target/linux/brcm2708/patches-4.4/0315-Revert-bcm2835-implement-channel-map-API.patch

   1 From 321cf99bd2206e741a89b5ac350dfe3f182a00a3 Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Fri, 29 Apr 2016 17:29:03 +0100
   4 Subject: [PATCH] Revert "bcm2835: implement channel map API"
   5
   6 This reverts commit 5efba3f8c180c39609a8d40033ef92046ef0de75.
   7 ---
   8  sound/arm/bcm2835-ctl.c   | 299 ----------------------------------------------
   9  sound/arm/bcm2835-pcm.c   |  69 ++---------
  10  sound/arm/bcm2835-vchiq.c |  13 --
  11  sound/arm/bcm2835.h       |   4 -
  12  4 files changed, 7 insertions(+), 378 deletions(-)
  13
  14 --- a/sound/arm/bcm2835-ctl.c
  15 +++ b/sound/arm/bcm2835-ctl.c
  16 @@ -327,304 +327,6 @@ static struct snd_kcontrol_new snd_bcm28
  17         },
  18  };
  19
  20 -struct cea_channel_speaker_allocation {
  21 -       int ca_index;
  22 -       int speakers[8];
  23 -};
  24 -
  25 -#define FL     SNDRV_CHMAP_FL
  26 -#define FR     SNDRV_CHMAP_FR
  27 -#define RL     SNDRV_CHMAP_RL
  28 -#define RR     SNDRV_CHMAP_RR
  29 -#define LFE    SNDRV_CHMAP_LFE
  30 -#define FC     SNDRV_CHMAP_FC
  31 -#define RLC    SNDRV_CHMAP_RLC
  32 -#define RRC    SNDRV_CHMAP_RRC
  33 -#define RC     SNDRV_CHMAP_RC
  34 -#define FLC    SNDRV_CHMAP_FLC
  35 -#define FRC    SNDRV_CHMAP_FRC
  36 -#define FLH    SNDRV_CHMAP_TFL
  37 -#define FRH    SNDRV_CHMAP_TFR
  38 -#define FLW    SNDRV_CHMAP_FLW
  39 -#define FRW    SNDRV_CHMAP_FRW
  40 -#define TC     SNDRV_CHMAP_TC
  41 -#define FCH    SNDRV_CHMAP_TFC
  42 -
  43 -/*
  44 - * CEA-861 channel maps
  45 - *
  46 - * Stolen from sound/pci/hda/patch_hdmi.c
  47 - * (unlike the source, this uses SNDRV_* constants directly, as by the
  48 - *  map_tables array in patch_hdmi.c)
  49 - * Unknown entries use 0, which unfortunately is SNDRV_CHMAP_UNKNOWN instead
  50 - * of SNDRV_CHMAP_NA.
  51 - */
  52 -static struct cea_channel_speaker_allocation channel_allocations[] = {
  53 -/*                       channel:   7     6    5    4    3     2    1    0  */
  54 -{ .ca_index = 0x00,  .speakers = {   0,    0,   0,   0,   0,    0,  FR,  FL } },
  55 -                                /* 2.1 */
  56 -{ .ca_index = 0x01,  .speakers = {   0,    0,   0,   0,   0,  LFE,  FR,  FL } },
  57 -                                /* Dolby Surround */
  58 -{ .ca_index = 0x02,  .speakers = {   0,    0,   0,   0,  FC,    0,  FR,  FL } },
  59 -                                /* surround40 */
  60 -{ .ca_index = 0x08,  .speakers = {   0,    0,  RR,  RL,   0,    0,  FR,  FL } },
  61 -                                /* surround41 */
  62 -{ .ca_index = 0x09,  .speakers = {   0,    0,  RR,  RL,   0,  LFE,  FR,  FL } },
  63 -                                /* surround50 */
  64 -{ .ca_index = 0x0a,  .speakers = {   0,    0,  RR,  RL,  FC,    0,  FR,  FL } },
  65 -                                /* surround51 */
  66 -{ .ca_index = 0x0b,  .speakers = {   0,    0,  RR,  RL,  FC,  LFE,  FR,  FL } },
  67 -                                /* 6.1 */
  68 -{ .ca_index = 0x0f,  .speakers = {   0,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
  69 -                                /* surround71 */
  70 -{ .ca_index = 0x13,  .speakers = { RRC,  RLC,  RR,  RL,  FC,  LFE,  FR,  FL } },
  71 -
  72 -{ .ca_index = 0x03,  .speakers = {   0,    0,   0,   0,  FC,  LFE,  FR,  FL } },
  73 -{ .ca_index = 0x04,  .speakers = {   0,    0,   0,  RC,   0,    0,  FR,  FL } },
  74 -{ .ca_index = 0x05,  .speakers = {   0,    0,   0,  RC,   0,  LFE,  FR,  FL } },
