xref: /freebsd/sys/dev/sound/pcm/channel.c (revision 5036d9652a5701d00e9e40ea942c278e9f77d33d)
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 PCMDIR_PLAY:
1165 		return (d->p_unr);
1166 	case PCMDIR_PLAY_VIRTUAL:
1167 		return (d->vp_unr);
1168 	case PCMDIR_REC:
1169 		return (d->r_unr);
1170 	case PCMDIR_REC_VIRTUAL:
1171 		return (d->vr_unr);
1172 	default:
1173 		__assert_unreachable();
1174 	}
1175 
1176 }
1177 
1178 char *
1179 chn_mkname(char *buf, size_t len, struct pcm_channel *c)
1180 {
1181 	const char *str;
1182 
1183 	KASSERT(buf != NULL && len != 0,
1184 	    ("%s(): bogus buf=%p len=%zu", __func__, buf, len));
1185 
1186 	switch (c->type) {
1187 	case PCMDIR_PLAY:
1188 		str = "play";
1189 		break;
1190 	case PCMDIR_PLAY_VIRTUAL:
1191 		str = "virtual_play";
1192 		break;
1193 	case PCMDIR_REC:
1194 		str = "record";
1195 		break;
1196 	case PCMDIR_REC_VIRTUAL:
1197 		str = "virtual_record";
1198 		break;
1199 	default:
1200 		__assert_unreachable();
1201 	}
1202 
1203 	snprintf(buf, len, "dsp%d.%s.%d",
1204 	    device_get_unit(c->dev), str, c->unit);
1205 
1206 	return (buf);
1207 }
1208 
1209 struct pcm_channel *
1210 chn_init(struct snddev_info *d, struct pcm_channel *parent, kobj_class_t cls,
1211     int dir, void *devinfo)
1212 {
1213 	struct pcm_channel *c;
1214 	struct feeder_class *fc;
1215 	struct snd_dbuf *b, *bs;
1216 	char buf[CHN_NAMELEN];
1217 	int i, direction;
1218 
1219 	PCM_BUSYASSERT(d);
1220 	PCM_LOCKASSERT(d);
1221 
1222 	switch (dir) {
1223 	case PCMDIR_PLAY:
1224 	case PCMDIR_PLAY_VIRTUAL:
1225 		direction = PCMDIR_PLAY;
1226 		break;
1227 	case PCMDIR_REC:
1228 	case PCMDIR_REC_VIRTUAL:
1229 		direction = PCMDIR_REC;
1230 		break;
1231 	default:
1232 		device_printf(d->dev,
1233 		    "%s(): invalid channel direction: %d\n",
1234 		    __func__, dir);
1235 		return (NULL);
1236 	}
1237 
1238 	PCM_UNLOCK(d);
1239 	b = NULL;
1240 	bs = NULL;
1241 
1242 	c = malloc(sizeof(*c), M_DEVBUF, M_WAITOK | M_ZERO);
1243 	c->methods = kobj_create(cls, M_DEVBUF, M_WAITOK | M_ZERO);
1244 	chn_lockinit(c, dir);
1245 	CHN_INIT(c, children);
1246 	CHN_INIT(c, children.busy);
1247 	c->direction = direction;
1248 	c->type = dir;
1249 	c->unit = alloc_unr(chn_getunr(d, c->type));
1250 	c->format = SND_FORMAT(AFMT_U8, 1, 0);
1251 	c->speed = DSP_DEFAULT_SPEED;
1252 	c->pid = -1;
1253 	c->latency = -1;
1254 	c->timeout = 1;
1255 	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
1256 	c->parentsnddev = d;
1257 	c->parentchannel = parent;
1258 	c->dev = d->dev;
1259 	c->trigger = PCMTRIG_STOP;
1260 	strlcpy(c->name, chn_mkname(buf, sizeof(buf), c), sizeof(c->name));
1261 
1262 	c->matrix = *feeder_matrix_id_map(SND_CHN_MATRIX_1_0);
1263 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1264 
1265 	for (i = 0; i < SND_CHN_T_MAX; i++)
1266 		c->volume[SND_VOL_C_MASTER][i] = SND_VOL_0DB_MASTER;
1267 
1268 	c->volume[SND_VOL_C_MASTER][SND_CHN_T_VOL_0DB] = SND_VOL_0DB_MASTER;
1269 	c->volume[SND_VOL_C_PCM][SND_CHN_T_VOL_0DB] = chn_vol_0db_pcm;
1270 
1271 	CHN_LOCK(c);
1272 	chn_vpc_reset(c, SND_VOL_C_PCM, 1);
1273 	CHN_UNLOCK(c);
1274 
1275 	fc = feeder_getclass(NULL);
1276 	if (fc == NULL) {
1277 		device_printf(d->dev, "%s(): failed to get feeder class\n",
1278 		    __func__);
1279 		goto fail;
1280 	}
1281 	if (feeder_add(c, fc, NULL)) {
1282 		device_printf(d->dev, "%s(): failed to add feeder\n", __func__);
1283 		goto fail;
1284 	}
1285 
1286 	b = sndbuf_create(c->dev, c->name, "primary", c);
1287 	bs = sndbuf_create(c->dev, c->name, "secondary", c);
1288 	if (b == NULL || bs == NULL) {
1289 		device_printf(d->dev, "%s(): failed to create %s buffer\n",
1290 		    __func__, b == NULL ? "hardware" : "software");
1291 		goto fail;
1292 	}
1293 	c->bufhard = b;
1294 	c->bufsoft = bs;
1295 
1296 	c->devinfo = CHANNEL_INIT(c->methods, devinfo, b, c, direction);
1297 	if (c->devinfo == NULL) {
1298 		device_printf(d->dev, "%s(): CHANNEL_INIT() failed\n", __func__);
1299 		goto fail;
1300 	}
1301 
1302 	if ((sndbuf_getsize(b) == 0) && ((c->flags & CHN_F_VIRTUAL) == 0)) {
1303 		device_printf(d->dev, "%s(): hardware buffer's size is 0\n",
1304 		    __func__);
1305 		goto fail;
1306 	}
1307 
1308 	sndbuf_setfmt(b, c->format);
1309 	sndbuf_setspd(b, c->speed);
1310 	sndbuf_setfmt(bs, c->format);
1311 	sndbuf_setspd(bs, c->speed);
1312 	sndbuf_setup(bs, NULL, 0);
1313 
1314 	/**
1315 	 * @todo Should this be moved somewhere else?  The primary buffer
1316 	 * 	 is allocated by the driver or via DMA map setup, and tmpbuf
1317 	 * 	 seems to only come into existence in sndbuf_resize().
