sys/dev/sound/pcm/vchan.c

   1 /*-
   2  * Copyright (c) 2001 Cameron Grant <cg@freebsd.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/dev/sound/pcm/vchan.c,v 1.17.2.5 2007/02/04 06:17:14 ariff Exp $
  27  * $DragonFly: src/sys/dev/sound/pcm/vchan.c,v 1.8 2008/01/06 16:55:51 swildner Exp $
  28  */
  29
  30 #include <dev/sound/pcm/sound.h>
  31 #include <dev/sound/pcm/vchan.h>
  32 #include "feeder_if.h"
  33
  34 SND_DECLARE_FILE("$DragonFly: src/sys/dev/sound/pcm/vchan.c,v 1.8 2008/01/06 16:55:51 swildner Exp $");
  35
  36 /*
  37  * Default speed
  38  */
  39 #define VCHAN_DEFAULT_SPEED     48000
  40
  41 extern int feeder_rate_ratemin;
  42 extern int feeder_rate_ratemax;
  43
  44 struct vchinfo {
  45         u_int32_t spd, fmt, blksz, bps, run;
  46         struct pcm_channel *channel, *parent;
  47         struct pcmchan_caps caps;
  48 };
  49
  50 static u_int32_t vchan_fmt[] = {
  51         AFMT_STEREO | AFMT_S16_LE,
  52         0
  53 };
  54
  55 /*
  56  * These values are: (1.022**v-1)*65536/(1.022**100-1)
  57  *
  58  * Inspired by inverting opensound (BSDL'd)'s mix_cvt.
  59  */
  60 static int log_mix_cvt[101] = {
  61 0, 184, 373, 565, 762, 964, 1170, 1380, 1595, 1814, 2039, 2268, 2503, 2742,
  62 2987, 3238, 3493, 3755, 4022, 4295, 4574, 4859, 5151, 5449, 5753, 6064, 6382,
  63 6707, 7039, 7379, 7726, 8080, 8442, 8813, 9191, 9578, 9973, 10377, 10790,
  64 11212, 11643, 12084, 12534, 12995, 13465, 13946, 14437, 14940, 15453, 15977,
  65 16513, 17061, 17621, 18193, 18778, 19376, 19987, 20611, 21249, 21901, 22567,
  66 23248, 23944, 24656, 25383, 26126, 26885, 27661, 28454, 29265, 30093, 30940,
  67 31805, 32689, 33593, 34517, 35461, 36425, 37411, 38419, 39449, 40501, 41577,
  68 42676, 43799, 44947, 46121, 47320, 48546, 49798, 51078, 52387, 53724, 55090,
  69 56487, 57914, 59373, 60864, 62387, 63944, 65536
  70 };
  71
  72 static int
  73 vchan_mix_s16(int16_t *to, int16_t *tmp, unsigned int count, int volume)
  74 {
  75         /*
  76          * to is the output buffer, tmp is the input buffer
  77          * count is the number of 16bit samples to mix
  78          * volume is in range 0-100, (left || (right << 8))
  79          */
  80         int i;
  81         int x;
  82         int scale[2];
  83         int doscale;
  84
  85         scale[0] = log_mix_cvt[volume & 0xff];
  86         scale[1] = log_mix_cvt[(volume >> 8) & 0xff];
  87         doscale = volume != (100 || (100 << 8));
  88
  89         for(i = 0; i < count; i++) {
  90                 x = to[i];
  91                 if (doscale)
  92                         x += ((int)tmp[i] * scale[i % 2]) >> 16;
  93                 else
  94                         x += tmp[i];
  95                 if (x < -32768) {
  96                         /* kprintf("%d + %d = %d (u)\n", to[i], tmp[i], x); */
  97                         x = -32768;
  98                 }
  99                 if (x > 32767) {
 100                         /* kprintf("%d + %d = %d (o)\n", to[i], tmp[i], x); */
 101                         x = 32767;
 102                 }
 103                 to[i] = x & 0x0000ffff;
 104         }
 105         return 0;
 106 }
 107
 108 static int
 109 feed_vchan_s16(struct pcm_feeder *f, struct pcm_channel *c, u_int8_t *b, u_int32_t count, void *source)
 110 {
 111         /* we're going to abuse things a bit */
 112         struct snd_dbuf *src = source;