  75 -{ .ca_index = 0x06,  .speakers = {   0,    0,   0,  RC,  FC,    0,  FR,  FL } },
  76 -{ .ca_index = 0x07,  .speakers = {   0,    0,   0,  RC,  FC,  LFE,  FR,  FL } },
  77 -{ .ca_index = 0x0c,  .speakers = {   0,   RC,  RR,  RL,   0,    0,  FR,  FL } },
  78 -{ .ca_index = 0x0d,  .speakers = {   0,   RC,  RR,  RL,   0,  LFE,  FR,  FL } },
  79 -{ .ca_index = 0x0e,  .speakers = {   0,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
  80 -{ .ca_index = 0x10,  .speakers = { RRC,  RLC,  RR,  RL,   0,    0,  FR,  FL } },
  81 -{ .ca_index = 0x11,  .speakers = { RRC,  RLC,  RR,  RL,   0,  LFE,  FR,  FL } },
  82 -{ .ca_index = 0x12,  .speakers = { RRC,  RLC,  RR,  RL,  FC,    0,  FR,  FL } },
  83 -{ .ca_index = 0x14,  .speakers = { FRC,  FLC,   0,   0,   0,    0,  FR,  FL } },
  84 -{ .ca_index = 0x15,  .speakers = { FRC,  FLC,   0,   0,   0,  LFE,  FR,  FL } },
  85 -{ .ca_index = 0x16,  .speakers = { FRC,  FLC,   0,   0,  FC,    0,  FR,  FL } },
  86 -{ .ca_index = 0x17,  .speakers = { FRC,  FLC,   0,   0,  FC,  LFE,  FR,  FL } },
  87 -{ .ca_index = 0x18,  .speakers = { FRC,  FLC,   0,  RC,   0,    0,  FR,  FL } },
  88 -{ .ca_index = 0x19,  .speakers = { FRC,  FLC,   0,  RC,   0,  LFE,  FR,  FL } },
  89 -{ .ca_index = 0x1a,  .speakers = { FRC,  FLC,   0,  RC,  FC,    0,  FR,  FL } },
  90 -{ .ca_index = 0x1b,  .speakers = { FRC,  FLC,   0,  RC,  FC,  LFE,  FR,  FL } },
  91 -{ .ca_index = 0x1c,  .speakers = { FRC,  FLC,  RR,  RL,   0,    0,  FR,  FL } },
  92 -{ .ca_index = 0x1d,  .speakers = { FRC,  FLC,  RR,  RL,   0,  LFE,  FR,  FL } },
  93 -{ .ca_index = 0x1e,  .speakers = { FRC,  FLC,  RR,  RL,  FC,    0,  FR,  FL } },
  94 -{ .ca_index = 0x1f,  .speakers = { FRC,  FLC,  RR,  RL,  FC,  LFE,  FR,  FL } },
  95 -{ .ca_index = 0x20,  .speakers = {   0,  FCH,  RR,  RL,  FC,    0,  FR,  FL } },
  96 -{ .ca_index = 0x21,  .speakers = {   0,  FCH,  RR,  RL,  FC,  LFE,  FR,  FL } },
  97 -{ .ca_index = 0x22,  .speakers = {  TC,    0,  RR,  RL,  FC,    0,  FR,  FL } },
  98 -{ .ca_index = 0x23,  .speakers = {  TC,    0,  RR,  RL,  FC,  LFE,  FR,  FL } },
  99 -{ .ca_index = 0x24,  .speakers = { FRH,  FLH,  RR,  RL,   0,    0,  FR,  FL } },
 100 -{ .ca_index = 0x25,  .speakers = { FRH,  FLH,  RR,  RL,   0,  LFE,  FR,  FL } },
 101 -{ .ca_index = 0x26,  .speakers = { FRW,  FLW,  RR,  RL,   0,    0,  FR,  FL } },
 102 -{ .ca_index = 0x27,  .speakers = { FRW,  FLW,  RR,  RL,   0,  LFE,  FR,  FL } },
 103 -{ .ca_index = 0x28,  .speakers = {  TC,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
 104 -{ .ca_index = 0x29,  .speakers = {  TC,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
 105 -{ .ca_index = 0x2a,  .speakers = { FCH,   RC,  RR,  RL,  FC,    0,  FR,  FL } },
 106 -{ .ca_index = 0x2b,  .speakers = { FCH,   RC,  RR,  RL,  FC,  LFE,  FR,  FL } },
 107 -{ .ca_index = 0x2c,  .speakers = {  TC,  FCH,  RR,  RL,  FC,    0,  FR,  FL } },
 108 -{ .ca_index = 0x2d,  .speakers = {  TC,  FCH,  RR,  RL,  FC,  LFE,  FR,  FL } },
 109 -{ .ca_index = 0x2e,  .speakers = { FRH,  FLH,  RR,  RL,  FC,    0,  FR,  FL } },
 110 -{ .ca_index = 0x2f,  .speakers = { FRH,  FLH,  RR,  RL,  FC,  LFE,  FR,  FL } },
 111 -{ .ca_index = 0x30,  .speakers = { FRW,  FLW,  RR,  RL,  FC,    0,  FR,  FL } },
 112 -{ .ca_index = 0x31,  .speakers = { FRW,  FLW,  RR,  RL,  FC,  LFE,  FR,  FL } },
 113 -};
 114 -
 115 -static int snd_bcm2835_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 116 -                                    unsigned int size, unsigned int __user *tlv)
 117 -{
 118 -       unsigned int __user *dst;
 119 -       int count = 0;
 120 -       int i;
