sound/usb/clock.c

   1 /*
   2  *   Clock domain and sample rate management functions
   3  *
   4  *   This program is free software; you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation; either version 2 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *   GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program; if not, write to the Free Software
  16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  *
  18  */
  19
  20 #include <linux/bitops.h>
  21 #include <linux/init.h>
  22 #include <linux/string.h>
  23 #include <linux/usb.h>
  24 #include <linux/usb/audio.h>
  25 #include <linux/usb/audio-v2.h>
  26 #include <linux/usb/audio-v3.h>
  27
  28 #include <sound/core.h>
  29 #include <sound/info.h>
  30 #include <sound/pcm.h>
  31
  32 #include "usbaudio.h"
  33 #include "card.h"
  34 #include "helper.h"
  35 #include "clock.h"
  36 #include "quirks.h"
  37
  38 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
  39                                  bool (*validator)(void *, int), u8 type)
  40 {
  41         void *cs = NULL;
  42
  43         while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
  44                                              cs, type))) {
  45                 if (validator(cs, id))
  46                         return cs;
  47         }
  48
  49         return NULL;
  50 }
  51
  52 static bool validate_clock_source_v2(void *p, int id)
  53 {
  54         struct uac_clock_source_descriptor *cs = p;
  55         return cs->bClockID == id;
  56 }
  57
  58 static bool validate_clock_source_v3(void *p, int id)
  59 {
  60         struct uac3_clock_source_descriptor *cs = p;
  61         return cs->bClockID == id;
  62 }
  63
  64 static bool validate_clock_selector_v2(void *p, int id)
  65 {
  66         struct uac_clock_selector_descriptor *cs = p;
  67         return cs->bClockID == id;
  68 }
  69
  70 static bool validate_clock_selector_v3(void *p, int id)
  71 {
  72         struct uac3_clock_selector_descriptor *cs = p;
  73         return cs->bClockID == id;
  74 }
  75
  76 static bool validate_clock_multiplier_v2(void *p, int id)
  77 {
  78         struct uac_clock_multiplier_descriptor *cs = p;
  79         return cs->bClockID == id;
  80 }
  81
  82 static bool validate_clock_multiplier_v3(void *p, int id)
  83 {
  84         struct uac3_clock_multiplier_descriptor *cs = p;
  85         return cs->bClockID == id;
  86 }
  87
  88 #define DEFINE_FIND_HELPER(name, obj, validator, type)          \
  89 static obj *name(struct usb_host_interface *iface, int id)      \
  90 {                                                               \
  91         return find_uac_clock_desc(iface, id, validator, type); \
  92 }
  93
  94 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
  95                    struct uac_clock_source_descriptor,
  96                    validate_clock_source_v2, UAC2_CLOCK_SOURCE);
  97 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
  98                    struct uac3_clock_source_descriptor,
  99                    validate_clock_source_v3, UAC3_CLOCK_SOURCE);
 100
 101 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
 102                    struct uac_clock_selector_descriptor,
 103                    validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
 104 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
 105                    struct uac3_clock_selector_descriptor,
 106                    validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
 107
 108 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
 109                    struct uac_clock_multiplier_descriptor,
 110                    validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
 111 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
 112                    struct uac3_clock_multiplier_descriptor,
 113                    validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
 114
 115 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
 116 {
 117         unsigned char buf;
 118         int ret;
 119
 120         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
 121                               UAC2_CS_CUR,
 122                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 123                               UAC2_CX_CLOCK_SELECTOR << 8,
 124                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 125                               &buf, sizeof(buf));
 126
 127         if (ret < 0)
 128                 return ret;
 129
 130         return buf;
 131 }
 132
 133 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
 134                                         unsigned char pin)
 135 {
 136         int ret;
 137
 138         ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
 139                               UAC2_CS_CUR,
 140                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 141                               UAC2_CX_CLOCK_SELECTOR << 8,
 142                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 143                               &pin, sizeof(pin));
 144         if (ret < 0)
 145                 return ret;
 146
 147         if (ret != sizeof(pin)) {
 148                 usb_audio_err(chip,
 149                         "setting selector (id %d) unexpected length %d\n",
 150                         selector_id, ret);
 151                 return -EINVAL;
 152         }
 153
 154         ret = uac_clock_selector_get_val(chip, selector_id);
 155         if (ret < 0)
 156                 return ret;
 157
 158         if (ret != pin) {
 159                 usb_audio_err(chip,
 160                         "setting selector (id %d) to %x failed (current: %d)\n",
 161                         selector_id, pin, ret);
 162                 return -EINVAL;
 163         }
 164
 165         return ret;
 166 }
 167
 168 /*
 169  * Assume the clock is valid if clock source supports only one single sample
 170  * rate, the terminal is connected directly to it (there is no clock selector)
 171  * and clock type is internal. This is to deal with some Denon DJ controllers
 172  * that always reports that clock is invalid.
