xref: /freebsd/sys/dev/sound/pcm/channel.c (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
1 /*-
2  * Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
3  * Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
4  * Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
5  * Portions Copyright (c) Luigi Rizzo <luigi@FreeBSD.org> - 1997-99
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include "opt_isa.h"
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 SND_DECLARE_FILE("$FreeBSD$");
42 
43 int report_soft_formats = 1;
44 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_formats, CTLFLAG_RW,
45 	&report_soft_formats, 1, "report software-emulated formats");
46 
47 int report_soft_matrix = 1;
48 SYSCTL_INT(_hw_snd, OID_AUTO, report_soft_matrix, CTLFLAG_RW,
49 	&report_soft_matrix, 1, "report software-emulated channel matrixing");
50 
51 int chn_latency = CHN_LATENCY_DEFAULT;
52 TUNABLE_INT("hw.snd.latency", &chn_latency);
53 
54 static int
55 sysctl_hw_snd_latency(SYSCTL_HANDLER_ARGS)
56 {
57 	int err, val;
58 
59 	val = chn_latency;
60 	err = sysctl_handle_int(oidp, &val, 0, req);
61 	if (err != 0 || req->newptr == NULL)
62 		return err;
63 	if (val < CHN_LATENCY_MIN || val > CHN_LATENCY_MAX)
64 		err = EINVAL;
65 	else
66 		chn_latency = val;
67 
68 	return err;
69 }
70 SYSCTL_PROC(_hw_snd, OID_AUTO, latency, CTLTYPE_INT | CTLFLAG_RW,
71 	0, sizeof(int), sysctl_hw_snd_latency, "I",
72 	"buffering latency (0=low ... 10=high)");
73 
74 int chn_latency_profile = CHN_LATENCY_PROFILE_DEFAULT;
75 TUNABLE_INT("hw.snd.latency_profile", &chn_latency_profile);
76 
77 static int
78 sysctl_hw_snd_latency_profile(SYSCTL_HANDLER_ARGS)
79 {
80 	int err, val;
81 
82 	val = chn_latency_profile;
83 	err = sysctl_handle_int(oidp, &val, 0, req);
84 	if (err != 0 || req->newptr == NULL)
85 		return err;
86 	if (val < CHN_LATENCY_PROFILE_MIN || val > CHN_LATENCY_PROFILE_MAX)
87 		err = EINVAL;
88 	else
89 		chn_latency_profile = val;
90 
91 	return err;
92 }
93 SYSCTL_PROC(_hw_snd, OID_AUTO, latency_profile, CTLTYPE_INT | CTLFLAG_RW,
94 	0, sizeof(int), sysctl_hw_snd_latency_profile, "I",
95 	"buffering latency profile (0=aggresive 1=safe)");
96 
97 static int chn_timeout = CHN_TIMEOUT;
98 TUNABLE_INT("hw.snd.timeout", &chn_timeout);
99 #ifdef SND_DEBUG
100 static int
101 sysctl_hw_snd_timeout(SYSCTL_HANDLER_ARGS)
102 {
103 	int err, val;
104 
105 	val = chn_timeout;
106 	err = sysctl_handle_int(oidp, &val, 0, req);
107 	if (err != 0 || req->newptr == NULL)
108 		return err;
109 	if (val < CHN_TIMEOUT_MIN || val > CHN_TIMEOUT_MAX)
110 		err = EINVAL;
111 	else
112 		chn_timeout = val;
113 
114 	return err;
115 }
116 SYSCTL_PROC(_hw_snd, OID_AUTO, timeout, CTLTYPE_INT | CTLFLAG_RW,
117 	0, sizeof(int), sysctl_hw_snd_timeout, "I",
118 	"interrupt timeout (1 - 10) seconds");
119 #endif
120 
121 static int chn_vpc_autoreset = 1;
122 TUNABLE_INT("hw.snd.vpc_autoreset", &chn_vpc_autoreset);
123 SYSCTL_INT(_hw_snd, OID_AUTO, vpc_autoreset, CTLFLAG_RW,
124 	&chn_vpc_autoreset, 0, "automatically reset channels volume to 0db");
125 
126 static int chn_vol_0db_pcm = SND_VOL_0DB_PCM;
127 TUNABLE_INT("hw.snd.vpc_0db", &chn_vol_0db_pcm);
128 
129 static void
130 chn_vpc_proc(int reset, int db)
131 {
132 	struct snddev_info *d;
133 	struct pcm_channel *c;
134 	int i;
135 
136 	for (i = 0; pcm_devclass != NULL &&
137 	    i < devclass_get_maxunit(pcm_devclass); i++) {
138 		d = devclass_get_softc(pcm_devclass, i);
139 		if (!PCM_REGISTERED(d))
140 			continue;
141 		PCM_LOCK(d);
142 		PCM_WAIT(d);
143 		PCM_ACQUIRE(d);
144 		CHN_FOREACH(c, d, channels.pcm) {
145 			CHN_LOCK(c);
146 			CHN_SETVOLUME(c, SND_VOL_C_PCM, SND_CHN_T_VOL_0DB, db);
147 			if (reset != 0)
148 				chn_vpc_reset(c, SND_VOL_C_PCM, 1);
149 			CHN_UNLOCK(c);
150 		}
151 		PCM_RELEASE(d);
152 		PCM_UNLOCK(d);
153 	}
154 }
155 
156 static int
157 sysctl_hw_snd_vpc_0db(SYSCTL_HANDLER_ARGS)
158 {
159 	int err, val;
160 
161 	val = chn_vol_0db_pcm;
162 	err = sysctl_handle_int(oidp, &val, 0, req);
163 	if (err != 0 || req->newptr == NULL)
164 		return (err);
165 	if (val < SND_VOL_0DB_MIN || val > SND_VOL_0DB_MAX)
166 		return (EINVAL);
167 
168 	chn_vol_0db_pcm = val;
169 	chn_vpc_proc(0, val);
170 
171 	return (0);
172 }
173 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_0db, CTLTYPE_INT | CTLFLAG_RW,
174 	0, sizeof(int), sysctl_hw_snd_vpc_0db, "I",
175 	"0db relative level");
176 
177 static int
178 sysctl_hw_snd_vpc_reset(SYSCTL_HANDLER_ARGS)
179 {
180 	int err, val;
181 
182 	val = 0;
183 	err = sysctl_handle_int(oidp, &val, 0, req);
184 	if (err != 0 || req->newptr == NULL || val == 0)
185 		return (err);
186 
187 	chn_vol_0db_pcm = SND_VOL_0DB_PCM;
188 	chn_vpc_proc(1, SND_VOL_0DB_PCM);
189 
190 	return (0);
191 }
192 SYSCTL_PROC(_hw_snd, OID_AUTO, vpc_reset, CTLTYPE_INT | CTLFLAG_RW,
193 	0, sizeof(int), sysctl_hw_snd_vpc_reset, "I",
194 	"reset volume on all channels");
195 
196 static int chn_usefrags = 0;
197 TUNABLE_INT("hw.snd.usefrags", &chn_usefrags);
198 static int chn_syncdelay = -1;
199 TUNABLE_INT("hw.snd.syncdelay", &chn_syncdelay);
200 #ifdef SND_DEBUG
201 SYSCTL_INT(_hw_snd, OID_AUTO, usefrags, CTLFLAG_RW,
202 	&chn_usefrags, 1, "prefer setfragments() over setblocksize()");
203 SYSCTL_INT(_hw_snd, OID_AUTO, syncdelay, CTLFLAG_RW,
204 	&chn_syncdelay, 1,
205 	"append (0-1000) millisecond trailing buffer delay on each sync");
206 #endif
207 
208 /**
209  * @brief Channel sync group lock
210  *
211  * Clients should acquire this lock @b without holding any channel locks
212  * before touching syncgroups or the main syncgroup list.
213  */
214 struct mtx snd_pcm_syncgroups_mtx;
215 MTX_SYSINIT(pcm_syncgroup, &snd_pcm_syncgroups_mtx, "PCM channel sync group lock", MTX_DEF);
216 /**
217  * @brief syncgroups' master list
218  *
219  * Each time a channel syncgroup is created, it's added to this list.  This
220  * list should only be accessed with @sa snd_pcm_syncgroups_mtx held.
221  *
222  * See SNDCTL_DSP_SYNCGROUP for more information.
223  */
224 struct pcm_synclist snd_pcm_syncgroups = SLIST_HEAD_INITIALIZER(snd_pcm_syncgroups);
225 
226 static void
227 chn_lockinit(struct pcm_channel *c, int dir)
228 {
229 	switch (dir) {
230 	case PCMDIR_PLAY:
231 		c->lock = snd_mtxcreate(c->name, "pcm play channel");
232 		cv_init(&c->intr_cv, "pcmwr");
233 		break;
234 	case PCMDIR_PLAY_VIRTUAL:
235 		c->lock = snd_mtxcreate(c->name, "pcm virtual play channel");
236 		cv_init(&c->intr_cv, "pcmwrv");
237 		break;
238 	case PCMDIR_REC:
239 		c->lock = snd_mtxcreate(c->name, "pcm record channel");
240 		cv_init(&c->intr_cv, "pcmrd");
241 		break;
242 	case PCMDIR_REC_VIRTUAL:
243 		c->lock = snd_mtxcreate(c->name, "pcm virtual record channel");
244 		cv_init(&c->intr_cv, "pcmrdv");
245 		break;
246 	default:
247 		panic("%s(): Invalid direction=%d", __func__, dir);
248 		break;
249 	}
250 
251 	cv_init(&c->cv, "pcmchn");
252 }
253 
254 static void
255 chn_lockdestroy(struct pcm_channel *c)
256 {
257 	CHN_LOCKASSERT(c);
258 
259 	CHN_BROADCAST(&c->cv);
260 	CHN_BROADCAST(&c->intr_cv);
261 
262 	cv_destroy(&c->cv);
263 	cv_destroy(&c->intr_cv);
264 
265 	snd_mtxfree(c->lock);
266 }
267 
268 /**
269  * @brief Determine channel is ready for I/O
270  *
271  * @retval 1 = ready for I/O
272  * @retval 0 = not ready for I/O
273  */
274 static int
275 chn_polltrigger(struct pcm_channel *c)
276 {
277 	struct snd_dbuf *bs = c->bufsoft;
278 	u_int delta;
279 
280 	CHN_LOCKASSERT(c);
281 
282 	if (c->flags & CHN_F_MMAP) {
283 		if (sndbuf_getprevtotal(bs) < c->lw)
284 			delta = c->lw;
285 		else
286 			delta = sndbuf_gettotal(bs) - sndbuf_getprevtotal(bs);
287 	} else {
288 		if (c->direction == PCMDIR_PLAY)
289 			delta = sndbuf_getfree(bs);
290 		else
291 			delta = sndbuf_getready(bs);
292 	}
293 
294 	return ((delta < c->lw) ? 0 : 1);
295 }
296 
297 static void
298 chn_pollreset(struct pcm_channel *c)
299 {
300 
301 	CHN_LOCKASSERT(c);
302 	sndbuf_updateprevtotal(c->bufsoft);
303 }
304 
305 static void
306 chn_wakeup(struct pcm_channel *c)
307 {
308 	struct snd_dbuf *bs;
309 	struct pcm_channel *ch;
310 
311 	CHN_LOCKASSERT(c);
312 
313 	bs = c->bufsoft;
314 
315 	if (CHN_EMPTY(c, children.busy)) {
316 		if (SEL_WAITING(sndbuf_getsel(bs)) && chn_polltrigger(c))
317 			selwakeuppri(sndbuf_getsel(bs), PRIBIO);
318 		if (c->flags & CHN_F_SLEEPING) {
319 			/*
320 			 * Ok, I can just panic it right here since it is
321 			 * quite obvious that we never allow multiple waiters
322 			 * from userland. I'm too generous...
323 			 */
324 			CHN_BROADCAST(&c->intr_cv);
325 		}
326 	} else {
327 		CHN_FOREACH(ch, c, children.busy) {
328 			CHN_LOCK(ch);
329 			chn_wakeup(ch);
330 			CHN_UNLOCK(ch);
331 		}
332 	}
333 }
334 
335 static int
336 chn_sleep(struct pcm_channel *c, int timeout)
337 {
338 	int ret;
339 
340 	CHN_LOCKASSERT(c);
341 
342 	if (c->flags & CHN_F_DEAD)
343 		return (EINVAL);
344 
345 	c->flags |= CHN_F_SLEEPING;
346 	ret = cv_timedwait_sig(&c->intr_cv, c->lock, timeout);
347 	c->flags &= ~CHN_F_SLEEPING;
348 
349 	return ((c->flags & CHN_F_DEAD) ? EINVAL : ret);
350 }
351 
352 /*
353  * chn_dmaupdate() tracks the status of a dma transfer,
354  * updating pointers.
