	 4Front drivers behave like this, but I'm
498 			 * 	 not sure if it at all violates the "write
499 			 * 	 should be allowed to block" model.
500 			 *
501 			 * 	 The idea is that, while set with CHN_F_NOTRIGGER,
502 			 * 	 a channel isn't playing, *but* without this we
503 			 * 	 end up with "interrupt timeout / channel dead".
504 			 */
505 			ret = EAGAIN;
506 		} else {
507    			ret = chn_sleep(c, timeout);
508 			if (ret == EAGAIN) {
509 				ret = EINVAL;
510 				c->flags |= CHN_F_DEAD;
511 				device_printf(c->dev, "%s(): %s: "
512 				    "play interrupt timeout, channel dead\n",
513 				    __func__, c->name);
514 			} else if (ret == ERESTART || ret == EINTR)
515 				c->flags |= CHN_F_ABORTING;
516 		}
517 	}
518 
519 	return (ret);
520 }
521 
522 /*
523  * Feed new data from the read buffer. Can be called in the bottom half.
524  */
525 static void
526 chn_rdfeed(struct pcm_channel *c)
527 {
528     	struct snd_dbuf *b = c->bufhard;
529     	struct snd_dbuf *bs = c->bufsoft;
530 	unsigned int amt;
531 
532 	CHN_LOCKASSERT(c);
533 
534 	if (c->flags & CHN_F_MMAP)
535 		sndbuf_dispose(bs, NULL, sndbuf_getready(bs));
536 
537 	amt = sndbuf_getfree(bs);
538 	if (amt > 0)
539 		sndbuf_feed(b, bs, c, c->feeder, amt);
540 
541 	amt = sndbuf_getready(b);
542 	if (amt > 0) {
543 		c->xruns++;
544 		sndbuf_dispose(b, NULL, amt);
545 	}
546 
547 	if (sndbuf_getready(bs) > 0)
548 		chn_wakeup(c);
549 }
550 
551 #if 0
552 static void
553 chn_rdupdate(struct pcm_channel *c)
554 {
555 
556 	CHN_LOCKASSERT(c);
557 	KASSERT(c->direction == PCMDIR_REC, ("chn_rdupdate on bad channel"));
558 
559 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
560 		return;
561 	chn_trigger(c, PCMTRIG_EMLDMARD);
562 	chn_dmaupdate(c);
563 	chn_rdfeed(c);
564 }
565 #endif
566 
567 /* read interrupt routine. Must be called with interrupts blocked. */
568 static void
569 chn_rdintr(struct pcm_channel *c)
570 {
571 
572 	CHN_LOCKASSERT(c);
573 	/* tell the driver to update the primary buffer if non-dma */
574 	chn_trigger(c, PCMTRIG_EMLDMARD);
575 	/* update pointers in primary buffer */
576 	chn_dmaupdate(c);
577 	/* ...and feed from primary to secondary */
578 	chn_rdfeed(c);
579 }
580 
581 /*
582  * user read routine - trigger if necessary, uiomove data from secondary buffer
583  * if blocking, sleep, rinse and repeat.
584  *
585  * called externally, so must handle locking
586  */
587 
588 int
589 chn_read(struct pcm_channel *c, struct uio *buf)
590 {
591 	struct snd_dbuf *bs = c->bufsoft;
592 	void *off;
593 	int ret, timeout, sz, t, p;
594 
595 	CHN_LOCKASSERT(c);
596 
597 	if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
598 		ret = chn_start(c, 0);
599 		if (ret != 0) {
600 			c->flags |= CHN_F_DEAD;
601 			return (ret);
602 		}
603 	}
604 
605 	ret = 0;
606 	timeout = chn_timeout * hz;
607 
608 	while (ret == 0 && buf->uio_resid > 0) {
609 		sz = min(buf->uio_resid, sndbuf_getready(bs));
610 		if (sz > 0) {
611 			/*
612 			 * The following assumes that the free space in
613 			 * the buffer can never be less around the
614 			 * unlock-uiomove-lock sequence.
615 			 */
616 			while (ret == 0 && sz > 0) {
617 				p = sndbuf_getreadyptr(bs);
618 				t = min(sz, sndbuf_getsize(bs) - p);
619 				off = sndbuf_getbufofs(bs, p);
620 				CHN_UNLOCK(c);
621 				ret = uiomove(off, t, buf);
622 				CHN_LOCK(c);
623 				sz -= t;
624 				sndbuf_dispose(bs, NULL, t);
625 			}
626 			ret = 0;
627 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER))
628 			ret = EAGAIN;
629 		else {
630    			ret = chn_sleep(c, timeout);
631 			if (ret == EAGAIN) {
632 				ret = EINVAL;
633 				c->flags |= CHN_F_DEAD;
634 				device_printf(c->dev, "%s(): %s: "
635 				    "record interrupt timeout, channel dead\n",
636 				    __func__, c->name);
637 			} else if (ret == ERESTART || ret == EINTR)
638 				c->flags |= CHN_F_ABORTING;
639 		}
640 	}
641 
642 	return (ret);
643 }
644 
645 void
646 chn_intr_locked(struct pcm_channel *c)
647 {
648 
649 	CHN_LOCKASSERT(c);
650 
651 	c->interrupts++;
652 
653 	if (c->direction == PCMDIR_PLAY)
654 		chn_wrintr(c);
655 	else
656 		chn_rdintr(c);
657 }
658 
659 void
660 chn_intr(struct pcm_channel *c)
661 {
662 
663 	if (CHN_LOCKOWNED(c)) {
664 		chn_intr_locked(c);
665 		return;
666 	}
667 
668 	CHN_LOCK(c);
669 	chn_intr_locked(c);
670 	CHN_UNLOCK(c);
671 }
672 
673 u_int32_t
674 chn_start(struct pcm_channel *c, int force)
675 {
676 	u_int32_t i, j;
677 	struct snd_dbuf *b = c->bufhard;
678 	struct snd_dbuf *bs = c->bufsoft;
679 	int err;
680 
681 	CHN_LOCKASSERT(c);
682 	/* if we're running, or if we're prevented from triggering, bail */
683 	if (CHN_STARTED(c) || ((c->flags & CHN_F_NOTRIGGER) && !force))
684 		return (EINVAL);
685 
686 	err = 0;
687 
688 	if (force) {
689 		i = 1;
690 		j = 0;
691 	} else {
692 		if (c->direction == PCMDIR_REC) {
693 			i = sndbuf_getfree(bs);
694 			j = (i > 0) ? 1 : sndbuf_getready(b);
695 		} else {
696 			if (sndbuf_getfree(bs) == 0) {
697 				i = 1;
698 				j = 0;
699 			} else {
700 				struct snd_dbuf *pb;
701 
702 				pb = CHN_BUF_PARENT(c, b);
703 				i = sndbuf_xbytes(sndbuf_getready(bs), bs, pb);
704 				j = sndbuf_getalign(pb);
705 			}
706 		}
707 		if (snd_verbose > 3 && CHN_EMPTY(c, children))
708 			device_printf(c->dev, "%s(): %s (%s) threshold "
709 			    "i=%d j=%d\n", __func__, CHN_DIRSTR(c),
710 			    (c->flags & CHN_F_VIRTUAL) ? "virtual" :
711 			    "hardware", i, j);
712 	}
713 
714 	if (i >= j) {
715 		c->flags |= CHN_F_TRIGGERED;
716 		sndbuf_setrun(b, 1);
717 		if (c->flags & CHN_F_CLOSING)
718 			c->feedcount = 2;
719 		else {
720 			c->feedcount = 0;
721 			c->interrupts = 0;
722 			c->xruns = 0;
723 		}
724 		if (c->parentchannel == NULL) {
725 			if (c->direction == PCMDIR_PLAY)
726 				sndbuf_fillsilence_rl(b,
727 				    sndbuf_xbytes(sndbuf_getsize(bs), bs, b));
728 			if (snd_verbose > 3)
729 				device_printf(c->dev,
730 				    "%s(): %s starting! (%s/%s) "
731 				    "(ready=%d force=%d i=%d j=%d "
732 				    "intrtimeout=%u latency=%dms)\n",
733 				    __func__,
734 				    (c->flags & CHN_F_HAS_VCHAN) ?
735 				    "VCHAN PARENT" : "HW", CHN_DIRSTR(c),
736 				    (c->flags & CHN_F_CLOSING) ? "closing" :
737 				    "running",
738 				    sndbuf_getready(b),
739 				    force, i, j, c->timeout,
740 				    (sndbuf_getsize(b) * 1000) /
741 				    (sndbuf_getalign(b) * sndbuf_getspd(b)));
742 		}
743 		err = chn_trigger(c, PCMTRIG_START);
744 	}
745 
746 	return (err);
747 }
748 
749 void
750 chn_resetbuf(struct pcm_channel *c)
751 {
752 	struct snd_dbuf *b = c->bufhard;
753 	struct snd_dbuf *bs = c->bufsoft;
754 
755 	c->blocks = 0;
756 	sndbuf_reset(b);
757 	sndbuf_reset(bs);
758 }
759 
760 /*
761  * chn_sync waits until the space in the given channel goes above
762  * a threshold. The threshold is checked against fl or rl respectively.
763  * Assume that the condition can become true, do not check here...
764  */
765 int
766 chn_sync(struct pcm_channel *c, int threshold)
767 {
768     	struct snd_dbuf *b, *bs;
769 	int ret, count, hcount, minflush, resid, residp, syncdelay, blksz;
770 	u_int32_t cflag;
771 
772 	CHN_LOCKASSERT(c);
773 
774 	if (c->direction != PCMDIR_PLAY)
775 		return (EINVAL);
776 
777 	bs = c->bufsoft;
778 
779 	if ((c->flags & (CHN_F_DEAD | CHN_F_ABORTING)) ||
780 	    (threshold < 1 && sndbuf_getready(bs) < 1))
781 		return (0);
782 
783 	/* if we haven't yet started and nothing is buffered, else start*/
784 	if (CHN_STOPPED(c)) {
785 		if (threshold > 0 || sndbuf_getready(bs) > 0) {
786 			ret = chn_start(c, 1);
787 			if (ret != 0)
788 				return (ret);
789 		} else
790 			return (0);
791 	}
792 
793 	b = CHN_BUF_PARENT(c, c->bufhard);
794 
795 	minflush = threshold + sndbuf_xbytes(sndbuf_getready(b), b, bs);
796 
797 	syncdelay = chn_syncdelay;
798 
799 	if (syncdelay < 0 && (threshold > 0 || sndbuf_getready(bs) > 0))
800 		minflush += sndbuf_xbytes(sndbuf_getsize(b), b, bs);
801 
802 	/*
803 	 * Append (0-1000) millisecond trailing buffer (if needed)
804 	 * for slower / high latency hardwares (notably USB audio)
805 	 * to avoid audible truncation.
