sound/firewire/oxfw/oxfw-stream.c

   1 /*
   2  * oxfw_stream.c - a part of driver for OXFW970/971 based devices
   3  *
   4  * Copyright (c) 2014 Takashi Sakamoto
   5  *
   6  * Licensed under the terms of the GNU General Public License, version 2.
   7  */
   8
   9 #include "oxfw.h"
  10 #include <linux/delay.h>
  11
  12 #define AVC_GENERIC_FRAME_MAXIMUM_BYTES 512
  13 #define CALLBACK_TIMEOUT        200
  14
  15 /*
  16  * According to datasheet of Oxford Semiconductor:
  17  *  OXFW970: 32.0/44.1/48.0/96.0 Khz, 8 audio channels I/O
  18  *  OXFW971: 32.0/44.1/48.0/88.2/96.0/192.0 kHz, 16 audio channels I/O, MIDI I/O
  19  */
  20 static const unsigned int oxfw_rate_table[] = {
  21         [0] = 32000,
  22         [1] = 44100,
  23         [2] = 48000,
  24         [3] = 88200,
  25         [4] = 96000,
  26         [5] = 192000,
  27 };
  28
  29 /*
  30  * See Table 5.7 – Sampling frequency for Multi-bit Audio
  31  * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
  32  */
  33 static const unsigned int avc_stream_rate_table[] = {
  34         [0] = 0x02,
  35         [1] = 0x03,
  36         [2] = 0x04,
  37         [3] = 0x0a,
  38         [4] = 0x05,
  39         [5] = 0x07,
  40 };
  41
  42 static int set_rate(struct snd_oxfw *oxfw, unsigned int rate)
  43 {
  44         int err;
  45
  46         err = avc_general_set_sig_fmt(oxfw->unit, rate,
  47                                       AVC_GENERAL_PLUG_DIR_IN, 0);
  48         if (err < 0)
  49                 goto end;
  50
  51         if (oxfw->has_output)
  52                 err = avc_general_set_sig_fmt(oxfw->unit, rate,
  53                                               AVC_GENERAL_PLUG_DIR_OUT, 0);
  54 end:
  55         return err;
  56 }
  57
  58 static int set_stream_format(struct snd_oxfw *oxfw, struct amdtp_stream *s,
  59                              unsigned int rate, unsigned int pcm_channels)
  60 {
  61         u8 **formats;
  62         struct snd_oxfw_stream_formation formation;
  63         enum avc_general_plug_dir dir;
  64         unsigned int len;
  65         int i, err;
  66
  67         if (s == &oxfw->tx_stream) {
  68                 formats = oxfw->tx_stream_formats;
  69                 dir = AVC_GENERAL_PLUG_DIR_OUT;
  70         } else {
  71                 formats = oxfw->rx_stream_formats;
  72                 dir = AVC_GENERAL_PLUG_DIR_IN;
  73         }
  74
  75         /* Seek stream format for requirements. */
  76         for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
  77                 err = snd_oxfw_stream_parse_format(formats[i], &formation);
  78                 if (err < 0)
  79                         return err;
  80
  81                 if ((formation.rate == rate) && (formation.pcm == pcm_channels))
  82                         break;
  83         }
  84         if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
  85                 return -EINVAL;
  86
  87         /* If assumed, just change rate. */
  88         if (oxfw->assumed)
  89                 return set_rate(oxfw, rate);
  90
  91         /* Calculate format length. */
  92         len = 5 + formats[i][4] * 2;
  93
  94         err = avc_stream_set_format(oxfw->unit, dir, 0, formats[i], len);
  95         if (err < 0)
  96                 return err;
  97
  98         /* Some requests just after changing format causes freezing. */
  99         msleep(100);
 100
 101         return 0;
 102 }
 103
 104 static void stop_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
 105 {
 106         amdtp_stream_pcm_abort(stream);
 107         amdtp_stream_stop(stream);
 108
 109         if (stream == &oxfw->tx_stream)
 110                 cmp_connection_break(&oxfw->out_conn);
 111         else
 112                 cmp_connection_break(&oxfw->in_conn);
 113 }
 114
 115 static int start_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream,
 116                         unsigned int rate, unsigned int pcm_channels)
 117 {
 118         u8 **formats;
 119         struct cmp_connection *conn;
 120         struct snd_oxfw_stream_formation formation;
 121         unsigned int i, midi_ports;
 122         int err;
 123