 173  */
 174 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
 175                                             struct audioformat *fmt,
 176                                             int source_id)
 177 {
 178         if (fmt->protocol == UAC_VERSION_2) {
 179                 struct uac_clock_source_descriptor *cs_desc =
 180                         snd_usb_find_clock_source(chip->ctrl_intf, source_id);
 181
 182                 if (!cs_desc)
 183                         return false;
 184
 185                 return (fmt->nr_rates == 1 &&
 186                         (fmt->clock & 0xff) == cs_desc->bClockID &&
 187                         (cs_desc->bmAttributes & 0x3) !=
 188                                 UAC_CLOCK_SOURCE_TYPE_EXT);
 189         }
 190
 191         return false;
 192 }
 193
 194 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
 195                                       struct audioformat *fmt,
 196                                       int source_id)
 197 {
 198         int err;
 199         unsigned char data;
 200         struct usb_device *dev = chip->dev;
 201         u32 bmControls;
 202
 203         if (fmt->protocol == UAC_VERSION_3) {
 204                 struct uac3_clock_source_descriptor *cs_desc =
 205                         snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
 206
 207                 if (!cs_desc)
 208                         return false;
 209                 bmControls = le32_to_cpu(cs_desc->bmControls);
 210         } else { /* UAC_VERSION_1/2 */
 211                 struct uac_clock_source_descriptor *cs_desc =
 212                         snd_usb_find_clock_source(chip->ctrl_intf, source_id);
 213
 214                 if (!cs_desc)
 215                         return false;
 216                 bmControls = cs_desc->bmControls;
 217         }
 218
 219         /* If a clock source can't tell us whether it's valid, we assume it is */
 220         if (!uac_v2v3_control_is_readable(bmControls,
 221                                       UAC2_CS_CONTROL_CLOCK_VALID))
 222                 return true;
 223
 224         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 225                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 226                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 227                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 228                               &data, sizeof(data));
 229
 230         if (err < 0) {
 231                 dev_warn(&dev->dev,
 232                          "%s(): cannot get clock validity for id %d\n",
 233                            __func__, source_id);
 234                 return false;
 235         }
 236
 237         if (data)
 238                 return true;
 239         else
 240                 return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
 241 }
 242
 243 static int __uac_clock_find_source(struct snd_usb_audio *chip,
 244                                    struct audioformat *fmt, int entity_id,
 245                                    unsigned long *visited, bool validate)
 246 {
 247         struct uac_clock_source_descriptor *source;
 248         struct uac_clock_selector_descriptor *selector;
 249         struct uac_clock_multiplier_descriptor *multiplier;
 250
 251         entity_id &= 0xff;
 252
 253         if (test_and_set_bit(entity_id, visited)) {
 254                 usb_audio_warn(chip,
 255                          "%s(): recursive clock topology detected, id %d.\n",
 256                          __func__, entity_id);
 257                 return -EINVAL;
 258         }
 259
 260         /* first, see if the ID we're looking for is a clock source already */
 261         source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
 262         if (source) {
 263                 entity_id = source->bClockID;
 264                 if (validate && !uac_clock_source_is_valid(chip, fmt,
 265                                                                 entity_id)) {
 266                         usb_audio_err(chip,
 267                                 "clock source %d is not valid, cannot use\n",
 268                                 entity_id);
 269                         return -ENXIO;
 270                 }
 271                 return entity_id;
 272         }
 273
 274         selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
 275         if (selector) {
 276                 int ret, i, cur, err;
 277
 278                 /* the entity ID we are looking for is a selector.