 121 -
 122 -       if (size < 8)
 123 -               return -ENOMEM;
 124 -       if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
 125 -               return -EFAULT;
 126 -       size -= 8;
 127 -       dst = tlv + 2;
 128 -       for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
 129 -               struct cea_channel_speaker_allocation *ch = &channel_allocations[i];
 130 -               int num_chs = 0;
 131 -               int chs_bytes;
 132 -               int c;
 133 -
 134 -               for (c = 0; c < 8; c++) {
 135 -                       if (ch->speakers[c])
 136 -                               num_chs++;
 137 -               }
 138 -
 139 -               chs_bytes = num_chs * 4;
 140 -               if (size < 8)
 141 -                       return -ENOMEM;
 142 -               if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
 143 -                   put_user(chs_bytes, dst + 1))
 144 -                       return -EFAULT;
 145 -               dst += 2;
 146 -               size -= 8;
 147 -               count += 8;
 148 -               if (size < chs_bytes)
 149 -                       return -ENOMEM;
 150 -               size -= chs_bytes;
 151 -               count += chs_bytes;
 152 -               for (c = 0; c < 8; c++) {
 153 -                       int sp = ch->speakers[7 - c];
 154 -                       if (sp) {
 155 -                               if (put_user(sp, dst))
 156 -                                       return -EFAULT;
 157 -                               dst++;
 158 -                       }
 159 -               }
 160 -       }
 161 -       if (put_user(count, tlv + 1))
 162 -               return -EFAULT;
 163 -       return 0;
 164 -}
 165 -
 166 -static int snd_bcm2835_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 167 -                                    struct snd_ctl_elem_value *ucontrol)
 168 -{
 169 -       struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 170 -       bcm2835_chip_t *chip = info->private_data;
 171 -       unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
 172 -       struct snd_pcm_substream *substream = snd_pcm_chmap_substream(info, idx);
 173 -       struct cea_channel_speaker_allocation *ch = NULL;
 174 -       int res = 0;
 175 -       int cur = 0;
 176 -       int i;
 177 -
 178 -       if (mutex_lock_interruptible(&chip->audio_mutex))
 179 -               return -EINTR;
 180 -
 181 -       if (!substream || !substream->runtime) {
 182 -               res = -ENODEV;
 183 -               goto unlock;
 184 -       }
 185 -
 186 -       for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
 187 -               if (channel_allocations[i].ca_index == chip->cea_chmap)
 188 -                       ch = &channel_allocations[i];
 189 -       }
 190 -
 191 -       /* If no layout was set yet, return a dummy. Apparently the userspace
 192 -        * API will be confused if we don't. */
 193 -       if (!ch)
 194 -               ch = &channel_allocations[0];
 195 -
 196 -       for (i = 0; i < 8; i++) {
 197 -               if (ch->speakers[7 - i])
 198 -                       ucontrol->value.integer.value[cur++] = ch->speakers[7 - i];
 199 -       }
 200 -       while (cur < 8)
 201 -               ucontrol->value.integer.value[cur++] = SNDRV_CHMAP_NA;
 202 -
 203 -unlock:
 204 -       mutex_unlock(&chip->audio_mutex);
 205 -       return res;
 206 -}
 207 -
 208 -static int snd_bcm2835_chmap_ctl_put(struct snd_kcontrol *kcontrol,
 209 -                                    struct snd_ctl_elem_value *ucontrol)
 210 -{