806 	 */
807 	if (syncdelay > 0)
808 		minflush += (sndbuf_getalign(bs) * sndbuf_getspd(bs) *
809 		    ((syncdelay > 1000) ? 1000 : syncdelay)) / 1000;
810 
811 	minflush -= minflush % sndbuf_getalign(bs);
812 
813 	if (minflush > 0) {
814 		threshold = min(minflush, sndbuf_getfree(bs));
815 		sndbuf_clear(bs, threshold);
816 		sndbuf_acquire(bs, NULL, threshold);
817 		minflush -= threshold;
818 	}
819 
820 	resid = sndbuf_getready(bs);
821 	residp = resid;
822 	blksz = sndbuf_getblksz(b);
823 	if (blksz < 1) {
824 		device_printf(c->dev,
825 		    "%s(): WARNING: blksz < 1 ! maxsize=%d [%d/%d/%d]\n",
826 		    __func__, sndbuf_getmaxsize(b), sndbuf_getsize(b),
827 		    sndbuf_getblksz(b), sndbuf_getblkcnt(b));
828 		if (sndbuf_getblkcnt(b) > 0)
829 			blksz = sndbuf_getsize(b) / sndbuf_getblkcnt(b);
830 		if (blksz < 1)
831 			blksz = 1;
832 	}
833 	count = sndbuf_xbytes(minflush + resid, bs, b) / blksz;
834 	hcount = count;
835 	ret = 0;
836 
837 	if (snd_verbose > 3)
838 		device_printf(c->dev, "%s(): [begin] timeout=%d count=%d "
839 		    "minflush=%d resid=%d\n", __func__, c->timeout, count,
840 		    minflush, resid);
841 
842 	cflag = c->flags & CHN_F_CLOSING;
843 	c->flags |= CHN_F_CLOSING;
844 	while (count > 0 && (resid > 0 || minflush > 0)) {
845 		ret = chn_sleep(c, c->timeout);
846     		if (ret == ERESTART || ret == EINTR) {
847 			c->flags |= CHN_F_ABORTING;
848 			break;
849 		} else if (ret == 0 || ret == EAGAIN) {
850 			resid = sndbuf_getready(bs);
851 			if (resid == residp) {
852 				--count;
853 				if (snd_verbose > 3)
854 					device_printf(c->dev,
855 					    "%s(): [stalled] timeout=%d "
856 					    "count=%d hcount=%d "
857 					    "resid=%d minflush=%d\n",
858 					    __func__, c->timeout, count,
859 					    hcount, resid, minflush);
860 			} else if (resid < residp && count < hcount) {
861 				++count;
862 				if (snd_verbose > 3)
863 					device_printf(c->dev,
864 					    "%s((): [resume] timeout=%d "
865 					    "count=%d hcount=%d "
866 					    "resid=%d minflush=%d\n",
867 					    __func__, c->timeout, count,
868 					    hcount, resid, minflush);
869 			}
870 			if (minflush > 0 && sndbuf_getfree(bs) > 0) {
871 				threshold = min(minflush,
872 				    sndbuf_getfree(bs));
873 				sndbuf_clear(bs, threshold);
874 				sndbuf_acquire(bs, NULL, threshold);
875 				resid = sndbuf_getready(bs);
876 				minflush -= threshold;
877 			}
878 			residp = resid;
879 		} else
880 			break;
881 	}
882 	c->flags &= ~CHN_F_CLOSING;
883 	c->flags |= cflag;
884 
885 	if (snd_verbose > 3)
886 		device_printf(c->dev,
887 		    "%s(): timeout=%d count=%d hcount=%d resid=%d residp=%d "
888 		    "minflush=%d ret=%d\n",
889 		    __func__, c->timeout, count, hcount, resid, residp,
890 		    minflush, ret);
891 
892     	return (0);
893 }
894 
895 /* called externally, handle locking */
896 int
897 chn_poll(struct pcm_channel *c, int ev, struct thread *td)
898 {
899 	struct snd_dbuf *bs = c->bufsoft;
900 	int ret;
901 
902 	CHN_LOCKASSERT(c);
903 
904     	if (!(c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED))) {
905 		ret = chn_start(c, 1);
906 		if (ret != 0)
907 			return (0);
908 	}
909 
910 	ret = 0;
911 	if (chn_polltrigger(c)) {
912 		chn_pollreset(c);
913 		ret = ev;
914 	} else
915 		selrecord(td, sndbuf_getsel(bs));
916 
917 	return (ret);
918 }
919 
920 /*
921  * chn_abort terminates a running dma transfer.  it may sleep up to 200ms.
922  * it returns the number of bytes that have not been transferred.
923  *
924  * called from: dsp_close, dsp_ioctl, with channel locked
925  */
926 int
927 chn_abort(struct pcm_channel *c)
928 {
929     	int missing = 0;
930     	struct snd_dbuf *b = c->bufhard;
931     	struct snd_dbuf *bs = c->bufsoft;
932 
933 	CHN_LOCKASSERT(c);
934 	if (CHN_STOPPED(c))
935 		return 0;
936 	c->flags |= CHN_F_ABORTING;
937 
938 	c->flags &= ~CHN_F_TRIGGERED;
939 	/* kill the channel */
940 	chn_trigger(c, PCMTRIG_ABORT);
941 	sndbuf_setrun(b, 0);
942 	if (!(c->flags & CHN_F_VIRTUAL))
943 		chn_dmaupdate(c);
944     	missing = sndbuf_getready(bs);
945 
946 	c->flags &= ~CHN_F_ABORTING;
947 	return missing;
948 }
949 
950 /*
951  * this routine tries to flush the dma transfer. It is called
952  * on a close of a playback channel.
953  * first, if there is data in the buffer, but the dma has not yet
954  * begun, we need to start it.
955  * next, we wait for the play buffer to drain
956  * finally, we stop the dma.
957  *
958  * called from: dsp_close, not valid for record channels.
959  */
960 
961 int
962 chn_flush(struct pcm_channel *c)
963 {
964     	struct snd_dbuf *b = c->bufhard;
965 
966 	CHN_LOCKASSERT(c);
967 	KASSERT(c->direction == PCMDIR_PLAY, ("chn_flush on bad channel"));
968     	DEB(printf("chn_flush: c->flags 0x%08x\n", c->flags));
969 
970 	c->flags |= CHN_F_CLOSING;
971 	chn_sync(c, 0);
972 	c->flags &= ~CHN_F_TRIGGERED;
973 	/* kill the channel */
974 	chn_trigger(c, PCMTRIG_ABORT);
975 	sndbuf_setrun(b, 0);
976 
977     	c->flags &= ~CHN_F_CLOSING;
978     	return 0;
979 }
980 
981 int
982 snd_fmtvalid(uint32_t fmt, uint32_t *fmtlist)
983 {
984 	int i;
985 
986 	for (i = 0; fmtlist[i] != 0; i++) {
987 		if (fmt == fmtlist[i] ||
988 		    ((fmt & AFMT_PASSTHROUGH) &&
989 		    (AFMT_ENCODING(fmt) & fmtlist[i])))
990 			return (1);
991 	}
992 
993 	return (0);
994 }
995 
996 static const struct {
997 	char *name, *alias1, *alias2;
998 	uint32_t afmt;
999 } afmt_tab[] = {
1000 	{  "alaw",  NULL, NULL, AFMT_A_LAW  },
1001 	{ "mulaw",  NULL, NULL, AFMT_MU_LAW },
1002 	{    "u8",   "8", NULL, AFMT_U8     },
1003 	{    "s8",  NULL, NULL, AFMT_S8     },
1004 #if BYTE_ORDER == LITTLE_ENDIAN
1005 	{ "s16le", "s16", "16", AFMT_S16_LE },
1006 	{ "s16be",  NULL, NULL, AFMT_S16_BE },
1007 #else
1008 	{ "s16le",  NULL, NULL, AFMT_S16_LE },
1009 	{ "s16be", "s16", "16", AFMT_S16_BE },
1010 #endif
1011 	{ "u16le",  NULL, NULL, AFMT_U16_LE },
1012 	{ "u16be",  NULL, NULL, AFMT_U16_BE },
1013 	{ "s24le",  NULL, NULL, AFMT_S24_LE },
1014 	{ "s24be",  NULL, NULL, AFMT_S24_BE },
1015 	{ "u24le",  NULL, NULL, AFMT_U24_LE },
1016 	{ "u24be",  NULL, NULL, AFMT_U24_BE },
1017 #if BYTE_ORDER == LITTLE_ENDIAN
1018 	{ "s32le", "s32", "32", AFMT_S32_LE },
1019 	{ "s32be",  NULL, NULL, AFMT_S32_BE },
1020 #else
1021 	{ "s32le",  NULL, NULL, AFMT_S32_LE },
1022 	{ "s32be", "s32", "32", AFMT_S32_BE },
1023 #endif
1024 	{ "u32le",  NULL, NULL, AFMT_U32_LE },
1025 	{ "u32be",  NULL, NULL, AFMT_U32_BE },
1026 	{   "ac3",  NULL, NULL, AFMT_AC3    },
1027 	{    NULL,  NULL, NULL, 0           }
1028 };
1029 
1030 uint32_t
1031 snd_str2afmt(const char *req)
1032 {
1033 	int ext;
1034 	int ch;
1035 	int i;
1036 	char b1[8];
1037 	char b2[8];
1038 
1039 	memset(b1, 0, sizeof(b1));
1040 	memset(b2, 0, sizeof(b2));
1041 
1042 	i = sscanf(req, "%5[^:]:%6s", b1, b2);
1043 
1044 	if (i == 1) {
1045 		if (strlen(req) != strlen(b1))
1046 			return (0);
1047 		strlcpy(b2, "2.0", sizeof(b2));
1048 	} else if (i == 2) {
1049 		if (strlen(req) != (strlen(b1) + 1 + strlen(b2)))
1050 			return (0);
1051 	} else
1052 		return (0);
1053 
1054 	i = sscanf(b2, "%d.%d", &ch, &ext);
1055 
1056 	if (i == 0) {
1057 		if (strcasecmp(b2, "mono") == 0) {
1058 			ch = 1;
1059 			ext = 0;
1060 		} else if (strcasecmp(b2, "stereo") == 0) {
1061 			ch = 2;
1062 			ext = 0;
1063 		} else if (strcasecmp(b2, "quad") == 0) {
1064 			ch = 4;
1065 			ext = 0;
1066 		} else
1067 			return (0);
1068 	} else if (i == 1) {
1069 		if (ch < 1 || ch > AFMT_CHANNEL_MAX)
1070 			return (0);
1071 		ext = 0;
1072 	} else if (i == 2) {
1073 		if (ext < 0 || ext > AFMT_EXTCHANNEL_MAX)
1074 			return (0);
1075 		if (ch < 1 || (ch + ext) > AFMT_CHANNEL_MAX)
1076 			return (0);