355  */
356 
357 static unsigned int
358 chn_dmaupdate(struct pcm_channel *c)
359 {
360 	struct snd_dbuf *b = c->bufhard;
361 	unsigned int delta, old, hwptr, amt;
362 
363 	KASSERT(sndbuf_getsize(b) > 0, ("bufsize == 0"));
364 	CHN_LOCKASSERT(c);
365 
366 	old = sndbuf_gethwptr(b);
367 	hwptr = chn_getptr(c);
368 	delta = (sndbuf_getsize(b) + hwptr - old) % sndbuf_getsize(b);
369 	sndbuf_sethwptr(b, hwptr);
370 
371 	if (c->direction == PCMDIR_PLAY) {
372 		amt = min(delta, sndbuf_getready(b));
373 		amt -= amt % sndbuf_getalign(b);
374 		if (amt > 0)
375 			sndbuf_dispose(b, NULL, amt);
376 	} else {
377 		amt = min(delta, sndbuf_getfree(b));
378 		amt -= amt % sndbuf_getalign(b);
379 		if (amt > 0)
380 		       sndbuf_acquire(b, NULL, amt);
381 	}
382 	if (snd_verbose > 3 && CHN_STARTED(c) && delta == 0) {
383 		device_printf(c->dev, "WARNING: %s DMA completion "
384 			"too fast/slow ! hwptr=%u, old=%u "
385 			"delta=%u amt=%u ready=%u free=%u\n",
386 			CHN_DIRSTR(c), hwptr, old, delta, amt,
387 			sndbuf_getready(b), sndbuf_getfree(b));
388 	}
389 
390 	return delta;
391 }
392 
393 static void
394 chn_wrfeed(struct pcm_channel *c)
395 {
396     	struct snd_dbuf *b = c->bufhard;
397     	struct snd_dbuf *bs = c->bufsoft;
398 	unsigned int amt, want, wasfree;
399 
400 	CHN_LOCKASSERT(c);
401 
402 	if ((c->flags & CHN_F_MMAP) && !(c->flags & CHN_F_CLOSING))
403 		sndbuf_acquire(bs, NULL, sndbuf_getfree(bs));
404 
405 	wasfree = sndbuf_getfree(b);
406 	want = min(sndbuf_getsize(b),
407 	    imax(0, sndbuf_xbytes(sndbuf_getsize(bs), bs, b) -
408 	     sndbuf_getready(b)));
409 	amt = min(wasfree, want);
410 	if (amt > 0)
411 		sndbuf_feed(bs, b, c, c->feeder, amt);
412 
413 	/*
414 	 * Possible xruns. There should be no empty space left in buffer.
415 	 */
416 	if (sndbuf_getready(b) < want)
417 		c->xruns++;
418 
419 	if (sndbuf_getfree(b) < wasfree)
420 		chn_wakeup(c);
421 }
422 
423 #if 0
424 static void
425 chn_wrupdate(struct pcm_channel *c)
426 {
427 
428 	CHN_LOCKASSERT(c);
429 	KASSERT(c->direction == PCMDIR_PLAY, ("%s(): bad channel", __func__));
430 
431 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
432 		return;
433 	chn_dmaupdate(c);
434 	chn_wrfeed(c);
435 	/* tell the driver we've updated the primary buffer */
436 	chn_trigger(c, PCMTRIG_EMLDMAWR);
437 }
438 #endif
439 
440 static void
441 chn_wrintr(struct pcm_channel *c)
442 {
443 
444 	CHN_LOCKASSERT(c);
445 	/* update pointers in primary buffer */
446 	chn_dmaupdate(c);
447 	/* ...and feed from secondary to primary */
448 	chn_wrfeed(c);
449 	/* tell the driver we've updated the primary buffer */
450 	chn_trigger(c, PCMTRIG_EMLDMAWR);
451 }
452 
453 /*
454  * user write routine - uiomove data into secondary buffer, trigger if necessary
455  * if blocking, sleep, rinse and repeat.
456  *
457  * called externally, so must handle locking
458  */
459 
460 int
461 chn_write(struct pcm_channel *c, struct uio *buf)
462 {
463 	struct snd_dbuf *bs = c->bufsoft;
464 	void *off;
465 	int ret, timeout, sz, t, p;
466 
467 	CHN_LOCKASSERT(c);
468 
469 	ret = 0;
470 	timeout = chn_timeout * hz;
471 
472 	while (ret == 0 && buf->uio_resid > 0) {
473 		sz = min(buf->uio_resid, sndbuf_getfree(bs));
474 		if (sz > 0) {
475 			/*
476 			 * The following assumes that the free space in
477 			 * the buffer can never be less around the
478 			 * unlock-uiomove-lock sequence.
479 			 */
480 			while (ret == 0 && sz > 0) {
481 				p = sndbuf_getfreeptr(bs);
482 				t = min(sz, sndbuf_getsize(bs) - p);
483 				off = sndbuf_getbufofs(bs, p);
484 				CHN_UNLOCK(c);
485 				ret = uiomove(off, t, buf);
486 				CHN_LOCK(c);
487 				sz -= t;
488 				sndbuf_acquire(bs, NULL, t);
489 			}
490 			ret = 0;
491 			if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
492 				ret = chn_start(c, 0);
493 				if (ret != 0)
494 					c->flags |= CHN_F_DEAD;
495 			}
496 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER)) {
497 			/**
498 			 * @todo Evaluate whether EAGAIN is truly desirable.
499 			 * 	 4Front drivers behave like this, but I'm
500 			 * 	 not sure if it at all violates the "write
501 			 * 	 should be allowed to block" model.
502 			 *
503 			 * 	 The idea is that, while set with CHN_F_NOTRIGGER,
504 			 * 	 a channel isn't playing, *but* without this we
505 			 * 	 end up with "interrupt timeout / channel dead".
506 			 */
507 			ret = EAGAIN;
508 		} else {
509    			ret = chn_sleep(c, timeout);
510 			if (ret == EAGAIN) {
511 				ret = EINVAL;
512 				c->flags |= CHN_F_DEAD;
513 				device_printf(c->dev, "%s(): %s: "
514 				    "play interrupt timeout, channel dead\n",
515 				    __func__, c->name);
516 			} else if (ret == ERESTART || ret == EINTR)
517 				c->flags |= CHN_F_ABORTING;
518 		}
519 	}
520 
521 	return (ret);
522 }
523 
524 /*
525  * Feed new data from the read buffer. Can be called in the bottom half.
526  */
527 static void
528 chn_rdfeed(struct pcm_channel *c)
529 {
530     	struct snd_dbuf *b = c->bufhard;
531     	struct snd_dbuf *bs = c->bufsoft;
532 	unsigned int amt;
533 
534 	CHN_LOCKASSERT(c);
535 
536 	if (c->flags & CHN_F_MMAP)
537 		sndbuf_dispose(bs, NULL, sndbuf_getready(bs));
538 
539 	amt = sndbuf_getfree(bs);
540 	if (amt > 0)
541 		sndbuf_feed(b, bs, c, c->feeder, amt);
542 
543 	amt = sndbuf_getready(b);
544 	if (amt > 0) {
545 		c->xruns++;
546 		sndbuf_dispose(b, NULL, amt);
547 	}
548 
549 	if (sndbuf_getready(bs) > 0)
550 		chn_wakeup(c);
551 }
552 
553 #if 0
554 static void
555 chn_rdupdate(struct pcm_channel *c)
556 {
557 
558 	CHN_LOCKASSERT(c);
559 	KASSERT(c->direction == PCMDIR_REC, ("chn_rdupdate on bad channel"));
560 
561 	if ((c->flags & (CHN_F_MMAP | CHN_F_VIRTUAL)) || CHN_STOPPED(c))
562 		return;
563 	chn_trigger(c, PCMTRIG_EMLDMARD);
564 	chn_dmaupdate(c);
565 	chn_rdfeed(c);
566 }
567 #endif
568 
569 /* read interrupt routine. Must be called with interrupts blocked. */
570 static void
571 chn_rdintr(struct pcm_channel *c)
572 {
573 
574 	CHN_LOCKASSERT(c);
575 	/* tell the driver to update the primary buffer if non-dma */
576 	chn_trigger(c, PCMTRIG_EMLDMARD);
577 	/* update pointers in primary buffer */
578 	chn_dmaupdate(c);
579 	/* ...and feed from primary to secondary */
580 	chn_rdfeed(c);
581 }
582 
583 /*
584  * user read routine - trigger if necessary, uiomove data from secondary buffer
585  * if blocking, sleep, rinse and repeat.
586  *
587  * called externally, so must handle locking
588  */
589 
590 int
591 chn_read(struct pcm_channel *c, struct uio *buf)
592 {
593 	struct snd_dbuf *bs = c->bufsoft;
594 	void *off;
595 	int ret, timeout, sz, t, p;
596 
597 	CHN_LOCKASSERT(c);
598 
599 	if (CHN_STOPPED(c) && !(c->flags & CHN_F_NOTRIGGER)) {
600 		ret = chn_start(c, 0);
601 		if (ret != 0) {
602 			c->flags |= CHN_F_DEAD;
603 			return (ret);
604 		}
605 	}
606 
607 	ret = 0;
608 	timeout = chn_timeout * hz;
609 
610 	while (ret == 0 && buf->uio_resid > 0) {
611 		sz = min(buf->uio_resid, sndbuf_getready(bs));
612 		if (sz > 0) {
613 			/*
614 			 * The following assumes that the free space in
615 			 * the buffer can never be less around the
616 			 * unlock-uiomove-lock sequence.
617 			 */
618 			while (ret == 0 && sz > 0) {
619 				p = sndbuf_getreadyptr(bs);
620 				t = min(sz, sndbuf_getsize(bs) - p);
621 				off = sndbuf_getbufofs(bs, p);
622 				CHN_UNLOCK(c);
623 				ret = uiomove(off, t, buf);
624 				CHN_LOCK(c);
625 				sz -= t;
626 				sndbuf_dispose(bs, NULL, t);
627 			}
628 			ret = 0;
629 		} else if (c->flags & (CHN_F_NBIO | CHN_F_NOTRIGGER))
630 			ret = EAGAIN;
631 		else {
632    			ret = chn_sleep(c, timeout);
633 			if (ret == EAGAIN) {
634 				ret = EINVAL;
635 				c->flags |= CHN_F_DEAD;
636 				device_printf(c->dev, "%s(): %s: "
637 				    "record interrupt timeout, channel dead\n",
638 				    __func__, c->name);
639 			} else if (ret == ERESTART || ret == EINTR)
640 				c->flags |= CHN_F_ABORTING;
641 		}
642 	}
643 
644 	return (ret);
645 }
646 
647 void
648 chn_intr_locked(struct pcm_channel *c)
649 {
650 
651 	CHN_LOCKASSERT(c);
652 
653 	c->interrupts++;
654 
655 	if (c->direction == PCMDIR_PLAY)
656 		chn_wrintr(c);
657 	else
658 		chn_rdintr(c);
659 }
660 
661 void
662 chn_intr(struct pcm_channel *c)
663 {
664 
665 	if (CHN_LOCKOWNED(c)) {
666 		chn_intr_locked(c);
667 		return;
668 	}
669 
670 	CHN_LOCK(c);
671 	chn_intr_locked(c);
672 	CHN_UNLOCK(c);
673 }
674 
675 u_int32_t
676 chn_start(struct pcm_channel *c, int force)
677 {
678 	u_int32_t i, j;
679 	struct snd_dbuf *b = c->bufhard;
680 	struct snd_dbuf *bs = c->bufsoft;
681 	int err;
682 
683 	CHN_LOCKASSERT(c);
684 	/* if we're running, or if we're prevented from triggering, bail */
685 	if (CHN_STARTED(c) || ((c->flags & CHN_F_NOTRIGGER) && !force))
686 		return (EINVAL);
687 
688 	err = 0;
689 
690 	if (force) {
691 		i = 1;
692 		j = 0;
693 	} else {
694 		if (c->direction == PCMDIR_REC) {
695 			i = sndbuf_getfree(bs);
696 			j = (i > 0) ? 1 : sndbuf_getready(b);
697 		} else {
698 			if (sndbuf_getfree(bs) == 0) {
699 				i = 1;
700 				j = 0;
701 			} else {
702 				struct snd_dbuf *pb;
703 
704 				pb = CHN_BUF_PARENT(c, b);
705 				i = sndbuf_xbytes(sndbuf_getready(bs), bs, pb);
706 				j = sndbuf_getalign(pb);
707 			}
708 		}
709 		if (snd_verbose > 3 && CHN_EMPTY(c, children))
710 			device_printf(c->dev, "%s(): %s (%s) threshold "
711 			    "i=%d j=%d\n", __func__, CHN_DIRSTR(c),
712 			    (c->flags & CHN_F_VIRTUAL) ? "virtual" :
713 			    "hardware", i, j);
714 	}
715 
716 	if (i >= j) {
717 		c->flags |= CHN_F_TRIGGERED;
718 		sndbuf_setrun(b, 1);
719 		if (c->flags & CHN_F_CLOSING)
720 			c->feedcount = 2;
721 		else {
722 			c->feedcount = 0;
723 			c->interrupts = 0;
724 			c->xruns = 0;
725 		}
726 		if (c->parentchannel == NULL) {
727 			if (c->direction == PCMDIR_PLAY)
728 				sndbuf_fillsilence_rl(b,
729 				    sndbuf_xbytes(sndbuf_getsize(bs), bs, b));
730 			if (snd_verbose > 3)
731 				device_printf(c->dev,
732 				    "%s(): %s starting! (%s/%s) "
733 				    "(ready=%d force=%d i=%d j=%d "
734 				    "intrtimeout=%u latency=%dms)\n",
735 				    __func__,
736 				    (c->flags & CHN_F_HAS_VCHAN) ?
