xref: /freebsd/sys/dev/sound/pcm/channel.c (revision 1da7f3f6f72b2245e458fc7195733268ae4a1136)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #ifdef HAVE_KERNEL_OPTION_HEADERS
33 #include "opt_snd.h"
34 #endif
35 
36 #include <dev/sound/pcm/sound.h>
37 #include <dev/sound/pcm/vchan.h>
38 
39 #include "feeder_if.h"
40 
41 int report_soft_formats = 1;
42 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_formats, CTLFLAG_RW,
43 	&report_soft_formats, 0, "report software-emulated formats");
44 
45 int report_soft_matrix = 1;
46 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_matrix, CTLFLAG_RW,
47 	&report_soft_matrix, 0, "report software-emulated channel matrixing");
48 
49 int chn_latency = CHN_LATENCY_DEFAULT;
50 
51 static int
52 sysctl_hw_snd_latency(SYSCTL_HANDLER_ARGS)
53 {
54 	int err, val;
55 
56 	val = chn_latency;
57 	err = sysctl_handle_int(oidp, &val, 0, req);
58 	if (err != 0 || req->newptr == NULL)
59 		return err;
60 	if (val < CHN_LATENCY_MIN || val > CHN_LATENCY_MAX)
61 		err = EINVAL;
62 	else
63 		chn_latency = val;
64 
65 	return err;
66 }
67 SYSCTL_PROC(_hw_snd, OID_AUTO, latency,
68     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
69     sysctl_hw_snd_latency, "I",
70     "buffering latency (0=low ... 10=high)");
71 
72 int chn_latency_profile = CHN_LATENCY_PROFILE_DEFAULT;
73 
74 static int
75 sysctl_hw_snd_latency_profile(SYSCTL_HANDLER_ARGS)
76 {
77 	int err, val;
78 
79 	val = chn_latency_profile;
80 	err = sysctl_handle_int(oidp, &val, 0, req);
81 	if (err != 0 || req->newptr == NULL)
82 		return err;
83 	if (val < CHN_LATENCY_PROFILE_MIN || val > CHN_LATENCY_PROFILE_MAX)
84 		err = EINVAL;
85 	else
86 		chn_latency_profile = val;
87 
88 	return err;
89 }
90 SYSCTL_PROC(_hw_snd, OID_AUTO, latency_profile,
91     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
92     sysctl_hw_snd_latency_profile, "I",
93     "buffering latency profile (0=aggressive 1=safe)");
94 
95 static int chn_timeout = CHN_TIMEOUT;
96 
97 static int
98 sysctl_hw_snd_timeout(SYSCTL_HANDLER_ARGS)
99 {
100 	int err, val;
101 
102 	val = chn_timeout;
103 	err = sysctl_handle_int(oidp, &val, 0, req);
104 	if (err != 0 || req->newptr == NULL)
105 		return err;
106 	if (val < CHN_TIMEOUT_MIN || val > CHN_TIMEOUT_MAX)
107 		err = EINVAL;
108 	else
109 		chn_timeout = val;
110 
111 	return err;
112 }
113 SYSCTL_PROC(_hw_snd, OID_AUTO, timeout,
114     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, sizeof(int),
115     sysctl_hw_snd_timeout, "I",
116     "interrupt timeout (1 - 10) seconds");
117 
118 static int chn_vpc_autoreset = 1;
119 SYSCTL_INT(_hw_snd, OID_AUTO, vpc_autoreset, CTLFLAG_RWTUN,
120 	&chn_vpc_autoreset, 0, "automatically reset channels volume to 0db");
121 
122 static int chn_vol_0db_pcm = SND_VOL_0DB_PCM;
123 
124 static void
125 chn_vpc_proc(int reset, int db)
126 {
127 	struct snddev_info *d;
128 	struct pcm_channel *c;
129 	int i;
130 
131 	for (i = 0; pcm_devclass != NULL &&
132 	    i < devclass_get_maxunit(pcm_devclass); i++) {
133 		d = devclass_get_softc(pcm_devclass, i);
134 		if (!PCM_REGISTERED(d))
135 			continue;
136 		PCM_LOCK(d);
137 		PCM_WAIT(d);
138 		PCM_ACQUIRE(d);
139 		CHN_FOREACH(c, d, channels.pcm) {
140 			CHN_LOCK(c);
141 			CHN_SETVOLUME(c, SND_VOL_C_PCM, SND_CHN_T_VOL_0DB, db);
142 			if (reset != 0)
143 				chn_vpc_reset(c, SND_VOL_C_PCM, 1);
144 			CHN_UNLOCK(c);
145 		}
146 		PCM_RELEASE(d);
147 		PCM_UNLOCK(d);
148 	}
149 }
150 
151 static int
152 sysctl_hw_snd_vpc_0db(SYSCTL_HANDLER_ARGS)
153 {
154 	int err, val;
155 
156 	val = chn_vol_0db_pcm;
157 	err = sysctl_handle_int(oidp, &val, 0, req);
158 	if (err != 0 || req->newptr == NULL)
159 		return (err);
160 	if (val < SND_VOL_0DB_MIN || val > SND_VOL_0DB_MAX)
161 		return (EINVAL);
162 
163 	chn_vol_0db_pcm = val;
164 	chn_vpc_proc(0, val);
165 
166 	return (0);
167 }
168 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_0db,
169     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int),
170     sysctl_hw_snd_vpc_0db, "I",
171     "0db relative level");
172 
173 static int
174 sysctl_hw_snd_vpc_reset(SYSCTL_HANDLER_ARGS)
175 {
176 	int err, val;
177 
178 	val = 0;
179 	err = sysctl_handle_int(oidp, &val, 0, req);
180 	if (err != 0 || req->newptr == NULL || val == 0)
181 		return (err);
182 
183 	chn_vol_0db_pcm = SND_VOL_0DB_PCM;
184 	chn_vpc_proc(1, SND_VOL_0DB_PCM);
185 
186 	return (0);
187 }
188 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_reset,
189     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int),
190     sysctl_hw_snd_vpc_reset, "I",
191     "reset volume on all channels");
192 
193 static int chn_usefrags = 0;
194 static int chn_syncdelay = -1;
195 
196 SYSCTL_INT(_hw_snd, OID_AUTO, usefrags, CTLFLAG_RWTUN,
197 	&chn_usefrags, 0, "prefer setfragments() over setblocksize()");
198 SYSCTL_INT(_hw_snd, OID_AUTO, syncdelay, CTLFLAG_RWTUN,
199 	&chn_syncdelay, 0,
200 	"append (0-1000) millisecond trailing buffer delay on each sync");
201 
202 /**
203  * @brief Channel sync group lock
204  *
205  * Clients should acquire this lock @b without holding any channel locks
206  * before touching syncgroups or the main syncgroup list.
207  */
208 struct mtx snd_pcm_syncgroups_mtx;
209 MTX_SYSINIT(pcm_syncgroup, &snd_pcm_syncgroups_mtx, "PCM channel sync group lock", MTX_DEF);
210 /**
211  * @brief syncgroups' master list
212  *
213  * Each time a channel syncgroup is created, it's added to this list.  This
214  * list should only be accessed with @sa snd_pcm_syncgroups_mtx held.
215  *
216  * See SNDCTL_DSP_SYNCGROUP for more information.
217  */
218 struct pcm_synclist snd_pcm_syncgroups = SLIST_HEAD_INITIALIZER(snd_pcm_syncgroups);
219 
220 static void
221 chn_lockinit(struct pcm_channel *c, int dir)
222 {
223 	switch (dir) {
224 	case PCMDIR_PLAY:
225 		c->lock = snd_mtxcreate(c->name, "pcm play channel");
226 		cv_init(&c->intr_cv, "pcmwr");
227 		break;
228 	case PCMDIR_PLAY_VIRTUAL:
229 		c->lock = snd_mtxcreate(c->name, "pcm virtual play channel");
230 		cv_init(&c->intr_cv, "pcmwrv");
231 		break;
232 	case PCMDIR_REC:
233 		c->lock = snd_mtxcreate(c->name, "pcm record channel");
234 		cv_init(&c->intr_cv, "pcmrd");
235 		break;
236 	case PCMDIR_REC_VIRTUAL:
237 		c->lock = snd_mtxcreate(c->name, "pcm virtual record channel");
238 		cv_init(&c->intr_cv, "pcmrdv");
239 		break;
240 	default:
241 		panic("%s(): Invalid direction=%d", __func__, dir);
242 		break;
243 	}
244 
245 	cv_init(&c->cv, "pcmchn");
246 }
247 
248 static void
249 chn_lockdestroy(struct pcm_channel *c)
250 {
251 	CHN_LOCKASSERT(c);
252 
253 	CHN_BROADCAST(&c->cv);
254 	CHN_BROADCAST(&c->intr_cv);
255 
256 	cv_destroy(&c->cv);
257 	cv_destroy(&c->intr_cv);
258 
259 	snd_mtxfree(c->lock);
260 }
261 
262 /**
263  * @brief Determine channel is ready for I/O
264  *
265  * @retval 1 = ready for I/O
266  * @retval 0 = not ready for I/O
267  */
268 static int
269 chn_polltrigger(struct pcm_channel *c)
270 {
271 	struct snd_dbuf *bs = c->bufsoft;
272 	u_int delta;
273 
274 	CHN_LOCKASSERT(c);
275 
276 	if (c->flags & CHN_F_MMAP) {
277 		if (sndbuf_getprevtotal(bs) < c->lw)
278 			delta = c->lw;
279 		else
280 			delta = sndbuf_gettotal(bs) - sndbuf_getprevtotal(bs);
281 	} else {
282 		if (c->direction == PCMDIR_PLAY)
283 			delta = sndbuf_getfree(bs);
284 		else
285 			delta = sndbuf_getready(bs);
286 	}
287 
288 	return ((delta < c->lw) ? 0 : 1);
289 }
290 
291 static void
292 chn_pollreset(struct pcm_channel *c)
293 {
294 
295 	CHN_LOCKASSERT(c);
296 	sndbuf_updateprevtotal(c->bufsoft);
297 }
298 
299 static void
300 chn_wakeup(struct pcm_channel *c)
301 {
302 	struct snd_dbuf *bs;
303 	struct pcm_channel *ch;
304 
305 	CHN_LOCKASSERT(c);
306 
307 	bs = c->bufsoft;
308 
309 	if (CHN_EMPTY(c, children.busy)) {
310 		if (SEL_WAITING(sndbuf_getsel(bs)) && chn_polltrigger(c))
311 			selwakeuppri(sndbuf_getsel(bs), PRIBIO);
312 		if (c->flags & CHN_F_SLEEPING) {
313 			/*
314 			 * Ok, I can just panic it right here since it is
315 			 * quite obvious that we never allow multiple waiters
316 			 * from userland. I'm too generous...
317 			 */
318 			CHN_BROADCAST(&c->intr_cv);
319 		}
320 	} else {
321 		CHN_FOREACH(ch, c, children.busy) {
322 			CHN_LOCK(ch);
323 			chn_wakeup(ch);
324 			CHN_UNLOCK(ch);
325 		}
326 	}
327 }
328 
329 static int
330 chn_sleep(struct pcm_channel *c, int timeout)
331 {
332 	int ret;
333 
334 	CHN_LOCKASSERT(c);
335 
336 	if (c->flags & CHN_F_DEAD)
337 		return (EINVAL);
338 
339 	c->flags |= CHN_F_SLEEPING;
340 	ret = cv_timedwait_sig(&c->intr_cv, c->lock, timeout);
341 	c->flags &= ~CHN_F_SLEEPING;
342 
343 	return ((c->flags & CHN_F_DEAD) ? EINVAL : ret);
344 }
345 
346 /*
347  * chn_dmaupdate() tracks the status of a dma transfer,
348  * updating pointers.
