xref: /freebsd/sys/dev/sound/pcm/channel.c (revision 92cd5abb64dd70c305535c9504c6a2b73552147f)
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 	KASSERT((c->flags & CHN_F_SLEEPING) == 0,
336 	    ("%s(): entered with CHN_F_SLEEPING", __func__));
337 
338 	if (c->flags & CHN_F_DEAD)
339 		return (EINVAL);
340 
341 	c->flags |= CHN_F_SLEEPING;
342 	ret = cv_timedwait_sig(&c->intr_cv, c->lock, timeout);
343 	c->flags &= ~CHN_F_SLEEPING;
344 
345 	return ((c->flags & CHN_F_DEAD) ? EINVAL : ret);
346 }
347 
348 /*
349  * chn_dmaupdate() tracks the status of a dma transfer,
350  * updating pointers.
351  */
352 
353 static unsigned int
354 chn_dmaupdate(struct pcm_channel *c)
355 {
356 	struct snd_dbuf *b = c->bufhard;
357 	unsigned int delta, old, hwptr, amt;
358 
359 	KASSERT(sndbuf_getsize(b) > 0, ("bufsize == 0"));
360 	CHN_LOCKASSERT(c);
361 
362 	old = sndbuf_gethwptr(b);
363 	hwptr = chn_getptr(c);
364 	delta = (sndbuf_getsize(b) + hwptr - old) % sndbuf_getsize(b);
365 	sndbuf_sethwptr(b, hwptr);
366 
367 	if (c->direction == PCMDIR_PLAY) {
368 		amt = min(delta, sndbuf_getready(b));
369 		amt -= amt % sndbuf_getalign(b);
370 		if (amt > 0)
371 			sndbuf_dispose(b, NULL, amt);
372 	} else {
373 		amt = min(delta, sndbuf_getfree(b));
374 		amt -= amt % sndbuf_getalign(b);
375 		if (amt > 0)
376 		       sndbuf_acquire(b, NULL, amt);
377 	}
378 	if (snd_verbose > 3 && CHN_STARTED(c) && delta == 0) {
379 		device_printf(c->dev, "WARNING: %s DMA completion "
380 			"too fast/slow ! hwptr=%u, old=%u "
381 			"delta=%u amt=%u ready=%u free=%u\n",
382 			CHN_DIRSTR(c), hwptr, old, delta, amt,
383 			sndbuf_getready(b), sndbuf_getfree(b));
384 	}
385 
386 	return delta;
387 }
388 
389 static void
390 chn_wrfeed(struct pcm_channel *c)
391 {
392     	struct snd_dbuf *b = c->bufhard;
393     	struct snd_dbuf *bs = c->bufsoft;
394 	unsigned int amt, want, wasfree;
395 
396 	CHN_LOCKASSERT(c);
397 
398 	if ((c->flags & CHN_F_MMAP) && !(c->flags & CHN_F_CLOSING))
399 		sndbuf_acquire(bs, NULL, sndbuf_getfree(bs));
400 
401 	wasfree = sndbuf_getfree(b);
402 	want = min(sndbuf_getsize(b),
403 	    imax(0, sndbuf_xbytes(sndbuf_getsize(bs), bs, b) -
404 	     sndbuf_getready(b)));
405 	amt = min(wasfree, want);
406 	if (amt > 0)
407 		sndbuf_feed(bs, b, c, c->feeder, amt);
408 
409 	/*
410 	 * Possible xruns. There should be no empty space left in buffer.
411 	 */
412 	if (sndbuf_getready(b) < want)
413 		c->xruns++;
414 
415 	if (sndbuf_getfree(b) < wasfree)
416 		chn_wakeup(c);
417 }
418 
419 #if 0
420 static void
421 chn_wrupdate(struct pcm_channel *c)
422 {
423 
424 	CHN_LOCKASSERT(c);
425 	KASSERT(c->direction == PCMDIR_PLAY, ("%s(): bad channel", __func__));
426 
427 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
428 		return;
429 	chn_dmaupdate(c);
430 	chn_wrfeed(c);
431 	/* tell the driver we've updated the primary buffer */
432 	chn_trigger(c, PCMTRIG_EMLDMAWR);
433 }
434 #endif
435 
436 static void
437 chn_wrintr(struct pcm_channel *c)
438 {
439 
440 	CHN_LOCKASSERT(c);
441 	/* update pointers in primary buffer */
442 	chn_dmaupdate(c);
443 	/* ...and feed from secondary to primary */
444 	chn_wrfeed(c);
445 	/* tell the driver we've updated the primary buffer */
446 	chn_trigger(c, PCMTRIG_EMLDMAWR);
447 }
448 
449 /*
450  * user write routine - uiomove data into secondary buffer, trigger if necessary
451  * if blocking, sleep, rinse and repeat.
452  *
453  * called externally, so must handle locking
454  */
455 
456 int
457 chn_write(struct pcm_channel *c, struct uio *buf)
458 {
459 	struct snd_dbuf *bs = c->bufsoft;
460 	void *off;
461 	int ret, timeout, sz, t, p;
462 
463 	CHN_LOCKASSERT(c);
464 
465 	ret = 0;
466 	timeout = chn_timeout * hz;
467 
468 	while (ret == 0 && buf->uio_resid > 0) {
469 		sz = min(buf->uio_resid, sndbuf_getfree(bs));
470 		if (sz > 0) {
471 			/*
472 			 * The following assumes that the free space in
473 			 * the buffer can never be less around the
474 			 * unlock-uiomove-lock sequence.
475 			 */
476 			while (ret == 0 && sz > 0) {
477 				p = sndbuf_getfreeptr(bs);
478 				t = min(sz, sndbuf_getsize(bs) - p);
479 				off = sndbuf_getbufofs(bs, p);
480 				CHN_UNLOCK(c);
481 				ret = uiomove(off, t, buf);
482 				CHN_LOCK(c);
483 				sz -= t;
484 				sndbuf_acquire(bs, NULL, t);
485 			}
486 			ret = 0;
487 			if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
488 				ret = chn_start(c, 0);
489 				if (ret != 0)
490 					c->flags |= CHN_F_DEAD;
491 			}
492 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER)) {
493 			/**
494 			 * @todo Evaluate whether EAGAIN is truly desirable.
495 			 * 	 4Front drivers behave like this, but I'm
496 			 * 	 not sure if it at all violates the "write
497 			 * 	 should be allowed to block" model.
498 			 *
499 			 * 	 The idea is that, while set with CHN_F_NOTRIGGER,
500 			 * 	 a channel isn't playing, *but* without this we
501 			 * 	 end up with "interrupt timeout / channel dead".
502 			 */
503 			ret = EAGAIN;
504 		} else {
505    			ret = chn_sleep(c, timeout);
506 			if (ret == EAGAIN) {
507 				ret = EINVAL;
508 				c->flags |= CHN_F_DEAD;
509 				device_printf(c->dev, "%s(): %s: "
510 				    "play interrupt timeout, channel dead\n",
511 				    __func__, c->name);
512 			} else if (ret == ERESTART || ret == EINTR)
513 				c->flags |= CHN_F_ABORTING;
514 		}
515 	}
516 
517 	return (ret);
518 }
519 
520 /*
521  * Feed new data from the read buffer. Can be called in the bottom half.
522  */
523 static void
524 chn_rdfeed(struct pcm_channel *c)
525 {
526     	struct snd_dbuf *b = c->bufhard;
527     	struct snd_dbuf *bs = c->bufsoft;
528 	unsigned int amt;
529 
530 	CHN_LOCKASSERT(c);
531 
532 	if (c->flags & CHN_F_MMAP)
533 		sndbuf_dispose(bs, NULL, sndbuf_getready(bs));
534 
535 	amt = sndbuf_getfree(bs);
536 	if (amt > 0)
537 		sndbuf_feed(b, bs, c, c->feeder, amt);
538 
539 	amt = sndbuf_getready(b);
540 	if (amt > 0) {
541 		c->xruns++;
542 		sndbuf_dispose(b, NULL, amt);
543 	}
544 
545 	if (sndbuf_getready(bs) > 0)
546 		chn_wakeup(c);
547 }
548 
549 #if 0
550 static void
551 chn_rdupdate(struct pcm_channel *c)
552 {
553 
554 	CHN_LOCKASSERT(c);
555 	KASSERT(c->direction == PCMDIR_REC, ("chn_rdupdate on bad channel"));
556 
557 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
558 		return;
559 	chn_trigger(c, PCMTRIG_EMLDMARD);
560 	chn_dmaupdate(c);
561 	chn_rdfeed(c);
562 }
563 #endif
564 
565 /* read interrupt routine. Must be called with interrupts blocked. */
566 static void
567 chn_rdintr(struct pcm_channel *c)
568 {
569 
570 	CHN_LOCKASSERT(c);
571 	/* tell the driver to update the primary buffer if non-dma */
572 	chn_trigger(c, PCMTRIG_EMLDMARD);
573 	/* update pointers in primary buffer */
574 	chn_dmaupdate(c);
575 	/* ...and feed from primary to secondary */
576 	chn_rdfeed(c);
577 }
578 
579 /*
580  * user read routine - trigger if necessary, uiomove data from secondary buffer
581  * if blocking, sleep, rinse and repeat.
582  *
583  * called externally, so must handle locking
584  */
585 
586 int
587 chn_read(struct pcm_channel *c, struct uio *buf)
588 {
589 	struct snd_dbuf *bs = c->bufsoft;
590 	void *off;
591 	int ret, timeout, sz, t, p;
592 
593 	CHN_LOCKASSERT(c);
594 
595 	if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
596 		ret = chn_start(c, 0);
597 		if (ret != 0) {
598 			c->flags |= CHN_F_DEAD;
599 			return (ret);
600 		}
601 	}
602 
603 	ret = 0;
604 	timeout = chn_timeout * hz;
605 
606 	while (ret == 0 && buf->uio_resid > 0) {
607 		sz = min(buf->uio_resid, sndbuf_getready(bs));
608 		if (sz > 0) {
609 			/*
610 			 * The following assumes that the free space in
611 			 * the buffer can never be less around the
612 			 * unlock-uiomove-lock sequence.