1318 	 */
1319 	if (c->direction == PCMDIR_PLAY) {
1320 		bs->sl = sndbuf_getmaxsize(bs);
1321 		bs->shadbuf = malloc(bs->sl, M_DEVBUF, M_WAITOK);
1322 	}
1323 
1324 	PCM_LOCK(d);
1325 	CHN_INSERT_SORT_ASCEND(d, c, channels.pcm);
1326 
1327 	switch (c->type) {
1328 	case PCMDIR_PLAY:
1329 		d->playcount++;
1330 		break;
1331 	case PCMDIR_PLAY_VIRTUAL:
1332 		d->pvchancount++;
1333 		break;
1334 	case PCMDIR_REC:
1335 		d->reccount++;
1336 		break;
1337 	case PCMDIR_REC_VIRTUAL:
1338 		d->rvchancount++;
1339 		break;
1340 	default:
1341 		__assert_unreachable();
1342 	}
1343 
1344 	return (c);
1345 
1346 fail:
1347 	free_unr(chn_getunr(d, c->type), c->unit);
1348 	feeder_remove(c);
1349 	if (c->devinfo && CHANNEL_FREE(c->methods, c->devinfo))
1350 		sndbuf_free(b);
1351 	if (bs)
1352 		sndbuf_destroy(bs);
1353 	if (b)
1354 		sndbuf_destroy(b);
1355 	CHN_LOCK(c);
1356 	chn_lockdestroy(c);
1357 
1358 	kobj_delete(c->methods, M_DEVBUF);
1359 	free(c, M_DEVBUF);
1360 
1361 	PCM_LOCK(d);
1362 
1363 	return (NULL);
1364 }
1365 
1366 void
1367 chn_kill(struct pcm_channel *c)
1368 {
1369 	struct snddev_info *d = c->parentsnddev;
1370 	struct snd_dbuf *b = c->bufhard;
1371 	struct snd_dbuf *bs = c->bufsoft;
1372 
1373 	PCM_BUSYASSERT(c->parentsnddev);
1374 
1375 	PCM_LOCK(d);
1376 	CHN_REMOVE(d, c, channels.pcm);
1377 
1378 	switch (c->type) {
1379 	case PCMDIR_PLAY:
1380 		d->playcount--;
1381 		break;
1382 	case PCMDIR_PLAY_VIRTUAL:
1383 		d->pvchancount--;
1384 		break;
1385 	case PCMDIR_REC:
1386 		d->reccount--;
1387 		break;
1388 	case PCMDIR_REC_VIRTUAL:
1389 		d->rvchancount--;
1390 		break;
1391 	default:
1392 		__assert_unreachable();
1393 	}
1394 	PCM_UNLOCK(d);
1395 
1396 	if (CHN_STARTED(c)) {
1397 		CHN_LOCK(c);
1398 		chn_trigger(c, PCMTRIG_ABORT);
1399 		CHN_UNLOCK(c);
1400 	}
1401 	free_unr(chn_getunr(c->parentsnddev, c->type), c->unit);
1402 	feeder_remove(c);
1403 	if (CHANNEL_FREE(c->methods, c->devinfo))
1404 		sndbuf_free(b);
1405 	sndbuf_destroy(bs);
1406 	sndbuf_destroy(b);
1407 	CHN_LOCK(c);
1408 	c->flags |= CHN_F_DEAD;
1409 	chn_lockdestroy(c);
1410 	kobj_delete(c->methods, M_DEVBUF);
1411 	free(c, M_DEVBUF);
1412 }
1413 
1414 void
1415 chn_shutdown(struct pcm_channel *c)
1416 {
1417 	CHN_LOCKASSERT(c);
1418 
1419 	chn_wakeup(c);
1420 	c->flags |= CHN_F_DEAD;
1421 }
1422 
1423 /* release a locked channel and unlock it */
1424 int
1425 chn_release(struct pcm_channel *c)
1426 {
1427 	PCM_BUSYASSERT(c->parentsnddev);
1428 	CHN_LOCKASSERT(c);
1429 
1430 	c->flags &= ~CHN_F_BUSY;
1431 	c->pid = -1;
1432 	strlcpy(c->comm, CHN_COMM_UNUSED, sizeof(c->comm));
1433 	CHN_UNLOCK(c);
1434 
1435 	return (0);
1436 }
1437 
1438 int
1439 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
1440     int center)
1441 {
1442 	int i, ret;
1443 
1444 	ret = 0;
1445 
1446 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1447 		if ((1 << i) & SND_CHN_LEFT_MASK)
1448 			ret |= chn_setvolume_matrix(c, vc, i, left);
1449 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1450 			ret |= chn_setvolume_matrix(c, vc, i, right) << 8;
1451 		else
1452 			ret |= chn_setvolume_matrix(c, vc, i, center) << 16;
1453 	}
1454 
1455 	return (ret);
1456 }
1457 
1458 int
1459 chn_setvolume_matrix(struct pcm_channel *c, int vc, int vt, int val)
1460 {
1461 	int i;
1462 
1463 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1464 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1465 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN &&
1466 	    vt <= SND_CHN_T_END)) && (vt != SND_CHN_T_VOL_0DB ||
1467 	    (val >= SND_VOL_0DB_MIN && val <= SND_VOL_0DB_MAX)),
1468 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d val=%d",
1469 	    __func__, c, vc, vt, val));
1470 	CHN_LOCKASSERT(c);
1471 
1472 	if (val < 0)
1473 		val = 0;
1474 	if (val > 100)
1475 		val = 100;
1476 
1477 	c->volume[vc][vt] = val;
1478 
1479 	/*
1480 	 * Do relative calculation here and store it into class + 1
1481 	 * to ease the job of feeder_volume.
1482 	 */
1483 	if (vc == SND_VOL_C_MASTER) {
1484 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1485 		    vc += SND_VOL_C_STEP)
1486 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1487 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1488 	} else if (vc & 1) {
1489 		if (vt == SND_CHN_T_VOL_0DB)
1490 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1491 			    i += SND_CHN_T_STEP) {
1492 				c->volume[SND_VOL_C_VAL(vc)][i] =
1493 				    SND_VOL_CALC_VAL(c->volume, vc, i);
1494 			}
1495 		else
1496 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1497 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1498 	}
1499 
1500 	return (val);
1501 }
1502 
1503 int
1504 chn_getvolume_matrix(struct pcm_channel *c, int vc, int vt)
1505 {
1506 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1507 	    (vt == SND_CHN_T_VOL_0DB ||
1508 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1509 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d",
1510 	    __func__, c, vc, vt));
1511 	CHN_LOCKASSERT(c);
1512 
1513 	return (c->volume[vc][vt]);
1514 }
1515 
1516 int
1517 chn_setmute_multi(struct pcm_channel *c, int vc, int mute)
1518 {
1519 	int i, ret;
1520 
1521 	ret = 0;
1522 
1523 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1524 		if ((1 << i) & SND_CHN_LEFT_MASK)
1525 			ret |= chn_setmute_matrix(c, vc, i, mute);
1526 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1527 			ret |= chn_setmute_matrix(c, vc, i, mute) << 8;
1528 		else
1529 			ret |= chn_setmute_matrix(c, vc, i, mute) << 16;
1530 	}
1531 	return (ret);
1532 }
1533 
1534 int
1535 chn_setmute_matrix(struct pcm_channel *c, int vc, int vt, int mute)
1536 {
1537 	int i;
1538 
1539 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1540 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1541 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1542 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d mute=%d",
1543 	    __func__, c, vc, vt, mute));
1544 
1545 	CHN_LOCKASSERT(c);
1546 
1547 	mute = (mute != 0);
1548 
1549 	c->muted[vc][vt] = mute;
1550 
1551 	/*
1552 	 * Do relative calculation here and store it into class + 1
1553 	 * to ease the job of feeder_volume.