 113         struct pcmchan_children *cce;
 114         struct pcm_channel *ch;
 115         uint32_t sz;
 116         int16_t *tmp, *dst;
 117         unsigned int cnt, rcnt = 0;
 118
 119         #if 0
 120         if (sndbuf_getsize(src) < count)
 121                 panic("feed_vchan_s16(%s): tmp buffer size %d < count %d, flags = 0x%x",
 122                     c->name, sndbuf_getsize(src), count, c->flags);
 123         #endif
 124         sz = sndbuf_getsize(src);
 125         if (sz < count)
 126                 count = sz;
 127         count &= ~1;
 128         if (count < 2)
 129                 return 0;
 130         bzero(b, count);
 131
 132         /*
 133          * we are going to use our source as a temporary buffer since it's
 134          * got no other purpose.  we obtain our data by traversing the channel
 135          * list of children and calling vchan_mix_* to mix count bytes from each
 136          * into our destination buffer, b
 137          */
 138         dst = (int16_t *)b;
 139         tmp = (int16_t *)sndbuf_getbuf(src);
 140         bzero(tmp, count);
 141         SLIST_FOREACH(cce, &c->children, link) {
 142                 ch = cce->channel;
 143                 CHN_LOCK(ch);
 144                 if (ch->flags & CHN_F_TRIGGERED) {
 145                         if (ch->flags & CHN_F_MAPPED)
 146                                 sndbuf_acquire(ch->bufsoft, NULL, sndbuf_getfree(ch->bufsoft));
 147                         cnt = FEEDER_FEED(ch->feeder, ch, (u_int8_t *)tmp, count, ch->bufsoft);
 148                         vchan_mix_s16(dst, tmp, cnt >> 1, ch->volume);
 149                         if (cnt > rcnt)
 150                                 rcnt = cnt;
 151                 }
 152                 CHN_UNLOCK(ch);
 153         }
 154
 155         return rcnt & ~1;
 156 }
 157
 158 static struct pcm_feederdesc feeder_vchan_s16_desc[] = {
 159         {FEEDER_MIXER, AFMT_S16_LE | AFMT_STEREO, AFMT_S16_LE | AFMT_STEREO, 0},
 160         {0},
 161 };
 162 static kobj_method_t feeder_vchan_s16_methods[] = {
 163         KOBJMETHOD(feeder_feed,         feed_vchan_s16),
 164         { 0, 0 }
 165 };
 166 FEEDER_DECLARE(feeder_vchan_s16, 2, NULL);
 167
 168 /************************************************************/
 169
 170 static void *
 171 vchan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, struct pcm_channel *c, int dir)
 172 {
 173         struct vchinfo *ch;
 174         struct pcm_channel *parent = devinfo;
 175
 176         KASSERT(dir == PCMDIR_PLAY, ("vchan_init: bad direction"));
 177         ch = kmalloc(sizeof(*ch), M_DEVBUF, M_WAITOK | M_ZERO);
 178         ch->parent = parent;
 179         ch->channel = c;
 180         ch->fmt = AFMT_U8;
 181         ch->spd = DSP_DEFAULT_SPEED;
 182         ch->blksz = 2048;
 183
 184         c->flags |= CHN_F_VIRTUAL;
 185
 186         return ch;
 187 }
 188
 189 static int
 190 vchan_free(kobj_t obj, void *data)
 191 {
 192         kfree(data, M_DEVBUF);
 193         return 0;
 194 }
 195
 196 static int
 197 vchan_setformat(kobj_t obj, void *data, u_int32_t format)
 198 {
 199         struct vchinfo *ch = data;
 200         struct pcm_channel *parent = ch->parent;
 201         struct pcm_channel *channel = ch->channel;
 202
 203         ch->fmt = format;
 204         ch->bps = 1;
 205         ch->bps <<= (ch->fmt & AFMT_STEREO)? 1 : 0;