1077 	} else
1078 		return (0);
1079 
1080 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1081 		if (strcasecmp(afmt_tab[i].name, b1) != 0) {
1082 			if (afmt_tab[i].alias1 == NULL)
1083 				continue;
1084 			if (strcasecmp(afmt_tab[i].alias1, b1) != 0) {
1085 				if (afmt_tab[i].alias2 == NULL)
1086 					continue;
1087 				if (strcasecmp(afmt_tab[i].alias2, b1) != 0)
1088 					continue;
1089 			}
1090 		}
1091 		/* found a match */
1092 		return (SND_FORMAT(afmt_tab[i].afmt, ch + ext, ext));
1093 	}
1094 	/* not a valid format */
1095 	return (0);
1096 }
1097 
1098 uint32_t
1099 snd_afmt2str(uint32_t afmt, char *buf, size_t len)
1100 {
1101 	uint32_t enc;
1102 	uint32_t ext;
1103 	uint32_t ch;
1104 	int i;
1105 
1106 	if (buf == NULL || len < AFMTSTR_LEN)
1107 		return (0);
1108 
1109 	memset(buf, 0, len);
1110 
1111 	enc = AFMT_ENCODING(afmt);
1112 	ch = AFMT_CHANNEL(afmt);
1113 	ext = AFMT_EXTCHANNEL(afmt);
1114 	/* check there is at least one channel */
1115 	if (ch <= ext)
1116 		return (0);
1117 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1118 		if (enc != afmt_tab[i].afmt)
1119 			continue;
1120 		/* found a match */
1121 		snprintf(buf, len, "%s:%d.%d",
1122 		    afmt_tab[i].name, ch - ext, ext);
1123 		return (SND_FORMAT(enc, ch, ext));
1124 	}
1125 	return (0);
1126 }
1127 
1128 int
1129 chn_reset(struct pcm_channel *c, uint32_t fmt, uint32_t spd)
1130 {
1131 	int r;
1132 
1133 	CHN_LOCKASSERT(c);
1134 	c->feedcount = 0;
1135 	c->flags &= CHN_F_RESET;
1136 	c->interrupts = 0;
1137 	c->timeout = 1;
1138 	c->xruns = 0;
1139 
1140 	c->flags |= (pcm_getflags(c->dev) & SD_F_BITPERFECT) ?
1141 	    CHN_F_BITPERFECT : 0;
1142 
1143 	r = CHANNEL_RESET(c->methods, c->devinfo);
1144 	if (r == 0 && fmt != 0 && spd != 0) {
1145 		r = chn_setparam(c, fmt, spd);
1146 		fmt = 0;
1147 		spd = 0;
1148 	}
1149 	if (r == 0 && fmt != 0)
1150 		r = chn_setformat(c, fmt);
1151 	if (r == 0 && spd != 0)
1152 		r = chn_setspeed(c, spd);
1153 	if (r == 0)
1154 		r = chn_setlatency(c, chn_latency);
1155 	if (r == 0) {
1156 		chn_resetbuf(c);
1157 		r = CHANNEL_RESETDONE(c->methods, c->devinfo);
1158 	}
1159 	return r;
1160 }
1161 
1162 int
1163 chn_init(struct pcm_channel *c, void *devinfo, int dir, int direction)
1164 {
1165 	struct feeder_class *fc;
1166 	struct snd_dbuf *b, *bs;
1167 	int i, ret;
1168 
1169 	if (chn_timeout < CHN_TIMEOUT_MIN || chn_timeout > CHN_TIMEOUT_MAX)
1170 		chn_timeout = CHN_TIMEOUT;
1171 
1172 	chn_lockinit(c, dir);
1173 
1174 	b = NULL;
1175 	bs = NULL;
1176 	CHN_INIT(c, children);
1177 	CHN_INIT(c, children.busy);
1178 	c->devinfo = NULL;
1179 	c->feeder = NULL;
1180 	c->latency = -1;
1181 	c->timeout = 1;
1182 
1183 	ret = ENOMEM;
1184 	b = sndbuf_create(c->dev, c->name, "primary", c);
1185 	if (b == NULL)
1186 		goto out;
1187 	bs = sndbuf_create(c->dev, c->name, "secondary", c);
1188 	if (bs == NULL)
1189 		goto out;
1190 
1191 	CHN_LOCK(c);
1192 
1193 	ret = EINVAL;
1194 	fc = feeder_getclass(NULL);
1195 	if (fc == NULL)
1196 		goto out;
1197 	if (chn_addfeeder(c, fc, NULL))
1198 		goto out;
1199 
1200 	/*
1201 	 * XXX - sndbuf_setup() & sndbuf_resize() expect to be called
1202 	 *	 with the channel unlocked because they are also called
1203 	 *	 from driver methods that don't know about locking
1204 	 */
1205 	CHN_UNLOCK(c);
1206 	sndbuf_setup(bs, NULL, 0);
1207 	CHN_LOCK(c);
1208 	c->bufhard = b;
1209 	c->bufsoft = bs;
1210 	c->flags = 0;
1211 	c->feederflags = 0;
1212 	c->sm = NULL;
1213 	c->format = SND_FORMAT(AFMT_U8, 1, 0);
1214 	c->speed = DSP_DEFAULT_SPEED;
1215 
1216 	c->matrix = *feeder_matrix_id_map(SND_CHN_MATRIX_1_0);
1217 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1218 
1219 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1220 		c->volume[SND_VOL_C_MASTER][i] = SND_VOL_0DB_MASTER;
1221 	}
1222 
1223 	c->volume[SND_VOL_C_MASTER][SND_CHN_T_VOL_0DB] = SND_VOL_0DB_MASTER;
1224 	c->volume[SND_VOL_C_PCM][SND_CHN_T_VOL_0DB] = chn_vol_0db_pcm;
1225 
1226 	memset(c->muted, 0, sizeof(c->muted));
1227 
1228 	chn_vpc_reset(c, SND_VOL_C_PCM, 1);
1229 
1230 	ret = ENODEV;
1231 	CHN_UNLOCK(c); /* XXX - Unlock for CHANNEL_INIT() malloc() call */
1232 	c->devinfo = CHANNEL_INIT(c->methods, devinfo, b, c, direction);
1233 	CHN_LOCK(c);
1234 	if (c->devinfo == NULL)
1235 		goto out;
1236 
1237 	ret = ENOMEM;
1238 	if ((sndbuf_getsize(b) == 0) && ((c->flags & CHN_F_VIRTUAL) == 0))
1239 		goto out;
1240 
1241 	ret = 0;
1242 	c->direction = direction;
1243 
1244 	sndbuf_setfmt(b, c->format);
1245 	sndbuf_setspd(b, c->speed);
1246 	sndbuf_setfmt(bs, c->format);
1247 	sndbuf_setspd(bs, c->speed);
1248 
1249 	/**
1250 	 * @todo Should this be moved somewhere else?  The primary buffer
1251 	 * 	 is allocated by the driver or via DMA map setup, and tmpbuf
1252 	 * 	 seems to only come into existence in sndbuf_resize().
1253 	 */
1254 	if (c->direction == PCMDIR_PLAY) {
1255 		bs->sl = sndbuf_getmaxsize(bs);
1256 		bs->shadbuf = malloc(bs->sl, M_DEVBUF, M_NOWAIT);
1257 		if (bs->shadbuf == NULL) {
1258 			ret = ENOMEM;
1259 			goto out;
1260 		}
1261 	}
1262 
1263 out:
1264 	CHN_UNLOCK(c);
1265 	if (ret) {
1266 		if (c->devinfo) {
1267 			if (CHANNEL_FREE(c->methods, c->devinfo))
1268 				sndbuf_free(b);
1269 		}
1270 		if (bs)
1271 			sndbuf_destroy(bs);
1272 		if (b)
1273 			sndbuf_destroy(b);
1274 		CHN_LOCK(c);
1275 		c->flags |= CHN_F_DEAD;
1276 		chn_lockdestroy(c);
1277 
1278 		return ret;
1279 	}
1280 
1281 	return 0;
1282 }
1283 
1284 int
1285 chn_kill(struct pcm_channel *c)
1286 {
1287     	struct snd_dbuf *b = c->bufhard;
1288     	struct snd_dbuf *bs = c->bufsoft;
1289 
1290 	if (CHN_STARTED(c)) {
1291 		CHN_LOCK(c);
1292 		chn_trigger(c, PCMTRIG_ABORT);
1293 		CHN_UNLOCK(c);
1294 	}
1295 	while (chn_removefeeder(c) == 0)
1296 		;
1297 	if (CHANNEL_FREE(c->methods, c->devinfo))
1298 		sndbuf_free(b);
1299 	sndbuf_destroy(bs);
1300 	sndbuf_destroy(b);
1301 	CHN_LOCK(c);
1302 	c->flags |= CHN_F_DEAD;
1303 	chn_lockdestroy(c);
1304 
1305 	return (0);
1306 }
1307 
1308 /* XXX Obsolete. Use *_matrix() variant instead. */
1309 int
1310 chn_setvolume(struct pcm_channel *c, int left, int right)
1311 {
1312 	int ret;
1313 
1314 	ret = chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FL, left);
1315 	ret |= chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FR,
1316 	    right) << 8;
1317 
1318 	return (ret);
1319 }
1320 
1321 int
1322 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
1323     int center)
1324 {
1325 	int i, ret;
1326 
1327 	ret = 0;
1328 
1329 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1330 		if ((1 << i) & SND_CHN_LEFT_MASK)
1331 			ret |= chn_setvolume_matrix(c, vc, i, left);
1332 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1333 			ret |= chn_setvolume_matrix(c, vc, i, right) << 8;
1334 		else
1335 			ret |= chn_setvolume_matrix(c, vc, i, center) << 16;
1336 	}
1337 
1338 	return (ret);
1339 }
1340 
1341 int
1342 chn_setvolume_matrix(struct pcm_channel *c, int vc, int vt, int val)
1343 {
1344 	int i;
1345 
1346 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1347 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1348 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN &&
1349 	    vt <= SND_CHN_T_END)) && (vt != SND_CHN_T_VOL_0DB ||
1350 	    (val >= SND_VOL_0DB_MIN && val <= SND_VOL_0DB_MAX)),
1351 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d val=%d",
1352 	    __func__, c, vc, vt, val));
1353 	CHN_LOCKASSERT(c);
1354 
1355 	if (val < 0)
1356 		val = 0;
1357 	if (val > 100)
1358 		val = 100;
1359 
1360 	c->volume[vc][vt] = val;
1361 
1362 	/*
1363 	 * Do relative calculation here and store it into class + 1
1364 	 * to ease the job of feeder_volume.