1554 	 */
1555 	if (vc == SND_VOL_C_MASTER) {
1556 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1557 		    vc += SND_VOL_C_STEP)
1558 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1559 	} else if (vc & 1) {
1560 		if (vt == SND_CHN_T_VOL_0DB) {
1561 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1562 			    i += SND_CHN_T_STEP) {
1563 				c->muted[SND_VOL_C_VAL(vc)][i] = mute;
1564 			}
1565 		} else {
1566 			c->muted[SND_VOL_C_VAL(vc)][vt] = mute;
1567 		}
1568 	}
1569 	return (mute);
1570 }
1571 
1572 int
1573 chn_getmute_matrix(struct pcm_channel *c, int vc, int vt)
1574 {
1575 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1576 	    (vt == SND_CHN_T_VOL_0DB ||
1577 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1578 	    ("%s(): invalid mute matrix c=%p vc=%d vt=%d",
1579 	    __func__, c, vc, vt));
1580 	CHN_LOCKASSERT(c);
1581 
1582 	return (c->muted[vc][vt]);
1583 }
1584 
1585 struct pcmchan_matrix *
1586 chn_getmatrix(struct pcm_channel *c)
1587 {
1588 
1589 	KASSERT(c != NULL, ("%s(): NULL channel", __func__));
1590 	CHN_LOCKASSERT(c);
1591 
1592 	if (!(c->format & AFMT_CONVERTIBLE))
1593 		return (NULL);
1594 
1595 	return (&c->matrix);
1596 }
1597 
1598 int
1599 chn_setmatrix(struct pcm_channel *c, struct pcmchan_matrix *m)
1600 {
1601 
1602 	KASSERT(c != NULL && m != NULL,
1603 	    ("%s(): NULL channel or matrix", __func__));
1604 	CHN_LOCKASSERT(c);
1605 
1606 	if (!(c->format & AFMT_CONVERTIBLE))
1607 		return (EINVAL);
1608 
1609 	c->matrix = *m;
1610 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1611 
1612 	return (chn_setformat(c, SND_FORMAT(c->format, m->channels, m->ext)));
1613 }
1614 
1615 /*
1616  * XXX chn_oss_* exists for the sake of compatibility.
1617  */
1618 int
1619 chn_oss_getorder(struct pcm_channel *c, unsigned long long *map)
1620 {
1621 
1622 	KASSERT(c != NULL && map != NULL,
1623 	    ("%s(): NULL channel or map", __func__));
1624 	CHN_LOCKASSERT(c);
1625 
1626 	if (!(c->format & AFMT_CONVERTIBLE))
1627 		return (EINVAL);
1628 
1629 	return (feeder_matrix_oss_get_channel_order(&c->matrix, map));
1630 }
1631 
1632 int
1633 chn_oss_setorder(struct pcm_channel *c, unsigned long long *map)
1634 {
1635 	struct pcmchan_matrix m;
1636 	int ret;
1637 
1638 	KASSERT(c != NULL && map != NULL,
1639 	    ("%s(): NULL channel or map", __func__));
1640 	CHN_LOCKASSERT(c);
1641 
1642 	if (!(c->format & AFMT_CONVERTIBLE))
1643 		return (EINVAL);
1644 
1645 	m = c->matrix;
1646 	ret = feeder_matrix_oss_set_channel_order(&m, map);
1647 	if (ret != 0)
1648 		return (ret);
1649 
1650 	return (chn_setmatrix(c, &m));
1651 }
1652 
1653 #define SND_CHN_OSS_FRONT	(SND_CHN_T_MASK_FL | SND_CHN_T_MASK_FR)
1654 #define SND_CHN_OSS_SURR	(SND_CHN_T_MASK_SL | SND_CHN_T_MASK_SR)
1655 #define SND_CHN_OSS_CENTER_LFE	(SND_CHN_T_MASK_FC | SND_CHN_T_MASK_LF)
1656 #define SND_CHN_OSS_REAR	(SND_CHN_T_MASK_BL | SND_CHN_T_MASK_BR)
1657 
1658 int
1659 chn_oss_getmask(struct pcm_channel *c, uint32_t *retmask)
1660 {
1661 	struct pcmchan_matrix *m;
1662 	struct pcmchan_caps *caps;
1663 	uint32_t i, format;
1664 
1665 	KASSERT(c != NULL && retmask != NULL,
1666 	    ("%s(): NULL channel or retmask", __func__));
1667 	CHN_LOCKASSERT(c);
1668 
1669 	caps = chn_getcaps(c);
1670 	if (caps == NULL || caps->fmtlist == NULL)
1671 		return (ENODEV);
1672 
1673 	for (i = 0; caps->fmtlist[i] != 0; i++) {
1674 		format = caps->fmtlist[i];
1675 		if (!(format & AFMT_CONVERTIBLE)) {
1676 			*retmask |= DSP_BIND_SPDIF;
1677 			continue;
1678 		}
1679 		m = CHANNEL_GETMATRIX(c->methods, c->devinfo, format);
1680 		if (m == NULL)
1681 			continue;
1682 		if (m->mask & SND_CHN_OSS_FRONT)
1683 			*retmask |= DSP_BIND_FRONT;
1684 		if (m->mask & SND_CHN_OSS_SURR)
1685 			*retmask |= DSP_BIND_SURR;
1686 		if (m->mask & SND_CHN_OSS_CENTER_LFE)
1687 			*retmask |= DSP_BIND_CENTER_LFE;
1688 		if (m->mask & SND_CHN_OSS_REAR)
1689 			*retmask |= DSP_BIND_REAR;
1690 	}
1691 
1692 	/* report software-supported binding mask */
1693 	if (!CHN_BITPERFECT(c) && report_soft_matrix)
1694 		*retmask |= DSP_BIND_FRONT | DSP_BIND_SURR |
1695 		    DSP_BIND_CENTER_LFE | DSP_BIND_REAR;
1696 
1697 	return (0);
1698 }
1699 
1700 void
1701 chn_vpc_reset(struct pcm_channel *c, int vc, int force)
1702 {
1703 	int i;
1704 
1705 	KASSERT(c != NULL && vc >= SND_VOL_C_BEGIN && vc <= SND_VOL_C_END,
1706 	    ("%s(): invalid reset c=%p vc=%d", __func__, c, vc));
1707 	CHN_LOCKASSERT(c);
1708 
1709 	if (force == 0 && chn_vpc_autoreset == 0)
1710 		return;
1711 
1712 	for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END; i += SND_CHN_T_STEP)
1713 		CHN_SETVOLUME(c, vc, i, c->volume[vc][SND_CHN_T_VOL_0DB]);
1714 }
1715 
1716 static u_int32_t
1717 round_pow2(u_int32_t v)
1718 {
1719 	u_int32_t ret;
1720 
1721 	if (v < 2)
1722 		v = 2;
1723 	ret = 0;
1724 	while (v >> ret)
1725 		ret++;
1726 	ret = 1 << (ret - 1);
1727 	while (ret < v)
1728 		ret <<= 1;
1729 	return ret;
1730 }
1731 
1732 static u_int32_t
1733 round_blksz(u_int32_t v, int round)
1734 {
1735 	u_int32_t ret, tmp;
1736 
1737 	if (round < 1)
1738 		round = 1;
1739 
1740 	ret = min(round_pow2(v), CHN_2NDBUFMAXSIZE >> 1);
1741 
1742 	if (ret > v && (ret >> 1) > 0 && (ret >> 1) >= ((v * 3) >> 2))
1743 		ret >>= 1;
1744 
1745 	tmp = ret - (ret % round);
1746 	while (tmp < 16 || tmp < round) {
1747 		ret <<= 1;
1748 		tmp = ret - (ret % round);
1749 	}
1750 
1751 	return ret;
1752 }
1753 
1754 /*
1755  * 4Front call it DSP Policy, while we call it "Latency Profile". The idea
1756  * is to keep 2nd buffer short so that it doesn't cause long queue during
1757  * buffer transfer.