349  */
350 
351 static unsigned int
352 chn_dmaupdate(struct pcm_channel *c)
353 {
354 	struct snd_dbuf *b = c->bufhard;
355 	unsigned int delta, old, hwptr, amt;
356 
357 	KASSERT(sndbuf_getsize(b) > 0, ("bufsize == 0"));
358 	CHN_LOCKASSERT(c);
359 
360 	old = sndbuf_gethwptr(b);
361 	hwptr = chn_getptr(c);
362 	delta = (sndbuf_getsize(b) + hwptr - old) % sndbuf_getsize(b);
363 	sndbuf_sethwptr(b, hwptr);
364 
365 	if (c->direction == PCMDIR_PLAY) {
366 		amt = min(delta, sndbuf_getready(b));
367 		amt -= amt % sndbuf_getalign(b);
368 		if (amt > 0)
369 			sndbuf_dispose(b, NULL, amt);
370 	} else {
371 		amt = min(delta, sndbuf_getfree(b));
372 		amt -= amt % sndbuf_getalign(b);
373 		if (amt > 0)
374 		       sndbuf_acquire(b, NULL, amt);
375 	}
376 	if (snd_verbose > 3 && CHN_STARTED(c) && delta == 0) {
377 		device_printf(c->dev, "WARNING: %s DMA completion "
378 			"too fast/slow ! hwptr=%u, old=%u "
379 			"delta=%u amt=%u ready=%u free=%u\n",
380 			CHN_DIRSTR(c), hwptr, old, delta, amt,
381 			sndbuf_getready(b), sndbuf_getfree(b));
382 	}
383 
384 	return delta;
385 }
386 
387 static void
388 chn_wrfeed(struct pcm_channel *c)
389 {
390     	struct snd_dbuf *b = c->bufhard;
391     	struct snd_dbuf *bs = c->bufsoft;
392 	unsigned int amt, want, wasfree;
393 
394 	CHN_LOCKASSERT(c);
395 
396 	if ((c->flags & CHN_F_MMAP) && !(c->flags & CHN_F_CLOSING))
397 		sndbuf_acquire(bs, NULL, sndbuf_getfree(bs));
398 
399 	wasfree = sndbuf_getfree(b);
400 	want = min(sndbuf_getsize(b),
401 	    imax(0, sndbuf_xbytes(sndbuf_getsize(bs), bs, b) -
402 	     sndbuf_getready(b)));
403 	amt = min(wasfree, want);
404 	if (amt > 0)
405 		sndbuf_feed(bs, b, c, c->feeder, amt);
406 
407 	/*
408 	 * Possible xruns. There should be no empty space left in buffer.
409 	 */
410 	if (sndbuf_getready(b) < want)
411 		c->xruns++;
412 
413 	if (sndbuf_getfree(b) < wasfree)
414 		chn_wakeup(c);
415 }
416 
417 #if 0
418 static void
419 chn_wrupdate(struct pcm_channel *c)
420 {
421 
422 	CHN_LOCKASSERT(c);
423 	KASSERT(c->direction == PCMDIR_PLAY, ("%s(): bad channel", __func__));
424 
425 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
426 		return;
427 	chn_dmaupdate(c);
428 	chn_wrfeed(c);
429 	/* tell the driver we've updated the primary buffer */
430 	chn_trigger(c, PCMTRIG_EMLDMAWR);
431 }
432 #endif
433 
434 static void
435 chn_wrintr(struct pcm_channel *c)
436 {
437 
438 	CHN_LOCKASSERT(c);
439 	/* update pointers in primary buffer */
440 	chn_dmaupdate(c);
441 	/* ...and feed from secondary to primary */
442 	chn_wrfeed(c);
443 	/* tell the driver we've updated the primary buffer */
444 	chn_trigger(c, PCMTRIG_EMLDMAWR);
445 }
446 
447 /*
448  * user write routine - uiomove data into secondary buffer, trigger if necessary
449  * if blocking, sleep, rinse and repeat.
450  *
451  * called externally, so must handle locking
452  */
453 
454 int
455 chn_write(struct pcm_channel *c, struct uio *buf)
456 {
457 	struct snd_dbuf *bs = c->bufsoft;
458 	void *off;
459 	int ret, timeout, sz, t, p;
460 
461 	CHN_LOCKASSERT(c);
462 
463 	ret = 0;
464 	timeout = chn_timeout * hz;
465 
466 	while (ret == 0 && buf->uio_resid > 0) {
467 		sz = min(buf->uio_resid, sndbuf_getfree(bs));
468 		if (sz > 0) {
469 			/*
470 			 * The following assumes that the free space in
471 			 * the buffer can never be less around the
472 			 * unlock-uiomove-lock sequence.
473 			 */
474 			while (ret == 0 && sz > 0) {
475 				p = sndbuf_getfreeptr(bs);
476 				t = min(sz, sndbuf_getsize(bs) - p);
477 				off = sndbuf_getbufofs(bs, p);
478 				CHN_UNLOCK(c);
479 				ret = uiomove(off, t, buf);
480 				CHN_LOCK(c);
481 				sz -= t;
482 				sndbuf_acquire(bs, NULL, t);
483 			}
484 			ret = 0;
485 			if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
486 				ret = chn_start(c, 0);
487 				if (ret != 0)
488 					c->flags |= CHN_F_DEAD;
489 			}
490 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER)) {
491 			/**
492 			 * @todo Evaluate whether EAGAIN is truly desirable.
493 			 * 	 4Front drivers behave like this, but I'm
494 			 * 	 not sure if it at all violates the "write
495 			 * 	 should be allowed to block" model.
496 			 *
497 			 * 	 The idea is that, while set with CHN_F_NOTRIGGER,
498 			 * 	 a channel isn't playing, *but* without this we
499 			 * 	 end up with "interrupt timeout / channel dead".
500 			 */
501 			ret = EAGAIN;
502 		} else {
503    			ret = chn_sleep(c, timeout);
504 			if (ret == EAGAIN) {
505 				ret = EINVAL;
506 				c->flags |= CHN_F_DEAD;
507 				device_printf(c->dev, "%s(): %s: "
508 				    "play interrupt timeout, channel dead\n",
509 				    __func__, c->name);
510 			} else if (ret == ERESTART || ret == EINTR)
511 				c->flags |= CHN_F_ABORTING;
512 		}
513 	}
514 
515 	return (ret);
516 }
517 
518 /*
519  * Feed new data from the read buffer. Can be called in the bottom half.
520  */
521 static void
522 chn_rdfeed(struct pcm_channel *c)
523 {
524     	struct snd_dbuf *b = c->bufhard;
525     	struct snd_dbuf *bs = c->bufsoft;
526 	unsigned int amt;
527 
528 	CHN_LOCKASSERT(c);
529 
530 	if (c->flags & CHN_F_MMAP)
531 		sndbuf_dispose(bs, NULL, sndbuf_getready(bs));
532 
533 	amt = sndbuf_getfree(bs);
534 	if (amt > 0)
535 		sndbuf_feed(b, bs, c, c->feeder, amt);
536 
537 	amt = sndbuf_getready(b);
538 	if (amt > 0) {
539 		c->xruns++;
540 		sndbuf_dispose(b, NULL, amt);
541 	}
542 
543 	if (sndbuf_getready(bs) > 0)
544 		chn_wakeup(c);
545 }
546 
547 #if 0
548 static void
549 chn_rdupdate(struct pcm_channel *c)
550 {
551 
552 	CHN_LOCKASSERT(c);
553 	KASSERT(c->direction == PCMDIR_REC, ("chn_rdupdate on bad channel"));
554 
555 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
556 		return;
557 	chn_trigger(c, PCMTRIG_EMLDMARD);
558 	chn_dmaupdate(c);
559 	chn_rdfeed(c);
560 }
561 #endif
562 
563 /* read interrupt routine. Must be called with interrupts blocked. */
564 static void
565 chn_rdintr(struct pcm_channel *c)
566 {
567 
568 	CHN_LOCKASSERT(c);
569 	/* tell the driver to update the primary buffer if non-dma */
570 	chn_trigger(c, PCMTRIG_EMLDMARD);
571 	/* update pointers in primary buffer */
572 	chn_dmaupdate(c);
573 	/* ...and feed from primary to secondary */
574 	chn_rdfeed(c);
575 }
576 
577 /*
578  * user read routine - trigger if necessary, uiomove data from secondary buffer
579  * if blocking, sleep, rinse and repeat.
580  *
581  * called externally, so must handle locking
582  */
583 
584 int
585 chn_read(struct pcm_channel *c, struct uio *buf)
586 {
587 	struct snd_dbuf *bs = c->bufsoft;
588 	void *off;
589 	int ret, timeout, sz, t, p;
590 
591 	CHN_LOCKASSERT(c);
592 
593 	if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
594 		ret = chn_start(c, 0);
595 		if (ret != 0) {
596 			c->flags |= CHN_F_DEAD;
597 			return (ret);
598 		}
599 	}
600 
601 	ret = 0;
602 	timeout = chn_timeout * hz;
603 
604 	while (ret == 0 && buf->uio_resid > 0) {
605 		sz = min(buf->uio_resid, sndbuf_getready(bs));
606 		if (sz > 0) {
607 			/*
608 			 * The following assumes that the free space in
609 			 * the buffer can never be less around the
610 			 * unlock-uiomove-lock sequence.
611 			 */
612 			while (ret == 0 && sz > 0) {
613 				p = sndbuf_getreadyptr(bs);
614 				t = min(sz, sndbuf_getsize(bs) - p);
615 				off = sndbuf_getbufofs(bs, p);
616 				CHN_UNLOCK(c);
617 				ret = uiomove(off, t, buf);
618 				CHN_LOCK(c);
619 				sz -= t;
620 				sndbuf_dispose(bs, NULL, t);
621 			}
622 			ret = 0;
623 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER))
624 			ret = EAGAIN;
625 		else {
626    			ret = chn_sleep(c, timeout);
627 			if (ret == EAGAIN) {
628 				ret = EINVAL;
629 				c->flags |= CHN_F_DEAD;
630 				device_printf(c->dev, "%s(): %s: "
631 				    "record interrupt timeout, channel dead\n",
632 				    __func__, c->name);
633 			} else if (ret == ERESTART || ret == EINTR)
634 				c->flags |= CHN_F_ABORTING;
635 		}
636 	}
637 
638 	return (ret);
639 }
640 
641 void
642 chn_intr_locked(struct pcm_channel *c)
643 {
644 
645 	CHN_LOCKASSERT(c);
646 
647 	c->interrupts++;
648 
649 	if (c->direction == PCMDIR_PLAY)
650 		chn_wrintr(c);
651 	else
652 		chn_rdintr(c);
653 }
654 
655 void
656 chn_intr(struct pcm_channel *c)
657 {
658 
659 	if (CHN_LOCKOWNED(c)) {
660 		chn_intr_locked(c);
661 		return;
662 	}
663 
664 	CHN_LOCK(c);
665 	chn_intr_locked(c);
666 	CHN_UNLOCK(c);
667 }
668 
669 u_int32_t
670 chn_start(struct pcm_channel *c, int force)
671 {
672 	u_int32_t i, j;
673 	struct snd_dbuf *b = c->bufhard;
674 	struct snd_dbuf *bs = c->bufsoft;
675 	int err;
676 
677 	CHN_LOCKASSERT(c);
678 	/* if we're running, or if we're prevented from triggering, bail */
679 	if (CHN_STARTED(c) || ((c->flags & CHN_F_NOTRIGGER) && !force))
680 		return (EINVAL);
681 
682 	err = 0;
683 
684 	if (force) {
685 		i = 1;
686 		j = 0;
687 	} else {
688 		if (c->direction == PCMDIR_REC) {
689 			i = sndbuf_getfree(bs);
690 			j = (i > 0) ? 1 : sndbuf_getready(b);
691 		} else {
692 			if (sndbuf_getfree(bs) == 0) {
693 				i = 1;
694 				j = 0;
695 			} else {
696 				struct snd_dbuf *pb;
697 
698 				pb = CHN_BUF_PARENT(c, b);
699 				i = sndbuf_xbytes(sndbuf_getready(bs), bs, pb);
700 				j = sndbuf_getalign(pb);
701 			}
702 		}
703 		if (snd_verbose > 3 && CHN_EMPTY(c, children))
704 			device_printf(c->dev, "%s(): %s (%s) threshold "
705 			    "i=%d j=%d\n", __func__, CHN_DIRSTR(c),
706 			    (c->flags & CHN_F_VIRTUAL) ? "virtual" :
707 			    "hardware", i, j);
708 	}
709 
710 	if (i >= j) {
711 		c->flags |= CHN_F_TRIGGERED;
712 		sndbuf_setrun(b, 1);
713 		if (c->flags & CHN_F_CLOSING)
714 			c->feedcount = 2;
715 		else {
716 			c->feedcount = 0;
717 			c->interrupts = 0;
718 			c->xruns = 0;
719 		}
720 		if (c->parentchannel == NULL) {
721 			if (c->direction == PCMDIR_PLAY)
722 				sndbuf_fillsilence_rl(b,
723 				    sndbuf_xbytes(sndbuf_getsize(bs), bs, b));
724 			if (snd_verbose > 3)
725 				device_printf(c->dev,
726 				    "%s(): %s starting! (%s/%s) "
727 				    "(ready=%d force=%d i=%d j=%d "
728 				    "intrtimeout=%u latency=%dms)\n",
729 				    __func__,
730 				    (c->flags & CHN_F_HAS_VCHAN) ?