613 			 */
614 			while (ret == 0 && sz > 0) {
615 				p = sndbuf_getreadyptr(bs);
616 				t = min(sz, sndbuf_getsize(bs) - p);
617 				off = sndbuf_getbufofs(bs, p);
618 				CHN_UNLOCK(c);
619 				ret = uiomove(off, t, buf);
620 				CHN_LOCK(c);
621 				sz -= t;
622 				sndbuf_dispose(bs, NULL, t);
623 			}
624 			ret = 0;
625 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER))
626 			ret = EAGAIN;
627 		else {
628    			ret = chn_sleep(c, timeout);
629 			if (ret == EAGAIN) {
630 				ret = EINVAL;
631 				c->flags |= CHN_F_DEAD;
632 				device_printf(c->dev, "%s(): %s: "
633 				    "record interrupt timeout, channel dead\n",
634 				    __func__, c->name);
635 			} else if (ret == ERESTART || ret == EINTR)
636 				c->flags |= CHN_F_ABORTING;
637 		}
638 	}
639 
640 	return (ret);
641 }
642 
643 void
644 chn_intr_locked(struct pcm_channel *c)
645 {
646 
647 	CHN_LOCKASSERT(c);
648 
649 	c->interrupts++;
650 
651 	if (c->direction == PCMDIR_PLAY)
652 		chn_wrintr(c);
653 	else
654 		chn_rdintr(c);
655 }
656 
657 void
658 chn_intr(struct pcm_channel *c)
659 {
660 
661 	if (CHN_LOCKOWNED(c)) {
662 		chn_intr_locked(c);
663 		return;
664 	}
665 
666 	CHN_LOCK(c);
667 	chn_intr_locked(c);
668 	CHN_UNLOCK(c);
669 }
670 
671 u_int32_t
672 chn_start(struct pcm_channel *c, int force)
673 {
674 	u_int32_t i, j;
675 	struct snd_dbuf *b = c->bufhard;
676 	struct snd_dbuf *bs = c->bufsoft;
677 	int err;
678 
679 	CHN_LOCKASSERT(c);
680 	/* if we're running, or if we're prevented from triggering, bail */
681 	if (CHN_STARTED(c) || ((c->flags & CHN_F_NOTRIGGER) && !force))
682 		return (EINVAL);
683 
684 	err = 0;
685 
686 	if (force) {
687 		i = 1;
688 		j = 0;
689 	} else {
690 		if (c->direction == PCMDIR_REC) {
691 			i = sndbuf_getfree(bs);
692 			j = (i > 0) ? 1 : sndbuf_getready(b);
693 		} else {
694 			if (sndbuf_getfree(bs) == 0) {
695 				i = 1;
696 				j = 0;
697 			} else {
698 				struct snd_dbuf *pb;
699 
700 				pb = CHN_BUF_PARENT(c, b);
701 				i = sndbuf_xbytes(sndbuf_getready(bs), bs, pb);
702 				j = sndbuf_getalign(pb);
703 			}
704 		}
705 		if (snd_verbose > 3 && CHN_EMPTY(c, children))
706 			device_printf(c->dev, "%s(): %s (%s) threshold "
707 			    "i=%d j=%d\n", __func__, CHN_DIRSTR(c),
708 			    (c->flags & CHN_F_VIRTUAL) ? "virtual" :
709 			    "hardware", i, j);
710 	}
711 
712 	if (i >= j) {
713 		c->flags |= CHN_F_TRIGGERED;
714 		sndbuf_setrun(b, 1);
715 		if (c->flags & CHN_F_CLOSING)
716 			c->feedcount = 2;
717 		else {
718 			c->feedcount = 0;
719 			c->interrupts = 0;
720 			c->xruns = 0;
721 		}
722 		if (c->parentchannel == NULL) {
723 			if (c->direction == PCMDIR_PLAY)
724 				sndbuf_fillsilence_rl(b,
725 				    sndbuf_xbytes(sndbuf_getsize(bs), bs, b));
726 			if (snd_verbose > 3)
727 				device_printf(c->dev,
728 				    "%s(): %s starting! (%s/%s) "
729 				    "(ready=%d force=%d i=%d j=%d "
730 				    "intrtimeout=%u latency=%dms)\n",
731 				    __func__,
732 				    (c->flags & CHN_F_HAS_VCHAN) ?
733 				    "VCHAN PARENT" : "HW", CHN_DIRSTR(c),
734 				    (c->flags & CHN_F_CLOSING) ? "closing" :
735 				    "running",
736 				    sndbuf_getready(b),
737 				    force, i, j, c->timeout,
738 				    (sndbuf_getsize(b) * 1000) /
739 				    (sndbuf_getalign(b) * sndbuf_getspd(b)));
740 		}
741 		err = chn_trigger(c, PCMTRIG_START);
742 	}
743 
744 	return (err);
745 }
746 
747 void
748 chn_resetbuf(struct pcm_channel *c)
749 {
750 	struct snd_dbuf *b = c->bufhard;
751 	struct snd_dbuf *bs = c->bufsoft;
752 
753 	c->blocks = 0;
754 	sndbuf_reset(b);
755 	sndbuf_reset(bs);
756 }
757 
758 /*
759  * chn_sync waits until the space in the given channel goes above
760  * a threshold. The threshold is checked against fl or rl respectively.
761  * Assume that the condition can become true, do not check here...
762  */
763 int
764 chn_sync(struct pcm_channel *c, int threshold)
765 {
766     	struct snd_dbuf *b, *bs;
767 	int ret, count, hcount, minflush, resid, residp, syncdelay, blksz;
768 	u_int32_t cflag;
769 
770 	CHN_LOCKASSERT(c);
771 
772 	if (c->direction != PCMDIR_PLAY)
773 		return (EINVAL);
774 
775 	bs = c->bufsoft;
776 
777 	if ((c->flags & (CHN_F_DEAD | CHN_F_ABORTING)) ||
778 	    (threshold < 1 && sndbuf_getready(bs) < 1))
779 		return (0);
780 
781 	/* if we haven't yet started and nothing is buffered, else start*/
782 	if (CHN_STOPPED(c)) {
783 		if (threshold > 0 || sndbuf_getready(bs) > 0) {
784 			ret = chn_start(c, 1);
785 			if (ret != 0)
786 				return (ret);
787 		} else
788 			return (0);
789 	}
790 
791 	b = CHN_BUF_PARENT(c, c->bufhard);
792 
793 	minflush = threshold + sndbuf_xbytes(sndbuf_getready(b), b, bs);
794 
795 	syncdelay = chn_syncdelay;
796 
797 	if (syncdelay < 0 && (threshold > 0 || sndbuf_getready(bs) > 0))
798 		minflush += sndbuf_xbytes(sndbuf_getsize(b), b, bs);
799 
800 	/*
801 	 * Append (0-1000) millisecond trailing buffer (if needed)
802 	 * for slower / high latency hardwares (notably USB audio)
803 	 * to avoid audible truncation.
804 	 */
805 	if (syncdelay > 0)
806 		minflush += (sndbuf_getalign(bs) * sndbuf_getspd(bs) *
807 		    ((syncdelay > 1000) ? 1000 : syncdelay)) / 1000;
808 
809 	minflush -= minflush % sndbuf_getalign(bs);
810 
811 	if (minflush > 0) {
812 		threshold = min(minflush, sndbuf_getfree(bs));
813 		sndbuf_clear(bs, threshold);
814 		sndbuf_acquire(bs, NULL, threshold);
815 		minflush -= threshold;
816 	}
817 
818 	resid = sndbuf_getready(bs);
819 	residp = resid;
820 	blksz = sndbuf_getblksz(b);
821 	if (blksz < 1) {
822 		device_printf(c->dev,
823 		    "%s(): WARNING: blksz < 1 ! maxsize=%d [%d/%d/%d]\n",
824 		    __func__, sndbuf_getmaxsize(b), sndbuf_getsize(b),
825 		    sndbuf_getblksz(b), sndbuf_getblkcnt(b));
826 		if (sndbuf_getblkcnt(b) > 0)
827 			blksz = sndbuf_getsize(b) / sndbuf_getblkcnt(b);
828 		if (blksz < 1)
829 			blksz = 1;
830 	}
831 	count = sndbuf_xbytes(minflush + resid, bs, b) / blksz;
832 	hcount = count;
833 	ret = 0;
834 
835 	if (snd_verbose > 3)
836 		device_printf(c->dev, "%s(): [begin] timeout=%d count=%d "
837 		    "minflush=%d resid=%d\n", __func__, c->timeout, count,
838 		    minflush, resid);
839 
840 	cflag = c->flags & CHN_F_CLOSING;
841 	c->flags |= CHN_F_CLOSING;
842 	while (count > 0 && (resid > 0 || minflush > 0)) {
843 		ret = chn_sleep(c, c->timeout);
844     		if (ret == ERESTART || ret == EINTR) {
845 			c->flags |= CHN_F_ABORTING;
846 			break;
847 		} else if (ret == 0 || ret == EAGAIN) {
848 			resid = sndbuf_getready(bs);
849 			if (resid == residp) {
850 				--count;
851 				if (snd_verbose > 3)
852 					device_printf(c->dev,
853 					    "%s(): [stalled] timeout=%d "
854 					    "count=%d hcount=%d "
855 					    "resid=%d minflush=%d\n",
856 					    __func__, c->timeout, count,
857 					    hcount, resid, minflush);
858 			} else if (resid < residp && count < hcount) {
859 				++count;
860 				if (snd_verbose > 3)
861 					device_printf(c->dev,
862 					    "%s((): [resume] timeout=%d "
863 					    "count=%d hcount=%d "
864 					    "resid=%d minflush=%d\n",
865 					    __func__, c->timeout, count,
866 					    hcount, resid, minflush);
867 			}
868 			if (minflush > 0 && sndbuf_getfree(bs) > 0) {
869 				threshold = min(minflush,
870 				    sndbuf_getfree(bs));
871 				sndbuf_clear(bs, threshold);
872 				sndbuf_acquire(bs, NULL, threshold);
873 				resid = sndbuf_getready(bs);
874 				minflush -= threshold;
875 			}
876 			residp = resid;
877 		} else
878 			break;
879 	}
880 	c->flags &= ~CHN_F_CLOSING;
881 	c->flags |= cflag;
882 
883 	if (snd_verbose > 3)
884 		device_printf(c->dev,
885 		    "%s(): timeout=%d count=%d hcount=%d resid=%d residp=%d "
886 		    "minflush=%d ret=%d\n",
887 		    __func__, c->timeout, count, hcount, resid, residp,
888 		    minflush, ret);
889 
890     	return (0);
891 }
892 
893 /* called externally, handle locking */
894 int
895 chn_poll(struct pcm_channel *c, int ev, struct thread *td)
896 {
897 	struct snd_dbuf *bs = c->bufsoft;
898 	int ret;
899 
900 	CHN_LOCKASSERT(c);
901 
902     	if (!(c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED))) {
903 		ret = chn_start(c, 1);
904 		if (ret != 0)
905 			return (0);
906 	}
907 
908 	ret = 0;
909 	if (chn_polltrigger(c)) {
910 		chn_pollreset(c);
911 		ret = ev;
912 	} else
913 		selrecord(td, sndbuf_getsel(bs));
914 
915 	return (ret);
916 }
917 
918 /*
919  * chn_abort terminates a running dma transfer.  it may sleep up to 200ms.
920  * it returns the number of bytes that have not been transferred.
921  *
922  * called from: dsp_close, dsp_ioctl, with channel locked
923  */
924 int
925 chn_abort(struct pcm_channel *c)
926 {
927     	int missing = 0;
928     	struct snd_dbuf *b = c->bufhard;
929     	struct snd_dbuf *bs = c->bufsoft;
930 
931 	CHN_LOCKASSERT(c);
932 	if (CHN_STOPPED(c))
933 		return 0;
934 	c->flags |= CHN_F_ABORTING;
935 
936 	c->flags &= ~CHN_F_TRIGGERED;
937 	/* kill the channel */
938 	chn_trigger(c, PCMTRIG_ABORT);
939 	sndbuf_setrun(b, 0);
940 	if (!(c->flags & CHN_F_VIRTUAL))
941 		chn_dmaupdate(c);
942     	missing = sndbuf_getready(bs);
943 
944 	c->flags &= ~CHN_F_ABORTING;
945 	return missing;
946 }
947 
948 /*
949  * this routine tries to flush the dma transfer. It is called
950  * on a close of a playback channel.
951  * first, if there is data in the buffer, but the dma has not yet
952  * begun, we need to start it.
953  * next, we wait for the play buffer to drain
954  * finally, we stop the dma.
955  *
956  * called from: dsp_close, not valid for record channels.