 124         if (stream == &oxfw->rx_stream) {
 125                 formats = oxfw->rx_stream_formats;
 126                 conn = &oxfw->in_conn;
 127         } else {
 128                 formats = oxfw->tx_stream_formats;
 129                 conn = &oxfw->out_conn;
 130         }
 131
 132         /* Get stream format */
 133         for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
 134                 if (formats[i] == NULL)
 135                         break;
 136
 137                 err = snd_oxfw_stream_parse_format(formats[i], &formation);
 138                 if (err < 0)
 139                         goto end;
 140                 if (rate != formation.rate)
 141                         continue;
 142                 if (pcm_channels == 0 ||  pcm_channels == formation.pcm)
 143                         break;
 144         }
 145         if (i == SND_OXFW_STREAM_FORMAT_ENTRIES) {
 146                 err = -EINVAL;
 147                 goto end;
 148         }
 149
 150         pcm_channels = formation.pcm;
 151         midi_ports = DIV_ROUND_UP(formation.midi, 8);
 152
 153         /* The stream should have one pcm channels at least */
 154         if (pcm_channels == 0) {
 155                 err = -EINVAL;
 156                 goto end;
 157         }
 158         amdtp_stream_set_parameters(stream, rate, pcm_channels, midi_ports);
 159
 160         err = cmp_connection_establish(conn,
 161                                        amdtp_stream_get_max_payload(stream));
 162         if (err < 0)
 163                 goto end;
 164
 165         err = amdtp_stream_start(stream,
 166                                  conn->resources.channel,
 167                                  conn->speed);
 168         if (err < 0) {
 169                 cmp_connection_break(conn);
 170                 goto end;
 171         }
 172
 173         /* Wait first packet */
 174         if (!amdtp_stream_wait_callback(stream, CALLBACK_TIMEOUT)) {
 175                 stop_stream(oxfw, stream);
 176                 err = -ETIMEDOUT;
 177         }
 178 end:
 179         return err;
 180 }
 181
 182 static int check_connection_used_by_others(struct snd_oxfw *oxfw,
 183                                            struct amdtp_stream *stream)
 184 {
 185         struct cmp_connection *conn;
 186         bool used;
 187         int err;
 188
 189         if (stream == &oxfw->tx_stream)
 190                 conn = &oxfw->out_conn;
 191         else
 192                 conn = &oxfw->in_conn;
 193
 194         err = cmp_connection_check_used(conn, &used);
 195         if ((err >= 0) && used && !amdtp_stream_running(stream)) {
 196                 dev_err(&oxfw->unit->device,
 197                         "Connection established by others: %cPCR[%d]\n",
 198                         (conn->direction == CMP_OUTPUT) ? 'o' : 'i',
 199                         conn->pcr_index);
 200                 err = -EBUSY;
 201         }
 202
 203         return err;
 204 }
 205
 206 int snd_oxfw_stream_init_simplex(struct snd_oxfw *oxfw,
 207                                  struct amdtp_stream *stream)
 208 {
 209         struct cmp_connection *conn;
 210         enum cmp_direction c_dir;
 211         enum amdtp_stream_direction s_dir;
 212         int err;
 213
 214         if (stream == &oxfw->tx_stream) {
 215                 conn = &oxfw->out_conn;
 216                 c_dir = CMP_OUTPUT;
 217                 s_dir = AMDTP_IN_STREAM;
 218         } else {
 219                 conn = &oxfw->in_conn;
 220                 c_dir = CMP_INPUT;
 221                 s_dir = AMDTP_OUT_STREAM;
 222         }
 223
 224         err = cmp_connection_init(conn, oxfw->unit, c_dir, 0);
 225         if (err < 0)
 226                 goto end;
 227
 228         err = amdtp_stream_init(stream, oxfw->unit, s_dir, CIP_NONBLOCKING);
 229         if (err < 0) {
 230                 amdtp_stream_destroy(stream);
 231                 cmp_connection_destroy(conn);
 232                 goto end;
 233         }
 234
 235         /* OXFW starts to transmit packets with non-zero dbc. */
 236         if (stream == &oxfw->tx_stream)
 237                 oxfw->tx_stream.flags |= CIP_SKIP_INIT_DBC_CHECK;