731 				    "VCHAN PARENT" : "HW", CHN_DIRSTR(c),
732 				    (c->flags & CHN_F_CLOSING) ? "closing" :
733 				    "running",
734 				    sndbuf_getready(b),
735 				    force, i, j, c->timeout,
736 				    (sndbuf_getsize(b) * 1000) /
737 				    (sndbuf_getalign(b) * sndbuf_getspd(b)));
738 		}
739 		err = chn_trigger(c, PCMTRIG_START);
740 	}
741 
742 	return (err);
743 }
744 
745 void
746 chn_resetbuf(struct pcm_channel *c)
747 {
748 	struct snd_dbuf *b = c->bufhard;
749 	struct snd_dbuf *bs = c->bufsoft;
750 
751 	c->blocks = 0;
752 	sndbuf_reset(b);
753 	sndbuf_reset(bs);
754 }
755 
756 /*
757  * chn_sync waits until the space in the given channel goes above
758  * a threshold. The threshold is checked against fl or rl respectively.
759  * Assume that the condition can become true, do not check here...
760  */
761 int
762 chn_sync(struct pcm_channel *c, int threshold)
763 {
764     	struct snd_dbuf *b, *bs;
765 	int ret, count, hcount, minflush, resid, residp, syncdelay, blksz;
766 	u_int32_t cflag;
767 
768 	CHN_LOCKASSERT(c);
769 
770 	if (c->direction != PCMDIR_PLAY)
771 		return (EINVAL);
772 
773 	bs = c->bufsoft;
774 
775 	if ((c->flags & (CHN_F_DEAD | CHN_F_ABORTING)) ||
776 	    (threshold < 1 && sndbuf_getready(bs) < 1))
777 		return (0);
778 
779 	/* if we haven't yet started and nothing is buffered, else start*/
780 	if (CHN_STOPPED(c)) {
781 		if (threshold > 0 || sndbuf_getready(bs) > 0) {
782 			ret = chn_start(c, 1);
783 			if (ret != 0)
784 				return (ret);
785 		} else
786 			return (0);
787 	}
788 
789 	b = CHN_BUF_PARENT(c, c->bufhard);
790 
791 	minflush = threshold + sndbuf_xbytes(sndbuf_getready(b), b, bs);
792 
793 	syncdelay = chn_syncdelay;
794 
795 	if (syncdelay < 0 && (threshold > 0 || sndbuf_getready(bs) > 0))
796 		minflush += sndbuf_xbytes(sndbuf_getsize(b), b, bs);
797 
798 	/*
799 	 * Append (0-1000) millisecond trailing buffer (if needed)
800 	 * for slower / high latency hardwares (notably USB audio)
801 	 * to avoid audible truncation.
802 	 */
803 	if (syncdelay > 0)
804 		minflush += (sndbuf_getalign(bs) * sndbuf_getspd(bs) *
805 		    ((syncdelay > 1000) ? 1000 : syncdelay)) / 1000;
806 
807 	minflush -= minflush % sndbuf_getalign(bs);
808 
809 	if (minflush > 0) {
810 		threshold = min(minflush, sndbuf_getfree(bs));
811 		sndbuf_clear(bs, threshold);
812 		sndbuf_acquire(bs, NULL, threshold);
813 		minflush -= threshold;
814 	}
815 
816 	resid = sndbuf_getready(bs);
817 	residp = resid;
818 	blksz = sndbuf_getblksz(b);
819 	if (blksz < 1) {
820 		device_printf(c->dev,
821 		    "%s(): WARNING: blksz < 1 ! maxsize=%d [%d/%d/%d]\n",
822 		    __func__, sndbuf_getmaxsize(b), sndbuf_getsize(b),
823 		    sndbuf_getblksz(b), sndbuf_getblkcnt(b));
824 		if (sndbuf_getblkcnt(b) > 0)
825 			blksz = sndbuf_getsize(b) / sndbuf_getblkcnt(b);
826 		if (blksz < 1)
827 			blksz = 1;
828 	}
829 	count = sndbuf_xbytes(minflush + resid, bs, b) / blksz;
830 	hcount = count;
831 	ret = 0;
832 
833 	if (snd_verbose > 3)
834 		device_printf(c->dev, "%s(): [begin] timeout=%d count=%d "
835 		    "minflush=%d resid=%d\n", __func__, c->timeout, count,
836 		    minflush, resid);
837 
838 	cflag = c->flags & CHN_F_CLOSING;
839 	c->flags |= CHN_F_CLOSING;
840 	while (count > 0 && (resid > 0 || minflush > 0)) {
841 		ret = chn_sleep(c, c->timeout);
842     		if (ret == ERESTART || ret == EINTR) {
843 			c->flags |= CHN_F_ABORTING;
844 			break;
845 		} else if (ret == 0 || ret == EAGAIN) {
846 			resid = sndbuf_getready(bs);
847 			if (resid == residp) {
848 				--count;
849 				if (snd_verbose > 3)
850 					device_printf(c->dev,
851 					    "%s(): [stalled] timeout=%d "
852 					    "count=%d hcount=%d "
853 					    "resid=%d minflush=%d\n",
854 					    __func__, c->timeout, count,
855 					    hcount, resid, minflush);
856 			} else if (resid < residp && count < hcount) {
857 				++count;
858 				if (snd_verbose > 3)
859 					device_printf(c->dev,
860 					    "%s((): [resume] timeout=%d "
861 					    "count=%d hcount=%d "
862 					    "resid=%d minflush=%d\n",
863 					    __func__, c->timeout, count,
864 					    hcount, resid, minflush);
865 			}
866 			if (minflush > 0 && sndbuf_getfree(bs) > 0) {
867 				threshold = min(minflush,
868 				    sndbuf_getfree(bs));
869 				sndbuf_clear(bs, threshold);
870 				sndbuf_acquire(bs, NULL, threshold);
871 				resid = sndbuf_getready(bs);
872 				minflush -= threshold;
873 			}
874 			residp = resid;
875 		} else
876 			break;
877 	}
878 	c->flags &= ~CHN_F_CLOSING;
879 	c->flags |= cflag;
880 
881 	if (snd_verbose > 3)
882 		device_printf(c->dev,
883 		    "%s(): timeout=%d count=%d hcount=%d resid=%d residp=%d "
884 		    "minflush=%d ret=%d\n",
885 		    __func__, c->timeout, count, hcount, resid, residp,
886 		    minflush, ret);
887 
888     	return (0);
889 }
890 
891 /* called externally, handle locking */
892 int
893 chn_poll(struct pcm_channel *c, int ev, struct thread *td)
894 {
895 	struct snd_dbuf *bs = c->bufsoft;
896 	int ret;
897 
898 	CHN_LOCKASSERT(c);
899 
900     	if (!(c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED))) {
901 		ret = chn_start(c, 1);
902 		if (ret != 0)
903 			return (0);
904 	}
905 
906 	ret = 0;
907 	if (chn_polltrigger(c)) {
908 		chn_pollreset(c);
909 		ret = ev;
910 	} else
911 		selrecord(td, sndbuf_getsel(bs));
912 
913 	return (ret);
914 }
915 
916 /*
917  * chn_abort terminates a running dma transfer.  it may sleep up to 200ms.
918  * it returns the number of bytes that have not been transferred.
919  *
920  * called from: dsp_close, dsp_ioctl, with channel locked
921  */
922 int
923 chn_abort(struct pcm_channel *c)
924 {
925     	int missing = 0;
926     	struct snd_dbuf *b = c->bufhard;
927     	struct snd_dbuf *bs = c->bufsoft;
928 
929 	CHN_LOCKASSERT(c);
930 	if (CHN_STOPPED(c))
931 		return 0;
932 	c->flags |= CHN_F_ABORTING;
933 
934 	c->flags &= ~CHN_F_TRIGGERED;
935 	/* kill the channel */
936 	chn_trigger(c, PCMTRIG_ABORT);
937 	sndbuf_setrun(b, 0);
938 	if (!(c->flags & CHN_F_VIRTUAL))
939 		chn_dmaupdate(c);
940     	missing = sndbuf_getready(bs);
941 
942 	c->flags &= ~CHN_F_ABORTING;
943 	return missing;
944 }
945 
946 /*
947  * this routine tries to flush the dma transfer. It is called
948  * on a close of a playback channel.
949  * first, if there is data in the buffer, but the dma has not yet
950  * begun, we need to start it.
951  * next, we wait for the play buffer to drain
952  * finally, we stop the dma.
953  *
954  * called from: dsp_close, not valid for record channels.