1758  *
1759  *    Latency reference table for 48khz stereo 16bit: (PLAY)
1760  *
1761  *      +---------+------------+-----------+------------+
1762  *      | Latency | Blockcount | Blocksize | Buffersize |
1763  *      +---------+------------+-----------+------------+
1764  *      |     0   |       2    |   64      |    128     |
1765  *      +---------+------------+-----------+------------+
1766  *      |     1   |       4    |   128     |    512     |
1767  *      +---------+------------+-----------+------------+
1768  *      |     2   |       8    |   512     |    4096    |
1769  *      +---------+------------+-----------+------------+
1770  *      |     3   |      16    |   512     |    8192    |
1771  *      +---------+------------+-----------+------------+
1772  *      |     4   |      32    |   512     |    16384   |
1773  *      +---------+------------+-----------+------------+
1774  *      |     5   |      32    |   1024    |    32768   |
1775  *      +---------+------------+-----------+------------+
1776  *      |     6   |      16    |   2048    |    32768   |
1777  *      +---------+------------+-----------+------------+
1778  *      |     7   |       8    |   4096    |    32768   |
1779  *      +---------+------------+-----------+------------+
1780  *      |     8   |       4    |   8192    |    32768   |
1781  *      +---------+------------+-----------+------------+
1782  *      |     9   |       2    |   16384   |    32768   |
1783  *      +---------+------------+-----------+------------+
1784  *      |    10   |       2    |   32768   |    65536   |
1785  *      +---------+------------+-----------+------------+
1786  *
1787  * Recording need a different reference table. All we care is
1788  * gobbling up everything within reasonable buffering threshold.
1789  *
1790  *    Latency reference table for 48khz stereo 16bit: (REC)
1791  *
1792  *      +---------+------------+-----------+------------+
1793  *      | Latency | Blockcount | Blocksize | Buffersize |
1794  *      +---------+------------+-----------+------------+
1795  *      |     0   |     512    |   32      |    16384   |
1796  *      +---------+------------+-----------+------------+
1797  *      |     1   |     256    |   64      |    16384   |
1798  *      +---------+------------+-----------+------------+
1799  *      |     2   |     128    |   128     |    16384   |
1800  *      +---------+------------+-----------+------------+
1801  *      |     3   |      64    |   256     |    16384   |
1802  *      +---------+------------+-----------+------------+
1803  *      |     4   |      32    |   512     |    16384   |
1804  *      +---------+------------+-----------+------------+
1805  *      |     5   |      32    |   1024    |    32768   |
1806  *      +---------+------------+-----------+------------+
1807  *      |     6   |      16    |   2048    |    32768   |
1808  *      +---------+------------+-----------+------------+
1809  *      |     7   |       8    |   4096    |    32768   |
1810  *      +---------+------------+-----------+------------+
1811  *      |     8   |       4    |   8192    |    32768   |
1812  *      +---------+------------+-----------+------------+
1813  *      |     9   |       2    |   16384   |    32768   |
1814  *      +---------+------------+-----------+------------+
1815  *      |    10   |       2    |   32768   |    65536   |
1816  *      +---------+------------+-----------+------------+
1817  *
1818  * Calculations for other data rate are entirely based on these reference
1819  * tables. For normal operation, Latency 5 seems give the best, well
1820  * balanced performance for typical workload. Anything below 5 will
1821  * eat up CPU to keep up with increasing context switches because of
1822  * shorter buffer space and usually require the application to handle it
1823  * aggressively through possibly real time programming technique.
1824  *
1825  */
1826 #define CHN_LATENCY_PBLKCNT_REF				\
1827 	{{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1},		\
1828 	{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1}}
1829 #define CHN_LATENCY_PBUFSZ_REF				\
1830 	{{7, 9, 12, 13, 14, 15, 15, 15, 15, 15, 16},	\
1831 	{11, 12, 13, 14, 15, 16, 16, 16, 16, 16, 17}}
1832 
1833 #define CHN_LATENCY_RBLKCNT_REF				\
1834 	{{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1},		\
1835 	{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1}}
1836 #define CHN_LATENCY_RBUFSZ_REF				\
1837 	{{14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16},	\
1838 	{15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17}}
1839 
1840 #define CHN_LATENCY_DATA_REF	192000 /* 48khz stereo 16bit ~ 48000 x 2 x 2 */
1841 
1842 static int
1843 chn_calclatency(int dir, int latency, int bps, u_int32_t datarate,
1844 				u_int32_t max, int *rblksz, int *rblkcnt)
1845 {
1846 	static int pblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1847 	    CHN_LATENCY_PBLKCNT_REF;
1848 	static int  pbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1849 	    CHN_LATENCY_PBUFSZ_REF;
1850 	static int rblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1851 	    CHN_LATENCY_RBLKCNT_REF;
1852 	static int  rbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1853 	    CHN_LATENCY_RBUFSZ_REF;
1854 	u_int32_t bufsz;
1855 	int lprofile, blksz, blkcnt;
1856 
1857 	if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX ||
1858 	    bps < 1 || datarate < 1 ||
1859 	    !(dir == PCMDIR_PLAY || dir == PCMDIR_REC)) {
1860 		if (rblksz != NULL)
1861 			*rblksz = CHN_2NDBUFMAXSIZE >> 1;
1862 		if (rblkcnt != NULL)
1863 			*rblkcnt = 2;
1864 		printf("%s(): FAILED dir=%d latency=%d bps=%d "
1865 		    "datarate=%u max=%u\n",
1866 		    __func__, dir, latency, bps, datarate, max);
1867 		return CHN_2NDBUFMAXSIZE;
1868 	}
1869 
1870 	lprofile = chn_latency_profile;
1871 
1872 	if (dir == PCMDIR_PLAY) {
1873 		blkcnt = pblkcnts[lprofile][latency];
1874 		bufsz = pbufszs[lprofile][latency];
1875 	} else {
1876 		blkcnt = rblkcnts[lprofile][latency];
1877 		bufsz = rbufszs[lprofile][latency];
1878 	}
1879 
1880 	bufsz = round_pow2(snd_xbytes(1 << bufsz, CHN_LATENCY_DATA_REF,
1881 	    datarate));
1882 	if (bufsz > max)
1883 		bufsz = max;
1884 	blksz = round_blksz(bufsz >> blkcnt, bps);
1885 
1886 	if (rblksz != NULL)
1887 		*rblksz = blksz;
1888 	if (rblkcnt != NULL)
1889 		*rblkcnt = 1 << blkcnt;
1890 
1891 	return blksz << blkcnt;
1892 }
1893 
1894 static int
1895 chn_resizebuf(struct pcm_channel *c, int latency,
1896 					int blkcnt, int blksz)
1897 {
1898 	struct snd_dbuf *b, *bs, *pb;
1899 	int sblksz, sblkcnt, hblksz, hblkcnt, limit = 0, nsblksz, nsblkcnt;
1900 	int ret;
1901 
1902 	CHN_LOCKASSERT(c);
1903 
1904 	if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
1905 	    !(c->direction == PCMDIR_PLAY || c->direction == PCMDIR_REC))
1906 		return EINVAL;
1907 
1908 	if (latency == -1) {
1909 		c->latency = -1;
1910 		latency = chn_latency;
1911 	} else if (latency == -2) {
1912 		latency = c->latency;
1913 		if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1914 			latency = chn_latency;
1915 	} else if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1916 		return EINVAL;
1917 	else {
1918 		c->latency = latency;
1919 	}
1920 
1921 	bs = c->bufsoft;
1922 	b = c->bufhard;
1923 
1924 	if (!(blksz == 0 || blkcnt == -1) &&
1925 	    (blksz < 16 || blksz < sndbuf_getalign(bs) || blkcnt < 2 ||
1926 	    (blksz * blkcnt) > CHN_2NDBUFMAXSIZE))
1927 		return EINVAL;
1928 
1929 	chn_calclatency(c->direction, latency, sndbuf_getalign(bs),
1930 	    sndbuf_getalign(bs) * sndbuf_getspd(bs), CHN_2NDBUFMAXSIZE,
1931 	    &sblksz, &sblkcnt);
1932 
1933 	if (blksz == 0 || blkcnt == -1) {
1934 		if (blkcnt == -1)
1935 			c->flags &= ~CHN_F_HAS_SIZE;
1936 		if (c->flags & CHN_F_HAS_SIZE) {
1937 			blksz = sndbuf_getblksz(bs);
1938 			blkcnt = sndbuf_getblkcnt(bs);
1939 		}
1940 	} else
1941 		c->flags |= CHN_F_HAS_SIZE;
1942 
1943 	if (c->flags & CHN_F_HAS_SIZE) {
1944 		/*
1945 		 * The application has requested their own blksz/blkcnt.