 206         if (ch->fmt & AFMT_16BIT)
 207                 ch->bps <<= 1;
 208         else if (ch->fmt & AFMT_24BIT)
 209                 ch->bps *= 3;
 210         else if (ch->fmt & AFMT_32BIT)
 211                 ch->bps <<= 2;
 212         CHN_UNLOCK(channel);
 213         chn_notify(parent, CHN_N_FORMAT);
 214         CHN_LOCK(channel);
 215         sndbuf_setfmt(channel->bufsoft, format);
 216         return 0;
 217 }
 218
 219 static int
 220 vchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 221 {
 222         struct vchinfo *ch = data;
 223         struct pcm_channel *parent = ch->parent;
 224         struct pcm_channel *channel = ch->channel;
 225
 226         ch->spd = speed;
 227         CHN_UNLOCK(channel);
 228         CHN_LOCK(parent);
 229         speed = sndbuf_getspd(parent->bufsoft);
 230         CHN_UNLOCK(parent);
 231         CHN_LOCK(channel);
 232         return speed;
 233 }
 234
 235 static int
 236 vchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 237 {
 238         struct vchinfo *ch = data;
 239         struct pcm_channel *channel = ch->channel;
 240         struct pcm_channel *parent = ch->parent;
 241         /* struct pcm_channel *channel = ch->channel; */
 242         int prate, crate;
 243
 244         ch->blksz = blocksize;
 245         /* CHN_UNLOCK(channel); */
 246         sndbuf_setblksz(channel->bufhard, blocksize);
 247         chn_notify(parent, CHN_N_BLOCKSIZE);
 248         CHN_LOCK(parent);
 249         /* CHN_LOCK(channel); */
 250
 251         crate = ch->spd * ch->bps;
 252         prate = sndbuf_getspd(parent->bufsoft) * sndbuf_getbps(parent->bufsoft);
 253         blocksize = sndbuf_getblksz(parent->bufsoft);
 254         CHN_UNLOCK(parent);
 255         blocksize *= prate;
 256         blocksize /= crate;
 257
 258         return blocksize;
 259 }
 260
 261 static int
 262 vchan_trigger(kobj_t obj, void *data, int go)
 263 {
 264         struct vchinfo *ch = data;
 265         struct pcm_channel *parent = ch->parent;
 266         struct pcm_channel *channel = ch->channel;
 267
 268         if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 269                 return 0;
 270
 271         ch->run = (go == PCMTRIG_START)? 1 : 0;
 272         CHN_UNLOCK(channel);
 273         chn_notify(parent, CHN_N_TRIGGER);
 274         CHN_LOCK(channel);
 275
 276         return 0;
 277 }
 278
 279 static struct pcmchan_caps *
 280 vchan_getcaps(kobj_t obj, void *data)
 281 {
 282         struct vchinfo *ch = data;
 283
 284         ch->caps.minspeed = sndbuf_getspd(ch->parent->bufsoft);
 285         ch->caps.maxspeed = ch->caps.minspeed;
 286         ch->caps.fmtlist = vchan_fmt;
 287         ch->caps.caps = 0;
 288
 289         return &ch->caps;
 290 }
 291
 292 static kobj_method_t vchan_methods[] = {
 293         KOBJMETHOD(channel_init,                vchan_init),
 294         KOBJMETHOD(channel_free,                vchan_free),
 295         KOBJMETHOD(channel_setformat,           vchan_setformat),
 296         KOBJMETHOD(channel_setspeed,            vchan_setspeed),
 297         KOBJMETHOD(channel_setblocksize,        vchan_setblocksize),
 298         KOBJMETHOD(channel_trigger,             vchan_trigger),
 299         KOBJMETHOD(channel_getcaps,             vchan_getcaps),
 300         { 0, 0 }
 301 };
 302 CHANNEL_DECLARE(vchan);
 303
 304 #if 0
 305 /*
 306  * On the fly vchan rate settings