955  */
956 
957 int
958 chn_flush(struct pcm_channel *c)
959 {
960     	struct snd_dbuf *b = c->bufhard;
961 
962 	CHN_LOCKASSERT(c);
963 	KASSERT(c->direction == PCMDIR_PLAY, ("chn_flush on bad channel"));
964     	DEB(printf("chn_flush: c->flags 0x%08x\n", c->flags));
965 
966 	c->flags |= CHN_F_CLOSING;
967 	chn_sync(c, 0);
968 	c->flags &= ~CHN_F_TRIGGERED;
969 	/* kill the channel */
970 	chn_trigger(c, PCMTRIG_ABORT);
971 	sndbuf_setrun(b, 0);
972 
973     	c->flags &= ~CHN_F_CLOSING;
974     	return 0;
975 }
976 
977 int
978 snd_fmtvalid(uint32_t fmt, uint32_t *fmtlist)
979 {
980 	int i;
981 
982 	for (i = 0; fmtlist[i] != 0; i++) {
983 		if (fmt == fmtlist[i] ||
984 		    ((fmt & AFMT_PASSTHROUGH) &&
985 		    (AFMT_ENCODING(fmt) & fmtlist[i])))
986 			return (1);
987 	}
988 
989 	return (0);
990 }
991 
992 static const struct {
993 	char *name, *alias1, *alias2;
994 	uint32_t afmt;
995 } afmt_tab[] = {
996 	{  "alaw",  NULL, NULL, AFMT_A_LAW  },
997 	{ "mulaw",  NULL, NULL, AFMT_MU_LAW },
998 	{    "u8",   "8", NULL, AFMT_U8     },
999 	{    "s8",  NULL, NULL, AFMT_S8     },
1000 #if BYTE_ORDER == LITTLE_ENDIAN
1001 	{ "s16le", "s16", "16", AFMT_S16_LE },
1002 	{ "s16be",  NULL, NULL, AFMT_S16_BE },
1003 #else
1004 	{ "s16le",  NULL, NULL, AFMT_S16_LE },
1005 	{ "s16be", "s16", "16", AFMT_S16_BE },
1006 #endif
1007 	{ "u16le",  NULL, NULL, AFMT_U16_LE },
1008 	{ "u16be",  NULL, NULL, AFMT_U16_BE },
1009 	{ "s24le",  NULL, NULL, AFMT_S24_LE },
1010 	{ "s24be",  NULL, NULL, AFMT_S24_BE },
1011 	{ "u24le",  NULL, NULL, AFMT_U24_LE },
1012 	{ "u24be",  NULL, NULL, AFMT_U24_BE },
1013 #if BYTE_ORDER == LITTLE_ENDIAN
1014 	{ "s32le", "s32", "32", AFMT_S32_LE },
1015 	{ "s32be",  NULL, NULL, AFMT_S32_BE },
1016 #else
1017 	{ "s32le",  NULL, NULL, AFMT_S32_LE },
1018 	{ "s32be", "s32", "32", AFMT_S32_BE },
1019 #endif
1020 	{ "u32le",  NULL, NULL, AFMT_U32_LE },
1021 	{ "u32be",  NULL, NULL, AFMT_U32_BE },
1022 	{   "ac3",  NULL, NULL, AFMT_AC3    },
1023 	{    NULL,  NULL, NULL, 0           }
1024 };
1025 
1026 uint32_t
1027 snd_str2afmt(const char *req)
1028 {
1029 	int ext;
1030 	int ch;
1031 	int i;
1032 	char b1[8];
1033 	char b2[8];
1034 
1035 	memset(b1, 0, sizeof(b1));
1036 	memset(b2, 0, sizeof(b2));
1037 
1038 	i = sscanf(req, "%5[^:]:%6s", b1, b2);
1039 
1040 	if (i == 1) {
1041 		if (strlen(req) != strlen(b1))
1042 			return (0);
1043 		strlcpy(b2, "2.0", sizeof(b2));
1044 	} else if (i == 2) {
1045 		if (strlen(req) != (strlen(b1) + 1 + strlen(b2)))
1046 			return (0);
1047 	} else
1048 		return (0);
1049 
1050 	i = sscanf(b2, "%d.%d", &ch, &ext);
1051 
1052 	if (i == 0) {
1053 		if (strcasecmp(b2, "mono") == 0) {
1054 			ch = 1;
1055 			ext = 0;
1056 		} else if (strcasecmp(b2, "stereo") == 0) {
1057 			ch = 2;
1058 			ext = 0;
1059 		} else if (strcasecmp(b2, "quad") == 0) {
1060 			ch = 4;
1061 			ext = 0;
1062 		} else
1063 			return (0);
1064 	} else if (i == 1) {
1065 		if (ch < 1 || ch > AFMT_CHANNEL_MAX)
1066 			return (0);
1067 		ext = 0;
1068 	} else if (i == 2) {
1069 		if (ext < 0 || ext > AFMT_EXTCHANNEL_MAX)
1070 			return (0);
1071 		if (ch < 1 || (ch + ext) > AFMT_CHANNEL_MAX)
1072 			return (0);
1073 	} else
1074 		return (0);
1075 
1076 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1077 		if (strcasecmp(afmt_tab[i].name, b1) != 0) {
1078 			if (afmt_tab[i].alias1 == NULL)
1079 				continue;
1080 			if (strcasecmp(afmt_tab[i].alias1, b1) != 0) {
1081 				if (afmt_tab[i].alias2 == NULL)
1082 					continue;
1083 				if (strcasecmp(afmt_tab[i].alias2, b1) != 0)
1084 					continue;
1085 			}
1086 		}
1087 		/* found a match */
1088 		return (SND_FORMAT(afmt_tab[i].afmt, ch + ext, ext));
1089 	}
1090 	/* not a valid format */
1091 	return (0);
1092 }
1093 
1094 uint32_t
1095 snd_afmt2str(uint32_t afmt, char *buf, size_t len)
1096 {
1097 	uint32_t enc;
1098 	uint32_t ext;
1099 	uint32_t ch;
1100 	int i;
1101 
1102 	if (buf == NULL || len < AFMTSTR_LEN)
1103 		return (0);
1104 
1105 	memset(buf, 0, len);
1106 
1107 	enc = AFMT_ENCODING(afmt);
1108 	ch = AFMT_CHANNEL(afmt);
1109 	ext = AFMT_EXTCHANNEL(afmt);
1110 	/* check there is at least one channel */
1111 	if (ch <= ext)
1112 		return (0);
1113 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1114 		if (enc != afmt_tab[i].afmt)
1115 			continue;
1116 		/* found a match */
1117 		snprintf(buf, len, "%s:%d.%d",
1118 		    afmt_tab[i].name, ch - ext, ext);
1119 		return (SND_FORMAT(enc, ch, ext));
1120 	}
1121 	return (0);
1122 }
1123 
1124 int
1125 chn_reset(struct pcm_channel *c, uint32_t fmt, uint32_t spd)
1126 {
1127 	int r;
1128 
1129 	CHN_LOCKASSERT(c);
1130 	c->feedcount = 0;
1131 	c->flags &= CHN_F_RESET;
1132 	c->interrupts = 0;
1133 	c->timeout = 1;
1134 	c->xruns = 0;
1135 
1136 	c->flags |= (pcm_getflags(c->dev) & SD_F_BITPERFECT) ?
1137 	    CHN_F_BITPERFECT : 0;
1138 
1139 	r = CHANNEL_RESET(c->methods, c->devinfo);
1140 	if (r == 0 && fmt != 0 && spd != 0) {
1141 		r = chn_setparam(c, fmt, spd);
1142 		fmt = 0;
1143 		spd = 0;
1144 	}
1145 	if (r == 0 && fmt != 0)
1146 		r = chn_setformat(c, fmt);
1147 	if (r == 0 && spd != 0)
1148 		r = chn_setspeed(c, spd);
1149 	if (r == 0)
1150 		r = chn_setlatency(c, chn_latency);
1151 	if (r == 0) {
1152 		chn_resetbuf(c);
1153 		r = CHANNEL_RESETDONE(c->methods, c->devinfo);
1154 	}
1155 	return r;
1156 }
1157 
1158 int
1159 chn_init(struct pcm_channel *c, void *devinfo, int dir, int direction)
1160 {
1161 	struct feeder_class *fc;
1162 	struct snd_dbuf *b, *bs;
1163 	int i, ret;
1164 
1165 	if (chn_timeout < CHN_TIMEOUT_MIN || chn_timeout > CHN_TIMEOUT_MAX)
1166 		chn_timeout = CHN_TIMEOUT;
1167 
1168 	chn_lockinit(c, dir);
1169 
1170 	b = NULL;
1171 	bs = NULL;
1172 	CHN_INIT(c, children);
1173 	CHN_INIT(c, children.busy);
1174 	c->devinfo = NULL;
1175 	c->feeder = NULL;
1176 	c->latency = -1;
1177 	c->timeout = 1;
1178 
1179 	ret = ENOMEM;
1180 	b = sndbuf_create(c->dev, c->name, "primary", c);
1181 	if (b == NULL)
1182 		goto out;
1183 	bs = sndbuf_create(c->dev, c->name, "secondary", c);
1184 	if (bs == NULL)
1185 		goto out;
1186 
1187 	CHN_LOCK(c);
1188 
1189 	ret = EINVAL;
1190 	fc = feeder_getclass(NULL);
1191 	if (fc == NULL)
1192 		goto out;
1193 	if (chn_addfeeder(c, fc, NULL))
1194 		goto out;
1195 
1196 	/*
1197 	 * XXX - sndbuf_setup() & sndbuf_resize() expect to be called
1198 	 *	 with the channel unlocked because they are also called
1199 	 *	 from driver methods that don't know about locking
1200 	 */
1201 	CHN_UNLOCK(c);
1202 	sndbuf_setup(bs, NULL, 0);
1203 	CHN_LOCK(c);
1204 	c->bufhard = b;
1205 	c->bufsoft = bs;
1206 	c->flags = 0;
1207 	c->feederflags = 0;
1208 	c->sm = NULL;
1209 	c->format = SND_FORMAT(AFMT_U8, 1, 0);
1210 	c->speed = DSP_DEFAULT_SPEED;
1211 
1212 	c->matrix = *feeder_matrix_id_map(SND_CHN_MATRIX_1_0);
1213 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1214 
1215 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1216 		c->volume[SND_VOL_C_MASTER][i] = SND_VOL_0DB_MASTER;
1217 	}
1218 
1219 	c->volume[SND_VOL_C_MASTER][SND_CHN_T_VOL_0DB] = SND_VOL_0DB_MASTER;
1220 	c->volume[SND_VOL_C_PCM][SND_CHN_T_VOL_0DB] = chn_vol_0db_pcm;
1221 
1222 	memset(c->muted, 0, sizeof(c->muted));
1223 
1224 	chn_vpc_reset(c, SND_VOL_C_PCM, 1);
1225 
1226 	ret = ENODEV;
1227 	CHN_UNLOCK(c); /* XXX - Unlock for CHANNEL_INIT() malloc() call */
1228 	c->devinfo = CHANNEL_INIT(c->methods, devinfo, b, c, direction);
1229 	CHN_LOCK(c);
1230 	if (c->devinfo == NULL)
1231 		goto out;
1232 
1233 	ret = ENOMEM;
1234 	if ((sndbuf_getsize(b) == 0) && ((c->flags & CHN_F_VIRTUAL) == 0))
1235 		goto out;
1236 
1237 	ret = 0;
1238 	c->direction = direction;
1239 
1240 	sndbuf_setfmt(b, c->format);
1241 	sndbuf_setspd(b, c->speed);
1242 	sndbuf_setfmt(bs, c->format);
1243 	sndbuf_setspd(bs, c->speed);
1244 
1245 	/**
1246 	 * @todo Should this be moved somewhere else?  The primary buffer
1247 	 * 	 is allocated by the driver or via DMA map setup, and tmpbuf
1248 	 * 	 seems to only come into existence in sndbuf_resize().
1249 	 */
1250 	if (c->direction == PCMDIR_PLAY) {
1251 		bs->sl = sndbuf_getmaxsize(bs);
1252 		bs->shadbuf = malloc(bs->sl, M_DEVBUF, M_NOWAIT);
1253 		if (bs->shadbuf == NULL) {
1254 			ret = ENOMEM;
1255 			goto out;
1256 		}
1257 	}
1258 
1259 out:
1260 	CHN_UNLOCK(c);
1261 	if (ret) {
1262 		if (c->devinfo) {
1263 			if (CHANNEL_FREE(c->methods, c->devinfo))
1264 				sndbuf_free(b);
1265 		}
1266 		if (bs)
1267 			sndbuf_destroy(bs);
1268 		if (b)
1269 			sndbuf_destroy(b);
1270 		CHN_LOCK(c);
1271 		c->flags |= CHN_F_DEAD;
1272 		chn_lockdestroy(c);
1273 
1274 		return ret;
1275 	}
1276 
1277 	return 0;
1278 }
1279 
1280 int
1281 chn_kill(struct pcm_channel *c)
1282 {
1283     	struct snd_dbuf *b = c->bufhard;
1284     	struct snd_dbuf *bs = c->bufsoft;
1285 
1286 	if (CHN_STARTED(c)) {
1287 		CHN_LOCK(c);
1288 		chn_trigger(c, PCMTRIG_ABORT);
1289 		CHN_UNLOCK(c);
1290 	}
1291 	while (chn_removefeeder(c) == 0)
1292 		;
1293 	if (CHANNEL_FREE(c->methods, c->devinfo))
1294 		sndbuf_free(b);
1295 	sndbuf_destroy(bs);
1296 	sndbuf_destroy(b);
1297 	CHN_LOCK(c);
1298 	c->flags |= CHN_F_DEAD;
1299 	chn_lockdestroy(c);
1300 
1301 	return (0);
1302 }
1303 
1304 /* XXX Obsolete. Use *_matrix() variant instead. */
1305 int
1306 chn_setvolume(struct pcm_channel *c, int left, int right)
1307 {
1308 	int ret;
1309 
1310 	ret = chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FL, left);
1311 	ret |= chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FR,
1312 	    right) << 8;
1313 
1314 	return (ret);
1315 }
1316 
1317 int
1318 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
1319     int center)
1320 {
1321 	int i, ret;
1322 
1323 	ret = 0;
1324 
1325 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1326 		if ((1 << i) & SND_CHN_LEFT_MASK)
1327 			ret |= chn_setvolume_matrix(c, vc, i, left);
1328 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1329 			ret |= chn_setvolume_matrix(c, vc, i, right) << 8;
1330 		else
1331 			ret |= chn_setvolume_matrix(c, vc, i, center) << 16;
1332 	}
1333 
1334 	return (ret);
1335 }
1336 
1337 int
1338 chn_setvolume_matrix(struct pcm_channel *c, int vc, int vt, int val)
1339 {
1340 	int i;
1341 
1342 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1343 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1344 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN &&
1345 	    vt <= SND_CHN_T_END)) && (vt != SND_CHN_T_VOL_0DB ||
1346 	    (val >= SND_VOL_0DB_MIN && val <= SND_VOL_0DB_MAX)),
1347 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d val=%d",
1348 	    __func__, c, vc, vt, val));
1349 	CHN_LOCKASSERT(c);
1350 
1351 	if (val < 0)
1352 		val = 0;
1353 	if (val > 100)
1354 		val = 100;
1355 
1356 	c->volume[vc][vt] = val;
1357 
1358 	/*
1359 	 * Do relative calculation here and store it into class + 1
1360 	 * to ease the job of feeder_volume.