 279                  * find out what it currently selects */
 280                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 281                 if (ret < 0)
 282                         return ret;
 283
 284                 /* Selector values are one-based */
 285
 286                 if (ret > selector->bNrInPins || ret < 1) {
 287                         usb_audio_err(chip,
 288                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 289                                 __func__, selector->bClockID, ret);
 290
 291                         return -EINVAL;
 292                 }
 293
 294                 cur = ret;
 295                 ret = __uac_clock_find_source(chip, fmt,
 296                                               selector->baCSourceID[ret - 1],
 297                                               visited, validate);
 298                 if (ret > 0) {
 299                         /*
 300                          * For Samsung USBC Headset (AKG), setting clock selector again
 301                          * will result in incorrect default clock setting problems
 302                          */
 303                         if (chip->usb_id == USB_ID(0x04e8, 0xa051))
 304                                 return ret;
 305                         err = uac_clock_selector_set_val(chip, entity_id, cur);
 306                         if (err < 0)
 307                                 return err;
 308                 }
 309
 310                 if (!validate || ret > 0 || !chip->autoclock)
 311                         return ret;
 312
 313                 /* The current clock source is invalid, try others. */
 314                 for (i = 1; i <= selector->bNrInPins; i++) {
 315                         if (i == cur)
 316                                 continue;
 317
 318                         ret = __uac_clock_find_source(chip, fmt,
 319                                                       selector->baCSourceID[i - 1],
 320                                                       visited, true);
 321                         if (ret < 0)
 322                                 continue;
 323
 324                         err = uac_clock_selector_set_val(chip, entity_id, i);
 325                         if (err < 0)
 326                                 continue;
 327
 328                         usb_audio_info(chip,
 329                                  "found and selected valid clock source %d\n",
 330                                  ret);
 331                         return ret;
 332                 }
 333
 334                 return -ENXIO;
 335         }
 336
 337         /* FIXME: multipliers only act as pass-thru element for now */
 338         multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
 339         if (multiplier)
 340                 return __uac_clock_find_source(chip, fmt,
 341                                                multiplier->bCSourceID,
 342                                                visited, validate);
 343
 344         return -EINVAL;
 345 }
 346
 347 static int __uac3_clock_find_source(struct snd_usb_audio *chip,
 348                                     struct audioformat *fmt, int entity_id,
 349                                     unsigned long *visited, bool validate)
 350 {
 351         struct uac3_clock_source_descriptor *source;
 352         struct uac3_clock_selector_descriptor *selector;
 353         struct uac3_clock_multiplier_descriptor *multiplier;
 354
 355         entity_id &= 0xff;
 356
 357         if (test_and_set_bit(entity_id, visited)) {
 358                 usb_audio_warn(chip,
 359                          "%s(): recursive clock topology detected, id %d.\n",
 360                          __func__, entity_id);
 361                 return -EINVAL;
 362         }
 363
 364         /* first, see if the ID we're looking for is a clock source already */
 365         source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
 366         if (source) {
 367                 entity_id = source->bClockID;
 368                 if (validate && !uac_clock_source_is_valid(chip, fmt,
 369                                                                 entity_id)) {
 370                         usb_audio_err(chip,
 371                                 "clock source %d is not valid, cannot use\n",
 372                                 entity_id);
 373                         return -ENXIO;
 374                 }
 375                 return entity_id;
 376         }
 377
 378         selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
 379         if (selector) {
 380                 int ret, i, cur, err;
 381
 382                 /* the entity ID we are looking for is a selector.