 238 end:
 239         return err;
 240 }
 241
 242 int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw,
 243                                   struct amdtp_stream *stream,
 244                                   unsigned int rate, unsigned int pcm_channels)
 245 {
 246         struct amdtp_stream *opposite;
 247         struct snd_oxfw_stream_formation formation;
 248         enum avc_general_plug_dir dir;
 249         unsigned int substreams, opposite_substreams;
 250         int err = 0;
 251
 252         if (stream == &oxfw->tx_stream) {
 253                 substreams = oxfw->capture_substreams;
 254                 opposite = &oxfw->rx_stream;
 255                 opposite_substreams = oxfw->playback_substreams;
 256                 dir = AVC_GENERAL_PLUG_DIR_OUT;
 257         } else {
 258                 substreams = oxfw->playback_substreams;
 259                 opposite_substreams = oxfw->capture_substreams;
 260
 261                 if (oxfw->has_output)
 262                         opposite = &oxfw->rx_stream;
 263                 else
 264                         opposite = NULL;
 265
 266                 dir = AVC_GENERAL_PLUG_DIR_IN;
 267         }
 268
 269         if (substreams == 0)
 270                 goto end;
 271
 272         /*
 273          * Considering JACK/FFADO streaming:
 274          * TODO: This can be removed hwdep functionality becomes popular.
 275          */
 276         err = check_connection_used_by_others(oxfw, stream);
 277         if (err < 0)
 278                 goto end;
 279
 280         /* packet queueing error */
 281         if (amdtp_streaming_error(stream))
 282                 stop_stream(oxfw, stream);
 283
 284         err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
 285         if (err < 0)
 286                 goto end;
 287         if (rate == 0)
 288                 rate = formation.rate;
 289         if (pcm_channels == 0)
 290                 pcm_channels = formation.pcm;
 291
 292         if ((formation.rate != rate) || (formation.pcm != pcm_channels)) {
 293                 if (opposite != NULL) {
 294                         err = check_connection_used_by_others(oxfw, opposite);
 295                         if (err < 0)
 296                                 goto end;
 297                         stop_stream(oxfw, opposite);
 298                 }
 299                 stop_stream(oxfw, stream);
 300
 301                 err = set_stream_format(oxfw, stream, rate, pcm_channels);
 302                 if (err < 0) {
 303                         dev_err(&oxfw->unit->device,
 304                                 "fail to set stream format: %d\n", err);
 305                         goto end;
 306                 }
 307
 308                 /* Start opposite stream if needed. */
 309                 if (opposite && !amdtp_stream_running(opposite) &&
 310                     (opposite_substreams > 0)) {
 311                         err = start_stream(oxfw, opposite, rate, 0);
 312                         if (err < 0) {
 313                                 dev_err(&oxfw->unit->device,
 314                                         "fail to restart stream: %d\n", err);
 315                                 goto end;
 316                         }
 317                 }
 318         }
 319
 320         /* Start requested stream. */
 321         if (!amdtp_stream_running(stream)) {
 322                 err = start_stream(oxfw, stream, rate, pcm_channels);
 323                 if (err < 0)
 324                         dev_err(&oxfw->unit->device,
 325                                 "fail to start stream: %d\n", err);
 326         }
 327 end:
 328         return err;
 329 }
 330
 331 void snd_oxfw_stream_stop_simplex(struct snd_oxfw *oxfw,
 332                                   struct amdtp_stream *stream)
 333 {
 334         if (((stream == &oxfw->tx_stream) && (oxfw->capture_substreams > 0)) ||
 335             ((stream == &oxfw->rx_stream) && (oxfw->playback_substreams > 0)))
 336                 return;
 337
 338         stop_stream(oxfw, stream);
 339 }
 340
 341 /*
 342  * This function should be called before starting the stream or after stopping
 343  * the streams.