1361 	 */
1362 	if (vc == SND_VOL_C_MASTER) {
1363 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1364 		    vc += SND_VOL_C_STEP)
1365 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1366 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1367 	} else if (vc & 1) {
1368 		if (vt == SND_CHN_T_VOL_0DB)
1369 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1370 			    i += SND_CHN_T_STEP) {
1371 				c->volume[SND_VOL_C_VAL(vc)][i] =
1372 				    SND_VOL_CALC_VAL(c->volume, vc, i);
1373 			}
1374 		else
1375 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1376 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1377 	}
1378 
1379 	return (val);
1380 }
1381 
1382 int
1383 chn_getvolume_matrix(struct pcm_channel *c, int vc, int vt)
1384 {
1385 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1386 	    (vt == SND_CHN_T_VOL_0DB ||
1387 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1388 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d",
1389 	    __func__, c, vc, vt));
1390 	CHN_LOCKASSERT(c);
1391 
1392 	return (c->volume[vc][vt]);
1393 }
1394 
1395 int
1396 chn_setmute_multi(struct pcm_channel *c, int vc, int mute)
1397 {
1398 	int i, ret;
1399 
1400 	ret = 0;
1401 
1402 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1403 		if ((1 << i) & SND_CHN_LEFT_MASK)
1404 			ret |= chn_setmute_matrix(c, vc, i, mute);
1405 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1406 			ret |= chn_setmute_matrix(c, vc, i, mute) << 8;
1407 		else
1408 			ret |= chn_setmute_matrix(c, vc, i, mute) << 16;
1409 	}
1410 	return (ret);
1411 }
1412 
1413 int
1414 chn_setmute_matrix(struct pcm_channel *c, int vc, int vt, int mute)
1415 {
1416 	int i;
1417 
1418 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1419 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1420 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1421 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d mute=%d",
1422 	    __func__, c, vc, vt, mute));
1423 
1424 	CHN_LOCKASSERT(c);
1425 
1426 	mute = (mute != 0);
1427 
1428 	c->muted[vc][vt] = mute;
1429 
1430 	/*
1431 	 * Do relative calculation here and store it into class + 1
1432 	 * to ease the job of feeder_volume.
1433 	 */
1434 	if (vc == SND_VOL_C_MASTER) {
1435 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1436 		    vc += SND_VOL_C_STEP)
1437 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1438 	} else if (vc & 1) {
1439 		if (vt == SND_CHN_T_VOL_0DB) {
1440 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1441 			    i += SND_CHN_T_STEP) {
1442 				c->muted[SND_VOL_C_VAL(vc)][i] = mute;
1443 			}
1444 		} else {
1445 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1446 		}
1447 	}
1448 	return (mute);
1449 }
1450 
1451 int
1452 chn_getmute_matrix(struct pcm_channel *c, int vc, int vt)
1453 {
1454 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1455 	    (vt == SND_CHN_T_VOL_0DB ||
1456 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1457 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d",
1458 	    __func__, c, vc, vt));
1459 	CHN_LOCKASSERT(c);
1460 
1461 	return (c->muted[vc][vt]);
1462 }
1463 
1464 struct pcmchan_matrix *
1465 chn_getmatrix(struct pcm_channel *c)
1466 {
1467 
1468 	KASSERT(c != NULL, ("%s(): NULL channel", __func__));
1469 	CHN_LOCKASSERT(c);
1470 
1471 	if (!(c->format & AFMT_CONVERTIBLE))
1472 		return (NULL);
1473 
1474 	return (&c->matrix);
1475 }
1476 
1477 int
1478 chn_setmatrix(struct pcm_channel *c, struct pcmchan_matrix *m)
1479 {
1480 
1481 	KASSERT(c != NULL && m != NULL,
1482 	    ("%s(): NULL channel or matrix", __func__));
1483 	CHN_LOCKASSERT(c);
1484 
1485 	if (!(c->format & AFMT_CONVERTIBLE))
1486 		return (EINVAL);
1487 
1488 	c->matrix = *m;
1489 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1490 
1491 	return (chn_setformat(c, SND_FORMAT(c->format, m->channels, m->ext)));
1492 }
1493 
1494 /*
1495  * XXX chn_oss_* exists for the sake of compatibility.
1496  */
1497 int
1498 chn_oss_getorder(struct pcm_channel *c, unsigned long long *map)
1499 {
1500 
1501 	KASSERT(c != NULL && map != NULL,
1502 	    ("%s(): NULL channel or map", __func__));
1503 	CHN_LOCKASSERT(c);
1504 
1505 	if (!(c->format & AFMT_CONVERTIBLE))
1506 		return (EINVAL);
1507 
1508 	return (feeder_matrix_oss_get_channel_order(&c->matrix, map));
1509 }
1510 
1511 int
1512 chn_oss_setorder(struct pcm_channel *c, unsigned long long *map)
1513 {
1514 	struct pcmchan_matrix m;
1515 	int ret;
1516 
1517 	KASSERT(c != NULL && map != NULL,
1518 	    ("%s(): NULL channel or map", __func__));
1519 	CHN_LOCKASSERT(c);
1520 
1521 	if (!(c->format & AFMT_CONVERTIBLE))
1522 		return (EINVAL);
1523 
1524 	m = c->matrix;
1525 	ret = feeder_matrix_oss_set_channel_order(&m, map);
1526 	if (ret != 0)
1527 		return (ret);
1528 
1529 	return (chn_setmatrix(c, &m));
1530 }
1531 
1532 #define SND_CHN_OSS_FRONT	(SND_CHN_T_MASK_FL | SND_CHN_T_MASK_FR)
1533 #define SND_CHN_OSS_SURR	(SND_CHN_T_MASK_SL | SND_CHN_T_MASK_SR)
1534 #define SND_CHN_OSS_CENTER_LFE	(SND_CHN_T_MASK_FC | SND_CHN_T_MASK_LF)
1535 #define SND_CHN_OSS_REAR	(SND_CHN_T_MASK_BL | SND_CHN_T_MASK_BR)
1536 
1537 int
1538 chn_oss_getmask(struct pcm_channel *c, uint32_t *retmask)
1539 {
1540 	struct pcmchan_matrix *m;
1541 	struct pcmchan_caps *caps;
1542 	uint32_t i, format;
1543 
1544 	KASSERT(c != NULL && retmask != NULL,
1545 	    ("%s(): NULL channel or retmask", __func__));
1546 	CHN_LOCKASSERT(c);
1547 
1548 	caps = chn_getcaps(c);
1549 	if (caps == NULL || caps->fmtlist == NULL)
1550 		return (ENODEV);
1551 
1552 	for (i = 0; caps->fmtlist[i] != 0; i++) {
1553 		format = caps->fmtlist[i];
1554 		if (!(format & AFMT_CONVERTIBLE)) {
1555 			*retmask |= DSP_BIND_SPDIF;
1556 			continue;
1557 		}
1558 		m = CHANNEL_GETMATRIX(c->methods, c->devinfo, format);
1559 		if (m == NULL)
1560 			continue;
1561 		if (m->mask & SND_CHN_OSS_FRONT)
1562 			*retmask |= DSP_BIND_FRONT;
1563 		if (m->mask & SND_CHN_OSS_SURR)
1564 			*retmask |= DSP_BIND_SURR;
1565 		if (m->mask & SND_CHN_OSS_CENTER_LFE)
1566 			*retmask |= DSP_BIND_CENTER_LFE;
1567 		if (m->mask & SND_CHN_OSS_REAR)
1568 			*retmask |= DSP_BIND_REAR;
1569 	}
1570 
1571 	/* report software-supported binding mask */
1572 	if (!CHN_BITPERFECT(c) && report_soft_matrix)
1573 		*retmask |= DSP_BIND_FRONT | DSP_BIND_SURR |
1574 		    DSP_BIND_CENTER_LFE | DSP_BIND_REAR;
1575 
1576 	return (0);
1577 }
1578 
1579 void
1580 chn_vpc_reset(struct pcm_channel *c, int vc, int force)
1581 {
1582 	int i;
1583 
1584 	KASSERT(c != NULL && vc >= SND_VOL_C_BEGIN && vc <= SND_VOL_C_END,
1585 	    ("%s(): invalid reset c=%p vc=%d", __func__, c, vc));
1586 	CHN_LOCKASSERT(c);
1587 
1588 	if (force == 0 && chn_vpc_autoreset == 0)
1589 		return;
1590 
1591 	for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END; i += SND_CHN_T_STEP)
1592 		CHN_SETVOLUME(c, vc, i, c->volume[vc][SND_CHN_T_VOL_0DB]);
1593 }
1594 
1595 static u_int32_t
1596 round_pow2(u_int32_t v)
1597 {
1598 	u_int32_t ret;
1599 
1600 	if (v < 2)
1601 		v = 2;
1602 	ret = 0;
1603 	while (v >> ret)
1604 		ret++;
1605 	ret = 1 << (ret - 1);
1606 	while (ret < v)
1607 		ret <<= 1;
1608 	return ret;
1609 }
1610 
1611 static u_int32_t
1612 round_blksz(u_int32_t v, int round)
1613 {
1614 	u_int32_t ret, tmp;
1615 
1616 	if (round < 1)
1617 		round = 1;
1618 
1619 	ret = min(round_pow2(v), CHN_2NDBUFMAXSIZE >> 1);
1620 
1621 	if (ret > v && (ret >> 1) > 0 && (ret >> 1) >= ((v * 3) >> 2))
1622 		ret >>= 1;
1623 
1624 	tmp = ret - (ret % round);
1625 	while (tmp < 16 || tmp < round) {
1626 		ret <<= 1;
1627 		tmp = ret - (ret % round);
1628 	}
1629 
1630 	return ret;
1631 }
1632 
1633 /*
1634  * 4Front call it DSP Policy, while we call it "Latency Profile". The idea
1635  * is to keep 2nd buffer short so that it doesn't cause long queue during
1636  * buffer transfer.
1637  *
1638  *    Latency reference table for 48khz stereo 16bit: (PLAY)
1639  *
1640  *      +---------+------------+-----------+------------+
1641  *      | Latency | Blockcount | Blocksize | Buffersize |
1642  *      +---------+------------+-----------+------------+
1643  *      |     0   |       2    |   64      |    128     |
1644  *      +---------+------------+-----------+------------+
1645  *      |     1   |       4    |   128     |    512     |
1646  *      +---------+------------+-----------+------------+
1647  *      |     2   |       8    |   512     |    4096    |
1648  *      +---------+------------+-----------+------------+
1649  *      |     3   |      16    |   512     |    8192    |
1650  *      +---------+------------+-----------+------------+
1651  *      |     4   |      32    |   512     |    16384   |
1652  *      +---------+------------+-----------+------------+
1653  *      |     5   |      32    |   1024    |    32768   |
1654  *      +---------+------------+-----------+------------+
1655  *      |     6   |      16    |   2048    |    32768   |
1656  *      +---------+------------+-----------+------------+
1657  *      |     7   |       8    |   4096    |    32768   |
1658  *      +---------+------------+-----------+------------+
1659  *      |     8   |       4    |   8192    |    32768   |
1660  *      +---------+------------+-----------+------------+
1661  *      |     9   |       2    |   16384   |    32768   |
1662  *      +---------+------------+-----------+------------+
1663  *      |    10   |       2    |   32768   |    65536   |
1664  *      +---------+------------+-----------+------------+
1665  *
1666  * Recording need a different reference table. All we care is
1667  * gobbling up everything within reasonable buffering threshold.