957  */
958 
959 int
960 chn_flush(struct pcm_channel *c)
961 {
962     	struct snd_dbuf *b = c->bufhard;
963 
964 	CHN_LOCKASSERT(c);
965 	KASSERT(c->direction == PCMDIR_PLAY, ("chn_flush on bad channel"));
966     	DEB(printf("chn_flush: c->flags 0x%08x\n", c->flags));
967 
968 	c->flags |= CHN_F_CLOSING;
969 	chn_sync(c, 0);
970 	c->flags &= ~CHN_F_TRIGGERED;
971 	/* kill the channel */
972 	chn_trigger(c, PCMTRIG_ABORT);
973 	sndbuf_setrun(b, 0);
974 
975     	c->flags &= ~CHN_F_CLOSING;
976     	return 0;
977 }
978 
979 int
980 snd_fmtvalid(uint32_t fmt, uint32_t *fmtlist)
981 {
982 	int i;
983 
984 	for (i = 0; fmtlist[i] != 0; i++) {
985 		if (fmt == fmtlist[i] ||
986 		    ((fmt & AFMT_PASSTHROUGH) &&
987 		    (AFMT_ENCODING(fmt) & fmtlist[i])))
988 			return (1);
989 	}
990 
991 	return (0);
992 }
993 
994 static const struct {
995 	char *name, *alias1, *alias2;
996 	uint32_t afmt;
997 } afmt_tab[] = {
998 	{  "alaw",  NULL, NULL, AFMT_A_LAW  },
999 	{ "mulaw",  NULL, NULL, AFMT_MU_LAW },
1000 	{    "u8",   "8", NULL, AFMT_U8     },
1001 	{    "s8",  NULL, NULL, AFMT_S8     },
1002 #if BYTE_ORDER == LITTLE_ENDIAN
1003 	{ "s16le", "s16", "16", AFMT_S16_LE },
1004 	{ "s16be",  NULL, NULL, AFMT_S16_BE },
1005 #else
1006 	{ "s16le",  NULL, NULL, AFMT_S16_LE },
1007 	{ "s16be", "s16", "16", AFMT_S16_BE },
1008 #endif
1009 	{ "u16le",  NULL, NULL, AFMT_U16_LE },
1010 	{ "u16be",  NULL, NULL, AFMT_U16_BE },
1011 	{ "s24le",  NULL, NULL, AFMT_S24_LE },
1012 	{ "s24be",  NULL, NULL, AFMT_S24_BE },
1013 	{ "u24le",  NULL, NULL, AFMT_U24_LE },
1014 	{ "u24be",  NULL, NULL, AFMT_U24_BE },
1015 #if BYTE_ORDER == LITTLE_ENDIAN
1016 	{ "s32le", "s32", "32", AFMT_S32_LE },
1017 	{ "s32be",  NULL, NULL, AFMT_S32_BE },
1018 #else
1019 	{ "s32le",  NULL, NULL, AFMT_S32_LE },
1020 	{ "s32be", "s32", "32", AFMT_S32_BE },
1021 #endif
1022 	{ "u32le",  NULL, NULL, AFMT_U32_LE },
1023 	{ "u32be",  NULL, NULL, AFMT_U32_BE },
1024 	{   "ac3",  NULL, NULL, AFMT_AC3    },
1025 	{    NULL,  NULL, NULL, 0           }
1026 };
1027 
1028 uint32_t
1029 snd_str2afmt(const char *req)
1030 {
1031 	int ext;
1032 	int ch;
1033 	int i;
1034 	char b1[8];
1035 	char b2[8];
1036 
1037 	memset(b1, 0, sizeof(b1));
1038 	memset(b2, 0, sizeof(b2));
1039 
1040 	i = sscanf(req, "%5[^:]:%6s", b1, b2);
1041 
1042 	if (i == 1) {
1043 		if (strlen(req) != strlen(b1))
1044 			return (0);
1045 		strlcpy(b2, "2.0", sizeof(b2));
1046 	} else if (i == 2) {
1047 		if (strlen(req) != (strlen(b1) + 1 + strlen(b2)))
1048 			return (0);
1049 	} else
1050 		return (0);
1051 
1052 	i = sscanf(b2, "%d.%d", &ch, &ext);
1053 
1054 	if (i == 0) {
1055 		if (strcasecmp(b2, "mono") == 0) {
1056 			ch = 1;
1057 			ext = 0;
1058 		} else if (strcasecmp(b2, "stereo") == 0) {
1059 			ch = 2;
1060 			ext = 0;
1061 		} else if (strcasecmp(b2, "quad") == 0) {
1062 			ch = 4;
1063 			ext = 0;
1064 		} else
1065 			return (0);
1066 	} else if (i == 1) {
1067 		if (ch < 1 || ch > AFMT_CHANNEL_MAX)
1068 			return (0);
1069 		ext = 0;
1070 	} else if (i == 2) {
1071 		if (ext < 0 || ext > AFMT_EXTCHANNEL_MAX)
1072 			return (0);
1073 		if (ch < 1 || (ch + ext) > AFMT_CHANNEL_MAX)
1074 			return (0);
1075 	} else
1076 		return (0);
1077 
1078 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1079 		if (strcasecmp(afmt_tab[i].name, b1) != 0) {
1080 			if (afmt_tab[i].alias1 == NULL)
1081 				continue;
1082 			if (strcasecmp(afmt_tab[i].alias1, b1) != 0) {
1083 				if (afmt_tab[i].alias2 == NULL)
1084 					continue;
1085 				if (strcasecmp(afmt_tab[i].alias2, b1) != 0)
1086 					continue;
1087 			}
1088 		}
1089 		/* found a match */
1090 		return (SND_FORMAT(afmt_tab[i].afmt, ch + ext, ext));
1091 	}
1092 	/* not a valid format */
1093 	return (0);
1094 }
1095 
1096 uint32_t
1097 snd_afmt2str(uint32_t afmt, char *buf, size_t len)
1098 {
1099 	uint32_t enc;
1100 	uint32_t ext;
1101 	uint32_t ch;
1102 	int i;
1103 
1104 	if (buf == NULL || len < AFMTSTR_LEN)
1105 		return (0);
1106 
1107 	memset(buf, 0, len);
1108 
1109 	enc = AFMT_ENCODING(afmt);
1110 	ch = AFMT_CHANNEL(afmt);
1111 	ext = AFMT_EXTCHANNEL(afmt);
1112 	/* check there is at least one channel */
1113 	if (ch <= ext)
1114 		return (0);
1115 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1116 		if (enc != afmt_tab[i].afmt)
1117 			continue;
1118 		/* found a match */
1119 		snprintf(buf, len, "%s:%d.%d",
1120 		    afmt_tab[i].name, ch - ext, ext);
1121 		return (SND_FORMAT(enc, ch, ext));
1122 	}
1123 	return (0);
1124 }
1125 
1126 int
1127 chn_reset(struct pcm_channel *c, uint32_t fmt, uint32_t spd)
1128 {
1129 	int r;
1130 
1131 	CHN_LOCKASSERT(c);
1132 	c->feedcount = 0;
1133 	c->flags &= CHN_F_RESET;
1134 	c->interrupts = 0;
1135 	c->timeout = 1;
1136 	c->xruns = 0;
1137 
1138 	c->flags |= (pcm_getflags(c->dev) & SD_F_BITPERFECT) ?
1139 	    CHN_F_BITPERFECT : 0;
1140 
1141 	r = CHANNEL_RESET(c->methods, c->devinfo);
1142 	if (r == 0 && fmt != 0 && spd != 0) {
1143 		r = chn_setparam(c, fmt, spd);
1144 		fmt = 0;
1145 		spd = 0;
1146 	}
1147 	if (r == 0 && fmt != 0)
1148 		r = chn_setformat(c, fmt);
1149 	if (r == 0 && spd != 0)
1150 		r = chn_setspeed(c, spd);
1151 	if (r == 0)
1152 		r = chn_setlatency(c, chn_latency);
1153 	if (r == 0) {
1154 		chn_resetbuf(c);
1155 		r = CHANNEL_RESETDONE(c->methods, c->devinfo);
1156 	}
1157 	return r;
1158 }
1159 
1160 static struct unrhdr *
1161 chn_getunr(struct snddev_info *d, int type)
1162 {
1163 	switch (type) {
1164 	case SND_DEV_DSPHW_PLAY:
1165 		return (d->p_unr);
1166 	case SND_DEV_DSPHW_VPLAY:
1167 		return (d->vp_unr);
1168 	case SND_DEV_DSPHW_REC:
1169 		return (d->r_unr);
1170 	case SND_DEV_DSPHW_VREC:
1171 		return (d->vr_unr);
1172 	default:
1173 		__assert_unreachable();
1174 	}
1175 
1176 }
1177 
1178 struct pcm_channel *
1179 chn_init(struct snddev_info *d, struct pcm_channel *parent, kobj_class_t cls,
1180     int dir, void *devinfo)
1181 {
1182 	struct pcm_channel *c;
1183 	struct feeder_class *fc;
1184 	struct snd_dbuf *b, *bs;
1185 	char buf[CHN_NAMELEN];
1186 	int i, direction, type;
1187 
1188 	PCM_BUSYASSERT(d);
1189 	PCM_LOCKASSERT(d);
1190 
1191 	switch (dir) {
1192 	case PCMDIR_PLAY:
1193 		direction = PCMDIR_PLAY;
1194 		type = SND_DEV_DSPHW_PLAY;
1195 		break;
1196 	case PCMDIR_PLAY_VIRTUAL:
1197 		direction = PCMDIR_PLAY;
1198 		type = SND_DEV_DSPHW_VPLAY;
1199 		break;
1200 	case PCMDIR_REC:
1201 		direction = PCMDIR_REC;
1202 		type = SND_DEV_DSPHW_REC;
1203 		break;
1204 	case PCMDIR_REC_VIRTUAL:
1205 		direction = PCMDIR_REC;
1206 		type = SND_DEV_DSPHW_VREC;
1207 		break;
1208 	default:
1209 		device_printf(d->dev,
1210 		    "%s(): invalid channel direction: %d\n",
1211 		    __func__, dir);
1212 		return (NULL);
1213 	}
1214 
1215 	PCM_UNLOCK(d);
1216 	b = NULL;
1217 	bs = NULL;
1218 
1219 	c = malloc(sizeof(*c), M_DEVBUF, M_WAITOK | M_ZERO);
1220 	c->methods = kobj_create(cls, M_DEVBUF, M_WAITOK | M_ZERO);
1221 	chn_lockinit(c, dir);
1222 	CHN_INIT(c, children);
1223 	CHN_INIT(c, children.busy);
1224 	c->direction = direction;
1225 	c->type = type;
1226 	c->unit = alloc_unr(chn_getunr(d, c->type));
1227 	c->format = SND_FORMAT(AFMT_U8, 1, 0);
1228 	c->speed = DSP_DEFAULT_SPEED;
1229 	c->pid = -1;
1230 	c->latency = -1;
1231 	c->timeout = 1;
1232 	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
1233 	c->parentsnddev = d;
1234 	c->parentchannel = parent;
1235 	c->dev = d->dev;
1236 	c->trigger = PCMTRIG_STOP;
1237 
1238 	strlcpy(c->name, dsp_unit2name(buf, sizeof(buf), c), sizeof(c->name));
1239 
1240 	c->matrix = *feeder_matrix_id_map(SND_CHN_MATRIX_1_0);
1241 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1242 
1243 	for (i = 0; i < SND_CHN_T_MAX; i++)
1244 		c->volume[SND_VOL_C_MASTER][i] = SND_VOL_0DB_MASTER;
1245 
1246 	c->volume[SND_VOL_C_MASTER][SND_CHN_T_VOL_0DB] = SND_VOL_0DB_MASTER;
1247 	c->volume[SND_VOL_C_PCM][SND_CHN_T_VOL_0DB] = chn_vol_0db_pcm;
1248 
1249 	CHN_LOCK(c);
1250 	chn_vpc_reset(c, SND_VOL_C_PCM, 1);
1251 	CHN_UNLOCK(c);
1252 
1253 	fc = feeder_getclass(NULL);
1254 	if (fc == NULL) {
1255 		device_printf(d->dev, "%s(): failed to get feeder class\n",
1256 		    __func__);
1257 		goto fail;
1258 	}
1259 	if (feeder_add(c, fc, NULL)) {
1260 		device_printf(d->dev, "%s(): failed to add feeder\n", __func__);
1261 		goto fail;
1262 	}
1263 
1264 	b = sndbuf_create(c->dev, c->name, "primary", c);
1265 	bs = sndbuf_create(c->dev, c->name, "secondary", c);
1266 	if (b == NULL || bs == NULL) {
1267 		device_printf(d->dev, "%s(): failed to create %s buffer\n",
1268 		    __func__, b == NULL ? "hardware" : "software");
1269 		goto fail;
1270 	}
1271 	c->bufhard = b;
1272 	c->bufsoft = bs;
1273 
1274 	c->devinfo = CHANNEL_INIT(c->methods, devinfo, b, c, direction);
1275 	if (c->devinfo == NULL) {
1276 		device_printf(d->dev, "%s(): CHANNEL_INIT() failed\n", __func__);
1277 		goto fail;
1278 	}
1279 
1280 	if ((sndbuf_getsize(b) == 0) && ((c->flags & CHN_F_VIRTUAL) == 0)) {
1281 		device_printf(d->dev, "%s(): hardware buffer's size is 0\n",
1282 		    __func__);
1283 		goto fail;
1284 	}
1285 
1286 	sndbuf_setfmt(b, c->format);
1287 	sndbuf_setspd(b, c->speed);
1288 	sndbuf_setfmt(bs, c->format);
1289 	sndbuf_setspd(bs, c->speed);
1290 	sndbuf_setup(bs, NULL, 0);
1291 
1292 	/**
1293 	 * @todo Should this be moved somewhere else?  The primary buffer
1294 	 * 	 is allocated by the driver or via DMA map setup, and tmpbuf
1295 	 * 	 seems to only come into existence in sndbuf_resize().