 307  */
 308 #ifdef SND_DYNSYSCTL
 309 static int
 310 sysctl_hw_snd_vchanrate(SYSCTL_HANDLER_ARGS)
 311 {
 312         struct snddev_info *d;
 313         struct snddev_channel *sce;
 314         struct pcm_channel *c, *ch = NULL, *fake;
 315         struct pcmchan_caps *caps;
 316         int err = 0;
 317         int newspd = 0;
 318
 319         d = oidp->oid_arg1;
 320         if (!(d->flags & SD_F_AUTOVCHAN) || d->vchancount < 1)
 321                 return EINVAL;
 322         if (pcm_inprog(d, 1) != 1 && req->newptr != NULL) {
 323                 pcm_inprog(d, -1);
 324                 return EINPROGRESS;
 325         }
 326         SLIST_FOREACH(sce, &d->channels, link) {
 327                 c = sce->channel;
 328                 CHN_LOCK(c);
 329                 if (c->direction == PCMDIR_PLAY) {
 330                         if (c->flags & CHN_F_VIRTUAL) {
 331                                 /* Sanity check */
 332                                 if (ch != NULL && ch != c->parentchannel) {
 333                                         CHN_UNLOCK(c);
 334                                         pcm_inprog(d, -1);
 335                                         return EINVAL;
 336                                 }
 337                                 if (req->newptr != NULL &&
 338                                                 (c->flags & CHN_F_BUSY)) {
 339                                         CHN_UNLOCK(c);
 340                                         pcm_inprog(d, -1);
 341                                         return EBUSY;
 342                                 }
 343                         } else if (c->flags & CHN_F_HAS_VCHAN) {
 344                                 /* No way!! */
 345                                 if (ch != NULL) {
 346                                         CHN_UNLOCK(c);
 347                                         pcm_inprog(d, -1);
 348                                         return EINVAL;
 349                                 }
 350                                 ch = c;
 351                                 newspd = ch->speed;
 352                         }
 353                 }
 354                 CHN_UNLOCK(c);
 355         }
 356         if (ch == NULL) {
 357                 pcm_inprog(d, -1);
 358                 return EINVAL;
 359         }
 360         err = sysctl_handle_int(oidp, &newspd, sizeof(newspd), req);
 361         if (err == 0 && req->newptr != NULL) {
 362                 if (newspd < 1 || newspd < feeder_rate_ratemin ||
 363                                 newspd > feeder_rate_ratemax) {
 364                         pcm_inprog(d, -1);
 365                         return EINVAL;
 366                 }
 367                 CHN_LOCK(ch);
 368                 caps = chn_getcaps(ch);
 369                 if (caps == NULL || newspd < caps->minspeed ||
 370                                 newspd > caps->maxspeed) {
 371                         CHN_UNLOCK(ch);
 372                         pcm_inprog(d, -1);
 373                         return EINVAL;
 374                 }
 375                 if (newspd != ch->speed) {
 376                         err = chn_setspeed(ch, newspd);
 377                         /*
 378                          * Try to avoid FEEDER_RATE on parent channel if the
 379                          * requested value is not supported by the hardware.