1946 		 * Just obey with it, and let them toast alone. We can
1947 		 * clamp it to the nearest latency profile, but that would
1948 		 * defeat the purpose of having custom control. The least
1949 		 * we can do is round it to the nearest ^2 and align it.
1950 		 */
1951 		sblksz = round_blksz(blksz, sndbuf_getalign(bs));
1952 		sblkcnt = round_pow2(blkcnt);
1953 	}
1954 
1955 	if (c->parentchannel != NULL) {
1956 		pb = c->parentchannel->bufsoft;
1957 		CHN_UNLOCK(c);
1958 		CHN_LOCK(c->parentchannel);
1959 		chn_notify(c->parentchannel, CHN_N_BLOCKSIZE);
1960 		CHN_UNLOCK(c->parentchannel);
1961 		CHN_LOCK(c);
1962 		if (c->direction == PCMDIR_PLAY) {
1963 			limit = (pb != NULL) ?
1964 			    sndbuf_xbytes(sndbuf_getsize(pb), pb, bs) : 0;
1965 		} else {
1966 			limit = (pb != NULL) ?
1967 			    sndbuf_xbytes(sndbuf_getblksz(pb), pb, bs) * 2 : 0;
1968 		}
1969 	} else {
1970 		hblkcnt = 2;
1971 		if (c->flags & CHN_F_HAS_SIZE) {
1972 			hblksz = round_blksz(sndbuf_xbytes(sblksz, bs, b),
1973 			    sndbuf_getalign(b));
1974 			hblkcnt = round_pow2(sndbuf_getblkcnt(bs));
1975 		} else
1976 			chn_calclatency(c->direction, latency,
1977 			    sndbuf_getalign(b),
1978 			    sndbuf_getalign(b) * sndbuf_getspd(b),
1979 			    CHN_2NDBUFMAXSIZE, &hblksz, &hblkcnt);
1980 
1981 		if ((hblksz << 1) > sndbuf_getmaxsize(b))
1982 			hblksz = round_blksz(sndbuf_getmaxsize(b) >> 1,
1983 			    sndbuf_getalign(b));
1984 
1985 		while ((hblksz * hblkcnt) > sndbuf_getmaxsize(b)) {
1986 			if (hblkcnt < 4)
1987 				hblksz >>= 1;
1988 			else
1989 				hblkcnt >>= 1;
1990 		}
1991 
1992 		hblksz -= hblksz % sndbuf_getalign(b);
1993 
1994 #if 0
1995 		hblksz = sndbuf_getmaxsize(b) >> 1;
1996 		hblksz -= hblksz % sndbuf_getalign(b);
1997 		hblkcnt = 2;
1998 #endif
1999 
2000 		CHN_UNLOCK(c);
2001 		if (chn_usefrags == 0 ||
2002 		    CHANNEL_SETFRAGMENTS(c->methods, c->devinfo,
2003 		    hblksz, hblkcnt) != 0)
2004 			sndbuf_setblksz(b, CHANNEL_SETBLOCKSIZE(c->methods,
2005 			    c->devinfo, hblksz));
2006 		CHN_LOCK(c);
2007 
2008 		if (!CHN_EMPTY(c, children)) {
2009 			nsblksz = round_blksz(
2010 			    sndbuf_xbytes(sndbuf_getblksz(b), b, bs),
2011 			    sndbuf_getalign(bs));
2012 			nsblkcnt = sndbuf_getblkcnt(b);
2013 			if (c->direction == PCMDIR_PLAY) {
2014 				do {
2015 					nsblkcnt--;
2016 				} while (nsblkcnt >= 2 &&
2017 				    nsblksz * nsblkcnt >= sblksz * sblkcnt);
2018 				nsblkcnt++;
2019 			}
2020 			sblksz = nsblksz;
2021 			sblkcnt = nsblkcnt;
2022 			limit = 0;
2023 		} else
2024 			limit = sndbuf_xbytes(sndbuf_getblksz(b), b, bs) * 2;
2025 	}
2026 
2027 	if (limit > CHN_2NDBUFMAXSIZE)
2028 		limit = CHN_2NDBUFMAXSIZE;
2029 
2030 #if 0
2031 	while (limit > 0 && (sblksz * sblkcnt) > limit) {
2032 		if (sblkcnt < 4)
2033 			break;
2034 		sblkcnt >>= 1;
2035 	}
2036 #endif
2037 
2038 	while ((sblksz * sblkcnt) < limit)
2039 		sblkcnt <<= 1;
2040 
2041 	while ((sblksz * sblkcnt) > CHN_2NDBUFMAXSIZE) {
2042 		if (sblkcnt < 4)
2043 			sblksz >>= 1;
2044 		else
2045 			sblkcnt >>= 1;
2046 	}
2047 
2048 	sblksz -= sblksz % sndbuf_getalign(bs);
2049 
2050 	if (sndbuf_getblkcnt(bs) != sblkcnt || sndbuf_getblksz(bs) != sblksz ||
2051 	    sndbuf_getsize(bs) != (sblkcnt * sblksz)) {
2052 		ret = sndbuf_remalloc(bs, sblkcnt, sblksz);
2053 		if (ret != 0) {
2054 			device_printf(c->dev, "%s(): Failed: %d %d\n",
2055 			    __func__, sblkcnt, sblksz);
2056 			return ret;
2057 		}
2058 	}
2059 
2060 	/*
2061 	 * Interrupt timeout
2062 	 */
2063 	c->timeout = ((u_int64_t)hz * sndbuf_getsize(bs)) /
2064 	    ((u_int64_t)sndbuf_getspd(bs) * sndbuf_getalign(bs));
2065 	if (c->parentchannel != NULL)
2066 		c->timeout = min(c->timeout, c->parentchannel->timeout);
2067 	if (c->timeout < 1)
2068 		c->timeout = 1;
2069 
2070 	/*
2071 	 * OSSv4 docs: "By default OSS will set the low water level equal
2072 	 * to the fragment size which is optimal in most cases."