737 				    "VCHAN PARENT" : "HW", CHN_DIRSTR(c),
738 				    (c->flags & CHN_F_CLOSING) ? "closing" :
739 				    "running",
740 				    sndbuf_getready(b),
741 				    force, i, j, c->timeout,
742 				    (sndbuf_getsize(b) * 1000) /
743 				    (sndbuf_getalign(b) * sndbuf_getspd(b)));
744 		}
745 		err = chn_trigger(c, PCMTRIG_START);
746 	}
747 
748 	return (err);
749 }
750 
751 void
752 chn_resetbuf(struct pcm_channel *c)
753 {
754 	struct snd_dbuf *b = c->bufhard;
755 	struct snd_dbuf *bs = c->bufsoft;
756 
757 	c->blocks = 0;
758 	sndbuf_reset(b);
759 	sndbuf_reset(bs);
760 }
761 
762 /*
763  * chn_sync waits until the space in the given channel goes above
764  * a threshold. The threshold is checked against fl or rl respectively.
765  * Assume that the condition can become true, do not check here...
766  */
767 int
768 chn_sync(struct pcm_channel *c, int threshold)
769 {
770     	struct snd_dbuf *b, *bs;
771 	int ret, count, hcount, minflush, resid, residp, syncdelay, blksz;
772 	u_int32_t cflag;
773 
774 	CHN_LOCKASSERT(c);
775 
776 	if (c->direction != PCMDIR_PLAY)
777 		return (EINVAL);
778 
779 	bs = c->bufsoft;
780 
781 	if ((c->flags & (CHN_F_DEAD | CHN_F_ABORTING)) ||
782 	    (threshold < 1 && sndbuf_getready(bs) < 1))
783 		return (0);
784 
785 	/* if we haven't yet started and nothing is buffered, else start*/
786 	if (CHN_STOPPED(c)) {
787 		if (threshold > 0 || sndbuf_getready(bs) > 0) {
788 			ret = chn_start(c, 1);
789 			if (ret != 0)
790 				return (ret);
791 		} else
792 			return (0);
793 	}
794 
795 	b = CHN_BUF_PARENT(c, c->bufhard);
796 
797 	minflush = threshold + sndbuf_xbytes(sndbuf_getready(b), b, bs);
798 
799 	syncdelay = chn_syncdelay;
800 
801 	if (syncdelay < 0 && (threshold > 0 || sndbuf_getready(bs) > 0))
802 		minflush += sndbuf_xbytes(sndbuf_getsize(b), b, bs);
803 
804 	/*
805 	 * Append (0-1000) millisecond trailing buffer (if needed)
806 	 * for slower / high latency hardwares (notably USB audio)
807 	 * to avoid audible truncation.
808 	 */
809 	if (syncdelay > 0)
810 		minflush += (sndbuf_getalign(bs) * sndbuf_getspd(bs) *
811 		    ((syncdelay > 1000) ? 1000 : syncdelay)) / 1000;
812 
813 	minflush -= minflush % sndbuf_getalign(bs);
814 
815 	if (minflush > 0) {
816 		threshold = min(minflush, sndbuf_getfree(bs));
817 		sndbuf_clear(bs, threshold);
818 		sndbuf_acquire(bs, NULL, threshold);
819 		minflush -= threshold;
820 	}
821 
822 	resid = sndbuf_getready(bs);
823 	residp = resid;
824 	blksz = sndbuf_getblksz(b);
825 	if (blksz < 1) {
826 		device_printf(c->dev,
827 		    "%s(): WARNING: blksz < 1 ! maxsize=%d [%d/%d/%d]\n",
828 		    __func__, sndbuf_getmaxsize(b), sndbuf_getsize(b),
829 		    sndbuf_getblksz(b), sndbuf_getblkcnt(b));
830 		if (sndbuf_getblkcnt(b) > 0)
831 			blksz = sndbuf_getsize(b) / sndbuf_getblkcnt(b);
832 		if (blksz < 1)
833 			blksz = 1;
834 	}
835 	count = sndbuf_xbytes(minflush + resid, bs, b) / blksz;
836 	hcount = count;
837 	ret = 0;
838 
839 	if (snd_verbose > 3)
840 		device_printf(c->dev, "%s(): [begin] timeout=%d count=%d "
841 		    "minflush=%d resid=%d\n", __func__, c->timeout, count,
842 		    minflush, resid);
843 
844 	cflag = c->flags & CHN_F_CLOSING;
845 	c->flags |= CHN_F_CLOSING;
846 	while (count > 0 && (resid > 0 || minflush > 0)) {
847 		ret = chn_sleep(c, c->timeout);
848     		if (ret == ERESTART || ret == EINTR) {
849 			c->flags |= CHN_F_ABORTING;
850 			break;
851 		} else if (ret == 0 || ret == EAGAIN) {
852 			resid = sndbuf_getready(bs);
853 			if (resid == residp) {
854 				--count;
855 				if (snd_verbose > 3)
856 					device_printf(c->dev,
857 					    "%s(): [stalled] timeout=%d "
858 					    "count=%d hcount=%d "
859 					    "resid=%d minflush=%d\n",
860 					    __func__, c->timeout, count,
861 					    hcount, resid, minflush);
862 			} else if (resid < residp && count < hcount) {
863 				++count;
864 				if (snd_verbose > 3)
865 					device_printf(c->dev,
866 					    "%s((): [resume] timeout=%d "
867 					    "count=%d hcount=%d "
868 					    "resid=%d minflush=%d\n",
869 					    __func__, c->timeout, count,
870 					    hcount, resid, minflush);
871 			}
872 			if (minflush > 0 && sndbuf_getfree(bs) > 0) {
873 				threshold = min(minflush,
874 				    sndbuf_getfree(bs));
875 				sndbuf_clear(bs, threshold);
876 				sndbuf_acquire(bs, NULL, threshold);
877 				resid = sndbuf_getready(bs);
878 				minflush -= threshold;
879 			}
880 			residp = resid;
881 		} else
882 			break;
883 	}
884 	c->flags &= ~CHN_F_CLOSING;
885 	c->flags |= cflag;
886 
887 	if (snd_verbose > 3)
888 		device_printf(c->dev,
889 		    "%s(): timeout=%d count=%d hcount=%d resid=%d residp=%d "
890 		    "minflush=%d ret=%d\n",
891 		    __func__, c->timeout, count, hcount, resid, residp,
892 		    minflush, ret);
893 
894     	return (0);
895 }
896 
897 /* called externally, handle locking */
898 int
899 chn_poll(struct pcm_channel *c, int ev, struct thread *td)
900 {
901 	struct snd_dbuf *bs = c->bufsoft;
902 	int ret;
903 
904 	CHN_LOCKASSERT(c);
905 
906     	if (!(c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED))) {
907 		ret = chn_start(c, 1);
908 		if (ret != 0)
909 			return (0);
910 	}
911 
912 	ret = 0;
913 	if (chn_polltrigger(c)) {
914 		chn_pollreset(c);
915 		ret = ev;
916 	} else
917 		selrecord(td, sndbuf_getsel(bs));
918 
919 	return (ret);
920 }
921 
922 /*
923  * chn_abort terminates a running dma transfer.  it may sleep up to 200ms.
924  * it returns the number of bytes that have not been transferred.
925  *
926  * called from: dsp_close, dsp_ioctl, with channel locked
927  */
928 int
929 chn_abort(struct pcm_channel *c)
930 {
931     	int missing = 0;
932     	struct snd_dbuf *b = c->bufhard;
933     	struct snd_dbuf *bs = c->bufsoft;
934 
935 	CHN_LOCKASSERT(c);
936 	if (CHN_STOPPED(c))
937 		return 0;
938 	c->flags |= CHN_F_ABORTING;
939 
940 	c->flags &= ~CHN_F_TRIGGERED;
941 	/* kill the channel */
942 	chn_trigger(c, PCMTRIG_ABORT);
943 	sndbuf_setrun(b, 0);
944 	if (!(c->flags & CHN_F_VIRTUAL))
945 		chn_dmaupdate(c);
946     	missing = sndbuf_getready(bs);
947 
948 	c->flags &= ~CHN_F_ABORTING;
949 	return missing;
950 }
951 
952 /*
953  * this routine tries to flush the dma transfer. It is called
954  * on a close of a playback channel.
955  * first, if there is data in the buffer, but the dma has not yet
956  * begun, we need to start it.
957  * next, we wait for the play buffer to drain
958  * finally, we stop the dma.
959  *
960  * called from: dsp_close, not valid for record channels.