1365 	 */
1366 	if (vc == SND_VOL_C_MASTER) {
1367 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1368 		    vc += SND_VOL_C_STEP)
1369 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1370 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1371 	} else if (vc & 1) {
1372 		if (vt == SND_CHN_T_VOL_0DB)
1373 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1374 			    i += SND_CHN_T_STEP) {
1375 				c->volume[SND_VOL_C_VAL(vc)][i] =
1376 				    SND_VOL_CALC_VAL(c->volume, vc, i);
1377 			}
1378 		else
1379 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1380 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1381 	}
1382 
1383 	return (val);
1384 }
1385 
1386 int
1387 chn_getvolume_matrix(struct pcm_channel *c, int vc, int vt)
1388 {
1389 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1390 	    (vt == SND_CHN_T_VOL_0DB ||
1391 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1392 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d",
1393 	    __func__, c, vc, vt));
1394 	CHN_LOCKASSERT(c);
1395 
1396 	return (c->volume[vc][vt]);
1397 }
1398 
1399 int
1400 chn_setmute_multi(struct pcm_channel *c, int vc, int mute)
1401 {
1402 	int i, ret;
1403 
1404 	ret = 0;
1405 
1406 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1407 		if ((1 << i) & SND_CHN_LEFT_MASK)
1408 			ret |= chn_setmute_matrix(c, vc, i, mute);
1409 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1410 			ret |= chn_setmute_matrix(c, vc, i, mute) << 8;
1411 		else
1412 			ret |= chn_setmute_matrix(c, vc, i, mute) << 16;
1413 	}
1414 	return (ret);
1415 }
1416 
1417 int
1418 chn_setmute_matrix(struct pcm_channel *c, int vc, int vt, int mute)
1419 {
1420 	int i;
1421 
1422 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1423 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1424 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1425 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d mute=%d",
1426 	    __func__, c, vc, vt, mute));
1427 
1428 	CHN_LOCKASSERT(c);
1429 
1430 	mute = (mute != 0);
1431 
1432 	c->muted[vc][vt] = mute;
1433 
1434 	/*
1435 	 * Do relative calculation here and store it into class + 1
1436 	 * to ease the job of feeder_volume.
1437 	 */
1438 	if (vc == SND_VOL_C_MASTER) {
1439 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1440 		    vc += SND_VOL_C_STEP)
1441 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1442 	} else if (vc & 1) {
1443 		if (vt == SND_CHN_T_VOL_0DB) {
1444 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1445 			    i += SND_CHN_T_STEP) {
1446 				c->muted[SND_VOL_C_VAL(vc)][i] = mute;
1447 			}
1448 		} else {
1449 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1450 		}
1451 	}
1452 	return (mute);
1453 }
1454 
1455 int
1456 chn_getmute_matrix(struct pcm_channel *c, int vc, int vt)
1457 {
1458 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1459 	    (vt == SND_CHN_T_VOL_0DB ||
1460 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1461 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d",
1462 	    __func__, c, vc, vt));
1463 	CHN_LOCKASSERT(c);
1464 
1465 	return (c->muted[vc][vt]);
1466 }
1467 
1468 struct pcmchan_matrix *
1469 chn_getmatrix(struct pcm_channel *c)
1470 {
1471 
1472 	KASSERT(c != NULL, ("%s(): NULL channel", __func__));
1473 	CHN_LOCKASSERT(c);
1474 
1475 	if (!(c->format & AFMT_CONVERTIBLE))
1476 		return (NULL);
1477 
1478 	return (&c->matrix);
1479 }
1480 
1481 int
1482 chn_setmatrix(struct pcm_channel *c, struct pcmchan_matrix *m)
1483 {
1484 
1485 	KASSERT(c != NULL && m != NULL,
1486 	    ("%s(): NULL channel or matrix", __func__));
1487 	CHN_LOCKASSERT(c);
1488 
1489 	if (!(c->format & AFMT_CONVERTIBLE))
1490 		return (EINVAL);
1491 
1492 	c->matrix = *m;
1493 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1494 
1495 	return (chn_setformat(c, SND_FORMAT(c->format, m->channels, m->ext)));
1496 }
1497 
1498 /*
1499  * XXX chn_oss_* exists for the sake of compatibility.
1500  */
1501 int
1502 chn_oss_getorder(struct pcm_channel *c, unsigned long long *map)
1503 {
1504 
1505 	KASSERT(c != NULL && map != NULL,
1506 	    ("%s(): NULL channel or map", __func__));
1507 	CHN_LOCKASSERT(c);
1508 
1509 	if (!(c->format & AFMT_CONVERTIBLE))
1510 		return (EINVAL);
1511 
1512 	return (feeder_matrix_oss_get_channel_order(&c->matrix, map));
1513 }
1514 
1515 int
1516 chn_oss_setorder(struct pcm_channel *c, unsigned long long *map)
1517 {
1518 	struct pcmchan_matrix m;
1519 	int ret;
1520 
1521 	KASSERT(c != NULL && map != NULL,
1522 	    ("%s(): NULL channel or map", __func__));
1523 	CHN_LOCKASSERT(c);
1524 
1525 	if (!(c->format & AFMT_CONVERTIBLE))
1526 		return (EINVAL);
1527 
1528 	m = c->matrix;
1529 	ret = feeder_matrix_oss_set_channel_order(&m, map);
1530 	if (ret != 0)
1531 		return (ret);
1532 
1533 	return (chn_setmatrix(c, &m));
1534 }
1535 
1536 #define SND_CHN_OSS_FRONT	(SND_CHN_T_MASK_FL | SND_CHN_T_MASK_FR)
1537 #define SND_CHN_OSS_SURR	(SND_CHN_T_MASK_SL | SND_CHN_T_MASK_SR)
1538 #define SND_CHN_OSS_CENTER_LFE	(SND_CHN_T_MASK_FC | SND_CHN_T_MASK_LF)
1539 #define SND_CHN_OSS_REAR	(SND_CHN_T_MASK_BL | SND_CHN_T_MASK_BR)
1540 
1541 int
1542 chn_oss_getmask(struct pcm_channel *c, uint32_t *retmask)
1543 {
1544 	struct pcmchan_matrix *m;
1545 	struct pcmchan_caps *caps;
1546 	uint32_t i, format;
1547 
1548 	KASSERT(c != NULL && retmask != NULL,
1549 	    ("%s(): NULL channel or retmask", __func__));
1550 	CHN_LOCKASSERT(c);
1551 
1552 	caps = chn_getcaps(c);
1553 	if (caps == NULL || caps->fmtlist == NULL)
1554 		return (ENODEV);
1555 
1556 	for (i = 0; caps->fmtlist[i] != 0; i++) {
1557 		format = caps->fmtlist[i];
1558 		if (!(format & AFMT_CONVERTIBLE)) {
1559 			*retmask |= DSP_BIND_SPDIF;
1560 			continue;
1561 		}
1562 		m = CHANNEL_GETMATRIX(c->methods, c->devinfo, format);
1563 		if (m == NULL)
1564 			continue;
1565 		if (m->mask & SND_CHN_OSS_FRONT)
1566 			*retmask |= DSP_BIND_FRONT;
1567 		if (m->mask & SND_CHN_OSS_SURR)
1568 			*retmask |= DSP_BIND_SURR;
1569 		if (m->mask & SND_CHN_OSS_CENTER_LFE)
1570 			*retmask |= DSP_BIND_CENTER_LFE;
1571 		if (m->mask & SND_CHN_OSS_REAR)
1572 			*retmask |= DSP_BIND_REAR;
1573 	}
1574 
1575 	/* report software-supported binding mask */
1576 	if (!CHN_BITPERFECT(c) && report_soft_matrix)
1577 		*retmask |= DSP_BIND_FRONT | DSP_BIND_SURR |
1578 		    DSP_BIND_CENTER_LFE | DSP_BIND_REAR;
1579 
1580 	return (0);
1581 }
1582 
1583 void
1584 chn_vpc_reset(struct pcm_channel *c, int vc, int force)
1585 {
1586 	int i;
1587 
1588 	KASSERT(c != NULL && vc >= SND_VOL_C_BEGIN && vc <= SND_VOL_C_END,
1589 	    ("%s(): invalid reset c=%p vc=%d", __func__, c, vc));
1590 	CHN_LOCKASSERT(c);
1591 
1592 	if (force == 0 && chn_vpc_autoreset == 0)
1593 		return;
1594 
1595 	for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END; i += SND_CHN_T_STEP)
1596 		CHN_SETVOLUME(c, vc, i, c->volume[vc][SND_CHN_T_VOL_0DB]);
1597 }
1598 
1599 static u_int32_t
1600 round_pow2(u_int32_t v)
1601 {
1602 	u_int32_t ret;
1603 
1604 	if (v < 2)
1605 		v = 2;
1606 	ret = 0;
1607 	while (v >> ret)
1608 		ret++;
1609 	ret = 1 << (ret - 1);
1610 	while (ret < v)
1611 		ret <<= 1;
1612 	return ret;
1613 }
1614 
1615 static u_int32_t
1616 round_blksz(u_int32_t v, int round)
1617 {
1618 	u_int32_t ret, tmp;
1619 
1620 	if (round < 1)
1621 		round = 1;
1622 
1623 	ret = min(round_pow2(v), CHN_2NDBUFMAXSIZE >> 1);
1624 
1625 	if (ret > v && (ret >> 1) > 0 && (ret >> 1) >= ((v * 3) >> 2))
1626 		ret >>= 1;
1627 
1628 	tmp = ret - (ret % round);
1629 	while (tmp < 16 || tmp < round) {
1630 		ret <<= 1;
1631 		tmp = ret - (ret % round);
1632 	}
1633 
1634 	return ret;
1635 }
1636 
1637 /*
1638  * 4Front call it DSP Policy, while we call it "Latency Profile". The idea
1639  * is to keep 2nd buffer short so that it doesn't cause long queue during
1640  * buffer transfer.