 380                          */
 381                         if (!err && (ch->feederflags & (1 << FEEDER_RATE))) {
 382                                 newspd = sndbuf_getspd(ch->bufhard);
 383                                 err = chn_setspeed(ch, newspd);
 384                         }
 385                         CHN_UNLOCK(ch);
 386                         if (err == 0) {
 387                                 fake = pcm_getfakechan(d);
 388                                 if (fake != NULL) {
 389                                         CHN_LOCK(fake);
 390                                         fake->speed = newspd;
 391                                         CHN_UNLOCK(fake);
 392                                 }
 393                         }
 394                 } else
 395                         CHN_UNLOCK(ch);
 396         }
 397         pcm_inprog(d, -1);
 398         return err;
 399 }
 400 #endif
 401 #endif
 402
 403 /* virtual channel interface */
 404
 405 int
 406 vchan_create(struct pcm_channel *parent)
 407 {
 408         struct snddev_info *d = parent->parentsnddev;
 409         struct pcmchan_children *pce;
 410         struct pcm_channel *child, *fake;
 411         struct pcmchan_caps *parent_caps;
 412         int err, first, speed = 0;
 413
 414         if (!(parent->flags & CHN_F_BUSY))
 415                 return EBUSY;
 416
 417
 418         CHN_UNLOCK(parent);
 419
 420         pce = kmalloc(sizeof(*pce), M_DEVBUF, M_WAITOK | M_ZERO);
 421
 422         /* create a new playback channel */
 423         child = pcm_chn_create(d, parent, &vchan_class, PCMDIR_VIRTUAL, parent);
 424         if (!child) {
 425                 kfree(pce, M_DEVBUF);
 426                 CHN_LOCK(parent);
 427                 return ENODEV;
 428         }
 429         pce->channel = child;
 430
 431         /* add us to our grandparent's channel list */
 432         /*
 433          * XXX maybe we shouldn't always add the dev_t
 434          */
 435         err = pcm_chn_add(d, child);
 436         if (err) {
 437                 pcm_chn_destroy(child);
 438                 kfree(pce, M_DEVBUF);
 439                 CHN_LOCK(parent);
 440                 return err;
 441         }
 442
 443         CHN_LOCK(parent);
 444         /* add us to our parent channel's children */
 445         first = SLIST_EMPTY(&parent->children);
 446         SLIST_INSERT_HEAD(&parent->children, pce, link);
 447         parent->flags |= CHN_F_HAS_VCHAN;
 448
 449         if (first) {
 450                 parent_caps = chn_getcaps(parent);
 451                 if (parent_caps == NULL)
 452                         err = EINVAL;
 453
 454                 if (!err)
 455                         err = chn_reset(parent, AFMT_STEREO | AFMT_S16_LE);
 456
 457                 if (!err) {
 458                         fake = pcm_getfakechan(d);
 459                         if (fake != NULL) {
 460                                 /*
 461                                  * Avoid querying kernel hint, use saved value
 462                                  * from fake channel.
 463                                  */
 464                                 CHN_UNLOCK(parent);
 465                                 CHN_LOCK(fake);
 466                                 speed = fake->speed;
 467                                 CHN_UNLOCK(fake);
 468                                 CHN_LOCK(parent);
 469                         }
 470
 471                         /*
 472                          * This is very sad. Few soundcards advertised as being
 473                          * able to do (insanely) higher/lower speed, but in
 474                          * reality, they simply can't. At least, we give user chance
 475                          * to set sane value via kernel hints or sysctl.
 476                          */
 477                         if (speed < 1) {
 478                                 int r;
 479                                 CHN_UNLOCK(parent);
 480                                 r = resource_int_value(device_get_name(parent->dev),
 481                                                         device_get_unit(parent->dev),
 482                                                                 "vchanrate", &speed);
 483                                 CHN_LOCK(parent);
 484                                 if (r != 0) {
 485                                         /*
 486                                          * Workaround for sb16 running
 487                                          * poorly at 45k / 49k.
 488                                          */
 489                                         switch (parent_caps->maxspeed) {
 490                                         case 45000:
 491                                         case 49000:
 492                                                 speed = 44100;
 493                                                 break;
 494                                         default:
 495                                                 speed = VCHAN_DEFAULT_SPEED;
 496                                                 break;
 497                                         }
 498                                 }
 499                         }
 500
 501                         /*
 502                          * Limit speed based on driver caps.
 503                          * This is supposed to help fixed rate, non-VRA
 504                          * AC97 cards, but.. (see below)
 505                          */
 506                         if (speed < parent_caps->minspeed)
 507                                 speed = parent_caps->minspeed;
 508                         if (speed > parent_caps->maxspeed)
 509                                 speed = parent_caps->maxspeed;
 510
 511                         /*
 512                          * We still need to limit the speed between
 513                          * feeder_rate_ratemin <-> feeder_rate_ratemax. This is
 514                          * just an escape goat if all of the above failed
 515                          * miserably.