961  */
962 
963 int
964 chn_flush(struct pcm_channel *c)
965 {
966     	struct snd_dbuf *b = c->bufhard;
967 
968 	CHN_LOCKASSERT(c);
969 	KASSERT(c->direction == PCMDIR_PLAY, ("chn_flush on bad channel"));
970     	DEB(printf("chn_flush: c->flags 0x%08x\n", c->flags));
971 
972 	c->flags |= CHN_F_CLOSING;
973 	chn_sync(c, 0);
974 	c->flags &= ~CHN_F_TRIGGERED;
975 	/* kill the channel */
976 	chn_trigger(c, PCMTRIG_ABORT);
977 	sndbuf_setrun(b, 0);
978 
979     	c->flags &= ~CHN_F_CLOSING;
980     	return 0;
981 }
982 
983 int
984 snd_fmtvalid(uint32_t fmt, uint32_t *fmtlist)
985 {
986 	int i;
987 
988 	for (i = 0; fmtlist[i] != 0; i++) {
989 		if (fmt == fmtlist[i] ||
990 		    ((fmt & AFMT_PASSTHROUGH) &&
991 		    (AFMT_ENCODING(fmt) & fmtlist[i])))
992 			return (1);
993 	}
994 
995 	return (0);
996 }
997 
998 static const struct {
999 	char *name, *alias1, *alias2;
1000 	uint32_t afmt;
1001 } afmt_tab[] = {
1002 	{  "alaw",  NULL, NULL, AFMT_A_LAW  },
1003 	{ "mulaw",  NULL, NULL, AFMT_MU_LAW },
1004 	{    "u8",   "8", NULL, AFMT_U8     },
1005 	{    "s8",  NULL, NULL, AFMT_S8     },
1006 #if BYTE_ORDER == LITTLE_ENDIAN
1007 	{ "s16le", "s16", "16", AFMT_S16_LE },
1008 	{ "s16be",  NULL, NULL, AFMT_S16_BE },
1009 #else
1010 	{ "s16le",  NULL, NULL, AFMT_S16_LE },
1011 	{ "s16be", "s16", "16", AFMT_S16_BE },
1012 #endif
1013 	{ "u16le",  NULL, NULL, AFMT_U16_LE },
1014 	{ "u16be",  NULL, NULL, AFMT_U16_BE },
1015 	{ "s24le",  NULL, NULL, AFMT_S24_LE },
1016 	{ "s24be",  NULL, NULL, AFMT_S24_BE },
1017 	{ "u24le",  NULL, NULL, AFMT_U24_LE },
1018 	{ "u24be",  NULL, NULL, AFMT_U24_BE },
1019 #if BYTE_ORDER == LITTLE_ENDIAN
1020 	{ "s32le", "s32", "32", AFMT_S32_LE },
1021 	{ "s32be",  NULL, NULL, AFMT_S32_BE },
1022 #else
1023 	{ "s32le",  NULL, NULL, AFMT_S32_LE },
1024 	{ "s32be", "s32", "32", AFMT_S32_BE },
1025 #endif
1026 	{ "u32le",  NULL, NULL, AFMT_U32_LE },
1027 	{ "u32be",  NULL, NULL, AFMT_U32_BE },
1028 	{   "ac3",  NULL, NULL, AFMT_AC3    },
1029 	{    NULL,  NULL, NULL, 0           }
1030 };
1031 
1032 static const struct {
1033 	char *name, *alias1, *alias2;
1034 	int matrix_id;
1035 } matrix_id_tab[] = {
1036 	{ "1.0",  "1",   "mono", SND_CHN_MATRIX_1_0     },
1037 	{ "2.0",  "2", "stereo", SND_CHN_MATRIX_2_0     },
1038 	{ "2.1", NULL,     NULL, SND_CHN_MATRIX_2_1     },
1039 	{ "3.0",  "3",     NULL, SND_CHN_MATRIX_3_0     },
1040 	{ "3.1", NULL,     NULL, SND_CHN_MATRIX_3_1     },
1041 	{ "4.0",  "4",   "quad", SND_CHN_MATRIX_4_0     },
1042 	{ "4.1", NULL,     NULL, SND_CHN_MATRIX_4_1     },
1043 	{ "5.0",  "5",     NULL, SND_CHN_MATRIX_5_0     },
1044 	{ "5.1",  "6",     NULL, SND_CHN_MATRIX_5_1     },
1045 	{ "6.0", NULL,     NULL, SND_CHN_MATRIX_6_0     },
1046 	{ "6.1",  "7",     NULL, SND_CHN_MATRIX_6_1     },
1047 	{ "7.0", NULL,     NULL, SND_CHN_MATRIX_7_0     },
1048 	{ "7.1",  "8",     NULL, SND_CHN_MATRIX_7_1     },
1049 	{  NULL, NULL,     NULL, SND_CHN_MATRIX_UNKNOWN }
1050 };
1051 
1052 uint32_t
1053 snd_str2afmt(const char *req)
1054 {
1055 	uint32_t i, afmt;
1056 	int matrix_id;
1057 	char b1[8], b2[8];
1058 
1059 	i = sscanf(req, "%5[^:]:%6s", b1, b2);
1060 
1061 	if (i == 1) {
1062 		if (strlen(req) != strlen(b1))
1063 			return (0);
1064 		strlcpy(b2, "2.0", sizeof(b2));
1065 	} else if (i == 2) {
1066 		if (strlen(req) != (strlen(b1) + 1 + strlen(b2)))
1067 			return (0);
1068 	} else
1069 		return (0);
1070 
1071 	afmt = 0;
1072 	matrix_id = SND_CHN_MATRIX_UNKNOWN;
1073 
1074 	for (i = 0; afmt == 0 && afmt_tab[i].name != NULL; i++) {
1075 		if (strcasecmp(afmt_tab[i].name, b1) == 0 ||
1076 		    (afmt_tab[i].alias1 != NULL &&
1077 		    strcasecmp(afmt_tab[i].alias1, b1) == 0) ||
1078 		    (afmt_tab[i].alias2 != NULL &&
1079 		    strcasecmp(afmt_tab[i].alias2, b1) == 0)) {
1080 			afmt = afmt_tab[i].afmt;
1081 			strlcpy(b1, afmt_tab[i].name, sizeof(b1));
1082 		}
1083 	}
1084 
1085 	if (afmt == 0)
1086 		return (0);
1087 
1088 	for (i = 0; matrix_id == SND_CHN_MATRIX_UNKNOWN &&
1089 	    matrix_id_tab[i].name != NULL; i++) {
1090 		if (strcmp(matrix_id_tab[i].name, b2) == 0 ||
1091 		    (matrix_id_tab[i].alias1 != NULL &&
1092 		    strcmp(matrix_id_tab[i].alias1, b2) == 0) ||
1093 		    (matrix_id_tab[i].alias2 != NULL &&
1094 		    strcasecmp(matrix_id_tab[i].alias2, b2) == 0)) {
1095 			matrix_id = matrix_id_tab[i].matrix_id;
1096 			strlcpy(b2, matrix_id_tab[i].name, sizeof(b2));
1097 		}
1098 	}
1099 
1100 	if (matrix_id == SND_CHN_MATRIX_UNKNOWN)
1101 		return (0);
1102 
1103 #ifndef _KERNEL
1104 	printf("Parse OK: '%s' -> '%s:%s' %d\n", req, b1, b2,
1105 	    (int)(b2[0]) - '0' + (int)(b2[2]) - '0');
1106 #endif
1107 
1108 	return (SND_FORMAT(afmt, b2[0] - '0' + b2[2] - '0', b2[2] - '0'));
1109 }
1110 
1111 uint32_t
1112 snd_afmt2str(uint32_t afmt, char *buf, size_t len)
1113 {
1114 	uint32_t i, enc, ch, ext;
1115 	char tmp[AFMTSTR_LEN];
1116 
1117 	if (buf == NULL || len < AFMTSTR_LEN)
1118 		return (0);
1119 
1120 
1121 	bzero(tmp, sizeof(tmp));
1122 
1123 	enc = AFMT_ENCODING(afmt);
1124 	ch = AFMT_CHANNEL(afmt);
1125 	ext = AFMT_EXTCHANNEL(afmt);
1126 
1127 	for (i = 0; afmt_tab[i].name != NULL; i++) {
1128 		if (enc == afmt_tab[i].afmt) {
1129 			strlcpy(tmp, afmt_tab[i].name, sizeof(tmp));
1130 			strlcat(tmp, ":", sizeof(tmp));
1131 			break;
1132 		}
1133 	}
1134 
1135 	if (strlen(tmp) == 0)
1136 		return (0);
1137 
1138 	for (i = 0; matrix_id_tab[i].name != NULL; i++) {
1139 		if (ch == (matrix_id_tab[i].name[0] - '0' +
1140 		    matrix_id_tab[i].name[2] - '0') &&
1141 		    ext == (matrix_id_tab[i].name[2] - '0')) {
1142 			strlcat(tmp, matrix_id_tab[i].name, sizeof(tmp));
1143 			break;
1144 		}
1145 	}
1146 
1147 	if (strlen(tmp) == 0)
1148 		return (0);
1149 
1150 	strlcpy(buf, tmp, len);
1151 
1152 	return (snd_str2afmt(buf));
1153 }
1154 
1155 int
1156 chn_reset(struct pcm_channel *c, uint32_t fmt, uint32_t spd)
1157 {
1158 	int r;
1159 
1160 	CHN_LOCKASSERT(c);
1161 	c->feedcount = 0;
1162 	c->flags &= CHN_F_RESET;
1163 	c->interrupts = 0;
1164 	c->timeout = 1;
1165 	c->xruns = 0;
1166 
1167 	c->flags |= (pcm_getflags(c->dev) & SD_F_BITPERFECT) ?
1168 	    CHN_F_BITPERFECT : 0;
1169 
1170 	r = CHANNEL_RESET(c->methods, c->devinfo);
1171 	if (r == 0 && fmt != 0 && spd != 0) {
1172 		r = chn_setparam(c, fmt, spd);
1173 		fmt = 0;
1174 		spd = 0;
1175 	}
1176 	if (r == 0 && fmt != 0)
1177 		r = chn_setformat(c, fmt);
1178 	if (r == 0 && spd != 0)
1179 		r = chn_setspeed(c, spd);
1180 	if (r == 0)
1181 		r = chn_setlatency(c, chn_latency);
1182 	if (r == 0) {
1183 		chn_resetbuf(c);
1184 		r = CHANNEL_RESETDONE(c->methods, c->devinfo);
1185 	}
1186 	return r;
1187 }
1188 
1189 int
1190 chn_init(struct pcm_channel *c, void *devinfo, int dir, int direction)
1191 {
1192 	struct feeder_class *fc;
1193 	struct snd_dbuf *b, *bs;
1194 	int i, ret;
1195 
1196 	if (chn_timeout < CHN_TIMEOUT_MIN || chn_timeout > CHN_TIMEOUT_MAX)
1197 		chn_timeout = CHN_TIMEOUT;
1198 
1199 	chn_lockinit(c, dir);
1200 
1201 	b = NULL;
1202 	bs = NULL;
1203 	CHN_INIT(c, children);
1204 	CHN_INIT(c, children.busy);
1205 	c->devinfo = NULL;
1206 	c->feeder = NULL;
1207 	c->latency = -1;
1208 	c->timeout = 1;
1209 
1210 	ret = ENOMEM;
1211 	b = sndbuf_create(c->dev, c->name, "primary", c);
1212 	if (b == NULL)
1213 		goto out;
1214 	bs = sndbuf_create(c->dev, c->name, "secondary", c);
1215 	if (bs == NULL)
1216 		goto out;
1217 
1218 	CHN_LOCK(c);
1219 
1220 	ret = EINVAL;
1221 	fc = feeder_getclass(NULL);
1222 	if (fc == NULL)
1223 		goto out;
1224 	if (chn_addfeeder(c, fc, NULL))
1225 		goto out;
1226 
1227 	/*
1228 	 * XXX - sndbuf_setup() & sndbuf_resize() expect to be called
1229 	 *	 with the channel unlocked because they are also called
1230 	 *	 from driver methods that don't know about locking
1231 	 */
1232 	CHN_UNLOCK(c);
1233 	sndbuf_setup(bs, NULL, 0);
1234 	CHN_LOCK(c);
1235 	c->bufhard = b;
1236 	c->bufsoft = bs;
1237 	c->flags = 0;
1238 	c->feederflags = 0;
1239 	c->sm = NULL;
1240 	c->format = SND_FORMAT(AFMT_U8, 1, 0);
1241 	c->speed = DSP_DEFAULT_SPEED;
1242 
1243 	c->matrix = *feeder_matrix_id_map(SND_CHN_MATRIX_1_0);
1244 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1245 
1246 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1247 		c->volume[SND_VOL_C_MASTER][i] = SND_VOL_0DB_MASTER;
1248 	}
1249 
1250 	c->volume[SND_VOL_C_MASTER][SND_CHN_T_VOL_0DB] = SND_VOL_0DB_MASTER;
1251 	c->volume[SND_VOL_C_PCM][SND_CHN_T_VOL_0DB] = chn_vol_0db_pcm;
1252 
1253 	chn_vpc_reset(c, SND_VOL_C_PCM, 1);
1254 
1255 	ret = ENODEV;
1256 	CHN_UNLOCK(c); /* XXX - Unlock for CHANNEL_INIT() malloc() call */
1257 	c->devinfo = CHANNEL_INIT(c->methods, devinfo, b, c, direction);
1258 	CHN_LOCK(c);
1259 	if (c->devinfo == NULL)
1260 		goto out;
1261 
1262 	ret = ENOMEM;
1263 	if ((sndbuf_getsize(b) == 0) && ((c->flags & CHN_F_VIRTUAL) == 0))
1264 		goto out;
1265 
1266 	ret = 0;
1267 	c->direction = direction;
1268 
1269 	sndbuf_setfmt(b, c->format);
1270 	sndbuf_setspd(b, c->speed);
1271 	sndbuf_setfmt(bs, c->format);
1272 	sndbuf_setspd(bs, c->speed);
1273 
1274 	/**
1275 	 * @todo Should this be moved somewhere else?  The primary buffer
1276 	 * 	 is allocated by the driver or via DMA map setup, and tmpbuf
1277 	 * 	 seems to only come into existence in sndbuf_resize().