1668  *
1669  *    Latency reference table for 48khz stereo 16bit: (REC)
1670  *
1671  *      +---------+------------+-----------+------------+
1672  *      | Latency | Blockcount | Blocksize | Buffersize |
1673  *      +---------+------------+-----------+------------+
1674  *      |     0   |     512    |   32      |    16384   |
1675  *      +---------+------------+-----------+------------+
1676  *      |     1   |     256    |   64      |    16384   |
1677  *      +---------+------------+-----------+------------+
1678  *      |     2   |     128    |   128     |    16384   |
1679  *      +---------+------------+-----------+------------+
1680  *      |     3   |      64    |   256     |    16384   |
1681  *      +---------+------------+-----------+------------+
1682  *      |     4   |      32    |   512     |    16384   |
1683  *      +---------+------------+-----------+------------+
1684  *      |     5   |      32    |   1024    |    32768   |
1685  *      +---------+------------+-----------+------------+
1686  *      |     6   |      16    |   2048    |    32768   |
1687  *      +---------+------------+-----------+------------+
1688  *      |     7   |       8    |   4096    |    32768   |
1689  *      +---------+------------+-----------+------------+
1690  *      |     8   |       4    |   8192    |    32768   |
1691  *      +---------+------------+-----------+------------+
1692  *      |     9   |       2    |   16384   |    32768   |
1693  *      +---------+------------+-----------+------------+
1694  *      |    10   |       2    |   32768   |    65536   |
1695  *      +---------+------------+-----------+------------+
1696  *
1697  * Calculations for other data rate are entirely based on these reference
1698  * tables. For normal operation, Latency 5 seems give the best, well
1699  * balanced performance for typical workload. Anything below 5 will
1700  * eat up CPU to keep up with increasing context switches because of
1701  * shorter buffer space and usually require the application to handle it
1702  * aggressively through possibly real time programming technique.
1703  *
1704  */
1705 #define CHN_LATENCY_PBLKCNT_REF				\
1706 	{{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1},		\
1707 	{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1}}
1708 #define CHN_LATENCY_PBUFSZ_REF				\
1709 	{{7, 9, 12, 13, 14, 15, 15, 15, 15, 15, 16},	\
1710 	{11, 12, 13, 14, 15, 16, 16, 16, 16, 16, 17}}
1711 
1712 #define CHN_LATENCY_RBLKCNT_REF				\
1713 	{{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1},		\
1714 	{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1}}
1715 #define CHN_LATENCY_RBUFSZ_REF				\
1716 	{{14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16},	\
1717 	{15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17}}
1718 
1719 #define CHN_LATENCY_DATA_REF	192000 /* 48khz stereo 16bit ~ 48000 x 2 x 2 */
1720 
1721 static int
1722 chn_calclatency(int dir, int latency, int bps, u_int32_t datarate,
1723 				u_int32_t max, int *rblksz, int *rblkcnt)
1724 {
1725 	static int pblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1726 	    CHN_LATENCY_PBLKCNT_REF;
1727 	static int  pbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1728 	    CHN_LATENCY_PBUFSZ_REF;
1729 	static int rblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1730 	    CHN_LATENCY_RBLKCNT_REF;
1731 	static int  rbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1732 	    CHN_LATENCY_RBUFSZ_REF;
1733 	u_int32_t bufsz;
1734 	int lprofile, blksz, blkcnt;
1735 
1736 	if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX ||
1737 	    bps < 1 || datarate < 1 ||
1738 	    !(dir == PCMDIR_PLAY || dir == PCMDIR_REC)) {
1739 		if (rblksz != NULL)
1740 			*rblksz = CHN_2NDBUFMAXSIZE >> 1;
1741 		if (rblkcnt != NULL)
1742 			*rblkcnt = 2;
1743 		printf("%s(): FAILED dir=%d latency=%d bps=%d "
1744 		    "datarate=%u max=%u\n",
1745 		    __func__, dir, latency, bps, datarate, max);
1746 		return CHN_2NDBUFMAXSIZE;
1747 	}
1748 
1749 	lprofile = chn_latency_profile;
1750 
1751 	if (dir == PCMDIR_PLAY) {
1752 		blkcnt = pblkcnts[lprofile][latency];
1753 		bufsz = pbufszs[lprofile][latency];
1754 	} else {
1755 		blkcnt = rblkcnts[lprofile][latency];
1756 		bufsz = rbufszs[lprofile][latency];
1757 	}
1758 
1759 	bufsz = round_pow2(snd_xbytes(1 << bufsz, CHN_LATENCY_DATA_REF,
1760 	    datarate));
1761 	if (bufsz > max)
1762 		bufsz = max;
1763 	blksz = round_blksz(bufsz >> blkcnt, bps);
1764 
1765 	if (rblksz != NULL)
1766 		*rblksz = blksz;
1767 	if (rblkcnt != NULL)
1768 		*rblkcnt = 1 << blkcnt;
1769 
1770 	return blksz << blkcnt;
1771 }
1772 
1773 static int
1774 chn_resizebuf(struct pcm_channel *c, int latency,
1775 					int blkcnt, int blksz)
1776 {
1777 	struct snd_dbuf *b, *bs, *pb;
1778 	int sblksz, sblkcnt, hblksz, hblkcnt, limit = 0, nsblksz, nsblkcnt;
1779 	int ret;
1780 
1781 	CHN_LOCKASSERT(c);
1782 
1783 	if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
1784 	    !(c->direction == PCMDIR_PLAY || c->direction == PCMDIR_REC))
1785 		return EINVAL;
1786 
1787 	if (latency == -1) {
1788 		c->latency = -1;
1789 		latency = chn_latency;
1790 	} else if (latency == -2) {
1791 		latency = c->latency;
1792 		if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1793 			latency = chn_latency;
1794 	} else if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1795 		return EINVAL;
1796 	else {
1797 		c->latency = latency;
1798 	}
1799 
1800 	bs = c->bufsoft;
1801 	b = c->bufhard;
1802 
1803 	if (!(blksz == 0 || blkcnt == -1) &&
1804 	    (blksz < 16 || blksz < sndbuf_getalign(bs) || blkcnt < 2 ||
1805 	    (blksz * blkcnt) > CHN_2NDBUFMAXSIZE))
1806 		return EINVAL;
1807 
1808 	chn_calclatency(c->direction, latency, sndbuf_getalign(bs),
1809 	    sndbuf_getalign(bs) * sndbuf_getspd(bs), CHN_2NDBUFMAXSIZE,
1810 	    &sblksz, &sblkcnt);
1811 
1812 	if (blksz == 0 || blkcnt == -1) {
1813 		if (blkcnt == -1)
1814 			c->flags &= ~CHN_F_HAS_SIZE;
1815 		if (c->flags & CHN_F_HAS_SIZE) {
1816 			blksz = sndbuf_getblksz(bs);
1817 			blkcnt = sndbuf_getblkcnt(bs);
1818 		}
1819 	} else
1820 		c->flags |= CHN_F_HAS_SIZE;
1821 
1822 	if (c->flags & CHN_F_HAS_SIZE) {
1823 		/*
1824 		 * The application has requested their own blksz/blkcnt.
1825 		 * Just obey with it, and let them toast alone. We can
1826 		 * clamp it to the nearest latency profile, but that would
1827 		 * defeat the purpose of having custom control. The least
1828 		 * we can do is round it to the nearest ^2 and align it.
1829 		 */
1830 		sblksz = round_blksz(blksz, sndbuf_getalign(bs));
1831 		sblkcnt = round_pow2(blkcnt);
1832 	}
1833 
1834 	if (c->parentchannel != NULL) {
1835 		pb = c->parentchannel->bufsoft;
1836 		CHN_UNLOCK(c);
1837 		CHN_LOCK(c->parentchannel);
1838 		chn_notify(c->parentchannel, CHN_N_BLOCKSIZE);
1839 		CHN_UNLOCK(c->parentchannel);
1840 		CHN_LOCK(c);
1841 		if (c->direction == PCMDIR_PLAY) {
1842 			limit = (pb != NULL) ?
1843 			    sndbuf_xbytes(sndbuf_getsize(pb), pb, bs) : 0;
1844 		} else {
1845 			limit = (pb != NULL) ?
1846 			    sndbuf_xbytes(sndbuf_getblksz(pb), pb, bs) * 2 : 0;
1847 		}
1848 	} else {
1849 		hblkcnt = 2;
1850 		if (c->flags & CHN_F_HAS_SIZE) {
1851 			hblksz = round_blksz(sndbuf_xbytes(sblksz, bs, b),
1852 			    sndbuf_getalign(b));
1853 			hblkcnt = round_pow2(sndbuf_getblkcnt(bs));
1854 		} else
1855 			chn_calclatency(c->direction, latency,
1856 			    sndbuf_getalign(b),
1857 			    sndbuf_getalign(b) * sndbuf_getspd(b),
1858 			    CHN_2NDBUFMAXSIZE, &hblksz, &hblkcnt);
1859 
1860 		if ((hblksz << 1) > sndbuf_getmaxsize(b))
1861 			hblksz = round_blksz(sndbuf_getmaxsize(b) >> 1,
1862 			    sndbuf_getalign(b));
1863 
1864 		while ((hblksz * hblkcnt) > sndbuf_getmaxsize(b)) {
1865 			if (hblkcnt < 4)
1866 				hblksz >>= 1;
1867 			else
1868 				hblkcnt >>= 1;
1869 		}
1870 
1871 		hblksz -= hblksz % sndbuf_getalign(b);
1872 
1873 #if 0
1874 		hblksz = sndbuf_getmaxsize(b) >> 1;
1875 		hblksz -= hblksz % sndbuf_getalign(b);
1876 		hblkcnt = 2;
1877 #endif
1878 
1879 		CHN_UNLOCK(c);
1880 		if (chn_usefrags == 0 ||
1881 		    CHANNEL_SETFRAGMENTS(c->methods, c->devinfo,
1882 		    hblksz, hblkcnt) != 0)
1883 			sndbuf_setblksz(b, CHANNEL_SETBLOCKSIZE(c->methods,
1884 			    c->devinfo, hblksz));
1885 		CHN_LOCK(c);
1886 
1887 		if (!CHN_EMPTY(c, children)) {
1888 			nsblksz = round_blksz(
1889 			    sndbuf_xbytes(sndbuf_getblksz(b), b, bs),
1890 			    sndbuf_getalign(bs));
1891 			nsblkcnt = sndbuf_getblkcnt(b);
1892 			if (c->direction == PCMDIR_PLAY) {
1893 				do {
1894 					nsblkcnt--;
1895 				} while (nsblkcnt >= 2 &&
1896 				    nsblksz * nsblkcnt >= sblksz * sblkcnt);
1897 				nsblkcnt++;
1898 			}
1899 			sblksz = nsblksz;
1900 			sblkcnt = nsblkcnt;
1901 			limit = 0;
1902 		} else
1903 			limit = sndbuf_xbytes(sndbuf_getblksz(b), b, bs) * 2;
1904 	}
1905 
1906 	if (limit > CHN_2NDBUFMAXSIZE)
1907 		limit = CHN_2NDBUFMAXSIZE;
1908 
1909 #if 0
1910 	while (limit > 0 && (sblksz * sblkcnt) > limit) {
1911 		if (sblkcnt < 4)
1912 			break;
1913 		sblkcnt >>= 1;
1914 	}
1915 #endif
1916 
1917 	while ((sblksz * sblkcnt) < limit)
1918 		sblkcnt <<= 1;
1919 
1920 	while ((sblksz * sblkcnt) > CHN_2NDBUFMAXSIZE) {
1921 		if (sblkcnt < 4)
1922 			sblksz >>= 1;
1923 		else
1924 			sblkcnt >>= 1;
1925 	}
1926 
1927 	sblksz -= sblksz % sndbuf_getalign(bs);
1928 
1929 	if (sndbuf_getblkcnt(bs) != sblkcnt || sndbuf_getblksz(bs) != sblksz ||
1930 	    sndbuf_getsize(bs) != (sblkcnt * sblksz)) {
1931 		ret = sndbuf_remalloc(bs, sblkcnt, sblksz);
1932 		if (ret != 0) {
1933 			device_printf(c->dev, "%s(): Failed: %d %d\n",
1934 			    __func__, sblkcnt, sblksz);
1935 			return ret;
1936 		}
1937 	}
1938 
1939 	/*
1940 	 * Interrupt timeout
1941 	 */
1942 	c->timeout = ((u_int64_t)hz * sndbuf_getsize(bs)) /
1943 	    ((u_int64_t)sndbuf_getspd(bs) * sndbuf_getalign(bs));
1944 	if (c->parentchannel != NULL)
1945 		c->timeout = min(c->timeout, c->parentchannel->timeout);
1946 	if (c->timeout < 1)
1947 		c->timeout = 1;
1948 
1949 	/*
1950 	 * OSSv4 docs: "By default OSS will set the low water level equal
1951 	 * to the fragment size which is optimal in most cases."