 383                  * find out what it currently selects */
 384                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 385                 if (ret < 0)
 386                         return ret;
 387
 388                 /* Selector values are one-based */
 389
 390                 if (ret > selector->bNrInPins || ret < 1) {
 391                         usb_audio_err(chip,
 392                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 393                                 __func__, selector->bClockID, ret);
 394
 395                         return -EINVAL;
 396                 }
 397
 398                 cur = ret;
 399                 ret = __uac3_clock_find_source(chip, fmt,
 400                                                selector->baCSourceID[ret - 1],
 401                                                visited, validate);
 402                 if (ret > 0) {
 403                         err = uac_clock_selector_set_val(chip, entity_id, cur);
 404                         if (err < 0)
 405                                 return err;
 406                 }
 407
 408                 if (!validate || ret > 0 || !chip->autoclock)
 409                         return ret;
 410
 411                 /* The current clock source is invalid, try others. */
 412                 for (i = 1; i <= selector->bNrInPins; i++) {
 413                         int err;
 414
 415                         if (i == cur)
 416                                 continue;
 417
 418                         ret = __uac3_clock_find_source(chip, fmt,
 419                                                        selector->baCSourceID[i - 1],
 420                                                        visited, true);
 421                         if (ret < 0)
 422                                 continue;
 423
 424                         err = uac_clock_selector_set_val(chip, entity_id, i);
 425                         if (err < 0)
 426                                 continue;
 427
 428                         usb_audio_info(chip,
 429                                  "found and selected valid clock source %d\n",
 430                                  ret);
 431                         return ret;
 432                 }
 433
 434                 return -ENXIO;
 435         }
 436
 437         /* FIXME: multipliers only act as pass-thru element for now */
 438         multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
 439                                                       entity_id);
 440         if (multiplier)
 441                 return __uac3_clock_find_source(chip, fmt,
 442                                                 multiplier->bCSourceID,
 443                                                 visited, validate);
 444
 445         return -EINVAL;
 446 }
 447
 448 /*
 449  * For all kinds of sample rate settings and other device queries,
 450  * the clock source (end-leaf) must be used. However, clock selectors,
 451  * clock multipliers and sample rate converters may be specified as
 452  * clock source input to terminal. This functions walks the clock path
 453  * to its end and tries to find the source.
 454  *
 455  * The 'visited' bitfield is used internally to detect recursive loops.
 456  *
 457  * Returns the clock source UnitID (>=0) on success, or an error.
 458  */
 459 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
 460                               struct audioformat *fmt, bool validate)
 461 {
 462         DECLARE_BITMAP(visited, 256);
 463         memset(visited, 0, sizeof(visited));
 464
 465         switch (fmt->protocol) {
 466         case UAC_VERSION_2:
 467                 return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
 468                                                validate);
 469         case UAC_VERSION_3:
 470                 return __uac3_clock_find_source(chip, fmt, fmt->clock, visited,
 471                                                validate);
 472         default:
 473                 return -EINVAL;
 474         }
 475 }
 476
 477 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
 478                               struct usb_host_interface *alts,
 479                               struct audioformat *fmt, int rate)
 480 {
 481         struct usb_device *dev = chip->dev;
 482         unsigned int ep;
 483         unsigned char data[3];
 484         int err, crate;
 485
 486         if (get_iface_desc(alts)->bNumEndpoints < 1)
 487                 return -EINVAL;
 488         ep = get_endpoint(alts, 0)->bEndpointAddress;
 489
 490         /* if endpoint doesn't have sampling rate control, bail out */
 491         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 492                 return 0;
 493
 494         data[0] = rate;
 495         data[1] = rate >> 8;
 496         data[2] = rate >> 16;
 497         err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 498                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 499                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 500                               data, sizeof(data));
 501         if (err < 0) {
 502                 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
 503                         iface, fmt->altsetting, rate, ep);
 504                 return err;
 505         }
 506
 507         /* Don't check the sample rate for devices which we know don't
 508          * support reading */
 509         if (snd_usb_get_sample_rate_quirk(chip))
 510                 return 0;
 511         /* the firmware is likely buggy, don't repeat to fail too many times */
 512         if (chip->sample_rate_read_error > 2)
 513                 return 0;
 514
 515         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 516                               USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 517                               UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 518                               data, sizeof(data));
 519         if (err < 0) {
 520                 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
 521                         iface, fmt->altsetting, ep);
 522                 chip->sample_rate_read_error++;
 523                 return 0; /* some devices don't support reading */
 524         }
 525
 526         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 527         if (!crate) {
 528                 dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
 529                 chip->sample_rate_read_error = 3; /* three strikes, see above */
 530                 return 0;
 531         }
 532
 533         if (crate != rate) {
 534                 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
 535                 // runtime->rate = crate;
 536         }
 537
 538         return 0;
 539 }
 540
 541 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 542                               int altsetting, int clock)
 543 {
 544         struct usb_device *dev = chip->dev;
 545         __le32 data;
 546         int err;
 547
 548         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 549                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 550                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 551                               snd_usb_ctrl_intf(chip) | (clock << 8),
 552                               &data, sizeof(data));
 553         if (err < 0) {
 554                 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
 555                          iface, altsetting, err);
 556                 return 0;
 557         }
 558
 559         return le32_to_cpu(data);
 560 }
 561
 562 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
 563                               struct usb_host_interface *alts,
 564                               struct audioformat *fmt, int rate)
 565 {
 566         struct usb_device *dev = chip->dev;
 567         __le32 data;
 568         int err, cur_rate, prev_rate;
 569         int clock;
 570         bool writeable;
 571         u32 bmControls;
 572
 573         /* First, try to find a valid clock. This may trigger
 574          * automatic clock selection if the current clock is not
 575          * valid.