1641  *
1642  *    Latency reference table for 48khz stereo 16bit: (PLAY)
1643  *
1644  *      +---------+------------+-----------+------------+
1645  *      | Latency | Blockcount | Blocksize | Buffersize |
1646  *      +---------+------------+-----------+------------+
1647  *      |     0   |       2    |   64      |    128     |
1648  *      +---------+------------+-----------+------------+
1649  *      |     1   |       4    |   128     |    512     |
1650  *      +---------+------------+-----------+------------+
1651  *      |     2   |       8    |   512     |    4096    |
1652  *      +---------+------------+-----------+------------+
1653  *      |     3   |      16    |   512     |    8192    |
1654  *      +---------+------------+-----------+------------+
1655  *      |     4   |      32    |   512     |    16384   |
1656  *      +---------+------------+-----------+------------+
1657  *      |     5   |      32    |   1024    |    32768   |
1658  *      +---------+------------+-----------+------------+
1659  *      |     6   |      16    |   2048    |    32768   |
1660  *      +---------+------------+-----------+------------+
1661  *      |     7   |       8    |   4096    |    32768   |
1662  *      +---------+------------+-----------+------------+
1663  *      |     8   |       4    |   8192    |    32768   |
1664  *      +---------+------------+-----------+------------+
1665  *      |     9   |       2    |   16384   |    32768   |
1666  *      +---------+------------+-----------+------------+
1667  *      |    10   |       2    |   32768   |    65536   |
1668  *      +---------+------------+-----------+------------+
1669  *
1670  * Recording need a different reference table. All we care is
1671  * gobbling up everything within reasonable buffering threshold.
1672  *
1673  *    Latency reference table for 48khz stereo 16bit: (REC)
1674  *
1675  *      +---------+------------+-----------+------------+
1676  *      | Latency | Blockcount | Blocksize | Buffersize |
1677  *      +---------+------------+-----------+------------+
1678  *      |     0   |     512    |   32      |    16384   |
1679  *      +---------+------------+-----------+------------+
1680  *      |     1   |     256    |   64      |    16384   |
1681  *      +---------+------------+-----------+------------+
1682  *      |     2   |     128    |   128     |    16384   |
1683  *      +---------+------------+-----------+------------+
1684  *      |     3   |      64    |   256     |    16384   |
1685  *      +---------+------------+-----------+------------+
1686  *      |     4   |      32    |   512     |    16384   |
1687  *      +---------+------------+-----------+------------+
1688  *      |     5   |      32    |   1024    |    32768   |
1689  *      +---------+------------+-----------+------------+
1690  *      |     6   |      16    |   2048    |    32768   |
1691  *      +---------+------------+-----------+------------+
1692  *      |     7   |       8    |   4096    |    32768   |
1693  *      +---------+------------+-----------+------------+
1694  *      |     8   |       4    |   8192    |    32768   |
1695  *      +---------+------------+-----------+------------+
1696  *      |     9   |       2    |   16384   |    32768   |
1697  *      +---------+------------+-----------+------------+
1698  *      |    10   |       2    |   32768   |    65536   |
1699  *      +---------+------------+-----------+------------+
1700  *
1701  * Calculations for other data rate are entirely based on these reference
1702  * tables. For normal operation, Latency 5 seems give the best, well
1703  * balanced performance for typical workload. Anything below 5 will
1704  * eat up CPU to keep up with increasing context switches because of
1705  * shorter buffer space and usually require the application to handle it
1706  * aggressively through possibly real time programming technique.
1707  *
1708  */
1709 #define CHN_LATENCY_PBLKCNT_REF				\
1710 	{{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1},		\
1711 	{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1}}
1712 #define CHN_LATENCY_PBUFSZ_REF				\
1713 	{{7, 9, 12, 13, 14, 15, 15, 15, 15, 15, 16},	\
1714 	{11, 12, 13, 14, 15, 16, 16, 16, 16, 16, 17}}
1715 
1716 #define CHN_LATENCY_RBLKCNT_REF				\
1717 	{{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1},		\
1718 	{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1}}
1719 #define CHN_LATENCY_RBUFSZ_REF				\
1720 	{{14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16},	\
1721 	{15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17}}
1722 
1723 #define CHN_LATENCY_DATA_REF	192000 /* 48khz stereo 16bit ~ 48000 x 2 x 2 */
1724 
1725 static int
1726 chn_calclatency(int dir, int latency, int bps, u_int32_t datarate,
1727 				u_int32_t max, int *rblksz, int *rblkcnt)
1728 {
1729 	static int pblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1730 	    CHN_LATENCY_PBLKCNT_REF;
1731 	static int  pbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1732 	    CHN_LATENCY_PBUFSZ_REF;
1733 	static int rblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1734 	    CHN_LATENCY_RBLKCNT_REF;
1735 	static int  rbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1736 	    CHN_LATENCY_RBUFSZ_REF;
1737 	u_int32_t bufsz;
1738 	int lprofile, blksz, blkcnt;
1739 
1740 	if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX ||
1741 	    bps < 1 || datarate < 1 ||
1742 	    !(dir == PCMDIR_PLAY || dir == PCMDIR_REC)) {
1743 		if (rblksz != NULL)
1744 			*rblksz = CHN_2NDBUFMAXSIZE >> 1;
1745 		if (rblkcnt != NULL)
1746 			*rblkcnt = 2;
1747 		printf("%s(): FAILED dir=%d latency=%d bps=%d "
1748 		    "datarate=%u max=%u\n",
1749 		    __func__, dir, latency, bps, datarate, max);
1750 		return CHN_2NDBUFMAXSIZE;
1751 	}
1752 
1753 	lprofile = chn_latency_profile;
1754 
1755 	if (dir == PCMDIR_PLAY) {
1756 		blkcnt = pblkcnts[lprofile][latency];
1757 		bufsz = pbufszs[lprofile][latency];
1758 	} else {
1759 		blkcnt = rblkcnts[lprofile][latency];
1760 		bufsz = rbufszs[lprofile][latency];
1761 	}
1762 
1763 	bufsz = round_pow2(snd_xbytes(1 << bufsz, CHN_LATENCY_DATA_REF,
1764 	    datarate));
1765 	if (bufsz > max)
1766 		bufsz = max;
1767 	blksz = round_blksz(bufsz >> blkcnt, bps);
1768 
1769 	if (rblksz != NULL)
1770 		*rblksz = blksz;
1771 	if (rblkcnt != NULL)
1772 		*rblkcnt = 1 << blkcnt;
1773 
1774 	return blksz << blkcnt;
1775 }
1776 
1777 static int
1778 chn_resizebuf(struct pcm_channel *c, int latency,
1779 					int blkcnt, int blksz)
1780 {
1781 	struct snd_dbuf *b, *bs, *pb;
1782 	int sblksz, sblkcnt, hblksz, hblkcnt, limit = 0, nsblksz, nsblkcnt;
1783 	int ret;
1784 
1785 	CHN_LOCKASSERT(c);
1786 
1787 	if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
1788 	    !(c->direction == PCMDIR_PLAY || c->direction == PCMDIR_REC))
1789 		return EINVAL;
1790 
1791 	if (latency == -1) {
1792 		c->latency = -1;
1793 		latency = chn_latency;
1794 	} else if (latency == -2) {
1795 		latency = c->latency;
1796 		if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1797 			latency = chn_latency;
1798 	} else if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1799 		return EINVAL;
1800 	else {
1801 		c->latency = latency;
1802 	}
1803 
1804 	bs = c->bufsoft;
1805 	b = c->bufhard;
1806 
1807 	if (!(blksz == 0 || blkcnt == -1) &&
1808 	    (blksz < 16 || blksz < sndbuf_getalign(bs) || blkcnt < 2 ||
1809 	    (blksz * blkcnt) > CHN_2NDBUFMAXSIZE))
1810 		return EINVAL;
1811 
1812 	chn_calclatency(c->direction, latency, sndbuf_getalign(bs),
1813 	    sndbuf_getalign(bs) * sndbuf_getspd(bs), CHN_2NDBUFMAXSIZE,
1814 	    &sblksz, &sblkcnt);
1815 
1816 	if (blksz == 0 || blkcnt == -1) {
1817 		if (blkcnt == -1)
1818 			c->flags &= ~CHN_F_HAS_SIZE;
1819 		if (c->flags & CHN_F_HAS_SIZE) {
1820 			blksz = sndbuf_getblksz(bs);
1821 			blkcnt = sndbuf_getblkcnt(bs);
1822 		}
1823 	} else
1824 		c->flags |= CHN_F_HAS_SIZE;
1825 
1826 	if (c->flags & CHN_F_HAS_SIZE) {
1827 		/*
1828 		 * The application has requested their own blksz/blkcnt.