 211 -       struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 212 -       bcm2835_chip_t *chip = info->private_data;
 213 -       unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
 214 -       struct snd_pcm_substream *substream = snd_pcm_chmap_substream(info, idx);
 215 -       int i, prepared = 0, cea_chmap = -1;
 216 -       int res = 0;
 217 -       int remap[8];
 218 -
 219 -       if (mutex_lock_interruptible(&chip->audio_mutex))
 220 -               return -EINTR;
 221 -
 222 -       if (!substream || !substream->runtime) {
 223 -               res = -ENODEV;
 224 -               goto unlock;
 225 -       }
 226 -
 227 -       switch (substream->runtime->status->state) {
 228 -       case SNDRV_PCM_STATE_OPEN:
 229 -       case SNDRV_PCM_STATE_SETUP:
 230 -               break;
 231 -       case SNDRV_PCM_STATE_PREPARED:
 232 -               prepared = 1;
 233 -               break;
 234 -       default:
 235 -               res = -EBUSY;
 236 -               goto unlock;
 237 -       }
 238 -
 239 -       for (i = 0; i < ARRAY_SIZE(channel_allocations); i++) {
 240 -               struct cea_channel_speaker_allocation *ch = &channel_allocations[i];
 241 -               int matches = 1;
 242 -               int cur = 0;
 243 -               int x;
 244 -               memset(remap, 0, sizeof(remap));
 245 -               for (x = 0; x < substream->runtime->channels; x++) {
 246 -                       int sp = ucontrol->value.integer.value[x];
 247 -                       while (cur < 8 && !ch->speakers[7 - cur])
 248 -                               cur++;
 249 -                       if (cur >= 8) {
 250 -                               /* user has more channels than ch */
 251 -                               matches = 0;
 252 -                               break;
 253 -                       }
 254 -                       if (ch->speakers[7 - cur] != sp) {
 255 -                               matches = 0;
 256 -                               break;
 257 -                       }
 258 -                       remap[x] = cur;
 259 -                       cur++;
 260 -               }
 261 -               for (x = cur; x < 8; x++) {
 262 -                       if (ch->speakers[7 - x]) {
 263 -                               /* ch has more channels than user */
 264 -                               matches = 0;
 265 -                               break;
 266 -                       }
 267 -               }
 268 -               if (matches) {
 269 -                       cea_chmap = ch->ca_index;
 270 -                       break;
 271 -               }
 272 -       }
 273 -
 274 -       if (cea_chmap < 0) {
 275 -               res = -EINVAL;
 276 -               goto unlock;
 277 -       }
 278 -
 279 -       /* don't change the layout if another substream is active */
 280 -       if (chip->opened != (1 << substream->number) && chip->cea_chmap != cea_chmap) {
 281 -               res = -EBUSY; /* unsure whether this is a good error code */
 282 -               goto unlock;
 283 -       }
 284 -
 285 -       chip->cea_chmap = cea_chmap;
 286 -       for (i = 0; i < 8; i++)
 287 -               chip->map_channels[i] = remap[i];
 288 -       if (prepared)
 289 -               snd_bcm2835_pcm_prepare_again(substream);
 290 -
 291 -unlock:
 292 -       mutex_unlock(&chip->audio_mutex);
 293 -       return res;
 294 -}
 295 -
 296 -static int snd_bcm2835_add_chmap_ctl(bcm2835_chip_t * chip)
 297 -{
 298 -       struct snd_pcm_chmap *chmap;
 299 -       struct snd_kcontrol *kctl;
 300 -       int err, i;
 301 -