1278 	 */
1279 	if (c->direction == PCMDIR_PLAY) {
1280 		bs->sl = sndbuf_getmaxsize(bs);
1281 		bs->shadbuf = malloc(bs->sl, M_DEVBUF, M_NOWAIT);
1282 		if (bs->shadbuf == NULL) {
1283 			ret = ENOMEM;
1284 			goto out;
1285 		}
1286 	}
1287 
1288 out:
1289 	CHN_UNLOCK(c);
1290 	if (ret) {
1291 		if (c->devinfo) {
1292 			if (CHANNEL_FREE(c->methods, c->devinfo))
1293 				sndbuf_free(b);
1294 		}
1295 		if (bs)
1296 			sndbuf_destroy(bs);
1297 		if (b)
1298 			sndbuf_destroy(b);
1299 		CHN_LOCK(c);
1300 		c->flags |= CHN_F_DEAD;
1301 		chn_lockdestroy(c);
1302 
1303 		return ret;
1304 	}
1305 
1306 	return 0;
1307 }
1308 
1309 int
1310 chn_kill(struct pcm_channel *c)
1311 {
1312     	struct snd_dbuf *b = c->bufhard;
1313     	struct snd_dbuf *bs = c->bufsoft;
1314 
1315 	if (CHN_STARTED(c)) {
1316 		CHN_LOCK(c);
1317 		chn_trigger(c, PCMTRIG_ABORT);
1318 		CHN_UNLOCK(c);
1319 	}
1320 	while (chn_removefeeder(c) == 0)
1321 		;
1322 	if (CHANNEL_FREE(c->methods, c->devinfo))
1323 		sndbuf_free(b);
1324 	sndbuf_destroy(bs);
1325 	sndbuf_destroy(b);
1326 	CHN_LOCK(c);
1327 	c->flags |= CHN_F_DEAD;
1328 	chn_lockdestroy(c);
1329 
1330 	return (0);
1331 }
1332 
1333 /* XXX Obsolete. Use *_matrix() variant instead. */
1334 int
1335 chn_setvolume(struct pcm_channel *c, int left, int right)
1336 {
1337 	int ret;
1338 
1339 	ret = chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FL, left);
1340 	ret |= chn_setvolume_matrix(c, SND_VOL_C_MASTER, SND_CHN_T_FR,
1341 	    right) << 8;
1342 
1343 	return (ret);
1344 }
1345 
1346 int
1347 chn_setvolume_multi(struct pcm_channel *c, int vc, int left, int right,
1348     int center)
1349 {
1350 	int i, ret;
1351 
1352 	ret = 0;
1353 
1354 	for (i = 0; i < SND_CHN_T_MAX; i++) {
1355 		if ((1 << i) & SND_CHN_LEFT_MASK)
1356 			ret |= chn_setvolume_matrix(c, vc, i, left);
1357 		else if ((1 << i) & SND_CHN_RIGHT_MASK)
1358 			ret |= chn_setvolume_matrix(c, vc, i, right) << 8;
1359 		else
1360 			ret |= chn_setvolume_matrix(c, vc, i, center) << 16;
1361 	}
1362 
1363 	return (ret);
1364 }
1365 
1366 int
1367 chn_setvolume_matrix(struct pcm_channel *c, int vc, int vt, int val)
1368 {
1369 	int i;
1370 
1371 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1372 	    (vc == SND_VOL_C_MASTER || (vc & 1)) &&
1373 	    (vt == SND_CHN_T_VOL_0DB || (vt >= SND_CHN_T_BEGIN &&
1374 	    vt <= SND_CHN_T_END)) && (vt != SND_CHN_T_VOL_0DB ||
1375 	    (val >= SND_VOL_0DB_MIN && val <= SND_VOL_0DB_MAX)),
1376 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d val=%d",
1377 	    __func__, c, vc, vt, val));
1378 	CHN_LOCKASSERT(c);
1379 
1380 	if (val < 0)
1381 		val = 0;
1382 	if (val > 100)
1383 		val = 100;
1384 
1385 	c->volume[vc][vt] = val;
1386 
1387 	/*
1388 	 * Do relative calculation here and store it into class + 1
1389 	 * to ease the job of feeder_volume.
1390 	 */
1391 	if (vc == SND_VOL_C_MASTER) {
1392 		for (vc = SND_VOL_C_BEGIN; vc <= SND_VOL_C_END;
1393 		    vc += SND_VOL_C_STEP)
1394 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1395 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1396 	} else if (vc & 1) {
1397 		if (vt == SND_CHN_T_VOL_0DB)
1398 			for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END;
1399 			    i += SND_CHN_T_STEP) {
1400 				c->volume[SND_VOL_C_VAL(vc)][i] =
1401 				    SND_VOL_CALC_VAL(c->volume, vc, i);
1402 			}
1403 		else
1404 			c->volume[SND_VOL_C_VAL(vc)][vt] =
1405 			    SND_VOL_CALC_VAL(c->volume, vc, vt);
1406 	}
1407 
1408 	return (val);
1409 }
1410 
1411 int
1412 chn_getvolume_matrix(struct pcm_channel *c, int vc, int vt)
1413 {
1414 	KASSERT(c != NULL && vc >= SND_VOL_C_MASTER && vc < SND_VOL_C_MAX &&
1415 	    (vt == SND_CHN_T_VOL_0DB ||
1416 	    (vt >= SND_CHN_T_BEGIN && vt <= SND_CHN_T_END)),
1417 	    ("%s(): invalid volume matrix c=%p vc=%d vt=%d",
1418 	    __func__, c, vc, vt));
1419 	CHN_LOCKASSERT(c);
1420 
1421 	return (c->volume[vc][vt]);
1422 }
1423 
1424 struct pcmchan_matrix *
1425 chn_getmatrix(struct pcm_channel *c)
1426 {
1427 
1428 	KASSERT(c != NULL, ("%s(): NULL channel", __func__));
1429 	CHN_LOCKASSERT(c);
1430 
1431 	if (!(c->format & AFMT_CONVERTIBLE))
1432 		return (NULL);
1433 
1434 	return (&c->matrix);
1435 }
1436 
1437 int
1438 chn_setmatrix(struct pcm_channel *c, struct pcmchan_matrix *m)
1439 {
1440 
1441 	KASSERT(c != NULL && m != NULL,
1442 	    ("%s(): NULL channel or matrix", __func__));
1443 	CHN_LOCKASSERT(c);
1444 
1445 	if (!(c->format & AFMT_CONVERTIBLE))
1446 		return (EINVAL);
1447 
1448 	c->matrix = *m;
1449 	c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
1450 
1451 	return (chn_setformat(c, SND_FORMAT(c->format, m->channels, m->ext)));
1452 }
1453 
1454 /*
1455  * XXX chn_oss_* exists for the sake of compatibility.
1456  */
1457 int
1458 chn_oss_getorder(struct pcm_channel *c, unsigned long long *map)
1459 {
1460 
1461 	KASSERT(c != NULL && map != NULL,
1462 	    ("%s(): NULL channel or map", __func__));
1463 	CHN_LOCKASSERT(c);
1464 
1465 	if (!(c->format & AFMT_CONVERTIBLE))
1466 		return (EINVAL);
1467 
1468 	return (feeder_matrix_oss_get_channel_order(&c->matrix, map));
1469 }
1470 
1471 int
1472 chn_oss_setorder(struct pcm_channel *c, unsigned long long *map)
1473 {
1474 	struct pcmchan_matrix m;
1475 	int ret;
1476 
1477 	KASSERT(c != NULL && map != NULL,
1478 	    ("%s(): NULL channel or map", __func__));
1479 	CHN_LOCKASSERT(c);
1480 
1481 	if (!(c->format & AFMT_CONVERTIBLE))
1482 		return (EINVAL);
1483 
1484 	m = c->matrix;
1485 	ret = feeder_matrix_oss_set_channel_order(&m, map);
1486 	if (ret != 0)
1487 		return (ret);
1488 
1489 	return (chn_setmatrix(c, &m));
1490 }
1491 
1492 #define SND_CHN_OSS_FRONT	(SND_CHN_T_MASK_FL | SND_CHN_T_MASK_FR)
1493 #define SND_CHN_OSS_SURR	(SND_CHN_T_MASK_SL | SND_CHN_T_MASK_SR)
1494 #define SND_CHN_OSS_CENTER_LFE	(SND_CHN_T_MASK_FC | SND_CHN_T_MASK_LF)
1495 #define SND_CHN_OSS_REAR	(SND_CHN_T_MASK_BL | SND_CHN_T_MASK_BR)
1496 
1497 int
1498 chn_oss_getmask(struct pcm_channel *c, uint32_t *retmask)
1499 {
1500 	struct pcmchan_matrix *m;
1501 	struct pcmchan_caps *caps;
1502 	uint32_t i, format;
1503 
1504 	KASSERT(c != NULL && retmask != NULL,
1505 	    ("%s(): NULL channel or retmask", __func__));
1506 	CHN_LOCKASSERT(c);
1507 
1508 	caps = chn_getcaps(c);
1509 	if (caps == NULL || caps->fmtlist == NULL)
1510 		return (ENODEV);
1511 
1512 	for (i = 0; caps->fmtlist[i] != 0; i++) {
1513 		format = caps->fmtlist[i];
1514 		if (!(format & AFMT_CONVERTIBLE)) {
1515 			*retmask |= DSP_BIND_SPDIF;
1516 			continue;
1517 		}
1518 		m = CHANNEL_GETMATRIX(c->methods, c->devinfo, format);
1519 		if (m == NULL)
1520 			continue;
1521 		if (m->mask & SND_CHN_OSS_FRONT)
1522 			*retmask |= DSP_BIND_FRONT;
1523 		if (m->mask & SND_CHN_OSS_SURR)
1524 			*retmask |= DSP_BIND_SURR;
1525 		if (m->mask & SND_CHN_OSS_CENTER_LFE)
1526 			*retmask |= DSP_BIND_CENTER_LFE;
1527 		if (m->mask & SND_CHN_OSS_REAR)
1528 			*retmask |= DSP_BIND_REAR;
1529 	}
1530 
1531 	/* report software-supported binding mask */
1532 	if (!CHN_BITPERFECT(c) && report_soft_matrix)
1533 		*retmask |= DSP_BIND_FRONT | DSP_BIND_SURR |
1534 		    DSP_BIND_CENTER_LFE | DSP_BIND_REAR;
1535 
1536 	return (0);
1537 }
1538 
1539 void
1540 chn_vpc_reset(struct pcm_channel *c, int vc, int force)
1541 {
1542 	int i;
1543 
1544 	KASSERT(c != NULL && vc >= SND_VOL_C_BEGIN && vc <= SND_VOL_C_END,
1545 	    ("%s(): invalid reset c=%p vc=%d", __func__, c, vc));
1546 	CHN_LOCKASSERT(c);
1547 
1548 	if (force == 0 && chn_vpc_autoreset == 0)
1549 		return;
1550 
1551 	for (i = SND_CHN_T_BEGIN; i <= SND_CHN_T_END; i += SND_CHN_T_STEP)
1552 		CHN_SETVOLUME(c, vc, i, c->volume[vc][SND_CHN_T_VOL_0DB]);
1553 }
1554 
1555 static u_int32_t
1556 round_pow2(u_int32_t v)
1557 {
1558 	u_int32_t ret;
1559 
1560 	if (v < 2)
1561 		v = 2;
1562 	ret = 0;
1563 	while (v >> ret)
1564 		ret++;
1565 	ret = 1 << (ret - 1);
1566 	while (ret < v)
1567 		ret <<= 1;
1568 	return ret;
1569 }
1570 
1571 static u_int32_t
1572 round_blksz(u_int32_t v, int round)
1573 {
1574 	u_int32_t ret, tmp;
1575 
1576 	if (round < 1)
1577 		round = 1;
1578 
1579 	ret = min(round_pow2(v), CHN_2NDBUFMAXSIZE >> 1);
1580 
1581 	if (ret > v && (ret >> 1) > 0 && (ret >> 1) >= ((v * 3) >> 2))
1582 		ret >>= 1;
1583 
1584 	tmp = ret - (ret % round);
1585 	while (tmp < 16 || tmp < round) {
1586 		ret <<= 1;
1587 		tmp = ret - (ret % round);
1588 	}
1589 
1590 	return ret;
1591 }
1592 
1593 /*
1594  * 4Front call it DSP Policy, while we call it "Latency Profile". The idea
1595  * is to keep 2nd buffer short so that it doesn't cause long queue during
1596  * buffer transfer.
1597  *
1598  *    Latency reference table for 48khz stereo 16bit: (PLAY)
1599  *
1600  *      +---------+------------+-----------+------------+
1601  *      | Latency | Blockcount | Blocksize | Buffersize |
1602  *      +---------+------------+-----------+------------+
1603  *      |     0   |       2    |   64      |    128     |
1604  *      +---------+------------+-----------+------------+
1605  *      |     1   |       4    |   128     |    512     |
1606  *      +---------+------------+-----------+------------+
1607  *      |     2   |       8    |   512     |    4096    |
1608  *      +---------+------------+-----------+------------+
1609  *      |     3   |      16    |   512     |    8192    |
1610  *      +---------+------------+-----------+------------+
1611  *      |     4   |      32    |   512     |    16384   |
1612  *      +---------+------------+-----------+------------+
1613  *      |     5   |      32    |   1024    |    32768   |
1614  *      +---------+------------+-----------+------------+
1615  *      |     6   |      16    |   2048    |    32768   |
1616  *      +---------+------------+-----------+------------+
1617  *      |     7   |       8    |   4096    |    32768   |
1618  *      +---------+------------+-----------+------------+
1619  *      |     8   |       4    |   8192    |    32768   |
1620  *      +---------+------------+-----------+------------+
1621  *      |     9   |       2    |   16384   |    32768   |
1622  *      +---------+------------+-----------+------------+
1623  *      |    10   |       2    |   32768   |    65536   |
1624  *      +---------+------------+-----------+------------+
1625  *
1626  * Recording need a different reference table. All we care is
1627  * gobbling up everything within reasonable buffering threshold.