1829 		 * Just obey with it, and let them toast alone. We can
1830 		 * clamp it to the nearest latency profile, but that would
1831 		 * defeat the purpose of having custom control. The least
1832 		 * we can do is round it to the nearest ^2 and align it.
1833 		 */
1834 		sblksz = round_blksz(blksz, sndbuf_getalign(bs));
1835 		sblkcnt = round_pow2(blkcnt);
1836 	}
1837 
1838 	if (c->parentchannel != NULL) {
1839 		pb = c->parentchannel->bufsoft;
1840 		CHN_UNLOCK(c);
1841 		CHN_LOCK(c->parentchannel);
1842 		chn_notify(c->parentchannel, CHN_N_BLOCKSIZE);
1843 		CHN_UNLOCK(c->parentchannel);
1844 		CHN_LOCK(c);
1845 		if (c->direction == PCMDIR_PLAY) {
1846 			limit = (pb != NULL) ?
1847 			    sndbuf_xbytes(sndbuf_getsize(pb), pb, bs) : 0;
1848 		} else {
1849 			limit = (pb != NULL) ?
1850 			    sndbuf_xbytes(sndbuf_getblksz(pb), pb, bs) * 2 : 0;
1851 		}
1852 	} else {
1853 		hblkcnt = 2;
1854 		if (c->flags & CHN_F_HAS_SIZE) {
1855 			hblksz = round_blksz(sndbuf_xbytes(sblksz, bs, b),
1856 			    sndbuf_getalign(b));
1857 			hblkcnt = round_pow2(sndbuf_getblkcnt(bs));
1858 		} else
1859 			chn_calclatency(c->direction, latency,
1860 			    sndbuf_getalign(b),
1861 			    sndbuf_getalign(b) * sndbuf_getspd(b),
1862 			    CHN_2NDBUFMAXSIZE, &hblksz, &hblkcnt);
1863 
1864 		if ((hblksz << 1) > sndbuf_getmaxsize(b))
1865 			hblksz = round_blksz(sndbuf_getmaxsize(b) >> 1,
1866 			    sndbuf_getalign(b));
1867 
1868 		while ((hblksz * hblkcnt) > sndbuf_getmaxsize(b)) {
1869 			if (hblkcnt < 4)
1870 				hblksz >>= 1;
1871 			else
1872 				hblkcnt >>= 1;
1873 		}
1874 
1875 		hblksz -= hblksz % sndbuf_getalign(b);
1876 
1877 #if 0
1878 		hblksz = sndbuf_getmaxsize(b) >> 1;
1879 		hblksz -= hblksz % sndbuf_getalign(b);
1880 		hblkcnt = 2;
1881 #endif
1882 
1883 		CHN_UNLOCK(c);
1884 		if (chn_usefrags == 0 ||
1885 		    CHANNEL_SETFRAGMENTS(c->methods, c->devinfo,
1886 		    hblksz, hblkcnt) != 0)
1887 			sndbuf_setblksz(b, CHANNEL_SETBLOCKSIZE(c->methods,
1888 			    c->devinfo, hblksz));
1889 		CHN_LOCK(c);
1890 
1891 		if (!CHN_EMPTY(c, children)) {
1892 			nsblksz = round_blksz(
1893 			    sndbuf_xbytes(sndbuf_getblksz(b), b, bs),
1894 			    sndbuf_getalign(bs));
1895 			nsblkcnt = sndbuf_getblkcnt(b);
1896 			if (c->direction == PCMDIR_PLAY) {
1897 				do {
1898 					nsblkcnt--;
1899 				} while (nsblkcnt >= 2 &&
1900 				    nsblksz * nsblkcnt >= sblksz * sblkcnt);
1901 				nsblkcnt++;
1902 			}
1903 			sblksz = nsblksz;
1904 			sblkcnt = nsblkcnt;
1905 			limit = 0;
1906 		} else
1907 			limit = sndbuf_xbytes(sndbuf_getblksz(b), b, bs) * 2;
1908 	}
1909 
1910 	if (limit > CHN_2NDBUFMAXSIZE)
1911 		limit = CHN_2NDBUFMAXSIZE;
1912 
1913 #if 0
1914 	while (limit > 0 && (sblksz * sblkcnt) > limit) {
1915 		if (sblkcnt < 4)
1916 			break;
1917 		sblkcnt >>= 1;
1918 	}
1919 #endif
1920 
1921 	while ((sblksz * sblkcnt) < limit)
1922 		sblkcnt <<= 1;
1923 
1924 	while ((sblksz * sblkcnt) > CHN_2NDBUFMAXSIZE) {
1925 		if (sblkcnt < 4)
1926 			sblksz >>= 1;
1927 		else
1928 			sblkcnt >>= 1;
1929 	}
1930 
1931 	sblksz -= sblksz % sndbuf_getalign(bs);
1932 
1933 	if (sndbuf_getblkcnt(bs) != sblkcnt || sndbuf_getblksz(bs) != sblksz ||
1934 	    sndbuf_getsize(bs) != (sblkcnt * sblksz)) {
1935 		ret = sndbuf_remalloc(bs, sblkcnt, sblksz);
1936 		if (ret != 0) {
1937 			device_printf(c->dev, "%s(): Failed: %d %d\n",
1938 			    __func__, sblkcnt, sblksz);
1939 			return ret;
1940 		}
1941 	}
1942 
1943 	/*
1944 	 * Interrupt timeout
1945 	 */
1946 	c->timeout = ((u_int64_t)hz * sndbuf_getsize(bs)) /
1947 	    ((u_int64_t)sndbuf_getspd(bs) * sndbuf_getalign(bs));
1948 	if (c->parentchannel != NULL)
1949 		c->timeout = min(c->timeout, c->parentchannel->timeout);
1950 	if (c->timeout < 1)
1951 		c->timeout = 1;
1952 
1953 	/*
1954 	 * OSSv4 docs: "By default OSS will set the low water level equal
1955 	 * to the fragment size which is optimal in most cases."
1956 	 */
1957 	c->lw = sndbuf_getblksz(bs);
1958 	chn_resetbuf(c);
1959 
1960 	if (snd_verbose > 3)
1961 		device_printf(c->dev, "%s(): %s (%s) timeout=%u "
1962 		    "b[%d/%d/%d] bs[%d/%d/%d] limit=%d\n",
1963 		    __func__, CHN_DIRSTR(c),
1964 		    (c->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
1965 		    c->timeout,
1966 		    sndbuf_getsize(b), sndbuf_getblksz(b),
1967 		    sndbuf_getblkcnt(b),
1968 		    sndbuf_getsize(bs), sndbuf_getblksz(bs),
1969 		    sndbuf_getblkcnt(bs), limit);
1970 
1971 	return 0;
1972 }
1973 
1974 int
1975 chn_setlatency(struct pcm_channel *c, int latency)
1976 {
1977 	CHN_LOCKASSERT(c);
1978 	/* Destroy blksz/blkcnt, enforce latency profile. */
1979 	return chn_resizebuf(c, latency, -1, 0);
1980 }
1981 
1982 int
1983 chn_setblocksize(struct pcm_channel *c, int blkcnt, int blksz)
1984 {
1985 	CHN_LOCKASSERT(c);
1986 	/* Destroy latency profile, enforce blksz/blkcnt */
1987 	return chn_resizebuf(c, -1, blkcnt, blksz);
1988 }
1989 
1990 int
1991 chn_setparam(struct pcm_channel *c, uint32_t format, uint32_t speed)
1992 {
1993 	struct pcmchan_caps *caps;
1994 	uint32_t hwspeed, delta;
1995 	int ret;
1996 
1997 	CHN_LOCKASSERT(c);
1998 
1999 	if (speed < 1 || format == 0 || CHN_STARTED(c))
2000 		return (EINVAL);
2001 
2002 	c->format = format;
2003 	c->speed = speed;
2004 
2005 	caps = chn_getcaps(c);
2006 
2007 	hwspeed = speed;
2008 	RANGE(hwspeed, caps->minspeed, caps->maxspeed);
2009 
2010 	sndbuf_setspd(c->bufhard, CHANNEL_SETSPEED(c->methods, c->devinfo,
2011 	    hwspeed));
2012 	hwspeed = sndbuf_getspd(c->bufhard);
2013 
2014 	delta = (hwspeed > speed) ? (hwspeed - speed) : (speed - hwspeed);
2015 
2016 	if (delta <= feeder_rate_round)
2017 		c->speed = hwspeed;
2018 
2019 	ret = feeder_chain(c);
2020 
2021 	if (ret == 0)
2022 		ret = CHANNEL_SETFORMAT(c->methods, c->devinfo,
2023 		    sndbuf_getfmt(c->bufhard));
2024 
2025 	if (ret == 0)
2026 		ret = chn_resizebuf(c, -2, 0, 0);
2027 
2028 	return (ret);
2029 }
2030 
2031 int
2032 chn_setspeed(struct pcm_channel *c, uint32_t speed)
2033 {
2034 	uint32_t oldformat, oldspeed, format;
2035 	int ret;
2036 
2037 #if 0
2038 	/* XXX force 48k */
2039 	if (c->format & AFMT_PASSTHROUGH)
2040 		speed = AFMT_PASSTHROUGH_RATE;
2041 #endif
2042 
2043 	oldformat = c->format;
2044 	oldspeed = c->speed;
2045 	format = oldformat;
2046 
2047 	ret = chn_setparam(c, format, speed);
2048 	if (ret != 0) {
2049 		if (snd_verbose > 3)
2050 			device_printf(c->dev,
2051 			    "%s(): Setting speed %d failed, "
2052 			    "falling back to %d\n",
2053 			    __func__, speed, oldspeed);
2054 		chn_setparam(c, c->format, oldspeed);
2055 	}
2056 
2057 	return (ret);
2058 }
2059 
2060 int
2061 chn_setformat(struct pcm_channel *c, uint32_t format)
2062 {
2063 	uint32_t oldformat, oldspeed, speed;
2064 	int ret;
2065 
2066 	/* XXX force stereo */
2067 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
2068 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,
2069 		    AFMT_PASSTHROUGH_EXTCHANNEL);
2070 	}
2071 
2072 	oldformat = c->format;
2073 	oldspeed = c->speed;
2074 	speed = oldspeed;
2075 
2076 	ret = chn_setparam(c, format, speed);
2077 	if (ret != 0) {
2078 		if (snd_verbose > 3)