 344  */
 345 void snd_oxfw_stream_destroy_simplex(struct snd_oxfw *oxfw,
 346                                      struct amdtp_stream *stream)
 347 {
 348         struct cmp_connection *conn;
 349
 350         if (stream == &oxfw->tx_stream)
 351                 conn = &oxfw->out_conn;
 352         else
 353                 conn = &oxfw->in_conn;
 354
 355         amdtp_stream_destroy(stream);
 356         cmp_connection_destroy(conn);
 357 }
 358
 359 void snd_oxfw_stream_update_simplex(struct snd_oxfw *oxfw,
 360                                     struct amdtp_stream *stream)
 361 {
 362         struct cmp_connection *conn;
 363
 364         if (stream == &oxfw->tx_stream)
 365                 conn = &oxfw->out_conn;
 366         else
 367                 conn = &oxfw->in_conn;
 368
 369         if (cmp_connection_update(conn) < 0)
 370                 stop_stream(oxfw, stream);
 371         else
 372                 amdtp_stream_update(stream);
 373 }
 374
 375 int snd_oxfw_stream_get_current_formation(struct snd_oxfw *oxfw,
 376                                 enum avc_general_plug_dir dir,
 377                                 struct snd_oxfw_stream_formation *formation)
 378 {
 379         u8 *format;
 380         unsigned int len;
 381         int err;
 382
 383         len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
 384         format = kmalloc(len, GFP_KERNEL);
 385         if (format == NULL)
 386                 return -ENOMEM;
 387
 388         err = avc_stream_get_format_single(oxfw->unit, dir, 0, format, &len);
 389         if (err < 0)
 390                 goto end;
 391         if (len < 3) {
 392                 err = -EIO;
 393                 goto end;
 394         }
 395
 396         err = snd_oxfw_stream_parse_format(format, formation);
 397 end:
 398         kfree(format);
 399         return err;
 400 }
 401
 402 /*
 403  * See Table 6.16 - AM824 Stream Format
 404  *     Figure 6.19 - format_information field for AM824 Compound
 405  * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
 406  * Also 'Clause 12 AM824 sequence adaption layers' in IEC 61883-6:2005
 407  */
 408 int snd_oxfw_stream_parse_format(u8 *format,
 409                                  struct snd_oxfw_stream_formation *formation)
 410 {
 411         unsigned int i, e, channels, type;
 412
 413         memset(formation, 0, sizeof(struct snd_oxfw_stream_formation));
 414
 415         /*
 416          * this module can support a hierarchy combination that:
 417          *  Root:       Audio and Music (0x90)
 418          *  Level 1:    AM824 Compound  (0x40)
 419          */
 420         if ((format[0] != 0x90) || (format[1] != 0x40))
 421                 return -ENOSYS;
 422
 423         /* check the sampling rate */
 424         for (i = 0; i < ARRAY_SIZE(avc_stream_rate_table); i++) {
 425                 if (format[2] == avc_stream_rate_table[i])
 426                         break;
 427         }
 428         if (i == ARRAY_SIZE(avc_stream_rate_table))
 429                 return -ENOSYS;
 430
 431         formation->rate = oxfw_rate_table[i];
 432
 433         for (e = 0; e < format[4]; e++) {
 434                 channels = format[5 + e * 2];
 435                 type = format[6 + e * 2];
 436
 437                 switch (type) {
 438                 /* IEC 60958 Conformant, currently handled as MBLA */
 439                 case 0x00:
 440                 /* Multi Bit Linear Audio (Raw) */
 441                 case 0x06:
 442                         formation->pcm += channels;
 443                         break;
 444                 /* MIDI Conformant */
 445                 case 0x0d:
 446                         formation->midi = channels;
 447                         break;
 448                 /* IEC 61937-3 to 7 */
 449                 case 0x01:
 450                 case 0x02:
 451                 case 0x03:
 452                 case 0x04:
 453                 case 0x05:
 454                 /* Multi Bit Linear Audio */
 455                 case 0x07:      /* DVD-Audio */
 456                 case 0x0c:      /* High Precision */
 457                 /* One Bit Audio */
 458                 case 0x08:      /* (Plain) Raw */
 459                 case 0x09:      /* (Plain) SACD */
 460                 case 0x0a:      /* (Encoded) Raw */