2073 	 */
2074 	c->lw = sndbuf_getblksz(bs);
2075 	chn_resetbuf(c);
2076 
2077 	if (snd_verbose > 3)
2078 		device_printf(c->dev, "%s(): %s (%s) timeout=%u "
2079 		    "b[%d/%d/%d] bs[%d/%d/%d] limit=%d\n",
2080 		    __func__, CHN_DIRSTR(c),
2081 		    (c->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
2082 		    c->timeout,
2083 		    sndbuf_getsize(b), sndbuf_getblksz(b),
2084 		    sndbuf_getblkcnt(b),
2085 		    sndbuf_getsize(bs), sndbuf_getblksz(bs),
2086 		    sndbuf_getblkcnt(bs), limit);
2087 
2088 	return 0;
2089 }
2090 
2091 int
2092 chn_setlatency(struct pcm_channel *c, int latency)
2093 {
2094 	CHN_LOCKASSERT(c);
2095 	/* Destroy blksz/blkcnt, enforce latency profile. */
2096 	return chn_resizebuf(c, latency, -1, 0);
2097 }
2098 
2099 int
2100 chn_setblocksize(struct pcm_channel *c, int blkcnt, int blksz)
2101 {
2102 	CHN_LOCKASSERT(c);
2103 	/* Destroy latency profile, enforce blksz/blkcnt */
2104 	return chn_resizebuf(c, -1, blkcnt, blksz);
2105 }
2106 
2107 int
2108 chn_setparam(struct pcm_channel *c, uint32_t format, uint32_t speed)
2109 {
2110 	struct pcmchan_caps *caps;
2111 	uint32_t hwspeed, delta;
2112 	int ret;
2113 
2114 	CHN_LOCKASSERT(c);
2115 
2116 	if (speed < 1 || format == 0 || CHN_STARTED(c))
2117 		return (EINVAL);
2118 
2119 	c->format = format;
2120 	c->speed = speed;
2121 
2122 	caps = chn_getcaps(c);
2123 
2124 	hwspeed = speed;
2125 	RANGE(hwspeed, caps->minspeed, caps->maxspeed);
2126 
2127 	sndbuf_setspd(c->bufhard, CHANNEL_SETSPEED(c->methods, c->devinfo,
2128 	    hwspeed));
2129 	hwspeed = sndbuf_getspd(c->bufhard);
2130 
2131 	delta = (hwspeed > speed) ? (hwspeed - speed) : (speed - hwspeed);
2132 
2133 	if (delta <= feeder_rate_round)
2134 		c->speed = hwspeed;
2135 
2136 	ret = feeder_chain(c);
2137 
2138 	if (ret == 0)
2139 		ret = CHANNEL_SETFORMAT(c->methods, c->devinfo,
2140 		    sndbuf_getfmt(c->bufhard));
2141 
2142 	if (ret == 0)
2143 		ret = chn_resizebuf(c, -2, 0, 0);
2144 
2145 	return (ret);
2146 }
2147 
2148 int
2149 chn_setspeed(struct pcm_channel *c, uint32_t speed)
2150 {
2151 	uint32_t oldformat, oldspeed, format;
2152 	int ret;
2153 
2154 #if 0
2155 	/* XXX force 48k */
2156 	if (c->format & AFMT_PASSTHROUGH)
2157 		speed = AFMT_PASSTHROUGH_RATE;
2158 #endif
2159 
2160 	oldformat = c->format;
2161 	oldspeed = c->speed;
2162 	format = oldformat;
2163 
2164 	ret = chn_setparam(c, format, speed);
2165 	if (ret != 0) {
2166 		if (snd_verbose > 3)
2167 			device_printf(c->dev,
2168 			    "%s(): Setting speed %d failed, "
2169 			    "falling back to %d\n",
2170 			    __func__, speed, oldspeed);
2171 		chn_setparam(c, c->format, oldspeed);
2172 	}
2173 
2174 	return (ret);
2175 }
2176 
2177 int
2178 chn_setformat(struct pcm_channel *c, uint32_t format)
2179 {
2180 	uint32_t oldformat, oldspeed, speed;
2181 	int ret;
2182 
2183 	/* XXX force stereo */
2184 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
2185 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,
2186 		    AFMT_PASSTHROUGH_EXTCHANNEL);
2187 	}
2188 
2189 	oldformat = c->format;
2190 	oldspeed = c->speed;
2191 	speed = oldspeed;
2192 
2193 	ret = chn_setparam(c, format, speed);
2194 	if (ret != 0) {
2195 		if (snd_verbose > 3)
2196 			device_printf(c->dev,
2197 			    "%s(): Format change 0x%08x failed, "
2198 			    "falling back to 0x%08x\n",
2199 			    __func__, format, oldformat);
2200 		chn_setparam(c, oldformat, oldspeed);
2201 	}
2202 
2203 	return (ret);
2204 }
2205 
2206 void
2207 chn_syncstate(struct pcm_channel *c)
2208 {
2209 	struct snddev_info *d;
2210 	struct snd_mixer *m;
2211 
2212 	d = (c != NULL) ? c->parentsnddev : NULL;
2213 	m = (d != NULL && d->mixer_dev != NULL) ? d->mixer_dev->si_drv1 :
2214 	    NULL;
2215 
2216 	if (d == NULL || m == NULL)
2217 		return;
2218 
2219 	CHN_LOCKASSERT(c);
2220 
2221 	if (c->feederflags & (1 << FEEDER_VOLUME)) {
2222 		uint32_t parent;
2223 		int vol, pvol, left, right, center;
2224 
2225 		if (c->direction == PCMDIR_PLAY &&
2226 		    (d->flags & SD_F_SOFTPCMVOL)) {
2227 			/* CHN_UNLOCK(c); */
2228 			vol = mix_get(m, SOUND_MIXER_PCM);
2229 			parent = mix_getparent(m, SOUND_MIXER_PCM);
2230 			if (parent != SOUND_MIXER_NONE)
2231 				pvol = mix_get(m, parent);
2232 			else
2233 				pvol = 100 | (100 << 8);
2234 			/* CHN_LOCK(c); */
2235 		} else {
2236 			vol = 100 | (100 << 8);
2237 			pvol = vol;
2238 		}
2239 
2240 		if (vol == -1) {
2241 			device_printf(c->dev,
2242 			    "Soft PCM Volume: Failed to read pcm "
2243 			    "default value\n");
2244 			vol = 100 | (100 << 8);
2245 		}
2246 
2247 		if (pvol == -1) {
2248 			device_printf(c->dev,
2249 			    "Soft PCM Volume: Failed to read parent "
2250 			    "default value\n");
2251 			pvol = 100 | (100 << 8);
2252 		}
2253 
2254 		left = ((vol & 0x7f) * (pvol & 0x7f)) / 100;
2255 		right = (((vol >> 8) & 0x7f) * ((pvol >> 8) & 0x7f)) / 100;
2256 		center = (left + right) >> 1;
2257 
2258 		chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right, center);
2259 	}
2260 
2261 	if (c->feederflags & (1 << FEEDER_EQ)) {
2262 		struct pcm_feeder *f;
2263 		int treble, bass, state;
2264 
2265 		/* CHN_UNLOCK(c); */
2266 		treble = mix_get(m, SOUND_MIXER_TREBLE);
2267 		bass = mix_get(m, SOUND_MIXER_BASS);