2079 			device_printf(c->dev,
2080 			    "%s(): Format change 0x%08x failed, "
2081 			    "falling back to 0x%08x\n",
2082 			    __func__, format, oldformat);
2083 		chn_setparam(c, oldformat, oldspeed);
2084 	}
2085 
2086 	return (ret);
2087 }
2088 
2089 void
2090 chn_syncstate(struct pcm_channel *c)
2091 {
2092 	struct snddev_info *d;
2093 	struct snd_mixer *m;
2094 
2095 	d = (c != NULL) ? c->parentsnddev : NULL;
2096 	m = (d != NULL && d->mixer_dev != NULL) ? d->mixer_dev->si_drv1 :
2097 	    NULL;
2098 
2099 	if (d == NULL || m == NULL)
2100 		return;
2101 
2102 	CHN_LOCKASSERT(c);
2103 
2104 	if (c->feederflags & (1 << FEEDER_VOLUME)) {
2105 		uint32_t parent;
2106 		int vol, pvol, left, right, center;
2107 
2108 		if (c->direction == PCMDIR_PLAY &&
2109 		    (d->flags & SD_F_SOFTPCMVOL)) {
2110 			/* CHN_UNLOCK(c); */
2111 			vol = mix_get(m, SOUND_MIXER_PCM);
2112 			parent = mix_getparent(m, SOUND_MIXER_PCM);
2113 			if (parent != SOUND_MIXER_NONE)
2114 				pvol = mix_get(m, parent);
2115 			else
2116 				pvol = 100 | (100 << 8);
2117 			/* CHN_LOCK(c); */
2118 		} else {
2119 			vol = 100 | (100 << 8);
2120 			pvol = vol;
2121 		}
2122 
2123 		if (vol == -1) {
2124 			device_printf(c->dev,
2125 			    "Soft PCM Volume: Failed to read pcm "
2126 			    "default value\n");
2127 			vol = 100 | (100 << 8);
2128 		}
2129 
2130 		if (pvol == -1) {
2131 			device_printf(c->dev,
2132 			    "Soft PCM Volume: Failed to read parent "
2133 			    "default value\n");
2134 			pvol = 100 | (100 << 8);
2135 		}
2136 
2137 		left = ((vol & 0x7f) * (pvol & 0x7f)) / 100;
2138 		right = (((vol >> 8) & 0x7f) * ((pvol >> 8) & 0x7f)) / 100;
2139 		center = (left + right) >> 1;
2140 
2141 		chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right, center);
2142 	}
2143 
2144 	if (c->feederflags & (1 << FEEDER_EQ)) {
2145 		struct pcm_feeder *f;
2146 		int treble, bass, state;
2147 
2148 		/* CHN_UNLOCK(c); */
2149 		treble = mix_get(m, SOUND_MIXER_TREBLE);
2150 		bass = mix_get(m, SOUND_MIXER_BASS);
2151 		/* CHN_LOCK(c); */
2152 
2153 		if (treble == -1)
2154 			treble = 50;
2155 		else
2156 			treble = ((treble & 0x7f) +
2157 			    ((treble >> 8) & 0x7f)) >> 1;
2158 
2159 		if (bass == -1)
2160 			bass = 50;
2161 		else
2162 			bass = ((bass & 0x7f) + ((bass >> 8) & 0x7f)) >> 1;
2163 
2164 		f = chn_findfeeder(c, FEEDER_EQ);
2165 		if (f != NULL) {
2166 			if (FEEDER_SET(f, FEEDEQ_TREBLE, treble) != 0)
2167 				device_printf(c->dev,
2168 				    "EQ: Failed to set treble -- %d\n",
2169 				    treble);
2170 			if (FEEDER_SET(f, FEEDEQ_BASS, bass) != 0)
2171 				device_printf(c->dev,
2172 				    "EQ: Failed to set bass -- %d\n",
2173 				    bass);
2174 			if (FEEDER_SET(f, FEEDEQ_PREAMP, d->eqpreamp) != 0)
2175 				device_printf(c->dev,
2176 				    "EQ: Failed to set preamp -- %d\n",
2177 				    d->eqpreamp);
2178 			if (d->flags & SD_F_EQ_BYPASSED)
2179 				state = FEEDEQ_BYPASS;
2180 			else if (d->flags & SD_F_EQ_ENABLED)
2181 				state = FEEDEQ_ENABLE;
2182 			else
2183 				state = FEEDEQ_DISABLE;
2184 			if (FEEDER_SET(f, FEEDEQ_STATE, state) != 0)
2185 				device_printf(c->dev,
2186 				    "EQ: Failed to set state -- %d\n", state);
2187 		}
2188 	}
2189 }
2190 
2191 int
2192 chn_trigger(struct pcm_channel *c, int go)
2193 {
2194 #ifdef DEV_ISA
2195     	struct snd_dbuf *b = c->bufhard;
2196 #endif
2197 	struct snddev_info *d = c->parentsnddev;
2198 	int ret;
2199 
2200 	CHN_LOCKASSERT(c);
2201 #ifdef DEV_ISA
2202 	if (SND_DMA(b) && (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD))
2203 		sndbuf_dmabounce(b);
2204 #endif
2205 	if (!PCMTRIG_COMMON(go))
2206 		return (CHANNEL_TRIGGER(c->methods, c->devinfo, go));
2207 
2208 	if (go == c->trigger)
2209 		return (0);
2210 
2211 	ret = CHANNEL_TRIGGER(c->methods, c->devinfo, go);
2212 	if (ret != 0)
2213 		return (ret);
2214 
2215 	switch (go) {
2216 	case PCMTRIG_START:
2217 		if (snd_verbose > 3)
2218 			device_printf(c->dev,
2219 			    "%s() %s: calling go=0x%08x , "
2220 			    "prev=0x%08x\n", __func__, c->name, go,
2221 			    c->trigger);
2222 		if (c->trigger != PCMTRIG_START) {
2223 			c->trigger = go;
2224 			CHN_UNLOCK(c);
2225 			PCM_LOCK(d);
2226 			CHN_INSERT_HEAD(d, c, channels.pcm.busy);
2227 			PCM_UNLOCK(d);
2228 			CHN_LOCK(c);
2229 			chn_syncstate(c);
2230 		}
2231 		break;
2232 	case PCMTRIG_STOP:
2233 	case PCMTRIG_ABORT:
2234 		if (snd_verbose > 3)
2235 			device_printf(c->dev,
2236 			    "%s() %s: calling go=0x%08x , "
2237 			    "prev=0x%08x\n", __func__, c->name, go,
2238 			    c->trigger);
2239 		if (c->trigger == PCMTRIG_START) {
2240 			c->trigger = go;
2241 			CHN_UNLOCK(c);
2242 			PCM_LOCK(d);
2243 			CHN_REMOVE(d, c, channels.pcm.busy);
2244 			PCM_UNLOCK(d);
2245 			CHN_LOCK(c);
2246 		}
2247 		break;
2248 	default:
2249 		break;
2250 	}
2251 
2252 	return (0);
2253 }
2254 
2255 /**
2256  * @brief Queries sound driver for sample-aligned hardware buffer pointer index
2257  *
2258  * This function obtains the hardware pointer location, then aligns it to
2259  * the current bytes-per-sample value before returning.  (E.g., a channel
2260  * running in 16 bit stereo mode would require 4 bytes per sample, so a
2261  * hwptr value ranging from 32-35 would be returned as 32.)
2262  *
2263  * @param c	PCM channel context
2264  * @returns 	sample-aligned hardware buffer pointer index
2265  */
2266 int
2267 chn_getptr(struct pcm_channel *c)
2268 {
2269 	int hwptr;
2270 
2271 	CHN_LOCKASSERT(c);
2272 	hwptr = (CHN_STARTED(c)) ? CHANNEL_GETPTR(c->methods, c->devinfo) : 0;
2273 	return (hwptr - (hwptr % sndbuf_getalign(c->bufhard)));
2274 }
2275 
2276 struct pcmchan_caps *
2277 chn_getcaps(struct pcm_channel *c)
2278 {
2279 	CHN_LOCKASSERT(c);
2280 	return CHANNEL_GETCAPS(c->methods, c->devinfo);
2281 }
2282 
2283 u_int32_t
2284 chn_getformats(struct pcm_channel *c)
2285 {
2286 	u_int32_t *fmtlist, fmts;
2287 	int i;
2288 
2289 	fmtlist = chn_getcaps(c)->fmtlist;
2290 	fmts = 0;
2291 	for (i = 0; fmtlist[i]; i++)
2292 		fmts |= fmtlist[i];
2293 
2294 	/* report software-supported formats */
2295 	if (!CHN_BITPERFECT(c) && report_soft_formats)
2296 		fmts |= AFMT_CONVERTIBLE;
2297 
2298 	return (AFMT_ENCODING(fmts));
2299 }
2300 
2301 int
2302 chn_notify(struct pcm_channel *c, u_int32_t flags)
2303 {
2304 	struct pcm_channel *ch;
2305 	struct pcmchan_caps *caps;
2306 	uint32_t bestformat, bestspeed, besthwformat, *vchanformat, *vchanrate;
2307 	uint32_t vpflags;
2308 	int dirty, err, run, nrun;
2309 
2310 	CHN_LOCKASSERT(c);
2311 
2312 	if (CHN_EMPTY(c, children))
2313 		return (ENODEV);
2314 
2315 	err = 0;
2316 
2317 	/*
2318 	 * If the hwchan is running, we can't change its rate, format or
2319 	 * blocksize
2320 	 */
2321 	run = (CHN_STARTED(c)) ? 1 : 0;
2322 	if (run)
2323 		flags &= CHN_N_VOLUME | CHN_N_TRIGGER;
2324 
2325 	if (flags & CHN_N_RATE) {
2326 		/*
2327 		 * XXX I'll make good use of this someday.
2328 		 *     However this is currently being superseded by
2329 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2330 		 */
2331 	}
2332 
2333 	if (flags & CHN_N_FORMAT) {
2334 		/*
2335 		 * XXX I'll make good use of this someday.