1296 	 */
1297 	if (c->direction == PCMDIR_PLAY) {
1298 		bs->sl = sndbuf_getmaxsize(bs);
1299 		bs->shadbuf = malloc(bs->sl, M_DEVBUF, M_WAITOK);
1300 	}
1301 
1302 	PCM_LOCK(d);
1303 	CHN_INSERT_SORT_ASCEND(d, c, channels.pcm);
1304 
1305 	switch (c->type) {
1306 	case SND_DEV_DSPHW_PLAY:
1307 		d->playcount++;
1308 		break;
1309 	case SND_DEV_DSPHW_VPLAY:
1310 		d->pvchancount++;
1311 		break;
1312 	case SND_DEV_DSPHW_REC:
1313 		d->reccount++;
1314 		break;
1315 	case SND_DEV_DSPHW_VREC:
1316 		d->rvchancount++;
1317 		break;
1318 	default:
1319 		__assert_unreachable();
1320 	}
1321 
1322 	return (c);
1323 
1324 fail:
1325 	free_unr(chn_getunr(d, c->type), c->unit);
1326 	feeder_remove(c);
1327 	if (c->devinfo && CHANNEL_FREE(c->methods, c->devinfo))
1328 		sndbuf_free(b);
1329 	if (bs)
1330 		sndbuf_destroy(bs);
1331 	if (b)
1332 		sndbuf_destroy(b);
1333 	CHN_LOCK(c);
1334 	chn_lockdestroy(c);
1335 
1336 	kobj_delete(c->methods, M_DEVBUF);
1337 	free(c, M_DEVBUF);
1338 
1339 	PCM_LOCK(d);
1340 
1341 	return (NULL);
1342 }
1343 
1344 void
1345 chn_kill(struct pcm_channel *c)
1346 {
1347 	struct snddev_info *d = c->parentsnddev;
1348 	struct snd_dbuf *b = c->bufhard;
1349 	struct snd_dbuf *bs = c->bufsoft;
1350 
1351 	PCM_BUSYASSERT(c->parentsnddev);
1352 
1353 	PCM_LOCK(d);
1354 	CHN_REMOVE(d, c, channels.pcm);
1355 
1356 	switch (c->type) {
1357 	case SND_DEV_DSPHW_PLAY:
1358 		d->playcount--;
1359 		break;
1360 	case SND_DEV_DSPHW_VPLAY:
1361 		d->pvchancount--;
1362 		break;
1363 	case SND_DEV_DSPHW_REC:
1364 		d->reccount--;
1365 		break;
1366 	case SND_DEV_DSPHW_VREC:
1367 		d->rvchancount--;
1368 		break;
1369 	default:
1370 		__assert_unreachable();
1371 	}
1372 	PCM_UNLOCK(d);
1373 
1374 	if (CHN_STARTED(c)) {
1375 		CHN_LOCK(c);
1376 		chn_trigger(c, PCMTRIG_ABORT);
1377 		CHN_UNLOCK(c);
1378 	}
1379 	free_unr(chn_getunr(c->parentsnddev, c->type), c->unit);
1380 	feeder_remove(c);
1381 	if (CHANNEL_FREE(c->methods, c->devinfo))
1382 		sndbuf_free(b);
1383 	sndbuf_destroy(bs);
1384 	sndbuf_destroy(b);
1385 	CHN_LOCK(c);
1386 	c->flags |= CHN_F_DEAD;
1387 	chn_lockdestroy(c);
1388 	kobj_delete(c->methods, M_DEVBUF);
1389 	free(c, M_DEVBUF);
1390 }
1391 
1392 void
1393 chn_shutdown(struct pcm_channel *c)
1394 {
1395 	CHN_LOCKASSERT(c);
1396 
1397 	chn_wakeup(c);
1398 	c->flags |= CHN_F_DEAD;
1399 }
1400 
1401 /* release a locked channel and unlock it */
1402 int
1403 chn_release(struct pcm_channel *c)
1404 {
1405 	PCM_BUSYASSERT(c->parentsnddev);
1406 	CHN_LOCKASSERT(c);
1407 
1408 	c->flags &= ~CHN_F_BUSY;
1409 	c->pid = -1;
1410 	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
1411 	CHN_UNLOCK(c);
1412 
1413 	return (0);
1414 }
1415 
1416 int
1417 chn_ref(struct pcm_channel *c, int ref)
1418 {
1419 	PCM_BUSYASSERT(c->parentsnddev);
1420 	CHN_LOCKASSERT(c);
1421 	KASSERT((c->refcount + ref) >= 0,
1422 	    ("%s(): new refcount will be negative", __func__));
1423 
1424 	c->refcount += ref;
1425 
1426 	return (c->refcount);
1427 }
1428 
1429 int
1430 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
1431     int center)
1432 {
1433 	int i, ret;
1434 
1435 	ret = 0;
1436 
1437 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1438 		if ((1 << i) & SND_CHN_LEFT_MASK)
1439 			ret |= chn_setvolume_matrix(c, vc, i, left);
1440 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1441 			ret |= chn_setvolume_matrix(c, vc, i, right) << 8;
1442 		else
1443 			ret |= chn_setvolume_matrix(c, vc, i, center) << 16;
1444 	}
1445 
1446 	return (ret);
1447 }
1448 
1449 int
1450 chn_setvolume_matrix(struct pcm_channel *c, int vc, int vt, int val)
1451 {
1452 	int i;
1453 
1454 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1455 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1456 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN &&
1457 	    vt <= SND_CHN_T_END)) && (vt != SND_CHN_T_VOL_0DB ||
1458 	    (val >= SND_VOL_0DB_MIN && val <= SND_VOL_0DB_MAX)),
1459 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d val=%d",
1460 	    __func__, c, vc, vt, val));
1461 	CHN_LOCKASSERT(c);
1462 
1463 	if (val < 0)
1464 		val = 0;
1465 	if (val > 100)
1466 		val = 100;
1467 
1468 	c->volume[vc][vt] = val;
1469 
1470 	/*
1471 	 * Do relative calculation here and store it into class + 1
1472 	 * to ease the job of feeder_volume.
1473 	 */
1474 	if (vc == SND_VOL_C_MASTER) {
1475 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1476 		    vc += SND_VOL_C_STEP)
1477 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1478 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1479 	} else if (vc & 1) {
1480 		if (vt == SND_CHN_T_VOL_0DB)
1481 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1482 			    i += SND_CHN_T_STEP) {
1483 				c->volume[SND_VOL_C_VAL(vc)][i] =
1484 				    SND_VOL_CALC_VAL(c->volume, vc, i);
1485 			}
1486 		else
1487 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1488 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1489 	}
1490 
1491 	return (val);
1492 }
1493 
1494 int
1495 chn_getvolume_matrix(struct pcm_channel *c, int vc, int vt)
1496 {
1497 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1498 	    (vt == SND_CHN_T_VOL_0DB ||
1499 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1500 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d",
1501 	    __func__, c, vc, vt));
1502 	CHN_LOCKASSERT(c);
1503 
1504 	return (c->volume[vc][vt]);
1505 }
1506 
1507 int
1508 chn_setmute_multi(struct pcm_channel *c, int vc, int mute)
1509 {
1510 	int i, ret;
1511 
1512 	ret = 0;
1513 
1514 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1515 		if ((1 << i) & SND_CHN_LEFT_MASK)
1516 			ret |= chn_setmute_matrix(c, vc, i, mute);
1517 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1518 			ret |= chn_setmute_matrix(c, vc, i, mute) << 8;
1519 		else
1520 			ret |= chn_setmute_matrix(c, vc, i, mute) << 16;
1521 	}
1522 	return (ret);
1523 }
1524 
1525 int
1526 chn_setmute_matrix(struct pcm_channel *c, int vc, int vt, int mute)
1527 {
1528 	int i;
1529 
1530 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1531 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1532 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1533 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d mute=%d",
1534 	    __func__, c, vc, vt, mute));
1535 
1536 	CHN_LOCKASSERT(c);
1537 
1538 	mute = (mute != 0);
1539 
1540 	c->muted[vc][vt] = mute;
1541 
1542 	/*
1543 	 * Do relative calculation here and store it into class + 1
1544 	 * to ease the job of feeder_volume.