2268 		/* CHN_LOCK(c); */
2269 
2270 		if (treble == -1)
2271 			treble = 50;
2272 		else
2273 			treble = ((treble & 0x7f) +
2274 			    ((treble >> 8) & 0x7f)) >> 1;
2275 
2276 		if (bass == -1)
2277 			bass = 50;
2278 		else
2279 			bass = ((bass & 0x7f) + ((bass >> 8) & 0x7f)) >> 1;
2280 
2281 		f = feeder_find(c, FEEDER_EQ);
2282 		if (f != NULL) {
2283 			if (FEEDER_SET(f, FEEDEQ_TREBLE, treble) != 0)
2284 				device_printf(c->dev,
2285 				    "EQ: Failed to set treble -- %d\n",
2286 				    treble);
2287 			if (FEEDER_SET(f, FEEDEQ_BASS, bass) != 0)
2288 				device_printf(c->dev,
2289 				    "EQ: Failed to set bass -- %d\n",
2290 				    bass);
2291 			if (FEEDER_SET(f, FEEDEQ_PREAMP, d->eqpreamp) != 0)
2292 				device_printf(c->dev,
2293 				    "EQ: Failed to set preamp -- %d\n",
2294 				    d->eqpreamp);
2295 			if (d->flags & SD_F_EQ_BYPASSED)
2296 				state = FEEDEQ_BYPASS;
2297 			else if (d->flags & SD_F_EQ_ENABLED)
2298 				state = FEEDEQ_ENABLE;
2299 			else
2300 				state = FEEDEQ_DISABLE;
2301 			if (FEEDER_SET(f, FEEDEQ_STATE, state) != 0)
2302 				device_printf(c->dev,
2303 				    "EQ: Failed to set state -- %d\n", state);
2304 		}
2305 	}
2306 }
2307 
2308 int
2309 chn_trigger(struct pcm_channel *c, int go)
2310 {
2311 	struct snddev_info *d = c->parentsnddev;
2312 	int ret;
2313 
2314 	CHN_LOCKASSERT(c);
2315 	if (!PCMTRIG_COMMON(go))
2316 		return (CHANNEL_TRIGGER(c->methods, c->devinfo, go));
2317 
2318 	if (go == c->trigger)
2319 		return (0);
2320 
2321 	ret = CHANNEL_TRIGGER(c->methods, c->devinfo, go);
2322 	if (ret != 0)
2323 		return (ret);
2324 
2325 	switch (go) {
2326 	case PCMTRIG_START:
2327 		if (snd_verbose > 3)
2328 			device_printf(c->dev,
2329 			    "%s() %s: calling go=0x%08x , "
2330 			    "prev=0x%08x\n", __func__, c->name, go,
2331 			    c->trigger);
2332 		if (c->trigger != PCMTRIG_START) {
2333 			c->trigger = go;
2334 			CHN_UNLOCK(c);
2335 			PCM_LOCK(d);
2336 			CHN_INSERT_HEAD(d, c, channels.pcm.busy);
2337 			PCM_UNLOCK(d);
2338 			CHN_LOCK(c);
2339 			chn_syncstate(c);
2340 		}
2341 		break;
2342 	case PCMTRIG_STOP:
2343 	case PCMTRIG_ABORT:
2344 		if (snd_verbose > 3)
2345 			device_printf(c->dev,
2346 			    "%s() %s: calling go=0x%08x , "
2347 			    "prev=0x%08x\n", __func__, c->name, go,
2348 			    c->trigger);
2349 		if (c->trigger == PCMTRIG_START) {
2350 			c->trigger = go;
2351 			CHN_UNLOCK(c);
2352 			PCM_LOCK(d);
2353 			CHN_REMOVE(d, c, channels.pcm.busy);
2354 			PCM_UNLOCK(d);
2355 			CHN_LOCK(c);
2356 		}
2357 		break;
2358 	default:
2359 		break;
2360 	}
2361 
2362 	return (0);
2363 }
2364 
2365 /**
2366  * @brief Queries sound driver for sample-aligned hardware buffer pointer index
2367  *
2368  * This function obtains the hardware pointer location, then aligns it to
2369  * the current bytes-per-sample value before returning.  (E.g., a channel
2370  * running in 16 bit stereo mode would require 4 bytes per sample, so a
2371  * hwptr value ranging from 32-35 would be returned as 32.)
2372  *
2373  * @param c	PCM channel context
2374  * @returns 	sample-aligned hardware buffer pointer index
2375  */
2376 int
2377 chn_getptr(struct pcm_channel *c)
2378 {
2379 	int hwptr;
2380 
2381 	CHN_LOCKASSERT(c);
2382 	hwptr = (CHN_STARTED(c)) ? CHANNEL_GETPTR(c->methods, c->devinfo) : 0;
2383 	return (hwptr - (hwptr % sndbuf_getalign(c->bufhard)));
2384 }
2385 
2386 struct pcmchan_caps *
2387 chn_getcaps(struct pcm_channel *c)
2388 {
2389 	CHN_LOCKASSERT(c);
2390 	return CHANNEL_GETCAPS(c->methods, c->devinfo);
2391 }
2392 
2393 u_int32_t
2394 chn_getformats(struct pcm_channel *c)
2395 {
2396 	u_int32_t *fmtlist, fmts;
2397 	int i;
2398 
2399 	fmtlist = chn_getcaps(c)->fmtlist;
2400 	fmts = 0;
2401 	for (i = 0; fmtlist[i]; i++)
2402 		fmts |= fmtlist[i];
2403 
2404 	/* report software-supported formats */
2405 	if (!CHN_BITPERFECT(c) && report_soft_formats)
2406 		fmts |= AFMT_CONVERTIBLE;
2407 
2408 	return (AFMT_ENCODING(fmts));
2409 }
2410 
2411 int
2412 chn_notify(struct pcm_channel *c, u_int32_t flags)
2413 {
2414 	struct pcm_channel *ch;
2415 	struct pcmchan_caps *caps;
2416 	uint32_t bestformat, bestspeed, besthwformat, *vchanformat, *vchanrate;
2417 	uint32_t vpflags;
2418 	int dirty, err, run, nrun;
2419 
2420 	CHN_LOCKASSERT(c);
2421 
2422 	if (CHN_EMPTY(c, children))
2423 		return (ENODEV);
2424 
2425 	err = 0;
2426 
2427 	/*
2428 	 * If the hwchan is running, we can't change its rate, format or
2429 	 * blocksize
2430 	 */
2431 	run = (CHN_STARTED(c)) ? 1 : 0;
2432 	if (run)
2433 		flags &= CHN_N_VOLUME | CHN_N_TRIGGER;
2434 
2435 	if (flags & CHN_N_RATE) {
2436 		/*
2437 		 * XXX I'll make good use of this someday.
2438 		 *     However this is currently being superseded by
2439 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2440 		 */
2441 	}
2442 
2443 	if (flags & CHN_N_FORMAT) {
2444 		/*
2445 		 * XXX I'll make good use of this someday.
2446 		 *     However this is currently being superseded by
2447 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2448 		 */
2449 	}
2450 
2451 	if (flags & CHN_N_VOLUME) {
2452 		/*
2453 		 * XXX I'll make good use of this someday, though
2454 		 *     soft volume control is currently pretty much
2455 		 *     integrated.