 576          */
 577         clock = snd_usb_clock_find_source(chip, fmt, true);
 578         if (clock < 0) {
 579                 /* We did not find a valid clock, but that might be
 580                  * because the current sample rate does not match an
 581                  * external clock source. Try again without validation
 582                  * and we will do another validation after setting the
 583                  * rate.
 584                  */
 585                 clock = snd_usb_clock_find_source(chip, fmt, false);
 586                 if (clock < 0)
 587                         return clock;
 588         }
 589
 590         prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
 591         if (prev_rate == rate)
 592                 goto validation;
 593
 594         if (fmt->protocol == UAC_VERSION_3) {
 595                 struct uac3_clock_source_descriptor *cs_desc;
 596
 597                 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
 598                 bmControls = le32_to_cpu(cs_desc->bmControls);
 599         } else {
 600                 struct uac_clock_source_descriptor *cs_desc;
 601
 602                 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
 603                 bmControls = cs_desc->bmControls;
 604         }
 605
 606         writeable = uac_v2v3_control_is_writeable(bmControls,
 607                                                   UAC2_CS_CONTROL_SAM_FREQ);
 608         if (writeable) {
 609                 data = cpu_to_le32(rate);
 610                 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 611                                       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 612                                       UAC2_CS_CONTROL_SAM_FREQ << 8,
 613                                       snd_usb_ctrl_intf(chip) | (clock << 8),
 614                                       &data, sizeof(data));
 615                 if (err < 0) {
 616                         usb_audio_err(chip,
 617                                 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
 618                                 iface, fmt->altsetting, rate, err);
 619                         return err;
 620                 }
 621
 622                 cur_rate = get_sample_rate_v2v3(chip, iface,
 623                                                 fmt->altsetting, clock);
 624         } else {
 625                 cur_rate = prev_rate;
 626         }
 627
 628         if (cur_rate != rate) {
 629                 if (!writeable) {
 630                         usb_audio_warn(chip,
 631                                  "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
 632                                  iface, fmt->altsetting, rate, cur_rate);
 633                         return -ENXIO;
 634                 }
 635                 usb_audio_dbg(chip,
 636                         "current rate %d is different from the runtime rate %d\n",
 637                         cur_rate, rate);
 638         }
 639
 640         /* Some devices doesn't respond to sample rate changes while the
 641          * interface is active. */
 642         if (rate != prev_rate) {
 643                 usb_set_interface(dev, iface, 0);
 644                 snd_usb_set_interface_quirk(dev);
 645                 usb_set_interface(dev, iface, fmt->altsetting);
 646                 snd_usb_set_interface_quirk(dev);
 647         }
 648
 649 validation:
 650         /* validate clock after rate change */
 651         if (!uac_clock_source_is_valid(chip, fmt, clock))
 652                 return -ENXIO;
 653         return 0;
 654 }
 655
 656 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 657                              struct usb_host_interface *alts,
 658                              struct audioformat *fmt, int rate)
 659 {
 660         switch (fmt->protocol) {
 661         case UAC_VERSION_1:
 662         default:
 663                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 664
 665         case UAC_VERSION_3:
 666                 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 667                         if (rate != UAC3_BADD_SAMPLING_RATE)
 668                                 return -ENXIO;
 669                         else
 670                                 return 0;
 671                 }
 672         /* fall through */
 673         case UAC_VERSION_2:
 674                 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
 675         }
 676 }
 677