1952 	 */
1953 	c->lw = sndbuf_getblksz(bs);
1954 	chn_resetbuf(c);
1955 
1956 	if (snd_verbose > 3)
1957 		device_printf(c->dev, "%s(): %s (%s) timeout=%u "
1958 		    "b[%d/%d/%d] bs[%d/%d/%d] limit=%d\n",
1959 		    __func__, CHN_DIRSTR(c),
1960 		    (c->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
1961 		    c->timeout,
1962 		    sndbuf_getsize(b), sndbuf_getblksz(b),
1963 		    sndbuf_getblkcnt(b),
1964 		    sndbuf_getsize(bs), sndbuf_getblksz(bs),
1965 		    sndbuf_getblkcnt(bs), limit);
1966 
1967 	return 0;
1968 }
1969 
1970 int
1971 chn_setlatency(struct pcm_channel *c, int latency)
1972 {
1973 	CHN_LOCKASSERT(c);
1974 	/* Destroy blksz/blkcnt, enforce latency profile. */
1975 	return chn_resizebuf(c, latency, -1, 0);
1976 }
1977 
1978 int
1979 chn_setblocksize(struct pcm_channel *c, int blkcnt, int blksz)
1980 {
1981 	CHN_LOCKASSERT(c);
1982 	/* Destroy latency profile, enforce blksz/blkcnt */
1983 	return chn_resizebuf(c, -1, blkcnt, blksz);
1984 }
1985 
1986 int
1987 chn_setparam(struct pcm_channel *c, uint32_t format, uint32_t speed)
1988 {
1989 	struct pcmchan_caps *caps;
1990 	uint32_t hwspeed, delta;
1991 	int ret;
1992 
1993 	CHN_LOCKASSERT(c);
1994 
1995 	if (speed < 1 || format == 0 || CHN_STARTED(c))
1996 		return (EINVAL);
1997 
1998 	c->format = format;
1999 	c->speed = speed;
2000 
2001 	caps = chn_getcaps(c);
2002 
2003 	hwspeed = speed;
2004 	RANGE(hwspeed, caps->minspeed, caps->maxspeed);
2005 
2006 	sndbuf_setspd(c->bufhard, CHANNEL_SETSPEED(c->methods, c->devinfo,
2007 	    hwspeed));
2008 	hwspeed = sndbuf_getspd(c->bufhard);
2009 
2010 	delta = (hwspeed > speed) ? (hwspeed - speed) : (speed - hwspeed);
2011 
2012 	if (delta <= feeder_rate_round)
2013 		c->speed = hwspeed;
2014 
2015 	ret = feeder_chain(c);
2016 
2017 	if (ret == 0)
2018 		ret = CHANNEL_SETFORMAT(c->methods, c->devinfo,
2019 		    sndbuf_getfmt(c->bufhard));
2020 
2021 	if (ret == 0)
2022 		ret = chn_resizebuf(c, -2, 0, 0);
2023 
2024 	return (ret);
2025 }
2026 
2027 int
2028 chn_setspeed(struct pcm_channel *c, uint32_t speed)
2029 {
2030 	uint32_t oldformat, oldspeed, format;
2031 	int ret;
2032 
2033 #if 0
2034 	/* XXX force 48k */
2035 	if (c->format & AFMT_PASSTHROUGH)
2036 		speed = AFMT_PASSTHROUGH_RATE;
2037 #endif
2038 
2039 	oldformat = c->format;
2040 	oldspeed = c->speed;
2041 	format = oldformat;
2042 
2043 	ret = chn_setparam(c, format, speed);
2044 	if (ret != 0) {
2045 		if (snd_verbose > 3)
2046 			device_printf(c->dev,
2047 			    "%s(): Setting speed %d failed, "
2048 			    "falling back to %d\n",
2049 			    __func__, speed, oldspeed);
2050 		chn_setparam(c, c->format, oldspeed);
2051 	}
2052 
2053 	return (ret);
2054 }
2055 
2056 int
2057 chn_setformat(struct pcm_channel *c, uint32_t format)
2058 {
2059 	uint32_t oldformat, oldspeed, speed;
2060 	int ret;
2061 
2062 	/* XXX force stereo */
2063 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
2064 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,
2065 		    AFMT_PASSTHROUGH_EXTCHANNEL);
2066 	}
2067 
2068 	oldformat = c->format;
2069 	oldspeed = c->speed;
2070 	speed = oldspeed;
2071 
2072 	ret = chn_setparam(c, format, speed);
2073 	if (ret != 0) {
2074 		if (snd_verbose > 3)
2075 			device_printf(c->dev,
2076 			    "%s(): Format change 0x%08x failed, "
2077 			    "falling back to 0x%08x\n",
2078 			    __func__, format, oldformat);
2079 		chn_setparam(c, oldformat, oldspeed);
2080 	}
2081 
2082 	return (ret);
2083 }
2084 
2085 void
2086 chn_syncstate(struct pcm_channel *c)
2087 {
2088 	struct snddev_info *d;
2089 	struct snd_mixer *m;
2090 
2091 	d = (c != NULL) ? c->parentsnddev : NULL;
2092 	m = (d != NULL && d->mixer_dev != NULL) ? d->mixer_dev->si_drv1 :
2093 	    NULL;
2094 
2095 	if (d == NULL || m == NULL)
2096 		return;
2097 
2098 	CHN_LOCKASSERT(c);
2099 
2100 	if (c->feederflags & (1 << FEEDER_VOLUME)) {
2101 		uint32_t parent;
2102 		int vol, pvol, left, right, center;
2103 
2104 		if (c->direction == PCMDIR_PLAY &&
2105 		    (d->flags & SD_F_SOFTPCMVOL)) {
2106 			/* CHN_UNLOCK(c); */
2107 			vol = mix_get(m, SOUND_MIXER_PCM);
2108 			parent = mix_getparent(m, SOUND_MIXER_PCM);
2109 			if (parent != SOUND_MIXER_NONE)
2110 				pvol = mix_get(m, parent);
2111 			else
2112 				pvol = 100 | (100 << 8);
2113 			/* CHN_LOCK(c); */
2114 		} else {
2115 			vol = 100 | (100 << 8);
2116 			pvol = vol;
2117 		}
2118 
2119 		if (vol == -1) {
2120 			device_printf(c->dev,
2121 			    "Soft PCM Volume: Failed to read pcm "
2122 			    "default value\n");
2123 			vol = 100 | (100 << 8);
2124 		}
2125 
2126 		if (pvol == -1) {
2127 			device_printf(c->dev,
2128 			    "Soft PCM Volume: Failed to read parent "
2129 			    "default value\n");
2130 			pvol = 100 | (100 << 8);
2131 		}
2132 
2133 		left = ((vol & 0x7f) * (pvol & 0x7f)) / 100;
2134 		right = (((vol >> 8) & 0x7f) * ((pvol >> 8) & 0x7f)) / 100;
2135 		center = (left + right) >> 1;
2136 
2137 		chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right, center);
2138 	}
2139 
2140 	if (c->feederflags & (1 << FEEDER_EQ)) {
2141 		struct pcm_feeder *f;
2142 		int treble, bass, state;
2143 
2144 		/* CHN_UNLOCK(c); */
2145 		treble = mix_get(m, SOUND_MIXER_TREBLE);
2146 		bass = mix_get(m, SOUND_MIXER_BASS);
2147 		/* CHN_LOCK(c); */
2148 
2149 		if (treble == -1)
2150 			treble = 50;
2151 		else
2152 			treble = ((treble & 0x7f) +
2153 			    ((treble >> 8) & 0x7f)) >> 1;
2154 
2155 		if (bass == -1)
2156 			bass = 50;
2157 		else
2158 			bass = ((bass & 0x7f) + ((bass >> 8) & 0x7f)) >> 1;
2159 
2160 		f = chn_findfeeder(c, FEEDER_EQ);
2161 		if (f != NULL) {
2162 			if (FEEDER_SET(f, FEEDEQ_TREBLE, treble) != 0)
2163 				device_printf(c->dev,
2164 				    "EQ: Failed to set treble -- %d\n",
2165 				    treble);
2166 			if (FEEDER_SET(f, FEEDEQ_BASS, bass) != 0)
2167 				device_printf(c->dev,
2168 				    "EQ: Failed to set bass -- %d\n",
2169 				    bass);
2170 			if (FEEDER_SET(f, FEEDEQ_PREAMP, d->eqpreamp) != 0)
2171 				device_printf(c->dev,
2172 				    "EQ: Failed to set preamp -- %d\n",
2173 				    d->eqpreamp);
2174 			if (d->flags & SD_F_EQ_BYPASSED)
2175 				state = FEEDEQ_BYPASS;
2176 			else if (d->flags & SD_F_EQ_ENABLED)
2177 				state = FEEDEQ_ENABLE;
2178 			else
2179 				state = FEEDEQ_DISABLE;
2180 			if (FEEDER_SET(f, FEEDEQ_STATE, state) != 0)
2181 				device_printf(c->dev,
2182 				    "EQ: Failed to set state -- %d\n", state);
2183 		}
2184 	}
2185 }
2186 
2187 int
2188 chn_trigger(struct pcm_channel *c, int go)
2189 {
2190 	struct snddev_info *d = c->parentsnddev;
2191 	int ret;
2192 
2193 	CHN_LOCKASSERT(c);
2194 	if (!PCMTRIG_COMMON(go))
2195 		return (CHANNEL_TRIGGER(c->methods, c->devinfo, go));
2196 
2197 	if (go == c->trigger)
2198 		return (0);
2199 
2200 	ret = CHANNEL_TRIGGER(c->methods, c->devinfo, go);
2201 	if (ret != 0)
2202 		return (ret);
2203 
2204 	switch (go) {
2205 	case PCMTRIG_START:
2206 		if (snd_verbose > 3)
2207 			device_printf(c->dev,
2208 			    "%s() %s: calling go=0x%08x , "
2209 			    "prev=0x%08x\n", __func__, c->name, go,
2210 			    c->trigger);
2211 		if (c->trigger != PCMTRIG_START) {
2212 			c->trigger = go;
2213 			CHN_UNLOCK(c);
2214 			PCM_LOCK(d);
2215 			CHN_INSERT_HEAD(d, c, channels.pcm.busy);
2216 			PCM_UNLOCK(d);
2217 			CHN_LOCK(c);
2218 			chn_syncstate(c);
2219 		}
2220 		break;
2221 	case PCMTRIG_STOP:
2222 	case PCMTRIG_ABORT:
2223 		if (snd_verbose > 3)
2224 			device_printf(c->dev,
2225 			    "%s() %s: calling go=0x%08x , "
2226 			    "prev=0x%08x\n", __func__, c->name, go,
2227 			    c->trigger);
2228 		if (c->trigger == PCMTRIG_START) {
2229 			c->trigger = go;
2230 			CHN_UNLOCK(c);
2231 			PCM_LOCK(d);
2232 			CHN_REMOVE(d, c, channels.pcm.busy);
2233 			PCM_UNLOCK(d);
2234 			CHN_LOCK(c);
2235 		}
2236 		break;
2237 	default:
2238 		break;
2239 	}
2240 
2241 	return (0);
2242 }
2243 
2244 /**
2245  * @brief Queries sound driver for sample-aligned hardware buffer pointer index
2246  *
2247  * This function obtains the hardware pointer location, then aligns it to
2248  * the current bytes-per-sample value before returning.  (E.g., a channel
2249  * running in 16 bit stereo mode would require 4 bytes per sample, so a
2250  * hwptr value ranging from 32-35 would be returned as 32.)