 461                 case 0x0b:      /* (Encoded) SACD */
 462                 /* SMPTE Time-Code conformant */
 463                 case 0x0e:
 464                 /* Sample Count */
 465                 case 0x0f:
 466                 /* Anciliary Data */
 467                 case 0x10:
 468                 /* Synchronization Stream (Stereo Raw audio) */
 469                 case 0x40:
 470                 /* Don't care */
 471                 case 0xff:
 472                 default:
 473                         return -ENOSYS; /* not supported */
 474                 }
 475         }
 476
 477         if (formation->pcm  > AMDTP_MAX_CHANNELS_FOR_PCM ||
 478             formation->midi > AMDTP_MAX_CHANNELS_FOR_MIDI)
 479                 return -ENOSYS;
 480
 481         return 0;
 482 }
 483
 484 static int
 485 assume_stream_formats(struct snd_oxfw *oxfw, enum avc_general_plug_dir dir,
 486                       unsigned int pid, u8 *buf, unsigned int *len,
 487                       u8 **formats)
 488 {
 489         struct snd_oxfw_stream_formation formation;
 490         unsigned int i, eid;
 491         int err;
 492
 493         /* get format at current sampling rate */
 494         err = avc_stream_get_format_single(oxfw->unit, dir, pid, buf, len);
 495         if (err < 0) {
 496                 dev_err(&oxfw->unit->device,
 497                 "fail to get current stream format for isoc %s plug %d:%d\n",
 498                         (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
 499                         pid, err);
 500                 goto end;
 501         }
 502
 503         /* parse and set stream format */
 504         eid = 0;
 505         err = snd_oxfw_stream_parse_format(buf, &formation);
 506         if (err < 0)
 507                 goto end;
 508
 509         formats[eid] = kmalloc(*len, GFP_KERNEL);
 510         if (formats[eid] == NULL) {
 511                 err = -ENOMEM;
 512                 goto end;
 513         }
 514         memcpy(formats[eid], buf, *len);
 515
 516         /* apply the format for each available sampling rate */
 517         for (i = 0; i < ARRAY_SIZE(oxfw_rate_table); i++) {
 518                 if (formation.rate == oxfw_rate_table[i])
 519                         continue;
 520
 521                 err = avc_general_inquiry_sig_fmt(oxfw->unit,
 522                                                   oxfw_rate_table[i],
 523                                                   dir, pid);
 524                 if (err < 0)
 525                         continue;
 526
 527                 eid++;
 528                 formats[eid] = kmalloc(*len, GFP_KERNEL);
 529                 if (formats[eid] == NULL) {
 530                         err = -ENOMEM;
 531                         goto end;
 532                 }
 533                 memcpy(formats[eid], buf, *len);
 534                 formats[eid][2] = avc_stream_rate_table[i];
 535         }
 536
 537         err = 0;
 538         oxfw->assumed = true;
 539 end:
 540         return err;
 541 }
 542
 543 static int fill_stream_formats(struct snd_oxfw *oxfw,
 544                                enum avc_general_plug_dir dir,
 545                                unsigned short pid)
 546 {
 547         u8 *buf, **formats;
 548         unsigned int len, eid = 0;
 549         struct snd_oxfw_stream_formation dummy;
 550         int err;
 551
 552         buf = kmalloc(AVC_GENERIC_FRAME_MAXIMUM_BYTES, GFP_KERNEL);
 553         if (buf == NULL)
 554                 return -ENOMEM;
 555
 556         if (dir == AVC_GENERAL_PLUG_DIR_OUT)
 557                 formats = oxfw->tx_stream_formats;
 558         else
 559                 formats = oxfw->rx_stream_formats;
 560
 561         /* get first entry */
 562         len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
 563         err = avc_stream_get_format_list(oxfw->unit, dir, 0, buf, &len, 0);
 564         if (err == -ENOSYS) {
 565                 /* LIST subfunction is not implemented */
 566                 len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
 567                 err = assume_stream_formats(oxfw, dir, pid, buf, &len,
 568                                             formats);
 569                 goto end;
 570         } else if (err < 0) {
 571                 dev_err(&oxfw->unit->device,