1628  *
1629  *    Latency reference table for 48khz stereo 16bit: (REC)
1630  *
1631  *      +---------+------------+-----------+------------+
1632  *      | Latency | Blockcount | Blocksize | Buffersize |
1633  *      +---------+------------+-----------+------------+
1634  *      |     0   |     512    |   32      |    16384   |
1635  *      +---------+------------+-----------+------------+
1636  *      |     1   |     256    |   64      |    16384   |
1637  *      +---------+------------+-----------+------------+
1638  *      |     2   |     128    |   128     |    16384   |
1639  *      +---------+------------+-----------+------------+
1640  *      |     3   |      64    |   256     |    16384   |
1641  *      +---------+------------+-----------+------------+
1642  *      |     4   |      32    |   512     |    16384   |
1643  *      +---------+------------+-----------+------------+
1644  *      |     5   |      32    |   1024    |    32768   |
1645  *      +---------+------------+-----------+------------+
1646  *      |     6   |      16    |   2048    |    32768   |
1647  *      +---------+------------+-----------+------------+
1648  *      |     7   |       8    |   4096    |    32768   |
1649  *      +---------+------------+-----------+------------+
1650  *      |     8   |       4    |   8192    |    32768   |
1651  *      +---------+------------+-----------+------------+
1652  *      |     9   |       2    |   16384   |    32768   |
1653  *      +---------+------------+-----------+------------+
1654  *      |    10   |       2    |   32768   |    65536   |
1655  *      +---------+------------+-----------+------------+
1656  *
1657  * Calculations for other data rate are entirely based on these reference
1658  * tables. For normal operation, Latency 5 seems give the best, well
1659  * balanced performance for typical workload. Anything below 5 will
1660  * eat up CPU to keep up with increasing context switches because of
1661  * shorter buffer space and usually require the application to handle it
1662  * aggresively through possibly real time programming technique.
1663  *
1664  */
1665 #define CHN_LATENCY_PBLKCNT_REF				\
1666 	{{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1},		\
1667 	{1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 1}}
1668 #define CHN_LATENCY_PBUFSZ_REF				\
1669 	{{7, 9, 12, 13, 14, 15, 15, 15, 15, 15, 16},	\
1670 	{11, 12, 13, 14, 15, 16, 16, 16, 16, 16, 17}}
1671 
1672 #define CHN_LATENCY_RBLKCNT_REF				\
1673 	{{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1},		\
1674 	{9, 8, 7, 6, 5, 5, 4, 3, 2, 1, 1}}
1675 #define CHN_LATENCY_RBUFSZ_REF				\
1676 	{{14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16},	\
1677 	{15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17}}
1678 
1679 #define CHN_LATENCY_DATA_REF	192000 /* 48khz stereo 16bit ~ 48000 x 2 x 2 */
1680 
1681 static int
1682 chn_calclatency(int dir, int latency, int bps, u_int32_t datarate,
1683 				u_int32_t max, int *rblksz, int *rblkcnt)
1684 {
1685 	static int pblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1686 	    CHN_LATENCY_PBLKCNT_REF;
1687 	static int  pbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1688 	    CHN_LATENCY_PBUFSZ_REF;
1689 	static int rblkcnts[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1690 	    CHN_LATENCY_RBLKCNT_REF;
1691 	static int  rbufszs[CHN_LATENCY_PROFILE_MAX + 1][CHN_LATENCY_MAX + 1] =
1692 	    CHN_LATENCY_RBUFSZ_REF;
1693 	u_int32_t bufsz;
1694 	int lprofile, blksz, blkcnt;
1695 
1696 	if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX ||
1697 	    bps < 1 || datarate < 1 ||
1698 	    !(dir == PCMDIR_PLAY || dir == PCMDIR_REC)) {
1699 		if (rblksz != NULL)
1700 			*rblksz = CHN_2NDBUFMAXSIZE >> 1;
1701 		if (rblkcnt != NULL)
1702 			*rblkcnt = 2;
1703 		printf("%s(): FAILED dir=%d latency=%d bps=%d "
1704 		    "datarate=%u max=%u\n",
1705 		    __func__, dir, latency, bps, datarate, max);
1706 		return CHN_2NDBUFMAXSIZE;
1707 	}
1708 
1709 	lprofile = chn_latency_profile;
1710 
1711 	if (dir == PCMDIR_PLAY) {
1712 		blkcnt = pblkcnts[lprofile][latency];
1713 		bufsz = pbufszs[lprofile][latency];
1714 	} else {
1715 		blkcnt = rblkcnts[lprofile][latency];
1716 		bufsz = rbufszs[lprofile][latency];
1717 	}
1718 
1719 	bufsz = round_pow2(snd_xbytes(1 << bufsz, CHN_LATENCY_DATA_REF,
1720 	    datarate));
1721 	if (bufsz > max)
1722 		bufsz = max;
1723 	blksz = round_blksz(bufsz >> blkcnt, bps);
1724 
1725 	if (rblksz != NULL)
1726 		*rblksz = blksz;
1727 	if (rblkcnt != NULL)
1728 		*rblkcnt = 1 << blkcnt;
1729 
1730 	return blksz << blkcnt;
1731 }
1732 
1733 static int
1734 chn_resizebuf(struct pcm_channel *c, int latency,
1735 					int blkcnt, int blksz)
1736 {
1737 	struct snd_dbuf *b, *bs, *pb;
1738 	int sblksz, sblkcnt, hblksz, hblkcnt, limit = 0, nsblksz, nsblkcnt;
1739 	int ret;
1740 
1741 	CHN_LOCKASSERT(c);
1742 
1743 	if ((c->flags & (CHN_F_MMAP | CHN_F_TRIGGERED)) ||
1744 	    !(c->direction == PCMDIR_PLAY || c->direction == PCMDIR_REC))
1745 		return EINVAL;
1746 
1747 	if (latency == -1) {
1748 		c->latency = -1;
1749 		latency = chn_latency;
1750 	} else if (latency == -2) {
1751 		latency = c->latency;
1752 		if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1753 			latency = chn_latency;
1754 	} else if (latency < CHN_LATENCY_MIN || latency > CHN_LATENCY_MAX)
1755 		return EINVAL;
1756 	else {
1757 		c->latency = latency;
1758 	}
1759 
1760 	bs = c->bufsoft;
1761 	b = c->bufhard;
1762 
1763 	if (!(blksz == 0 || blkcnt == -1) &&
1764 	    (blksz < 16 || blksz < sndbuf_getalign(bs) || blkcnt < 2 ||
1765 	    (blksz * blkcnt) > CHN_2NDBUFMAXSIZE))
1766 		return EINVAL;
1767 
1768 	chn_calclatency(c->direction, latency, sndbuf_getalign(bs),
1769 	    sndbuf_getalign(bs) * sndbuf_getspd(bs), CHN_2NDBUFMAXSIZE,
1770 	    &sblksz, &sblkcnt);
1771 
1772 	if (blksz == 0 || blkcnt == -1) {
1773 		if (blkcnt == -1)
1774 			c->flags &= ~CHN_F_HAS_SIZE;
1775 		if (c->flags & CHN_F_HAS_SIZE) {
1776 			blksz = sndbuf_getblksz(bs);
1777 			blkcnt = sndbuf_getblkcnt(bs);
1778 		}
1779 	} else
1780 		c->flags |= CHN_F_HAS_SIZE;
1781 
1782 	if (c->flags & CHN_F_HAS_SIZE) {
1783 		/*
1784 		 * The application has requested their own blksz/blkcnt.
1785 		 * Just obey with it, and let them toast alone. We can
1786 		 * clamp it to the nearest latency profile, but that would
1787 		 * defeat the purpose of having custom control. The least
1788 		 * we can do is round it to the nearest ^2 and align it.
1789 		 */
1790 		sblksz = round_blksz(blksz, sndbuf_getalign(bs));
1791 		sblkcnt = round_pow2(blkcnt);
1792 	}
1793 
1794 	if (c->parentchannel != NULL) {
1795 		pb = c->parentchannel->bufsoft;
1796 		CHN_UNLOCK(c);
1797 		CHN_LOCK(c->parentchannel);
1798 		chn_notify(c->parentchannel, CHN_N_BLOCKSIZE);
1799 		CHN_UNLOCK(c->parentchannel);
1800 		CHN_LOCK(c);
1801 		if (c->direction == PCMDIR_PLAY) {
1802 			limit = (pb != NULL) ?
1803 			    sndbuf_xbytes(sndbuf_getsize(pb), pb, bs) : 0;
1804 		} else {
1805 			limit = (pb != NULL) ?
1806 			    sndbuf_xbytes(sndbuf_getblksz(pb), pb, bs) * 2 : 0;
1807 		}
1808 	} else {
1809 		hblkcnt = 2;
1810 		if (c->flags & CHN_F_HAS_SIZE) {
1811 			hblksz = round_blksz(sndbuf_xbytes(sblksz, bs, b),
1812 			    sndbuf_getalign(b));
1813 			hblkcnt = round_pow2(sndbuf_getblkcnt(bs));
1814 		} else
1815 			chn_calclatency(c->direction, latency,
1816 			    sndbuf_getalign(b),
1817 			    sndbuf_getalign(b) * sndbuf_getspd(b),
1818 			    CHN_2NDBUFMAXSIZE, &hblksz, &hblkcnt);
1819 
1820 		if ((hblksz << 1) > sndbuf_getmaxsize(b))
1821 			hblksz = round_blksz(sndbuf_getmaxsize(b) >> 1,
1822 			    sndbuf_getalign(b));
1823 
1824 		while ((hblksz * hblkcnt) > sndbuf_getmaxsize(b)) {
1825 			if (hblkcnt < 4)
1826 				hblksz >>= 1;
1827 			else
1828 				hblkcnt >>= 1;
1829 		}
1830 
1831 		hblksz -= hblksz % sndbuf_getalign(b);
1832 
1833 #if 0
1834 		hblksz = sndbuf_getmaxsize(b) >> 1;
1835 		hblksz -= hblksz % sndbuf_getalign(b);
1836 		hblkcnt = 2;
1837 #endif
1838 
1839 		CHN_UNLOCK(c);
1840 		if (chn_usefrags == 0 ||
1841 		    CHANNEL_SETFRAGMENTS(c->methods, c->devinfo,
1842 		    hblksz, hblkcnt) != 0)
1843 			sndbuf_setblksz(b, CHANNEL_SETBLOCKSIZE(c->methods,
1844 			    c->devinfo, hblksz));
1845 		CHN_LOCK(c);
1846 
1847 		if (!CHN_EMPTY(c, children)) {
1848 			nsblksz = round_blksz(
1849 			    sndbuf_xbytes(sndbuf_getblksz(b), b, bs),
1850 			    sndbuf_getalign(bs));
1851 			nsblkcnt = sndbuf_getblkcnt(b);
1852 			if (c->direction == PCMDIR_PLAY) {
1853 				do {
1854 					nsblkcnt--;
1855 				} while (nsblkcnt >= 2 &&
1856 				    nsblksz * nsblkcnt >= sblksz * sblkcnt);
1857 				nsblkcnt++;
1858 			}
1859 			sblksz = nsblksz;
1860 			sblkcnt = nsblkcnt;
1861 			limit = 0;
1862 		} else
1863 			limit = sndbuf_xbytes(sndbuf_getblksz(b), b, bs) * 2;
1864 	}
1865 
1866 	if (limit > CHN_2NDBUFMAXSIZE)
1867 		limit = CHN_2NDBUFMAXSIZE;
1868 
1869 #if 0
1870 	while (limit > 0 && (sblksz * sblkcnt) > limit) {
1871 		if (sblkcnt < 4)
1872 			break;
1873 		sblkcnt >>= 1;
1874 	}
1875 #endif
1876 
1877 	while ((sblksz * sblkcnt) < limit)
1878 		sblkcnt <<= 1;
1879 
1880 	while ((sblksz * sblkcnt) > CHN_2NDBUFMAXSIZE) {
1881 		if (sblkcnt < 4)
1882 			sblksz >>= 1;
1883 		else
1884 			sblkcnt >>= 1;
1885 	}
1886 
1887 	sblksz -= sblksz % sndbuf_getalign(bs);
1888 
1889 	if (sndbuf_getblkcnt(bs) != sblkcnt || sndbuf_getblksz(bs) != sblksz ||
1890 	    sndbuf_getsize(bs) != (sblkcnt * sblksz)) {
1891 		ret = sndbuf_remalloc(bs, sblkcnt, sblksz);
1892 		if (ret != 0) {
1893 			device_printf(c->dev, "%s(): Failed: %d %d\n",
1894 			    __func__, sblkcnt, sblksz);
1895 			return ret;
1896 		}
1897 	}
1898 
1899 	/*
1900 	 * Interrupt timeout
1901 	 */
1902 	c->timeout = ((u_int64_t)hz * sndbuf_getsize(bs)) /
1903 	    ((u_int64_t)sndbuf_getspd(bs) * sndbuf_getalign(bs));
1904 	if (c->parentchannel != NULL)
1905 		c->timeout = min(c->timeout, c->parentchannel->timeout);
1906 	if (c->timeout < 1)
1907 		c->timeout = 1;
1908 
1909 	/*
1910 	 * OSSv4 docs: "By default OSS will set the low water level equal
1911 	 * to the fragment size which is optimal in most cases."