1545 	 */
1546 	if (vc == SND_VOL_C_MASTER) {
1547 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1548 		    vc += SND_VOL_C_STEP)
1549 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1550 	} else if (vc & 1) {
1551 		if (vt == SND_CHN_T_VOL_0DB) {
1552 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1553 			    i += SND_CHN_T_STEP) {
1554 				c->muted[SND_VOL_C_VAL(vc)][i] = mute;
1555 			}
1556 		} else {
1557 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1558 		}
1559 	}
1560 	return (mute);
1561 }
1562 
1563 int
1564 chn_getmute_matrix(struct pcm_channel *c, int vc, int vt)
1565 {
1566 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1567 	    (vt == SND_CHN_T_VOL_0DB ||
1568 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1569 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d",
1570 	    __func__, c, vc, vt));
1571 	CHN_LOCKASSERT(c);
1572 
1573 	return (c->muted[vc][vt]);
1574 }
1575 
1576 struct pcmchan_matrix *
1577 chn_getmatrix(struct pcm_channel *c)
1578 {
1579 
1580 	KASSERT(c != NULL, ("%s(): NULL channel", __func__));
1581 	CHN_LOCKASSERT(c);
1582 
1583 	if (!(c->format & AFMT_CONVERTIBLE))
1584 		return (NULL);
1585 
1586 	return (&c->matrix);
1587 }
1588 
1589 int
1590 chn_setmatrix(struct pcm_channel *c, struct pcmchan_matrix *m)
1591 {
1592 
1593 	KASSERT(c != NULL && m != NULL,
1594 	    ("%s(): NULL channel or matrix", __func__));
1595 	CHN_LOCKASSERT(c);
1596 
1597 	if (!(c->format & AFMT_CONVERTIBLE))
1598 		return (EINVAL);
1599 
1600 	c->matrix = *m;
1601 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1602 
1603 	return (chn_setformat(c, SND_FORMAT(c->format, m->channels, m->ext)));
1604 }
1605 
1606 /*
1607  * XXX chn_oss_* exists for the sake of compatibility.
1608  */
1609 int
1610 chn_oss_getorder(struct pcm_channel *c, unsigned long long *map)
1611 {
1612 
1613 	KASSERT(c != NULL && map != NULL,
1614 	    ("%s(): NULL channel or map", __func__));
1615 	CHN_LOCKASSERT(c);
1616 
1617 	if (!(c->format & AFMT_CONVERTIBLE))
1618 		return (EINVAL);
1619 
1620 	return (feeder_matrix_oss_get_channel_order(&c->matrix, map));
1621 }
1622 
1623 int
1624 chn_oss_setorder(struct pcm_channel *c, unsigned long long *map)
1625 {
1626 	struct pcmchan_matrix m;
1627 	int ret;
1628 
1629 	KASSERT(c != NULL && map != NULL,
1630 	    ("%s(): NULL channel or map", __func__));
1631 	CHN_LOCKASSERT(c);
1632 
1633 	if (!(c->format & AFMT_CONVERTIBLE))
1634 		return (EINVAL);
1635 
1636 	m = c->matrix;
1637 	ret = feeder_matrix_oss_set_channel_order(&m, map);
1638 	if (ret != 0)
1639 		return (ret);
1640 
1641 	return (chn_setmatrix(c, &m));
1642 }
1643 
1644 #define SND_CHN_OSS_FRONT	(SND_CHN_T_MASK_FL | SND_CHN_T_MASK_FR)
1645 #define SND_CHN_OSS_SURR	(SND_CHN_T_MASK_SL | SND_CHN_T_MASK_SR)
1646 #define SND_CHN_OSS_CENTER_LFE	(SND_CHN_T_MASK_FC | SND_CHN_T_MASK_LF)
1647 #define SND_CHN_OSS_REAR	(SND_CHN_T_MASK_BL | SND_CHN_T_MASK_BR)
1648 
1649 int
1650 chn_oss_getmask(struct pcm_channel *c, uint32_t *retmask)
1651 {
1652 	struct pcmchan_matrix *m;
1653 	struct pcmchan_caps *caps;
1654 	uint32_t i, format;
1655 
1656 	KASSERT(c != NULL && retmask != NULL,
1657 	    ("%s(): NULL channel or retmask", __func__));
1658 	CHN_LOCKASSERT(c);
1659 
1660 	caps = chn_getcaps(c);
1661 	if (caps == NULL || caps->fmtlist == NULL)
1662 		return (ENODEV);
1663 
1664 	for (i = 0; caps->fmtlist[i] != 0; i++) {
1665 		format = caps->fmtlist[i];
1666 		if (!(format & AFMT_CONVERTIBLE)) {
1667 			*retmask |= DSP_BIND_SPDIF;
1668 			continue;
1669 		}
1670 		m = CHANNEL_GETMATRIX(c->methods, c->devinfo, format);
1671 		if (m == NULL)
1672 			continue;
1673 		if (m->mask & SND_CHN_OSS_FRONT)
1674 			*retmask |= DSP_BIND_FRONT;
1675 		if (m->mask & SND_CHN_OSS_SURR)
1676 			*retmask |= DSP_BIND_SURR;
1677 		if (m->mask & SND_CHN_OSS_CENTER_LFE)
1678 			*retmask |= DSP_BIND_CENTER_LFE;
1679 		if (m->mask & SND_CHN_OSS_REAR)
1680 			*retmask |= DSP_BIND_REAR;
1681 	}
1682 
1683 	/* report software-supported binding mask */
1684 	if (!CHN_BITPERFECT(c) && report_soft_matrix)
1685 		*retmask |= DSP_BIND_FRONT | DSP_BIND_SURR |
1686 		    DSP_BIND_CENTER_LFE | DSP_BIND_REAR;
1687 
1688 	return (0);
1689 }
1690 
1691 void
1692 chn_vpc_reset(struct pcm_channel *c, int vc, int force)
1693 {
1694 	int i;
1695 
1696 	KASSERT(c != NULL && vc >= SND_VOL_C_BEGIN && vc <= SND_VOL_C_END,
1697 	    ("%s(): invalid reset c=%p vc=%d", __func__, c, vc));
1698 	CHN_LOCKASSERT(c);
1699 
1700 	if (force == 0 && chn_vpc_autoreset == 0)
1701 		return;
1702 
1703 	for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END; i += SND_CHN_T_STEP)
1704 		CHN_SETVOLUME(c, vc, i, c->volume[vc][SND_CHN_T_VOL_0DB]);
1705 }
1706 
1707 static u_int32_t
1708 round_pow2(u_int32_t v)
1709 {
1710 	u_int32_t ret;
1711 
1712 	if (v < 2)
1713 		v = 2;
1714 	ret = 0;
1715 	while (v >> ret)
1716 		ret++;
1717 	ret = 1 << (ret - 1);
1718 	while (ret < v)
1719 		ret <<= 1;
1720 	return ret;
1721 }
1722 
1723 static u_int32_t
1724 round_blksz(u_int32_t v, int round)
1725 {
1726 	u_int32_t ret, tmp;
1727 
1728 	if (round < 1)
1729 		round = 1;
1730 
1731 	ret = min(round_pow2(v), CHN_2NDBUFMAXSIZE >> 1);
1732 
1733 	if (ret > v && (ret >> 1) > 0 && (ret >> 1) >= ((v * 3) >> 2))
1734 		ret >>= 1;
1735 
1736 	tmp = ret - (ret % round);
1737 	while (tmp < 16 || tmp < round) {
1738 		ret <<= 1;
1739 		tmp = ret - (ret % round);
1740 	}
1741 
1742 	return ret;
1743 }
1744 
1745 /*
1746  * 4Front call it DSP Policy, while we call it "Latency Profile". The idea
1747  * is to keep 2nd buffer short so that it doesn't cause long queue during
1748  * buffer transfer.
1749  *
1750  *    Latency reference table for 48khz stereo 16bit: (PLAY)
1751  *
1752  *      +---------+------------+-----------+------------+
1753  *      | Latency | Blockcount | Blocksize | Buffersize |
1754  *      +---------+------------+-----------+------------+
1755  *      |     0   |       2    |   64      |    128     |
1756  *      +---------+------------+-----------+------------+
1757  *      |     1   |       4    |   128     |    512     |
1758  *      +---------+------------+-----------+------------+
1759  *      |     2   |       8    |   512     |    4096    |
1760  *      +---------+------------+-----------+------------+
1761  *      |     3   |      16    |   512     |    8192    |
1762  *      +---------+------------+-----------+------------+
1763  *      |     4   |      32    |   512     |    16384   |
1764  *      +---------+------------+-----------+------------+
1765  *      |     5   |      32    |   1024    |    32768   |
1766  *      +---------+------------+-----------+------------+
1767  *      |     6   |      16    |   2048    |    32768   |
1768  *      +---------+------------+-----------+------------+
1769  *      |     7   |       8    |   4096    |    32768   |
1770  *      +---------+------------+-----------+------------+
1771  *      |     8   |       4    |   8192    |    32768   |
1772  *      +---------+------------+-----------+------------+
1773  *      |     9   |       2    |   16384   |    32768   |
1774  *      +---------+------------+-----------+------------+
1775  *      |    10   |       2    |   32768   |    65536   |
1776  *      +---------+------------+-----------+------------+
1777  *
1778  * Recording need a different reference table. All we care is
1779  * gobbling up everything within reasonable buffering threshold.
1780  *
1781  *    Latency reference table for 48khz stereo 16bit: (REC)
1782  *
1783  *      +---------+------------+-----------+------------+
1784  *      | Latency | Blockcount | Blocksize | Buffersize |
1785  *      +---------+------------+-----------+------------+
1786  *      |     0   |     512    |   32      |    16384   |
1787  *      +---------+------------+-----------+------------+
1788  *      |     1   |     256    |   64      |    16384   |
1789  *      +---------+------------+-----------+------------+
1790  *      |     2   |     128    |   128     |    16384   |
1791  *      +---------+------------+-----------+------------+
1792  *      |     3   |      64    |   256     |    16384   |
1793  *      +---------+------------+-----------+------------+
1794  *      |     4   |      32    |   512     |    16384   |
1795  *      +---------+------------+-----------+------------+
1796  *      |     5   |      32    |   1024    |    32768   |
1797  *      +---------+------------+-----------+------------+
1798  *      |     6   |      16    |   2048    |    32768   |
1799  *      +---------+------------+-----------+------------+
1800  *      |     7   |       8    |   4096    |    32768   |
1801  *      +---------+------------+-----------+------------+
1802  *      |     8   |       4    |   8192    |    32768   |
1803  *      +---------+------------+-----------+------------+
1804  *      |     9   |       2    |   16384   |    32768   |
1805  *      +---------+------------+-----------+------------+
1806  *      |    10   |       2    |   32768   |    65536   |
1807  *      +---------+------------+-----------+------------+
1808  *
1809  * Calculations for other data rate are entirely based on these reference
1810  * tables. For normal operation, Latency 5 seems give the best, well
1811  * balanced performance for typical workload. Anything below 5 will
1812  * eat up CPU to keep up with increasing context switches because of
1813  * shorter buffer space and usually require the application to handle it
1814  * aggressively through possibly real time programming technique.