 516                          */
 517                         if (speed < feeder_rate_ratemin)
 518                                 speed = feeder_rate_ratemin;
 519                         if (speed > feeder_rate_ratemax)
 520                                 speed = feeder_rate_ratemax;
 521
 522                         err = chn_setspeed(parent, speed);
 523                         /*
 524                          * Try to avoid FEEDER_RATE on parent channel if the
 525                          * requested value is not supported by the hardware.
 526                          */
 527                         if (!err && (parent->feederflags & (1 << FEEDER_RATE))) {
 528                                 speed = sndbuf_getspd(parent->bufhard);
 529                                 err = chn_setspeed(parent, speed);
 530                         }
 531
 532                         if (!err && fake != NULL) {
 533                                 /*
 534                                  * Save new value to fake channel.
 535                                  */
 536                                 CHN_UNLOCK(parent);
 537                                 CHN_LOCK(fake);
 538                                 fake->speed = speed;
 539                                 CHN_UNLOCK(fake);
 540                                 CHN_LOCK(parent);
 541                         }
 542                 }
 543
 544                 if (err) {
 545                         SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
 546                         parent->flags &= ~CHN_F_HAS_VCHAN;
 547                         CHN_UNLOCK(parent);
 548                         kfree(pce, M_DEVBUF);
 549                         if (pcm_chn_remove(d, child) == 0)
 550                                 pcm_chn_destroy(child);
 551                         CHN_LOCK(parent);
 552                         return err;
 553                 }
 554         }
 555
 556         return 0;
 557 }
 558
 559 int
 560 vchan_destroy(struct pcm_channel *c)
 561 {
 562         struct pcm_channel *parent = c->parentchannel;
 563         struct snddev_info *d = parent->parentsnddev;
 564         struct pcmchan_children *pce;
 565         struct snddev_channel *sce;
 566         uint32_t spd;
 567         int err;
 568
 569         CHN_LOCK(parent);
 570         if (!(parent->flags & CHN_F_BUSY)) {
 571                 CHN_UNLOCK(parent);
 572                 return EBUSY;
 573         }
 574         if (SLIST_EMPTY(&parent->children)) {
 575                 CHN_UNLOCK(parent);
 576                 return EINVAL;
 577         }
 578
 579         /* remove us from our parent's children list */
 580         SLIST_FOREACH(pce, &parent->children, link) {
 581                 if (pce->channel == c)
 582                         goto gotch;
 583         }
 584         CHN_UNLOCK(parent);
 585         return EINVAL;
 586 gotch:
 587         SLIST_FOREACH(sce, &d->channels, link) {
 588                 if (sce->channel == c) {
 589                         if (sce->dsp_dev) {
 590                                 destroy_dev(sce->dsp_dev);
 591                                 sce->dsp_dev = NULL;
 592                         }
 593                         d->devcount--;
 594                         break;
 595                 }
 596         }
 597         SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
 598         kfree(pce, M_DEVBUF);
 599
 600         if (SLIST_EMPTY(&parent->children)) {
 601                 parent->flags &= ~(CHN_F_BUSY | CHN_F_HAS_VCHAN);
 602                 spd = parent->speed;
 603                 if (chn_reset(parent, parent->format) == 0)
 604                         chn_setspeed(parent, spd);
 605         }
 606
 607         /* remove us from our grandparent's channel list */
 608         err = pcm_chn_remove(d, c);
 609
 610         CHN_UNLOCK(parent);
 611         /* destroy ourselves */
 612         if (!err)
 613                 err = pcm_chn_destroy(c);
 614
 615         return err;
 616 }
 617
 618 int
 619 vchan_initsys(device_t dev)
 620 {
 621 #ifdef SND_DYNSYSCTL
 622         struct snddev_info *d;
 623
 624         d = device_get_softc(dev);
 625         SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
 626             OID_AUTO, "vchans", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
 627             sysctl_hw_snd_vchans, "I", "");
 628 #if 0
 629         SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
 630             OID_AUTO, "vchanrate", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
 631             sysctl_hw_snd_vchanrate, "I", "");
 632 #endif
 633 #endif
 634
 635         return 0;
 636 }