2251  *
2252  * @param c	PCM channel context
2253  * @returns 	sample-aligned hardware buffer pointer index
2254  */
2255 int
2256 chn_getptr(struct pcm_channel *c)
2257 {
2258 	int hwptr;
2259 
2260 	CHN_LOCKASSERT(c);
2261 	hwptr = (CHN_STARTED(c)) ? CHANNEL_GETPTR(c->methods, c->devinfo) : 0;
2262 	return (hwptr - (hwptr % sndbuf_getalign(c->bufhard)));
2263 }
2264 
2265 struct pcmchan_caps *
2266 chn_getcaps(struct pcm_channel *c)
2267 {
2268 	CHN_LOCKASSERT(c);
2269 	return CHANNEL_GETCAPS(c->methods, c->devinfo);
2270 }
2271 
2272 u_int32_t
2273 chn_getformats(struct pcm_channel *c)
2274 {
2275 	u_int32_t *fmtlist, fmts;
2276 	int i;
2277 
2278 	fmtlist = chn_getcaps(c)->fmtlist;
2279 	fmts = 0;
2280 	for (i = 0; fmtlist[i]; i++)
2281 		fmts |= fmtlist[i];
2282 
2283 	/* report software-supported formats */
2284 	if (!CHN_BITPERFECT(c) && report_soft_formats)
2285 		fmts |= AFMT_CONVERTIBLE;
2286 
2287 	return (AFMT_ENCODING(fmts));
2288 }
2289 
2290 int
2291 chn_notify(struct pcm_channel *c, u_int32_t flags)
2292 {
2293 	struct pcm_channel *ch;
2294 	struct pcmchan_caps *caps;
2295 	uint32_t bestformat, bestspeed, besthwformat, *vchanformat, *vchanrate;
2296 	uint32_t vpflags;
2297 	int dirty, err, run, nrun;
2298 
2299 	CHN_LOCKASSERT(c);
2300 
2301 	if (CHN_EMPTY(c, children))
2302 		return (ENODEV);
2303 
2304 	err = 0;
2305 
2306 	/*
2307 	 * If the hwchan is running, we can't change its rate, format or
2308 	 * blocksize
2309 	 */
2310 	run = (CHN_STARTED(c)) ? 1 : 0;
2311 	if (run)
2312 		flags &= CHN_N_VOLUME | CHN_N_TRIGGER;
2313 
2314 	if (flags & CHN_N_RATE) {
2315 		/*
2316 		 * XXX I'll make good use of this someday.
2317 		 *     However this is currently being superseded by
2318 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2319 		 */
2320 	}
2321 
2322 	if (flags & CHN_N_FORMAT) {
2323 		/*
2324 		 * XXX I'll make good use of this someday.
2325 		 *     However this is currently being superseded by
2326 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2327 		 */
2328 	}
2329 
2330 	if (flags & CHN_N_VOLUME) {
2331 		/*
2332 		 * XXX I'll make good use of this someday, though
2333 		 *     soft volume control is currently pretty much
2334 		 *     integrated.
2335 		 */
2336 	}
2337 
2338 	if (flags & CHN_N_BLOCKSIZE) {
2339 		/*
2340 		 * Set to default latency profile
2341 		 */
2342 		chn_setlatency(c, chn_latency);
2343 	}
2344 
2345 	if ((flags & CHN_N_TRIGGER) && !(c->flags & CHN_F_VCHAN_DYNAMIC)) {
2346 		nrun = CHN_EMPTY(c, children.busy) ? 0 : 1;
2347 		if (nrun && !run)
2348 			err = chn_start(c, 1);
2349 		if (!nrun && run)
2350 			chn_abort(c);
2351 		flags &= ~CHN_N_TRIGGER;
2352 	}
2353 
2354 	if (flags & CHN_N_TRIGGER) {
2355 		if (c->direction == PCMDIR_PLAY) {
2356 			vchanformat = &c->parentsnddev->pvchanformat;
2357 			vchanrate = &c->parentsnddev->pvchanrate;
2358 		} else {
2359 			vchanformat = &c->parentsnddev->rvchanformat;
2360 			vchanrate = &c->parentsnddev->rvchanrate;
2361 		}
2362 
2363 		/* Dynamic Virtual Channel */
2364 		if (!(c->flags & CHN_F_VCHAN_ADAPTIVE)) {
2365 			bestformat = *vchanformat;
2366 			bestspeed = *vchanrate;
2367 		} else {
2368 			bestformat = 0;
2369 			bestspeed = 0;
2370 		}
2371 
2372 		besthwformat = 0;
2373 		nrun = 0;
2374 		caps = chn_getcaps(c);
2375 		dirty = 0;
2376 		vpflags = 0;
2377 
2378 		CHN_FOREACH(ch, c, children.busy) {
2379 			CHN_LOCK(ch);
2380 			if ((ch->format & AFMT_PASSTHROUGH) &&
2381 			    snd_fmtvalid(ch->format, caps->fmtlist)) {
2382 				bestformat = ch->format;
2383 				bestspeed = ch->speed;
2384 				CHN_UNLOCK(ch);
2385 				vpflags = CHN_F_PASSTHROUGH;
2386 				nrun++;
2387 				break;
2388 			}
2389 			if ((ch->flags & CHN_F_EXCLUSIVE) && vpflags == 0) {
2390 				if (c->flags & CHN_F_VCHAN_ADAPTIVE) {
2391 					bestspeed = ch->speed;
2392 					RANGE(bestspeed, caps->minspeed,
2393 					    caps->maxspeed);
2394 					besthwformat = snd_fmtbest(ch->format,
2395 					    caps->fmtlist);
2396 					if (besthwformat != 0)
2397 						bestformat = besthwformat;
2398 				}
2399 				CHN_UNLOCK(ch);
2400 				vpflags = CHN_F_EXCLUSIVE;
2401 				nrun++;
2402 				continue;
2403 			}
2404 			if (!(c->flags & CHN_F_VCHAN_ADAPTIVE) ||
2405 			    vpflags != 0) {
2406 				CHN_UNLOCK(ch);
2407 				nrun++;
2408 				continue;
2409 			}
2410 			if (ch->speed > bestspeed) {
2411 				bestspeed = ch->speed;
2412 				RANGE(bestspeed, caps->minspeed,
2413 				    caps->maxspeed);
2414 			}
2415 			besthwformat = snd_fmtbest(ch->format, caps->fmtlist);
2416 			if (!(besthwformat & AFMT_VCHAN)) {
2417 				CHN_UNLOCK(ch);
2418 				nrun++;
2419 				continue;
2420 			}
2421 			if (AFMT_CHANNEL(besthwformat) >
2422 			    AFMT_CHANNEL(bestformat))
2423 				bestformat = besthwformat;
2424 			else if (AFMT_CHANNEL(besthwformat) ==
2425 			    AFMT_CHANNEL(bestformat) &&
2426 			    AFMT_BIT(besthwformat) > AFMT_BIT(bestformat))
2427 				bestformat = besthwformat;
2428 			CHN_UNLOCK(ch);
2429 			nrun++;
2430 		}
2431 
2432 		if (bestformat == 0)
2433 			bestformat = c->format;
2434 		if (bestspeed == 0)
2435 			bestspeed = c->speed;
2436 
2437 		if (bestformat != c->format || bestspeed != c->speed)
2438 			dirty = 1;
2439 
2440 		c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2441 		c->flags |= vpflags;
2442 
2443 		if (nrun && !run) {
2444 			if (dirty) {
2445 				bestspeed = CHANNEL_SETSPEED(c->methods,
2446 				    c->devinfo, bestspeed);
2447 				err = chn_reset(c, bestformat, bestspeed);
2448 			}
2449 			if (err == 0 && dirty) {
2450 				CHN_FOREACH(ch, c, children.busy) {
2451 					CHN_LOCK(ch);
2452 					if (VCHAN_SYNC_REQUIRED(ch))
2453 						vchan_sync(ch);
2454 					CHN_UNLOCK(ch);
2455 				}
2456 			}
2457 			if (err == 0) {
2458 				if (dirty)
2459 					c->flags |= CHN_F_DIRTY;
2460 				err = chn_start(c, 1);
2461 			}
2462 		}
2463 
2464 		if (nrun && run && dirty) {
2465 			chn_abort(c);
2466 			bestspeed = CHANNEL_SETSPEED(c->methods, c->devinfo,
2467 			    bestspeed);
2468 			err = chn_reset(c, bestformat, bestspeed);
2469 			if (err == 0) {
2470 				CHN_FOREACH(ch, c, children.busy) {
2471 					CHN_LOCK(ch);
2472 					if (VCHAN_SYNC_REQUIRED(ch))
2473 						vchan_sync(ch);
2474 					CHN_UNLOCK(ch);
2475 				}
2476 			}
2477 			if (err == 0) {
2478 				c->flags |= CHN_F_DIRTY;
2479 				err = chn_start(c, 1);
2480 			}
2481 		}
2482 
2483 		if (err == 0 && !(bestformat & AFMT_PASSTHROUGH) &&
2484 		    (bestformat & AFMT_VCHAN)) {
2485 			*vchanformat = bestformat;
2486 			*vchanrate = bestspeed;
2487 		}
2488 
2489 		if (!nrun && run) {
2490 			c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2491 			bestformat = *vchanformat;
2492 			bestspeed = *vchanrate;
2493 			chn_abort(c);
2494 			if (c->format != bestformat || c->speed != bestspeed)
2495 				chn_reset(c, bestformat, bestspeed);
2496 		}
2497 	}
2498 
2499 	return (err);
2500 }
2501 
2502 /**
2503  * @brief Fetch array of supported discrete sample rates
2504  *
2505  * Wrapper for CHANNEL_GETRATES.  Please see channel_if.m:getrates() for
2506  * detailed information.
2507  *
2508  * @note If the operation isn't supported, this function will just return 0
2509  *       (no rates in the array), and *rates will be set to NULL.  Callers
2510  *       should examine rates @b only if this function returns non-zero.
2511  *
2512  * @param c	pcm channel to examine
2513  * @param rates	pointer to array of integers; rate table will be recorded here
2514  *
2515  * @return number of rates in the array pointed to be @c rates
2516  */
2517 int
2518 chn_getrates(struct pcm_channel *c, int **rates)
2519 {
2520 	KASSERT(rates != NULL, ("rates is null"));
2521 	CHN_LOCKASSERT(c);
2522 	return CHANNEL_GETRATES(c->methods, c->devinfo, rates);
2523 }
2524 
2525 /**
2526  * @brief Remove channel from a sync group, if there is one.
2527  *
2528  * This function is initially intended for the following conditions:
2529  *   - Starting a syncgroup (@c SNDCTL_DSP_SYNCSTART ioctl)
2530  *   - Closing a device.  (A channel can't be destroyed if it's still in use.)
2531  *
2532  * @note Before calling this function, the syncgroup list mutex must be
2533  * held.  (Consider pcm_channel::sm protected by the SG list mutex
2534  * whether @c c is locked or not.)
2535  *
2536  * @param c	channel device to be started or closed
2537  * @returns	If this channel was the only member of a group, the group ID
2538  * 		is returned to the caller so that the caller can release it
2539  * 		via free_unr() after giving up the syncgroup lock.  Else it
2540  * 		returns 0.
2541  */
2542 int
2543 chn_syncdestroy(struct pcm_channel *c)
2544 {
2545 	struct pcmchan_syncmember *sm;
2546 	struct pcmchan_syncgroup *sg;
2547 	int sg_id;
2548 
2549 	sg_id = 0;
2550 
2551 	PCM_SG_LOCKASSERT(MA_OWNED);
2552 
2553 	if (c->sm != NULL) {
2554 		sm = c->sm;
2555 		sg = sm->parent;
2556 		c->sm = NULL;
2557 
2558 		KASSERT(sg != NULL, ("syncmember has null parent"));
2559 
2560 		SLIST_REMOVE(&sg->members, sm, pcmchan_syncmember, link);
2561 		free(sm, M_DEVBUF);
2562 
2563 		if (SLIST_EMPTY(&sg->members)) {
2564 			SLIST_REMOVE(&snd_pcm_syncgroups, sg, pcmchan_syncgroup, link);
2565 			sg_id = sg->id;
2566 			free(sg, M_DEVBUF);
2567 		}
2568 	}
2569 
2570 	return sg_id;
2571 }
2572 
2573 #ifdef OSSV4_EXPERIMENT
2574 int
2575 chn_getpeaks(struct pcm_channel *c, int *lpeak, int *rpeak)
2576 {
2577 	CHN_LOCKASSERT(c);
2578 	return CHANNEL_GETPEAKS(c->methods, c->devinfo, lpeak, rpeak);
2579 }
2580 #endif
2581