1815  *
1816  */
1817 #define CHN_LATENCY_PBLKCNT_REF				\
1818 	{{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1},		\
1819 	{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1}}
1820 #define CHN_LATENCY_PBUFSZ_REF				\
1821 	{{7, 9, 12, 13, 14, 15, 15, 15, 15, 15, 16},	\
1822 	{11, 12, 13, 14, 15, 16, 16, 16, 16, 16, 17}}
1823 
1824 #define CHN_LATENCY_RBLKCNT_REF				\
1825 	{{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1},		\
1826 	{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1}}
1827 #define CHN_LATENCY_RBUFSZ_REF				\
1828 	{{14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16},	\
1829 	{15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17}}
1830 
1831 #define CHN_LATENCY_DATA_REF	192000 /* 48khz stereo 16bit ~ 48000 x 2 x 2 */
1832 
1833 static int
1834 chn_calclatency(int dir, int latency, int bps, u_int32_t datarate,
1835 				u_int32_t max, int *rblksz, int *rblkcnt)
1836 {
1837 	static int pblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1838 	    CHN_LATENCY_PBLKCNT_REF;
1839 	static int  pbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1840 	    CHN_LATENCY_PBUFSZ_REF;
1841 	static int rblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1842 	    CHN_LATENCY_RBLKCNT_REF;
1843 	static int  rbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1844 	    CHN_LATENCY_RBUFSZ_REF;
1845 	u_int32_t bufsz;
1846 	int lprofile, blksz, blkcnt;
1847 
1848 	if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX ||
1849 	    bps < 1 || datarate < 1 ||
1850 	    !(dir == PCMDIR_PLAY || dir == PCMDIR_REC)) {
1851 		if (rblksz != NULL)
1852 			*rblksz = CHN_2NDBUFMAXSIZE >> 1;
1853 		if (rblkcnt != NULL)
1854 			*rblkcnt = 2;
1855 		printf("%s(): FAILED dir=%d latency=%d bps=%d "
1856 		    "datarate=%u max=%u\n",
1857 		    __func__, dir, latency, bps, datarate, max);
1858 		return CHN_2NDBUFMAXSIZE;
1859 	}
1860 
1861 	lprofile = chn_latency_profile;
1862 
1863 	if (dir == PCMDIR_PLAY) {
1864 		blkcnt = pblkcnts[lprofile][latency];
1865 		bufsz = pbufszs[lprofile][latency];
1866 	} else {
1867 		blkcnt = rblkcnts[lprofile][latency];
1868 		bufsz = rbufszs[lprofile][latency];
1869 	}
1870 
1871 	bufsz = round_pow2(snd_xbytes(1 << bufsz, CHN_LATENCY_DATA_REF,
1872 	    datarate));
1873 	if (bufsz > max)
1874 		bufsz = max;
1875 	blksz = round_blksz(bufsz >> blkcnt, bps);
1876 
1877 	if (rblksz != NULL)
1878 		*rblksz = blksz;
1879 	if (rblkcnt != NULL)
1880 		*rblkcnt = 1 << blkcnt;
1881 
1882 	return blksz << blkcnt;
1883 }
1884 
1885 static int
1886 chn_resizebuf(struct pcm_channel *c, int latency,
1887 					int blkcnt, int blksz)
1888 {
1889 	struct snd_dbuf *b, *bs, *pb;
1890 	int sblksz, sblkcnt, hblksz, hblkcnt, limit = 0, nsblksz, nsblkcnt;
1891 	int ret;
1892 
1893 	CHN_LOCKASSERT(c);
1894 
1895 	if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
1896 	    !(c->direction == PCMDIR_PLAY || c->direction == PCMDIR_REC))
1897 		return EINVAL;
1898 
1899 	if (latency == -1) {
1900 		c->latency = -1;
1901 		latency = chn_latency;
1902 	} else if (latency == -2) {
1903 		latency = c->latency;
1904 		if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1905 			latency = chn_latency;
1906 	} else if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1907 		return EINVAL;
1908 	else {
1909 		c->latency = latency;
1910 	}
1911 
1912 	bs = c->bufsoft;
1913 	b = c->bufhard;
1914 
1915 	if (!(blksz == 0 || blkcnt == -1) &&
1916 	    (blksz < 16 || blksz < sndbuf_getalign(bs) || blkcnt < 2 ||
1917 	    (blksz * blkcnt) > CHN_2NDBUFMAXSIZE))
1918 		return EINVAL;
1919 
1920 	chn_calclatency(c->direction, latency, sndbuf_getalign(bs),
1921 	    sndbuf_getalign(bs) * sndbuf_getspd(bs), CHN_2NDBUFMAXSIZE,
1922 	    &sblksz, &sblkcnt);
1923 
1924 	if (blksz == 0 || blkcnt == -1) {
1925 		if (blkcnt == -1)
1926 			c->flags &= ~CHN_F_HAS_SIZE;
1927 		if (c->flags & CHN_F_HAS_SIZE) {
1928 			blksz = sndbuf_getblksz(bs);
1929 			blkcnt = sndbuf_getblkcnt(bs);
1930 		}
1931 	} else
1932 		c->flags |= CHN_F_HAS_SIZE;
1933 
1934 	if (c->flags & CHN_F_HAS_SIZE) {
1935 		/*
1936 		 * The application has requested their own blksz/blkcnt.
1937 		 * Just obey with it, and let them toast alone. We can
1938 		 * clamp it to the nearest latency profile, but that would
1939 		 * defeat the purpose of having custom control. The least
1940 		 * we can do is round it to the nearest ^2 and align it.
1941 		 */
1942 		sblksz = round_blksz(blksz, sndbuf_getalign(bs));
1943 		sblkcnt = round_pow2(blkcnt);
1944 	}
1945 
1946 	if (c->parentchannel != NULL) {
1947 		pb = c->parentchannel->bufsoft;
1948 		CHN_UNLOCK(c);
1949 		CHN_LOCK(c->parentchannel);
1950 		chn_notify(c->parentchannel, CHN_N_BLOCKSIZE);
1951 		CHN_UNLOCK(c->parentchannel);
1952 		CHN_LOCK(c);
1953 		if (c->direction == PCMDIR_PLAY) {
1954 			limit = (pb != NULL) ?
1955 			    sndbuf_xbytes(sndbuf_getsize(pb), pb, bs) : 0;
1956 		} else {
1957 			limit = (pb != NULL) ?
1958 			    sndbuf_xbytes(sndbuf_getblksz(pb), pb, bs) * 2 : 0;
1959 		}
1960 	} else {
1961 		hblkcnt = 2;
1962 		if (c->flags & CHN_F_HAS_SIZE) {
1963 			hblksz = round_blksz(sndbuf_xbytes(sblksz, bs, b),
1964 			    sndbuf_getalign(b));
1965 			hblkcnt = round_pow2(sndbuf_getblkcnt(bs));
1966 		} else
1967 			chn_calclatency(c->direction, latency,
1968 			    sndbuf_getalign(b),
1969 			    sndbuf_getalign(b) * sndbuf_getspd(b),
1970 			    CHN_2NDBUFMAXSIZE, &hblksz, &hblkcnt);
1971 
1972 		if ((hblksz << 1) > sndbuf_getmaxsize(b))
1973 			hblksz = round_blksz(sndbuf_getmaxsize(b) >> 1,
1974 			    sndbuf_getalign(b));
1975 
1976 		while ((hblksz * hblkcnt) > sndbuf_getmaxsize(b)) {
1977 			if (hblkcnt < 4)
1978 				hblksz >>= 1;
1979 			else
1980 				hblkcnt >>= 1;
1981 		}
1982 
1983 		hblksz -= hblksz % sndbuf_getalign(b);
1984 
1985 #if 0
1986 		hblksz = sndbuf_getmaxsize(b) >> 1;
1987 		hblksz -= hblksz % sndbuf_getalign(b);
1988 		hblkcnt = 2;
1989 #endif
1990 
1991 		CHN_UNLOCK(c);
1992 		if (chn_usefrags == 0 ||
1993 		    CHANNEL_SETFRAGMENTS(c->methods, c->devinfo,
1994 		    hblksz, hblkcnt) != 0)
1995 			sndbuf_setblksz(b, CHANNEL_SETBLOCKSIZE(c->methods,
1996 			    c->devinfo, hblksz));
1997 		CHN_LOCK(c);
1998 
1999 		if (!CHN_EMPTY(c, children)) {
2000 			nsblksz = round_blksz(
2001 			    sndbuf_xbytes(sndbuf_getblksz(b), b, bs),
2002 			    sndbuf_getalign(bs));
2003 			nsblkcnt = sndbuf_getblkcnt(b);
2004 			if (c->direction == PCMDIR_PLAY) {
2005 				do {
2006 					nsblkcnt--;
2007 				} while (nsblkcnt >= 2 &&
2008 				    nsblksz * nsblkcnt >= sblksz * sblkcnt);
2009 				nsblkcnt++;
2010 			}
2011 			sblksz = nsblksz;
2012 			sblkcnt = nsblkcnt;
2013 			limit = 0;
2014 		} else
2015 			limit = sndbuf_xbytes(sndbuf_getblksz(b), b, bs) * 2;
2016 	}
2017 
2018 	if (limit > CHN_2NDBUFMAXSIZE)
2019 		limit = CHN_2NDBUFMAXSIZE;
2020 
2021 #if 0
2022 	while (limit > 0 && (sblksz * sblkcnt) > limit) {
2023 		if (sblkcnt < 4)
2024 			break;
2025 		sblkcnt >>= 1;
2026 	}
2027 #endif
2028 
2029 	while ((sblksz * sblkcnt) < limit)
2030 		sblkcnt <<= 1;
2031 
2032 	while ((sblksz * sblkcnt) > CHN_2NDBUFMAXSIZE) {
2033 		if (sblkcnt < 4)
2034 			sblksz >>= 1;
2035 		else
2036 			sblkcnt >>= 1;
2037 	}
2038 
2039 	sblksz -= sblksz % sndbuf_getalign(bs);
2040 
2041 	if (sndbuf_getblkcnt(bs) != sblkcnt || sndbuf_getblksz(bs) != sblksz ||
2042 	    sndbuf_getsize(bs) != (sblkcnt * sblksz)) {
2043 		ret = sndbuf_remalloc(bs, sblkcnt, sblksz);
2044 		if (ret != 0) {
2045 			device_printf(c->dev, "%s(): Failed: %d %d\n",
2046 			    __func__, sblkcnt, sblksz);
2047 			return ret;
2048 		}
2049 	}
2050 
2051 	/*
2052 	 * Interrupt timeout
2053 	 */
2054 	c->timeout = ((u_int64_t)hz * sndbuf_getsize(bs)) /
2055 	    ((u_int64_t)sndbuf_getspd(bs) * sndbuf_getalign(bs));
2056 	if (c->parentchannel != NULL)
2057 		c->timeout = min(c->timeout, c->parentchannel->timeout);
2058 	if (c->timeout < 1)
2059 		c->timeout = 1;
2060 
2061 	/*
2062 	 * OSSv4 docs: "By default OSS will set the low water level equal
2063 	 * to the fragment size which is optimal in most cases."