1912 	 */
1913 	c->lw = sndbuf_getblksz(bs);
1914 	chn_resetbuf(c);
1915 
1916 	if (snd_verbose > 3)
1917 		device_printf(c->dev, "%s(): %s (%s) timeout=%u "
1918 		    "b[%d/%d/%d] bs[%d/%d/%d] limit=%d\n",
1919 		    __func__, CHN_DIRSTR(c),
1920 		    (c->flags & CHN_F_VIRTUAL) ? "virtual" : "hardware",
1921 		    c->timeout,
1922 		    sndbuf_getsize(b), sndbuf_getblksz(b),
1923 		    sndbuf_getblkcnt(b),
1924 		    sndbuf_getsize(bs), sndbuf_getblksz(bs),
1925 		    sndbuf_getblkcnt(bs), limit);
1926 
1927 	return 0;
1928 }
1929 
1930 int
1931 chn_setlatency(struct pcm_channel *c, int latency)
1932 {
1933 	CHN_LOCKASSERT(c);
1934 	/* Destroy blksz/blkcnt, enforce latency profile. */
1935 	return chn_resizebuf(c, latency, -1, 0);
1936 }
1937 
1938 int
1939 chn_setblocksize(struct pcm_channel *c, int blkcnt, int blksz)
1940 {
1941 	CHN_LOCKASSERT(c);
1942 	/* Destroy latency profile, enforce blksz/blkcnt */
1943 	return chn_resizebuf(c, -1, blkcnt, blksz);
1944 }
1945 
1946 int
1947 chn_setparam(struct pcm_channel *c, uint32_t format, uint32_t speed)
1948 {
1949 	struct pcmchan_caps *caps;
1950 	uint32_t hwspeed, delta;
1951 	int ret;
1952 
1953 	CHN_LOCKASSERT(c);
1954 
1955 	if (speed < 1 || format == 0 || CHN_STARTED(c))
1956 		return (EINVAL);
1957 
1958 	c->format = format;
1959 	c->speed = speed;
1960 
1961 	caps = chn_getcaps(c);
1962 
1963 	hwspeed = speed;
1964 	RANGE(hwspeed, caps->minspeed, caps->maxspeed);
1965 
1966 	sndbuf_setspd(c->bufhard, CHANNEL_SETSPEED(c->methods, c->devinfo,
1967 	    hwspeed));
1968 	hwspeed = sndbuf_getspd(c->bufhard);
1969 
1970 	delta = (hwspeed > speed) ? (hwspeed - speed) : (speed - hwspeed);
1971 
1972 	if (delta <= feeder_rate_round)
1973 		c->speed = hwspeed;
1974 
1975 	ret = feeder_chain(c);
1976 
1977 	if (ret == 0)
1978 		ret = CHANNEL_SETFORMAT(c->methods, c->devinfo,
1979 		    sndbuf_getfmt(c->bufhard));
1980 
1981 	if (ret == 0)
1982 		ret = chn_resizebuf(c, -2, 0, 0);
1983 
1984 	return (ret);
1985 }
1986 
1987 int
1988 chn_setspeed(struct pcm_channel *c, uint32_t speed)
1989 {
1990 	uint32_t oldformat, oldspeed, format;
1991 	int ret;
1992 
1993 #if 0
1994 	/* XXX force 48k */
1995 	if (c->format & AFMT_PASSTHROUGH)
1996 		speed = AFMT_PASSTHROUGH_RATE;
1997 #endif
1998 
1999 	oldformat = c->format;
2000 	oldspeed = c->speed;
2001 	format = oldformat;
2002 
2003 	ret = chn_setparam(c, format, speed);
2004 	if (ret != 0) {
2005 		if (snd_verbose > 3)
2006 			device_printf(c->dev,
2007 			    "%s(): Setting speed %d failed, "
2008 			    "falling back to %d\n",
2009 			    __func__, speed, oldspeed);
2010 		chn_setparam(c, c->format, oldspeed);
2011 	}
2012 
2013 	return (ret);
2014 }
2015 
2016 int
2017 chn_setformat(struct pcm_channel *c, uint32_t format)
2018 {
2019 	uint32_t oldformat, oldspeed, speed;
2020 	int ret;
2021 
2022 	/* XXX force stereo */
2023 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
2024 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,
2025 		    AFMT_PASSTHROUGH_EXTCHANNEL);
2026 	}
2027 
2028 	oldformat = c->format;
2029 	oldspeed = c->speed;
2030 	speed = oldspeed;
2031 
2032 	ret = chn_setparam(c, format, speed);
2033 	if (ret != 0) {
2034 		if (snd_verbose > 3)
2035 			device_printf(c->dev,
2036 			    "%s(): Format change 0x%08x failed, "
2037 			    "falling back to 0x%08x\n",
2038 			    __func__, format, oldformat);
2039 		chn_setparam(c, oldformat, oldspeed);
2040 	}
2041 
2042 	return (ret);
2043 }
2044 
2045 void
2046 chn_syncstate(struct pcm_channel *c)
2047 {
2048 	struct snddev_info *d;
2049 	struct snd_mixer *m;
2050 
2051 	d = (c != NULL) ? c->parentsnddev : NULL;
2052 	m = (d != NULL && d->mixer_dev != NULL) ? d->mixer_dev->si_drv1 :
2053 	    NULL;
2054 
2055 	if (d == NULL || m == NULL)
2056 		return;
2057 
2058 	CHN_LOCKASSERT(c);
2059 
2060 	if (c->feederflags & (1 << FEEDER_VOLUME)) {
2061 		uint32_t parent;
2062 		int vol, pvol, left, right, center;
2063 
2064 		if (c->direction == PCMDIR_PLAY &&
2065 		    (d->flags & SD_F_SOFTPCMVOL)) {
2066 			/* CHN_UNLOCK(c); */
2067 			vol = mix_get(m, SOUND_MIXER_PCM);
2068 			parent = mix_getparent(m, SOUND_MIXER_PCM);
2069 			if (parent != SOUND_MIXER_NONE)
2070 				pvol = mix_get(m, parent);
2071 			else
2072 				pvol = 100 | (100 << 8);
2073 			/* CHN_LOCK(c); */
2074 		} else {
2075 			vol = 100 | (100 << 8);
2076 			pvol = vol;
2077 		}
2078 
2079 		if (vol == -1) {
2080 			device_printf(c->dev,
2081 			    "Soft PCM Volume: Failed to read pcm "
2082 			    "default value\n");
2083 			vol = 100 | (100 << 8);
2084 		}
2085 
2086 		if (pvol == -1) {
2087 			device_printf(c->dev,
2088 			    "Soft PCM Volume: Failed to read parent "
2089 			    "default value\n");
2090 			pvol = 100 | (100 << 8);
2091 		}
2092 
2093 		left = ((vol & 0x7f) * (pvol & 0x7f)) / 100;
2094 		right = (((vol >> 8) & 0x7f) * ((pvol >> 8) & 0x7f)) / 100;
2095 		center = (left + right) >> 1;
2096 
2097 		chn_setvolume_multi(c, SND_VOL_C_MASTER, left, right, center);
2098 	}
2099 
2100 	if (c->feederflags & (1 << FEEDER_EQ)) {
2101 		struct pcm_feeder *f;
2102 		int treble, bass, state;
2103 
2104 		/* CHN_UNLOCK(c); */
2105 		treble = mix_get(m, SOUND_MIXER_TREBLE);
2106 		bass = mix_get(m, SOUND_MIXER_BASS);
2107 		/* CHN_LOCK(c); */
2108 
2109 		if (treble == -1)
2110 			treble = 50;
2111 		else
2112 			treble = ((treble & 0x7f) +
2113 			    ((treble >> 8) & 0x7f)) >> 1;
2114 
2115 		if (bass == -1)
2116 			bass = 50;
2117 		else
2118 			bass = ((bass & 0x7f) + ((bass >> 8) & 0x7f)) >> 1;
2119 
2120 		f = chn_findfeeder(c, FEEDER_EQ);
2121 		if (f != NULL) {
2122 			if (FEEDER_SET(f, FEEDEQ_TREBLE, treble) != 0)
2123 				device_printf(c->dev,
2124 				    "EQ: Failed to set treble -- %d\n",
2125 				    treble);
2126 			if (FEEDER_SET(f, FEEDEQ_BASS, bass) != 0)
2127 				device_printf(c->dev,
2128 				    "EQ: Failed to set bass -- %d\n",
2129 				    bass);
2130 			if (FEEDER_SET(f, FEEDEQ_PREAMP, d->eqpreamp) != 0)
2131 				device_printf(c->dev,
2132 				    "EQ: Failed to set preamp -- %d\n",
2133 				    d->eqpreamp);
2134 			if (d->flags & SD_F_EQ_BYPASSED)
2135 				state = FEEDEQ_BYPASS;
2136 			else if (d->flags & SD_F_EQ_ENABLED)
2137 				state = FEEDEQ_ENABLE;
2138 			else
2139 				state = FEEDEQ_DISABLE;
2140 			if (FEEDER_SET(f, FEEDEQ_STATE, state) != 0)
2141 				device_printf(c->dev,
2142 				    "EQ: Failed to set state -- %d\n", state);
2143 		}
2144 	}
2145 }
2146 
2147 int
2148 chn_trigger(struct pcm_channel *c, int go)
2149 {
2150 #ifdef DEV_ISA
2151     	struct snd_dbuf *b = c->bufhard;
2152 #endif
2153 	struct snddev_info *d = c->parentsnddev;
2154 	int ret;
2155 
2156 	CHN_LOCKASSERT(c);
2157 #ifdef DEV_ISA
2158 	if (SND_DMA(b) && (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD))
2159 		sndbuf_dmabounce(b);
2160 #endif
2161 	if (!PCMTRIG_COMMON(go))
2162 		return (CHANNEL_TRIGGER(c->methods, c->devinfo, go));
2163 
2164 	if (go == c->trigger)
2165 		return (0);
2166 
2167 	ret = CHANNEL_TRIGGER(c->methods, c->devinfo, go);
2168 	if (ret != 0)
2169 		return (ret);
2170 
2171 	switch (go) {
2172 	case PCMTRIG_START:
2173 		if (snd_verbose > 3)
2174 			device_printf(c->dev,
2175 			    "%s() %s: calling go=0x%08x , "
2176 			    "prev=0x%08x\n", __func__, c->name, go,
2177 			    c->trigger);
2178 		if (c->trigger != PCMTRIG_START) {
2179 			c->trigger = go;
2180 			CHN_UNLOCK(c);
2181 			PCM_LOCK(d);
2182 			CHN_INSERT_HEAD(d, c, channels.pcm.busy);
2183 			PCM_UNLOCK(d);
2184 			CHN_LOCK(c);
2185 			chn_syncstate(c);
2186 		}
2187 		break;
2188 	case PCMTRIG_STOP:
2189 	case PCMTRIG_ABORT:
2190 		if (snd_verbose > 3)
2191 			device_printf(c->dev,
2192 			    "%s() %s: calling go=0x%08x , "
2193 			    "prev=0x%08x\n", __func__, c->name, go,
2194 			    c->trigger);
2195 		if (c->trigger == PCMTRIG_START) {
2196 			c->trigger = go;
2197 			CHN_UNLOCK(c);
2198 			PCM_LOCK(d);
2199 			CHN_REMOVE(d, c, channels.pcm.busy);
2200 			PCM_UNLOCK(d);
2201 			CHN_LOCK(c);
2202 		}
2203 		break;
2204 	default:
2205 		break;
2206 	}
2207 
2208 	return (0);
2209 }
2210 
2211 /**
2212  * @brief Queries sound driver for sample-aligned hardware buffer pointer index
2213  *
2214  * This function obtains the hardware pointer location, then aligns it to
2215  * the current bytes-per-sample value before returning.  (E.g., a channel
2216  * running in 16 bit stereo mode would require 4 bytes per sample, so a
2217  * hwptr value ranging from 32-35 would be returned as 32.)