 572                         "fail to get stream format %d for isoc %s plug %d:%d\n",
 573                         eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
 574                         pid, err);
 575                 goto end;
 576         }
 577
 578         /* LIST subfunction is implemented */
 579         while (eid < SND_OXFW_STREAM_FORMAT_ENTRIES) {
 580                 /* The format is too short. */
 581                 if (len < 3) {
 582                         err = -EIO;
 583                         break;
 584                 }
 585
 586                 /* parse and set stream format */
 587                 err = snd_oxfw_stream_parse_format(buf, &dummy);
 588                 if (err < 0)
 589                         break;
 590
 591                 formats[eid] = kmalloc(len, GFP_KERNEL);
 592                 if (formats[eid] == NULL) {
 593                         err = -ENOMEM;
 594                         break;
 595                 }
 596                 memcpy(formats[eid], buf, len);
 597
 598                 /* get next entry */
 599                 len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
 600                 err = avc_stream_get_format_list(oxfw->unit, dir, 0,
 601                                                  buf, &len, ++eid);
 602                 /* No entries remained. */
 603                 if (err == -EINVAL) {
 604                         err = 0;
 605                         break;
 606                 } else if (err < 0) {
 607                         dev_err(&oxfw->unit->device,
 608                         "fail to get stream format %d for isoc %s plug %d:%d\n",
 609                                 eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" :
 610                                                                         "out",
 611                                 pid, err);
 612                         break;
 613                 }
 614         }
 615 end:
 616         kfree(buf);
 617         return err;
 618 }
 619
 620 int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
 621 {
 622         u8 plugs[AVC_PLUG_INFO_BUF_BYTES];
 623         int err;
 624
 625         /* the number of plugs for isoc in/out, ext in/out  */
 626         err = avc_general_get_plug_info(oxfw->unit, 0x1f, 0x07, 0x00, plugs);
 627         if (err < 0) {
 628                 dev_err(&oxfw->unit->device,
 629                 "fail to get info for isoc/external in/out plugs: %d\n",
 630                         err);
 631                 goto end;
 632         } else if ((plugs[0] == 0) && (plugs[1] == 0)) {
 633                 err = -ENOSYS;
 634                 goto end;
 635         }
 636
 637         /* use oPCR[0] if exists */
 638         if (plugs[1] > 0) {
 639                 err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_OUT, 0);
 640                 if (err < 0)
 641                         goto end;
 642                 oxfw->has_output = true;
 643         }
 644
 645         /* use iPCR[0] if exists */
 646         if (plugs[0] > 0)
 647                 err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_IN, 0);
 648 end:
 649         return err;
 650 }
 651
 652 void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
 653 {
 654         oxfw->dev_lock_changed = true;
 655         wake_up(&oxfw->hwdep_wait);
 656 }
 657
 658 int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
 659 {
 660         int err;
 661
 662         spin_lock_irq(&oxfw->lock);
 663
 664         /* user land lock this */
 665         if (oxfw->dev_lock_count < 0) {
 666                 err = -EBUSY;
 667                 goto end;
 668         }
 669
 670         /* this is the first time */
 671         if (oxfw->dev_lock_count++ == 0)
 672                 snd_oxfw_stream_lock_changed(oxfw);
 673         err = 0;
 674 end:
 675         spin_unlock_irq(&oxfw->lock);
 676         return err;
 677 }
 678
 679 void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
 680 {
 681         spin_lock_irq(&oxfw->lock);
 682
 683         if (WARN_ON(oxfw->dev_lock_count <= 0))
 684                 goto end;
 685         if (--oxfw->dev_lock_count == 0)
 686                 snd_oxfw_stream_lock_changed(oxfw);
 687 end:
 688         spin_unlock_irq(&oxfw->lock);
 689 }