2064 	 */
2065 	c->lw = sndbuf_getblksz(bs);
2066 	chn_resetbuf(c);
2067 
2068 	if (snd_verbose > 3)
2069 		device_printf(c->dev, "%s(): %s (%s) timeout=%u "
2070 		    "b[%d/%d/%d] bs[%d/%d/%d] limit=%d\n",
2071 		    __func__, CHN_DIRSTR(c),
2072 		    (c->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
2073 		    c->timeout,
2074 		    sndbuf_getsize(b), sndbuf_getblksz(b),
2075 		    sndbuf_getblkcnt(b),
2076 		    sndbuf_getsize(bs), sndbuf_getblksz(bs),
2077 		    sndbuf_getblkcnt(bs), limit);
2078 
2079 	return 0;
2080 }
2081 
2082 int
2083 chn_setlatency(struct pcm_channel *c, int latency)
2084 {
2085 	CHN_LOCKASSERT(c);
2086 	/* Destroy blksz/blkcnt, enforce latency profile. */
2087 	return chn_resizebuf(c, latency, -1, 0);
2088 }
2089 
2090 int
2091 chn_setblocksize(struct pcm_channel *c, int blkcnt, int blksz)
2092 {
2093 	CHN_LOCKASSERT(c);
2094 	/* Destroy latency profile, enforce blksz/blkcnt */
2095 	return chn_resizebuf(c, -1, blkcnt, blksz);
2096 }
2097 
2098 int
2099 chn_setparam(struct pcm_channel *c, uint32_t format, uint32_t speed)
2100 {
2101 	struct pcmchan_caps *caps;
2102 	uint32_t hwspeed, delta;
2103 	int ret;
2104 
2105 	CHN_LOCKASSERT(c);
2106 
2107 	if (speed < 1 || format == 0 || CHN_STARTED(c))
2108 		return (EINVAL);
2109 
2110 	c->format = format;
2111 	c->speed = speed;
2112 
2113 	caps = chn_getcaps(c);
2114 
2115 	hwspeed = speed;
2116 	RANGE(hwspeed, caps->minspeed, caps->maxspeed);
2117 
2118 	sndbuf_setspd(c->bufhard, CHANNEL_SETSPEED(c->methods, c->devinfo,
2119 	    hwspeed));
2120 	hwspeed = sndbuf_getspd(c->bufhard);
2121 
2122 	delta = (hwspeed > speed) ? (hwspeed - speed) : (speed - hwspeed);
2123 
2124 	if (delta <= feeder_rate_round)
2125 		c->speed = hwspeed;
2126 
2127 	ret = feeder_chain(c);
2128 
2129 	if (ret == 0)
2130 		ret = CHANNEL_SETFORMAT(c->methods, c->devinfo,
2131 		    sndbuf_getfmt(c->bufhard));
2132 
2133 	if (ret == 0)
2134 		ret = chn_resizebuf(c, -2, 0, 0);
2135 
2136 	return (ret);
2137 }
2138 
2139 int
2140 chn_setspeed(struct pcm_channel *c, uint32_t speed)
2141 {
2142 	uint32_t oldformat, oldspeed, format;
2143 	int ret;
2144 
2145 #if 0
2146 	/* XXX force 48k */
2147 	if (c->format & AFMT_PASSTHROUGH)
2148 		speed = AFMT_PASSTHROUGH_RATE;
2149 #endif
2150 
2151 	oldformat = c->format;
2152 	oldspeed = c->speed;
2153 	format = oldformat;
2154 
2155 	ret = chn_setparam(c, format, speed);
2156 	if (ret != 0) {
2157 		if (snd_verbose > 3)
2158 			device_printf(c->dev,
2159 			    "%s(): Setting speed %d failed, "
2160 			    "falling back to %d\n",
2161 			    __func__, speed, oldspeed);
2162 		chn_setparam(c, c->format, oldspeed);
2163 	}
2164 
2165 	return (ret);
2166 }
2167 
2168 int
2169 chn_setformat(struct pcm_channel *c, uint32_t format)
2170 {
2171 	uint32_t oldformat, oldspeed, speed;
2172 	int ret;
2173 
2174 	/* XXX force stereo */
2175 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
2176 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,
2177 		    AFMT_PASSTHROUGH_EXTCHANNEL);
2178 	}
2179 
2180 	oldformat = c->format;
2181 	oldspeed = c->speed;
2182 	speed = oldspeed;
2183 
2184 	ret = chn_setparam(c, format, speed);
2185 	if (ret != 0) {
2186 		if (snd_verbose > 3)
2187 			device_printf(c->dev,
2188 			    "%s(): Format change 0x%08x failed, "
2189 			    "falling back to 0x%08x\n",
2190 			    __func__, format, oldformat);
2191 		chn_setparam(c, oldformat, oldspeed);
2192 	}
2193 
2194 	return (ret);
2195 }
2196 
2197 void
2198 chn_syncstate(struct pcm_channel *c)
2199 {
2200 	struct snddev_info *d;
2201 	struct snd_mixer *m;
2202 
2203 	d = (c != NULL) ? c->parentsnddev : NULL;
2204 	m = (d != NULL && d->mixer_dev != NULL) ? d->mixer_dev->si_drv1 :
2205 	    NULL;
2206 
2207 	if (d == NULL || m == NULL)
2208 		return;
2209 
2210 	CHN_LOCKASSERT(c);
2211 
2212 	if (c->feederflags & (1 << FEEDER_VOLUME)) {
2213 		uint32_t parent;
2214 		int vol, pvol, left, right, center;
2215 
2216 		if (c->direction == PCMDIR_PLAY &&
2217 		    (d->flags & SD_F_SOFTPCMVOL)) {
2218 			/* CHN_UNLOCK(c); */
2219 			vol = mix_get(m, SOUND_MIXER_PCM);
2220 			parent = mix_getparent(m, SOUND_MIXER_PCM);
2221 			if (parent != SOUND_MIXER_NONE)
2222 				pvol = mix_get(m, parent);
2223 			else
2224 				pvol = 100 | (100 << 8);
2225 			/* CHN_LOCK(c); */
2226 		} else {
2227 			vol = 100 | (100 << 8);
2228 			pvol = vol;
2229 		}
2230 
2231 		if (vol == -1) {
2232 			device_printf(c->dev,
2233 			    "Soft PCM Volume: Failed to read pcm "
2234 			    "default value\n");
2235 			vol = 100 | (100 << 8);
2236 		}
2237 
2238 		if (pvol == -1) {
2239 			device_printf(c->dev,
2240 			    "Soft PCM Volume: Failed to read parent "
2241 			    "default value\n");
2242 			pvol = 100 | (100 << 8);
2243 		}
2244 
2245 		left = ((vol & 0x7f) * (pvol & 0x7f)) / 100;
2246 		right = (((vol >> 8) & 0x7f) * ((pvol >> 8) & 0x7f)) / 100;
2247 		center = (left + right) >> 1;
2248 
2249 		chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right, center);
2250 	}
2251 
2252 	if (c->feederflags & (1 << FEEDER_EQ)) {
2253 		struct pcm_feeder *f;
2254 		int treble, bass, state;
2255 
2256 		/* CHN_UNLOCK(c); */
2257 		treble = mix_get(m, SOUND_MIXER_TREBLE);
2258 		bass = mix_get(m, SOUND_MIXER_BASS);
2259 		/* CHN_LOCK(c); */
2260 
2261 		if (treble == -1)
2262 			treble = 50;
2263 		else
2264 			treble = ((treble & 0x7f) +
2265 			    ((treble >> 8) & 0x7f)) >> 1;
2266 
2267 		if (bass == -1)
2268 			bass = 50;
2269 		else
2270 			bass = ((bass & 0x7f) + ((bass >> 8) & 0x7f)) >> 1;
2271 
2272 		f = feeder_find(c, FEEDER_EQ);
2273 		if (f != NULL) {
2274 			if (FEEDER_SET(f, FEEDEQ_TREBLE, treble) != 0)
2275 				device_printf(c->dev,
2276 				    "EQ: Failed to set treble -- %d\n",
2277 				    treble);
2278 			if (FEEDER_SET(f, FEEDEQ_BASS, bass) != 0)
2279 				device_printf(c->dev,
2280 				    "EQ: Failed to set bass -- %d\n",
2281 				    bass);
2282 			if (FEEDER_SET(f, FEEDEQ_PREAMP, d->eqpreamp) != 0)
2283 				device_printf(c->dev,
2284 				    "EQ: Failed to set preamp -- %d\n",
2285 				    d->eqpreamp);
2286 			if (d->flags & SD_F_EQ_BYPASSED)
2287 				state = FEEDEQ_BYPASS;
2288 			else if (d->flags & SD_F_EQ_ENABLED)
2289 				state = FEEDEQ_ENABLE;
2290 			else
2291 				state = FEEDEQ_DISABLE;
2292 			if (FEEDER_SET(f, FEEDEQ_STATE, state) != 0)
2293 				device_printf(c->dev,
2294 				    "EQ: Failed to set state -- %d\n", state);
2295 		}
2296 	}
2297 }
2298 
2299 int
2300 chn_trigger(struct pcm_channel *c, int go)
2301 {
2302 	struct snddev_info *d = c->parentsnddev;
2303 	int ret;
2304 
2305 	CHN_LOCKASSERT(c);
2306 	if (!PCMTRIG_COMMON(go))
2307 		return (CHANNEL_TRIGGER(c->methods, c->devinfo, go));
2308 
2309 	if (go == c->trigger)
2310 		return (0);
2311 
2312 	ret = CHANNEL_TRIGGER(c->methods, c->devinfo, go);
2313 	if (ret != 0)
2314 		return (ret);
2315 
2316 	switch (go) {
2317 	case PCMTRIG_START:
2318 		if (snd_verbose > 3)
2319 			device_printf(c->dev,
2320 			    "%s() %s: calling go=0x%08x , "
2321 			    "prev=0x%08x\n", __func__, c->name, go,
2322 			    c->trigger);
2323 		if (c->trigger != PCMTRIG_START) {
2324 			c->trigger = go;
2325 			CHN_UNLOCK(c);
2326 			PCM_LOCK(d);
2327 			CHN_INSERT_HEAD(d, c, channels.pcm.busy);
2328 			PCM_UNLOCK(d);
2329 			CHN_LOCK(c);
2330 			chn_syncstate(c);
2331 		}
2332 		break;
2333 	case PCMTRIG_STOP:
2334 	case PCMTRIG_ABORT:
2335 		if (snd_verbose > 3)
2336 			device_printf(c->dev,
2337 			    "%s() %s: calling go=0x%08x , "
2338 			    "prev=0x%08x\n", __func__, c->name, go,
2339 			    c->trigger);
2340 		if (c->trigger == PCMTRIG_START) {
2341 			c->trigger = go;
2342 			CHN_UNLOCK(c);
2343 			PCM_LOCK(d);
2344 			CHN_REMOVE(d, c, channels.pcm.busy);
2345 			PCM_UNLOCK(d);
2346 			CHN_LOCK(c);
2347 		}
2348 		break;
2349 	default:
2350 		break;
2351 	}
2352 
2353 	return (0);
2354 }
2355 
2356 /**
2357  * @brief Queries sound driver for sample-aligned hardware buffer pointer index
2358  *
2359  * This function obtains the hardware pointer location, then aligns it to
2360  * the current bytes-per-sample value before returning.  (E.g., a channel
2361  * running in 16 bit stereo mode would require 4 bytes per sample, so a
2362  * hwptr value ranging from 32-35 would be returned as 32.)
2363  *
2364  * @param c	PCM channel context
2365  * @returns 	sample-aligned hardware buffer pointer index
2366  */
2367 int
2368 chn_getptr(struct pcm_channel *c)
2369 {
2370 	int hwptr;
2371 
2372 	CHN_LOCKASSERT(c);
2373 	hwptr = (CHN_STARTED(c)) ? CHANNEL_GETPTR(c->methods, c->devinfo) : 0;
2374 	return (hwptr - (hwptr % sndbuf_getalign(c->bufhard)));
2375 }
2376 
2377 struct pcmchan_caps *
2378 chn_getcaps(struct pcm_channel *c)
2379 {
2380 	CHN_LOCKASSERT(c);
2381 	return CHANNEL_GETCAPS(c->methods, c->devinfo);
2382 }
2383 
2384 u_int32_t
2385 chn_getformats(struct pcm_channel *c)
2386 {
2387 	u_int32_t *fmtlist, fmts;
2388 	int i;
2389 
2390 	fmtlist = chn_getcaps(c)->fmtlist;
2391 	fmts = 0;
2392 	for (i = 0; fmtlist[i]; i++)
2393 		fmts |= fmtlist[i];
2394 
2395 	/* report software-supported formats */
2396 	if (!CHN_BITPERFECT(c) && report_soft_formats)
2397 		fmts |= AFMT_CONVERTIBLE;
2398 
2399 	return (AFMT_ENCODING(fmts));
2400 }
2401 
2402 int
2403 chn_notify(struct pcm_channel *c, u_int32_t flags)
2404 {
2405 	struct pcm_channel *ch;
2406 	struct pcmchan_caps *caps;
2407 	uint32_t bestformat, bestspeed, besthwformat, *vchanformat, *vchanrate;
2408 	uint32_t vpflags;
2409 	int dirty, err, run, nrun;
2410 
2411 	CHN_LOCKASSERT(c);
2412 
2413 	if (CHN_EMPTY(c, children))
2414 		return (ENODEV);
2415 
2416 	err = 0;
2417 
2418 	/*
2419 	 * If the hwchan is running, we can't change its rate, format or
2420 	 * blocksize
2421 	 */
2422 	run = (CHN_STARTED(c)) ? 1 : 0;
2423 	if (run)
2424 		flags &= CHN_N_VOLUME | CHN_N_TRIGGER;
2425 
2426 	if (flags & CHN_N_RATE) {
2427 		/*
2428 		 * XXX I'll make good use of this someday.