2218  *
2219  * @param c	PCM channel context
2220  * @returns 	sample-aligned hardware buffer pointer index
2221  */
2222 int
2223 chn_getptr(struct pcm_channel *c)
2224 {
2225 	int hwptr;
2226 
2227 	CHN_LOCKASSERT(c);
2228 	hwptr = (CHN_STARTED(c)) ? CHANNEL_GETPTR(c->methods, c->devinfo) : 0;
2229 	return (hwptr - (hwptr % sndbuf_getalign(c->bufhard)));
2230 }
2231 
2232 struct pcmchan_caps *
2233 chn_getcaps(struct pcm_channel *c)
2234 {
2235 	CHN_LOCKASSERT(c);
2236 	return CHANNEL_GETCAPS(c->methods, c->devinfo);
2237 }
2238 
2239 u_int32_t
2240 chn_getformats(struct pcm_channel *c)
2241 {
2242 	u_int32_t *fmtlist, fmts;
2243 	int i;
2244 
2245 	fmtlist = chn_getcaps(c)->fmtlist;
2246 	fmts = 0;
2247 	for (i = 0; fmtlist[i]; i++)
2248 		fmts |= fmtlist[i];
2249 
2250 	/* report software-supported formats */
2251 	if (!CHN_BITPERFECT(c) && report_soft_formats)
2252 		fmts |= AFMT_CONVERTIBLE;
2253 
2254 	return (AFMT_ENCODING(fmts));
2255 }
2256 
2257 int
2258 chn_notify(struct pcm_channel *c, u_int32_t flags)
2259 {
2260 	struct pcm_channel *ch;
2261 	struct pcmchan_caps *caps;
2262 	uint32_t bestformat, bestspeed, besthwformat, *vchanformat, *vchanrate;
2263 	uint32_t vpflags;
2264 	int dirty, err, run, nrun;
2265 
2266 	CHN_LOCKASSERT(c);
2267 
2268 	if (CHN_EMPTY(c, children))
2269 		return (ENODEV);
2270 
2271 	err = 0;
2272 
2273 	/*
2274 	 * If the hwchan is running, we can't change its rate, format or
2275 	 * blocksize
2276 	 */
2277 	run = (CHN_STARTED(c)) ? 1 : 0;
2278 	if (run)
2279 		flags &= CHN_N_VOLUME | CHN_N_TRIGGER;
2280 
2281 	if (flags & CHN_N_RATE) {
2282 		/*
2283 		 * XXX I'll make good use of this someday.
2284 		 *     However this is currently being superseded by
2285 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2286 		 */
2287 	}
2288 
2289 	if (flags & CHN_N_FORMAT) {
2290 		/*
2291 		 * XXX I'll make good use of this someday.
2292 		 *     However this is currently being superseded by
2293 		 *     the availability of CHN_F_VCHAN_DYNAMIC.
2294 		 */
2295 	}
2296 
2297 	if (flags & CHN_N_VOLUME) {
2298 		/*
2299 		 * XXX I'll make good use of this someday, though
2300 		 *     soft volume control is currently pretty much
2301 		 *     integrated.
2302 		 */
2303 	}
2304 
2305 	if (flags & CHN_N_BLOCKSIZE) {
2306 		/*
2307 		 * Set to default latency profile
2308 		 */
2309 		chn_setlatency(c, chn_latency);
2310 	}
2311 
2312 	if ((flags & CHN_N_TRIGGER) && !(c->flags & CHN_F_VCHAN_DYNAMIC)) {
2313 		nrun = CHN_EMPTY(c, children.busy) ? 0 : 1;
2314 		if (nrun && !run)
2315 			err = chn_start(c, 1);
2316 		if (!nrun && run)
2317 			chn_abort(c);
2318 		flags &= ~CHN_N_TRIGGER;
2319 	}
2320 
2321 	if (flags & CHN_N_TRIGGER) {
2322 		if (c->direction == PCMDIR_PLAY) {
2323 			vchanformat = &c->parentsnddev->pvchanformat;
2324 			vchanrate = &c->parentsnddev->pvchanrate;
2325 		} else {
2326 			vchanformat = &c->parentsnddev->rvchanformat;
2327 			vchanrate = &c->parentsnddev->rvchanrate;
2328 		}
2329 
2330 		/* Dynamic Virtual Channel */
2331 		if (!(c->flags & CHN_F_VCHAN_ADAPTIVE)) {
2332 			bestformat = *vchanformat;
2333 			bestspeed = *vchanrate;
2334 		} else {
2335 			bestformat = 0;
2336 			bestspeed = 0;
2337 		}
2338 
2339 		besthwformat = 0;
2340 		nrun = 0;
2341 		caps = chn_getcaps(c);
2342 		dirty = 0;
2343 		vpflags = 0;
2344 
2345 		CHN_FOREACH(ch, c, children.busy) {
2346 			CHN_LOCK(ch);
2347 			if ((ch->format & AFMT_PASSTHROUGH) &&
2348 			    snd_fmtvalid(ch->format, caps->fmtlist)) {
2349 				bestformat = ch->format;
2350 				bestspeed = ch->speed;
2351 				CHN_UNLOCK(ch);
2352 				vpflags = CHN_F_PASSTHROUGH;
2353 				nrun++;
2354 				break;
2355 			}
2356 			if ((ch->flags & CHN_F_EXCLUSIVE) && vpflags == 0) {
2357 				if (c->flags & CHN_F_VCHAN_ADAPTIVE) {
2358 					bestspeed = ch->speed;
2359 					RANGE(bestspeed, caps->minspeed,
2360 					    caps->maxspeed);
2361 					besthwformat = snd_fmtbest(ch->format,
2362 					    caps->fmtlist);
2363 					if (besthwformat != 0)
2364 						bestformat = besthwformat;
2365 				}
2366 				CHN_UNLOCK(ch);
2367 				vpflags = CHN_F_EXCLUSIVE;
2368 				nrun++;
2369 				continue;
2370 			}
2371 			if (!(c->flags & CHN_F_VCHAN_ADAPTIVE) ||
2372 			    vpflags != 0) {
2373 				CHN_UNLOCK(ch);
2374 				nrun++;
2375 				continue;
2376 			}
2377 			if (ch->speed > bestspeed) {
2378 				bestspeed = ch->speed;
2379 				RANGE(bestspeed, caps->minspeed,
2380 				    caps->maxspeed);
2381 			}
2382 			besthwformat = snd_fmtbest(ch->format, caps->fmtlist);
2383 			if (!(besthwformat & AFMT_VCHAN)) {
2384 				CHN_UNLOCK(ch);
2385 				nrun++;
2386 				continue;
2387 			}
2388 			if (AFMT_CHANNEL(besthwformat) >
2389 			    AFMT_CHANNEL(bestformat))
2390 				bestformat = besthwformat;
2391 			else if (AFMT_CHANNEL(besthwformat) ==
2392 			    AFMT_CHANNEL(bestformat) &&
2393 			    AFMT_BIT(besthwformat) > AFMT_BIT(bestformat))
2394 				bestformat = besthwformat;
2395 			CHN_UNLOCK(ch);
2396 			nrun++;
2397 		}
2398 
2399 		if (bestformat == 0)
2400 			bestformat = c->format;
2401 		if (bestspeed == 0)
2402 			bestspeed = c->speed;
2403 
2404 		if (bestformat != c->format || bestspeed != c->speed)
2405 			dirty = 1;
2406 
2407 		c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2408 		c->flags |= vpflags;
2409 
2410 		if (nrun && !run) {
2411 			if (dirty) {
2412 				bestspeed = CHANNEL_SETSPEED(c->methods,
2413 				    c->devinfo, bestspeed);
2414 				err = chn_reset(c, bestformat, bestspeed);
2415 			}
2416 			if (err == 0 && dirty) {
2417 				CHN_FOREACH(ch, c, children.busy) {
2418 					CHN_LOCK(ch);
2419 					if (VCHAN_SYNC_REQUIRED(ch))
2420 						vchan_sync(ch);
2421 					CHN_UNLOCK(ch);
2422 				}
2423 			}
2424 			if (err == 0) {
2425 				if (dirty)
2426 					c->flags |= CHN_F_DIRTY;
2427 				err = chn_start(c, 1);
2428 			}
2429 		}
2430 
2431 		if (nrun && run && dirty) {
2432 			chn_abort(c);
2433 			bestspeed = CHANNEL_SETSPEED(c->methods, c->devinfo,
2434 			    bestspeed);
2435 			err = chn_reset(c, bestformat, bestspeed);
2436 			if (err == 0) {
2437 				CHN_FOREACH(ch, c, children.busy) {
2438 					CHN_LOCK(ch);
2439 					if (VCHAN_SYNC_REQUIRED(ch))
2440 						vchan_sync(ch);
2441 					CHN_UNLOCK(ch);
2442 				}
2443 			}
2444 			if (err == 0) {
2445 				c->flags |= CHN_F_DIRTY;
2446 				err = chn_start(c, 1);
2447 			}
2448 		}
2449 
2450 		if (err == 0 && !(bestformat & AFMT_PASSTHROUGH) &&
2451 		    (bestformat & AFMT_VCHAN)) {
2452 			*vchanformat = bestformat;
2453 			*vchanrate = bestspeed;
2454 		}
2455 
2456 		if (!nrun && run) {
2457 			c->flags &= ~(CHN_F_PASSTHROUGH | CHN_F_EXCLUSIVE);
2458 			bestformat = *vchanformat;
2459 			bestspeed = *vchanrate;
2460 			chn_abort(c);
2461 			if (c->format != bestformat || c->speed != bestspeed)
2462 				chn_reset(c, bestformat, bestspeed);
2463 		}
2464 	}
2465 
2466 	return (err);
2467 }
2468 
2469 /**
2470  * @brief Fetch array of supported discrete sample rates
2471  *
2472  * Wrapper for CHANNEL_GETRATES.  Please see channel_if.m:getrates() for
2473  * detailed information.
2474  *
2475  * @note If the operation isn't supported, this function will just return 0
2476  *       (no rates in the array), and *rates will be set to NULL.  Callers
2477  *       should examine rates @b only if this function returns non-zero.
2478  *
2479  * @param c	pcm channel to examine
2480  * @param rates	pointer to array of integers; rate table will be recorded here
2481  *
2482  * @return number of rates in the array pointed to be @c rates
2483  */
2484 int
2485 chn_getrates(struct pcm_channel *c, int **rates)
2486 {
2487 	KASSERT(rates != NULL, ("rates is null"));
2488 	CHN_LOCKASSERT(c);
2489 	return CHANNEL_GETRATES(c->methods, c->devinfo, rates);
2490 }
2491 
2492 /**
2493  * @brief Remove channel from a sync group, if there is one.
2494  *
2495  * This function is initially intended for the following conditions:
2496  *   - Starting a syncgroup (@c SNDCTL_DSP_SYNCSTART ioctl)
2497  *   - Closing a device.  (A channel can't be destroyed if it's still in use.)
2498  *
2499  * @note Before calling this function, the syncgroup list mutex must be
2500  * held.  (Consider pcm_channel::sm protected by the SG list mutex
2501  * whether @c c is locked or not.)
2502  *
2503  * @param c	channel device to be started or closed
2504  * @returns	If this channel was the only member of a group, the group ID
2505  * 		is returned to the caller so that the caller can release it
2506  * 		via free_unr() after giving up the syncgroup lock.  Else it
2507  * 		returns 0.
2508  */
2509 int
2510 chn_syncdestroy(struct pcm_channel *c)
2511 {
2512 	struct pcmchan_syncmember *sm;
2513 	struct pcmchan_syncgroup *sg;
2514 	int sg_id;
2515 
2516 	sg_id = 0;
2517 
2518 	PCM_SG_LOCKASSERT(MA_OWNED);
2519 
2520 	if (c->sm != NULL) {
2521 		sm = c->sm;
2522 		sg = sm->parent;
2523 		c->sm = NULL;
2524 
2525 		KASSERT(sg != NULL, ("syncmember has null parent"));
2526 
2527 		SLIST_REMOVE(&sg->members, sm, pcmchan_syncmember, link);
2528 		free(sm, M_DEVBUF);
2529 
2530 		if (SLIST_EMPTY(&sg->members)) {
2531 			SLIST_REMOVE(&snd_pcm_syncgroups, sg, pcmchan_syncgroup, link);
2532 			sg_id = sg->id;
2533 			free(sg, M_DEVBUF);
2534 		}
2535 	}
2536 
2537 	return sg_id;
2538 }
2539 
2540 #ifdef OSSV4_EXPERIMENT
2541 int
2542 chn_getpeaks(struct pcm_channel *c, int *lpeak, int *rpeak)
2543 {
2544 	CHN_LOCKASSERT(c);
2545 	return CHANNEL_GETPEAKS(c->methods, c->devinfo, lpeak, rpeak);
2546 }
2547 #endif
2548