2336 		 *     However this is currently being superseded by
2337 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2338 		 */
2339 	}
2340 
2341 	if (flags & CHN_N_VOLUME) {
2342 		/*
2343 		 * XXX I'll make good use of this someday, though
2344 		 *     soft volume control is currently pretty much
2345 		 *     integrated.
2346 		 */
2347 	}
2348 
2349 	if (flags & CHN_N_BLOCKSIZE) {
2350 		/*
2351 		 * Set to default latency profile
2352 		 */
2353 		chn_setlatency(c, chn_latency);
2354 	}
2355 
2356 	if ((flags & CHN_N_TRIGGER) && !(c->flags & CHN_F_VCHAN_DYNAMIC)) {
2357 		nrun = CHN_EMPTY(c, children.busy) ? 0 : 1;
2358 		if (nrun && !run)
2359 			err = chn_start(c, 1);
2360 		if (!nrun && run)
2361 			chn_abort(c);
2362 		flags &= ~CHN_N_TRIGGER;
2363 	}
2364 
2365 	if (flags & CHN_N_TRIGGER) {
2366 		if (c->direction == PCMDIR_PLAY) {
2367 			vchanformat = &c->parentsnddev->pvchanformat;
2368 			vchanrate = &c->parentsnddev->pvchanrate;
2369 		} else {
2370 			vchanformat = &c->parentsnddev->rvchanformat;
2371 			vchanrate = &c->parentsnddev->rvchanrate;
2372 		}
2373 
2374 		/* Dynamic Virtual Channel */
2375 		if (!(c->flags & CHN_F_VCHAN_ADAPTIVE)) {
2376 			bestformat = *vchanformat;
2377 			bestspeed = *vchanrate;
2378 		} else {
2379 			bestformat = 0;
2380 			bestspeed = 0;
2381 		}
2382 
2383 		besthwformat = 0;
2384 		nrun = 0;
2385 		caps = chn_getcaps(c);
2386 		dirty = 0;
2387 		vpflags = 0;
2388 
2389 		CHN_FOREACH(ch, c, children.busy) {
2390 			CHN_LOCK(ch);
2391 			if ((ch->format & AFMT_PASSTHROUGH) &&
2392 			    snd_fmtvalid(ch->format, caps->fmtlist)) {
2393 				bestformat = ch->format;
2394 				bestspeed = ch->speed;
2395 				CHN_UNLOCK(ch);
2396 				vpflags = CHN_F_PASSTHROUGH;
2397 				nrun++;
2398 				break;
2399 			}
2400 			if ((ch->flags & CHN_F_EXCLUSIVE) && vpflags == 0) {
2401 				if (c->flags & CHN_F_VCHAN_ADAPTIVE) {
2402 					bestspeed = ch->speed;
2403 					RANGE(bestspeed, caps->minspeed,
2404 					    caps->maxspeed);
2405 					besthwformat = snd_fmtbest(ch->format,
2406 					    caps->fmtlist);
2407 					if (besthwformat != 0)
2408 						bestformat = besthwformat;
2409 				}
2410 				CHN_UNLOCK(ch);
2411 				vpflags = CHN_F_EXCLUSIVE;
2412 				nrun++;
2413 				continue;
2414 			}
2415 			if (!(c->flags & CHN_F_VCHAN_ADAPTIVE) ||
2416 			    vpflags != 0) {
2417 				CHN_UNLOCK(ch);
2418 				nrun++;
2419 				continue;
2420 			}
2421 			if (ch->speed > bestspeed) {
2422 				bestspeed = ch->speed;
2423 				RANGE(bestspeed, caps->minspeed,
2424 				    caps->maxspeed);
2425 			}
2426 			besthwformat = snd_fmtbest(ch->format, caps->fmtlist);
2427 			if (!(besthwformat & AFMT_VCHAN)) {
2428 				CHN_UNLOCK(ch);
2429 				nrun++;
2430 				continue;
2431 			}
2432 			if (AFMT_CHANNEL(besthwformat) >
2433 			    AFMT_CHANNEL(bestformat))
2434 				bestformat = besthwformat;
2435 			else if (AFMT_CHANNEL(besthwformat) ==
2436 			    AFMT_CHANNEL(bestformat) &&
2437 			    AFMT_BIT(besthwformat) > AFMT_BIT(bestformat))
2438 				bestformat = besthwformat;
2439 			CHN_UNLOCK(ch);
2440 			nrun++;
2441 		}
2442 
2443 		if (bestformat == 0)
2444 			bestformat = c->format;
2445 		if (bestspeed == 0)
2446 			bestspeed = c->speed;
2447 
2448 		if (bestformat != c->format || bestspeed != c->speed)
2449 			dirty = 1;
2450 
2451 		c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2452 		c->flags |= vpflags;
2453 
2454 		if (nrun && !run) {
2455 			if (dirty) {
2456 				bestspeed = CHANNEL_SETSPEED(c->methods,
2457 				    c->devinfo, bestspeed);
2458 				err = chn_reset(c, bestformat, bestspeed);
2459 			}
2460 			if (err == 0 && dirty) {
2461 				CHN_FOREACH(ch, c, children.busy) {
2462 					CHN_LOCK(ch);
2463 					if (VCHAN_SYNC_REQUIRED(ch))
2464 						vchan_sync(ch);
2465 					CHN_UNLOCK(ch);
2466 				}
2467 			}
2468 			if (err == 0) {
2469 				if (dirty)
2470 					c->flags |= CHN_F_DIRTY;
2471 				err = chn_start(c, 1);
2472 			}
2473 		}
2474 
2475 		if (nrun && run && dirty) {
2476 			chn_abort(c);
2477 			bestspeed = CHANNEL_SETSPEED(c->methods, c->devinfo,
2478 			    bestspeed);
2479 			err = chn_reset(c, bestformat, bestspeed);
2480 			if (err == 0) {
2481 				CHN_FOREACH(ch, c, children.busy) {
2482 					CHN_LOCK(ch);
2483 					if (VCHAN_SYNC_REQUIRED(ch))
2484 						vchan_sync(ch);
2485 					CHN_UNLOCK(ch);
2486 				}
2487 			}
2488 			if (err == 0) {
2489 				c->flags |= CHN_F_DIRTY;
2490 				err = chn_start(c, 1);
2491 			}
2492 		}
2493 
2494 		if (err == 0 && !(bestformat & AFMT_PASSTHROUGH) &&
2495 		    (bestformat & AFMT_VCHAN)) {
2496 			*vchanformat = bestformat;
2497 			*vchanrate = bestspeed;
2498 		}
2499 
2500 		if (!nrun && run) {
2501 			c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2502 			bestformat = *vchanformat;
2503 			bestspeed = *vchanrate;
2504 			chn_abort(c);
2505 			if (c->format != bestformat || c->speed != bestspeed)
2506 				chn_reset(c, bestformat, bestspeed);
2507 		}
2508 	}
2509 
2510 	return (err);
2511 }
2512 
2513 /**
2514  * @brief Fetch array of supported discrete sample rates
2515  *
2516  * Wrapper for CHANNEL_GETRATES.  Please see channel_if.m:getrates() for
2517  * detailed information.
2518  *
2519  * @note If the operation isn't supported, this function will just return 0
2520  *       (no rates in the array), and *rates will be set to NULL.  Callers
2521  *       should examine rates @b only if this function returns non-zero.
2522  *
2523  * @param c	pcm channel to examine
2524  * @param rates	pointer to array of integers; rate table will be recorded here
2525  *
2526  * @return number of rates in the array pointed to be @c rates
2527  */
2528 int
2529 chn_getrates(struct pcm_channel *c, int **rates)
2530 {
2531 	KASSERT(rates != NULL, ("rates is null"));
2532 	CHN_LOCKASSERT(c);
2533 	return CHANNEL_GETRATES(c->methods, c->devinfo, rates);
2534 }
2535 
2536 /**
2537  * @brief Remove channel from a sync group, if there is one.
2538  *
2539  * This function is initially intended for the following conditions:
2540  *   - Starting a syncgroup (@c SNDCTL_DSP_SYNCSTART ioctl)
2541  *   - Closing a device.  (A channel can't be destroyed if it's still in use.)
2542  *
2543  * @note Before calling this function, the syncgroup list mutex must be
2544  * held.  (Consider pcm_channel::sm protected by the SG list mutex
2545  * whether @c c is locked or not.)
2546  *
2547  * @param c	channel device to be started or closed
2548  * @returns	If this channel was the only member of a group, the group ID
2549  * 		is returned to the caller so that the caller can release it
2550  * 		via free_unr() after giving up the syncgroup lock.  Else it
2551  * 		returns 0.
2552  */
2553 int
2554 chn_syncdestroy(struct pcm_channel *c)
2555 {
2556 	struct pcmchan_syncmember *sm;
2557 	struct pcmchan_syncgroup *sg;
2558 	int sg_id;
2559 
2560 	sg_id = 0;
2561 
2562 	PCM_SG_LOCKASSERT(MA_OWNED);
2563 
2564 	if (c->sm != NULL) {
2565 		sm = c->sm;
2566 		sg = sm->parent;
2567 		c->sm = NULL;
2568 
2569 		KASSERT(sg != NULL, ("syncmember has null parent"));
2570 
2571 		SLIST_REMOVE(&sg->members, sm, pcmchan_syncmember, link);
2572 		free(sm, M_DEVBUF);
2573 
2574 		if (SLIST_EMPTY(&sg->members)) {
2575 			SLIST_REMOVE(&snd_pcm_syncgroups, sg, pcmchan_syncgroup, link);
2576 			sg_id = sg->id;
2577 			free(sg, M_DEVBUF);
2578 		}
2579 	}
2580 
2581 	return sg_id;
2582 }
2583 
2584 #ifdef OSSV4_EXPERIMENT
2585 int
2586 chn_getpeaks(struct pcm_channel *c, int *lpeak, int *rpeak)
2587 {
2588 	CHN_LOCKASSERT(c);
2589 	return CHANNEL_GETPEAKS(c->methods, c->devinfo, lpeak, rpeak);
2590 }
2591 #endif
2592