2429 		 *     However this is currently being superseded by
2430 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2431 		 */
2432 	}
2433 
2434 	if (flags & CHN_N_FORMAT) {
2435 		/*
2436 		 * XXX I'll make good use of this someday.
2437 		 *     However this is currently being superseded by
2438 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2439 		 */
2440 	}
2441 
2442 	if (flags & CHN_N_VOLUME) {
2443 		/*
2444 		 * XXX I'll make good use of this someday, though
2445 		 *     soft volume control is currently pretty much
2446 		 *     integrated.
2447 		 */
2448 	}
2449 
2450 	if (flags & CHN_N_BLOCKSIZE) {
2451 		/*
2452 		 * Set to default latency profile
2453 		 */
2454 		chn_setlatency(c, chn_latency);
2455 	}
2456 
2457 	if ((flags & CHN_N_TRIGGER) && !(c->flags & CHN_F_VCHAN_DYNAMIC)) {
2458 		nrun = CHN_EMPTY(c, children.busy) ? 0 : 1;
2459 		if (nrun && !run)
2460 			err = chn_start(c, 1);
2461 		if (!nrun && run)
2462 			chn_abort(c);
2463 		flags &= ~CHN_N_TRIGGER;
2464 	}
2465 
2466 	if (flags & CHN_N_TRIGGER) {
2467 		if (c->direction == PCMDIR_PLAY) {
2468 			vchanformat = &c->parentsnddev->pvchanformat;
2469 			vchanrate = &c->parentsnddev->pvchanrate;
2470 		} else {
2471 			vchanformat = &c->parentsnddev->rvchanformat;
2472 			vchanrate = &c->parentsnddev->rvchanrate;
2473 		}
2474 
2475 		/* Dynamic Virtual Channel */
2476 		if (!(c->flags & CHN_F_VCHAN_ADAPTIVE)) {
2477 			bestformat = *vchanformat;
2478 			bestspeed = *vchanrate;
2479 		} else {
2480 			bestformat = 0;
2481 			bestspeed = 0;
2482 		}
2483 
2484 		besthwformat = 0;
2485 		nrun = 0;
2486 		caps = chn_getcaps(c);
2487 		dirty = 0;
2488 		vpflags = 0;
2489 
2490 		CHN_FOREACH(ch, c, children.busy) {
2491 			CHN_LOCK(ch);
2492 			if ((ch->format & AFMT_PASSTHROUGH) &&
2493 			    snd_fmtvalid(ch->format, caps->fmtlist)) {
2494 				bestformat = ch->format;
2495 				bestspeed = ch->speed;
2496 				CHN_UNLOCK(ch);
2497 				vpflags = CHN_F_PASSTHROUGH;
2498 				nrun++;
2499 				break;
2500 			}
2501 			if ((ch->flags & CHN_F_EXCLUSIVE) && vpflags == 0) {
2502 				if (c->flags & CHN_F_VCHAN_ADAPTIVE) {
2503 					bestspeed = ch->speed;
2504 					RANGE(bestspeed, caps->minspeed,
2505 					    caps->maxspeed);
2506 					besthwformat = snd_fmtbest(ch->format,
2507 					    caps->fmtlist);
2508 					if (besthwformat != 0)
2509 						bestformat = besthwformat;
2510 				}
2511 				CHN_UNLOCK(ch);
2512 				vpflags = CHN_F_EXCLUSIVE;
2513 				nrun++;
2514 				continue;
2515 			}
2516 			if (!(c->flags & CHN_F_VCHAN_ADAPTIVE) ||
2517 			    vpflags != 0) {
2518 				CHN_UNLOCK(ch);
2519 				nrun++;
2520 				continue;
2521 			}
2522 			if (ch->speed > bestspeed) {
2523 				bestspeed = ch->speed;
2524 				RANGE(bestspeed, caps->minspeed,
2525 				    caps->maxspeed);
2526 			}
2527 			besthwformat = snd_fmtbest(ch->format, caps->fmtlist);
2528 			if (!(besthwformat & AFMT_VCHAN)) {
2529 				CHN_UNLOCK(ch);
2530 				nrun++;
2531 				continue;
2532 			}
2533 			if (AFMT_CHANNEL(besthwformat) >
2534 			    AFMT_CHANNEL(bestformat))
2535 				bestformat = besthwformat;
2536 			else if (AFMT_CHANNEL(besthwformat) ==
2537 			    AFMT_CHANNEL(bestformat) &&
2538 			    AFMT_BIT(besthwformat) > AFMT_BIT(bestformat))
2539 				bestformat = besthwformat;
2540 			CHN_UNLOCK(ch);
2541 			nrun++;
2542 		}
2543 
2544 		if (bestformat == 0)
2545 			bestformat = c->format;
2546 		if (bestspeed == 0)
2547 			bestspeed = c->speed;
2548 
2549 		if (bestformat != c->format || bestspeed != c->speed)
2550 			dirty = 1;
2551 
2552 		c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2553 		c->flags |= vpflags;
2554 
2555 		if (nrun && !run) {
2556 			if (dirty) {
2557 				bestspeed = CHANNEL_SETSPEED(c->methods,
2558 				    c->devinfo, bestspeed);
2559 				err = chn_reset(c, bestformat, bestspeed);
2560 			}
2561 			if (err == 0 && dirty) {
2562 				CHN_FOREACH(ch, c, children.busy) {
2563 					CHN_LOCK(ch);
2564 					if (VCHAN_SYNC_REQUIRED(ch))
2565 						vchan_sync(ch);
2566 					CHN_UNLOCK(ch);
2567 				}
2568 			}
2569 			if (err == 0) {
2570 				if (dirty)
2571 					c->flags |= CHN_F_DIRTY;
2572 				err = chn_start(c, 1);
2573 			}
2574 		}
2575 
2576 		if (nrun && run && dirty) {
2577 			chn_abort(c);
2578 			bestspeed = CHANNEL_SETSPEED(c->methods, c->devinfo,
2579 			    bestspeed);
2580 			err = chn_reset(c, bestformat, bestspeed);
2581 			if (err == 0) {
2582 				CHN_FOREACH(ch, c, children.busy) {
2583 					CHN_LOCK(ch);
2584 					if (VCHAN_SYNC_REQUIRED(ch))
2585 						vchan_sync(ch);
2586 					CHN_UNLOCK(ch);
2587 				}
2588 			}
2589 			if (err == 0) {
2590 				c->flags |= CHN_F_DIRTY;
2591 				err = chn_start(c, 1);
2592 			}
2593 		}
2594 
2595 		if (err == 0 && !(bestformat & AFMT_PASSTHROUGH) &&
2596 		    (bestformat & AFMT_VCHAN)) {
2597 			*vchanformat = bestformat;
2598 			*vchanrate = bestspeed;
2599 		}
2600 
2601 		if (!nrun && run) {
2602 			c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2603 			bestformat = *vchanformat;
2604 			bestspeed = *vchanrate;
2605 			chn_abort(c);
2606 			if (c->format != bestformat || c->speed != bestspeed)
2607 				chn_reset(c, bestformat, bestspeed);
2608 		}
2609 	}
2610 
2611 	return (err);
2612 }
2613 
2614 /**
2615  * @brief Fetch array of supported discrete sample rates
2616  *
2617  * Wrapper for CHANNEL_GETRATES.  Please see channel_if.m:getrates() for
2618  * detailed information.
2619  *
2620  * @note If the operation isn't supported, this function will just return 0
2621  *       (no rates in the array), and *rates will be set to NULL.  Callers
2622  *       should examine rates @b only if this function returns non-zero.
2623  *
2624  * @param c	pcm channel to examine
2625  * @param rates	pointer to array of integers; rate table will be recorded here
2626  *
2627  * @return number of rates in the array pointed to be @c rates
2628  */
2629 int
2630 chn_getrates(struct pcm_channel *c, int **rates)
2631 {
2632 	KASSERT(rates != NULL, ("rates is null"));
2633 	CHN_LOCKASSERT(c);
2634 	return CHANNEL_GETRATES(c->methods, c->devinfo, rates);
2635 }
2636 
2637 /**
2638  * @brief Remove channel from a sync group, if there is one.
2639  *
2640  * This function is initially intended for the following conditions:
2641  *   - Starting a syncgroup (@c SNDCTL_DSP_SYNCSTART ioctl)
2642  *   - Closing a device.  (A channel can't be destroyed if it's still in use.)
2643  *
2644  * @note Before calling this function, the syncgroup list mutex must be
2645  * held.  (Consider pcm_channel::sm protected by the SG list mutex
2646  * whether @c c is locked or not.)
2647  *
2648  * @param c	channel device to be started or closed
2649  * @returns	If this channel was the only member of a group, the group ID
2650  * 		is returned to the caller so that the caller can release it
2651  * 		via free_unr() after giving up the syncgroup lock.  Else it
2652  * 		returns 0.
2653  */
2654 int
2655 chn_syncdestroy(struct pcm_channel *c)
2656 {
2657 	struct pcmchan_syncmember *sm;
2658 	struct pcmchan_syncgroup *sg;
2659 	int sg_id;
2660 
2661 	sg_id = 0;
2662 
2663 	PCM_SG_LOCKASSERT(MA_OWNED);
2664 
2665 	if (c->sm != NULL) {
2666 		sm = c->sm;
2667 		sg = sm->parent;
2668 		c->sm = NULL;
2669 
2670 		KASSERT(sg != NULL, ("syncmember has null parent"));
2671 
2672 		SLIST_REMOVE(&sg->members, sm, pcmchan_syncmember, link);
2673 		free(sm, M_DEVBUF);
2674 
2675 		if (SLIST_EMPTY(&sg->members)) {
2676 			SLIST_REMOVE(&snd_pcm_syncgroups, sg, pcmchan_syncgroup, link);
2677 			sg_id = sg->id;
2678 			free(sg, M_DEVBUF);
2679 		}
2680 	}
2681 
2682 	return sg_id;
2683 }
2684 
2685 #ifdef OSSV4_EXPERIMENT
2686 int
2687 chn_getpeaks(struct pcm_channel *c, int *lpeak, int *rpeak)
2688 {
2689 	CHN_LOCKASSERT(c);
2690 	return CHANNEL_GETPEAKS(c->methods, c->devinfo, lpeak, rpeak);
2691 }
2692 #endif
2693