2456 		 */
2457 	}
2458 
2459 	if (flags & CHN_N_BLOCKSIZE) {
2460 		/*
2461 		 * Set to default latency profile
2462 		 */
2463 		chn_setlatency(c, chn_latency);
2464 	}
2465 
2466 	if ((flags & CHN_N_TRIGGER) && !(c->flags & CHN_F_VCHAN_DYNAMIC)) {
2467 		nrun = CHN_EMPTY(c, children.busy) ? 0 : 1;
2468 		if (nrun && !run)
2469 			err = chn_start(c, 1);
2470 		if (!nrun && run)
2471 			chn_abort(c);
2472 		flags &= ~CHN_N_TRIGGER;
2473 	}
2474 
2475 	if (flags & CHN_N_TRIGGER) {
2476 		if (c->direction == PCMDIR_PLAY) {
2477 			vchanformat = &c->parentsnddev->pvchanformat;
2478 			vchanrate = &c->parentsnddev->pvchanrate;
2479 		} else {
2480 			vchanformat = &c->parentsnddev->rvchanformat;
2481 			vchanrate = &c->parentsnddev->rvchanrate;
2482 		}
2483 
2484 		/* Dynamic Virtual Channel */
2485 		if (!(c->flags & CHN_F_VCHAN_ADAPTIVE)) {
2486 			bestformat = *vchanformat;
2487 			bestspeed = *vchanrate;
2488 		} else {
2489 			bestformat = 0;
2490 			bestspeed = 0;
2491 		}
2492 
2493 		besthwformat = 0;
2494 		nrun = 0;
2495 		caps = chn_getcaps(c);
2496 		dirty = 0;
2497 		vpflags = 0;
2498 
2499 		CHN_FOREACH(ch, c, children.busy) {
2500 			CHN_LOCK(ch);
2501 			if ((ch->format & AFMT_PASSTHROUGH) &&
2502 			    snd_fmtvalid(ch->format, caps->fmtlist)) {
2503 				bestformat = ch->format;
2504 				bestspeed = ch->speed;
2505 				CHN_UNLOCK(ch);
2506 				vpflags = CHN_F_PASSTHROUGH;
2507 				nrun++;
2508 				break;
2509 			}
2510 			if ((ch->flags & CHN_F_EXCLUSIVE) && vpflags == 0) {
2511 				if (c->flags & CHN_F_VCHAN_ADAPTIVE) {
2512 					bestspeed = ch->speed;
2513 					RANGE(bestspeed, caps->minspeed,
2514 					    caps->maxspeed);
2515 					besthwformat = snd_fmtbest(ch->format,
2516 					    caps->fmtlist);
2517 					if (besthwformat != 0)
2518 						bestformat = besthwformat;
2519 				}
2520 				CHN_UNLOCK(ch);
2521 				vpflags = CHN_F_EXCLUSIVE;
2522 				nrun++;
2523 				continue;
2524 			}
2525 			if (!(c->flags & CHN_F_VCHAN_ADAPTIVE) ||
2526 			    vpflags != 0) {
2527 				CHN_UNLOCK(ch);
2528 				nrun++;
2529 				continue;
2530 			}
2531 			if (ch->speed > bestspeed) {
2532 				bestspeed = ch->speed;
2533 				RANGE(bestspeed, caps->minspeed,
2534 				    caps->maxspeed);
2535 			}
2536 			besthwformat = snd_fmtbest(ch->format, caps->fmtlist);
2537 			if (!(besthwformat & AFMT_VCHAN)) {
2538 				CHN_UNLOCK(ch);
2539 				nrun++;
2540 				continue;
2541 			}
2542 			if (AFMT_CHANNEL(besthwformat) >
2543 			    AFMT_CHANNEL(bestformat))
2544 				bestformat = besthwformat;
2545 			else if (AFMT_CHANNEL(besthwformat) ==
2546 			    AFMT_CHANNEL(bestformat) &&
2547 			    AFMT_BIT(besthwformat) > AFMT_BIT(bestformat))
2548 				bestformat = besthwformat;
2549 			CHN_UNLOCK(ch);
2550 			nrun++;
2551 		}
2552 
2553 		if (bestformat == 0)
2554 			bestformat = c->format;
2555 		if (bestspeed == 0)
2556 			bestspeed = c->speed;
2557 
2558 		if (bestformat != c->format || bestspeed != c->speed)
2559 			dirty = 1;
2560 
2561 		c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2562 		c->flags |= vpflags;
2563 
2564 		if (nrun && !run) {
2565 			if (dirty) {
2566 				bestspeed = CHANNEL_SETSPEED(c->methods,
2567 				    c->devinfo, bestspeed);
2568 				err = chn_reset(c, bestformat, bestspeed);
2569 			}
2570 			if (err == 0 && dirty) {
2571 				CHN_FOREACH(ch, c, children.busy) {
2572 					CHN_LOCK(ch);
2573 					if (VCHAN_SYNC_REQUIRED(ch))
2574 						vchan_sync(ch);
2575 					CHN_UNLOCK(ch);
2576 				}
2577 			}
2578 			if (err == 0) {
2579 				if (dirty)
2580 					c->flags |= CHN_F_DIRTY;
2581 				err = chn_start(c, 1);
2582 			}
2583 		}
2584 
2585 		if (nrun && run && dirty) {
2586 			chn_abort(c);
2587 			bestspeed = CHANNEL_SETSPEED(c->methods, c->devinfo,
2588 			    bestspeed);
2589 			err = chn_reset(c, bestformat, bestspeed);
2590 			if (err == 0) {
2591 				CHN_FOREACH(ch, c, children.busy) {
2592 					CHN_LOCK(ch);
2593 					if (VCHAN_SYNC_REQUIRED(ch))
2594 						vchan_sync(ch);
2595 					CHN_UNLOCK(ch);
2596 				}
2597 			}
2598 			if (err == 0) {
2599 				c->flags |= CHN_F_DIRTY;
2600 				err = chn_start(c, 1);
2601 			}
2602 		}
2603 
2604 		if (err == 0 && !(bestformat & AFMT_PASSTHROUGH) &&
2605 		    (bestformat & AFMT_VCHAN)) {
2606 			*vchanformat = bestformat;
2607 			*vchanrate = bestspeed;
2608 		}
2609 
2610 		if (!nrun && run) {
2611 			c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2612 			bestformat = *vchanformat;
2613 			bestspeed = *vchanrate;
2614 			chn_abort(c);
2615 			if (c->format != bestformat || c->speed != bestspeed)
2616 				chn_reset(c, bestformat, bestspeed);
2617 		}
2618 	}
2619 
2620 	return (err);
2621 }
2622 
2623 /**
2624  * @brief Fetch array of supported discrete sample rates
2625  *
2626  * Wrapper for CHANNEL_GETRATES.  Please see channel_if.m:getrates() for
2627  * detailed information.
2628  *
2629  * @note If the operation isn't supported, this function will just return 0
2630  *       (no rates in the array), and *rates will be set to NULL.  Callers
2631  *       should examine rates @b only if this function returns non-zero.
2632  *
2633  * @param c	pcm channel to examine
2634  * @param rates	pointer to array of integers; rate table will be recorded here
2635  *
2636  * @return number of rates in the array pointed to be @c rates
2637  */
2638 int
2639 chn_getrates(struct pcm_channel *c, int **rates)
2640 {
2641 	KASSERT(rates != NULL, ("rates is null"));
2642 	CHN_LOCKASSERT(c);
2643 	return CHANNEL_GETRATES(c->methods, c->devinfo, rates);
2644 }
2645 
2646 /**
2647  * @brief Remove channel from a sync group, if there is one.
2648  *
2649  * This function is initially intended for the following conditions:
2650  *   - Starting a syncgroup (@c SNDCTL_DSP_SYNCSTART ioctl)
2651  *   - Closing a device.  (A channel can't be destroyed if it's still in use.)
2652  *
2653  * @note Before calling this function, the syncgroup list mutex must be
2654  * held.  (Consider pcm_channel::sm protected by the SG list mutex
2655  * whether @c c is locked or not.)
2656  *
2657  * @param c	channel device to be started or closed
2658  * @returns	If this channel was the only member of a group, the group ID
2659  * 		is returned to the caller so that the caller can release it
2660  * 		via free_unr() after giving up the syncgroup lock.  Else it
2661  * 		returns 0.
2662  */
2663 int
2664 chn_syncdestroy(struct pcm_channel *c)
2665 {
2666 	struct pcmchan_syncmember *sm;
2667 	struct pcmchan_syncgroup *sg;
2668 	int sg_id;
2669 
2670 	sg_id = 0;
2671 
2672 	PCM_SG_LOCKASSERT(MA_OWNED);
2673 
2674 	if (c->sm != NULL) {
2675 		sm = c->sm;
2676 		sg = sm->parent;
2677 		c->sm = NULL;
2678 
2679 		KASSERT(sg != NULL, ("syncmember has null parent"));
2680 
2681 		SLIST_REMOVE(&sg->members, sm, pcmchan_syncmember, link);
2682 		free(sm, M_DEVBUF);
2683 
2684 		if (SLIST_EMPTY(&sg->members)) {
2685 			SLIST_REMOVE(&snd_pcm_syncgroups, sg, pcmchan_syncgroup, link);
2686 			sg_id = sg->id;
2687 			free(sg, M_DEVBUF);
2688 		}
2689 	}
2690 
2691 	return sg_id;
2692 }
2693 
2694 #ifdef OSSV4_EXPERIMENT
2695 int
2696 chn_getpeaks(struct pcm_channel *c, int *lpeak, int *rpeak)
2697 {
2698 	CHN_LOCKASSERT(c);
2699 	return CHANNEL_GETPEAKS(c->methods, c->devinfo, lpeak, rpeak);
2700 }
2701 #endif
2702