 302 -       err = snd_pcm_add_chmap_ctls(chip->pcm,
 303 -                                    SNDRV_PCM_STREAM_PLAYBACK,
 304 -                                    NULL, 8, 0, &chmap);
 305 -       if (err < 0)
 306 -               return err;
 307 -       /* override handlers */
 308 -       chmap->private_data = chip;
 309 -       kctl = chmap->kctl;
 310 -       for (i = 0; i < kctl->count; i++)
 311 -               kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_WRITE;
 312 -       kctl->get = snd_bcm2835_chmap_ctl_get;
 313 -       kctl->put = snd_bcm2835_chmap_ctl_put;
 314 -       kctl->tlv.c = snd_bcm2835_chmap_ctl_tlv;
 315 -       return 0;
 316 -}
 317 -
 318  int snd_bcm2835_new_ctl(bcm2835_chip_t * chip)
 319  {
 320         int err;
 321 @@ -638,7 +340,6 @@ int snd_bcm2835_new_ctl(bcm2835_chip_t *
 322                 if (err < 0)
 323                         return err;
 324         }
 325 -       snd_bcm2835_add_chmap_ctl(chip);
 326         for (idx = 0; idx < ARRAY_SIZE(snd_bcm2835_spdif); idx++) {
 327                 err = snd_ctl_add(chip->card,
 328                                 snd_ctl_new1(&snd_bcm2835_spdif[idx], chip));
 329 --- a/sound/arm/bcm2835-pcm.c
 330 +++ b/sound/arm/bcm2835-pcm.c
 331 @@ -19,9 +19,6 @@
 332
 333  #include "bcm2835.h"
 334
 335 -/* The hardware can not do much more num_channels*samplerate then this value */
 336 -#define MAX_COMBINED_RATE 768000
 337 -
 338  /* hardware definition */
 339  static struct snd_pcm_hardware snd_bcm2835_playback_hw = {
 340         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
 341 @@ -110,31 +107,6 @@ static irqreturn_t bcm2835_playback_fifo
 342         return IRQ_HANDLED;
 343  }
 344
 345 -
 346 -static int rate_hw_constraint_rate(struct snd_pcm_hw_params *params,
 347 -                                  struct snd_pcm_hw_rule *rule)
 348 -{
 349 -       struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 350 -       struct snd_interval rates = {
 351 -               .min = 8000,
 352 -               .max = min(192000u, MAX_COMBINED_RATE / max(channels->min, 1u)),
 353 -       };
 354 -       struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
 355 -       return snd_interval_refine(rate, &rates);
 356 -}
 357 -
 358 -static int rate_hw_constraint_channels(struct snd_pcm_hw_params *params,
 359 -                                      struct snd_pcm_hw_rule *rule)
 360 -{
 361 -       struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
 362 -       struct snd_interval channels_interval = {
 363 -               .min = 1,
 364 -               .max = min(8u, MAX_COMBINED_RATE / max(rate->min, 1u)),
 365 -       };
 366 -       struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 367 -       return snd_interval_refine(channels, &channels_interval);
 368 -}
 369 -
 370  /* open callback */
 371  static int snd_bcm2835_playback_open_generic(
 372                 struct snd_pcm_substream *substream, int spdif)
 373 @@ -216,24 +188,8 @@ static int snd_bcm2835_playback_open_gen
 374         snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
 375                                    16);
 376
 377 -       /* When playing PCM, pretend that we support the full range of channels
 378 -        * and sample rates. The GPU can't output it, but is able to resample
 379 -        * the data to a rate the hardware can handle it. This won't work with
 380 -        * compressed data; the resampler would just destroy it. */
 381 -       if (spdif) {
 382 -               err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
 383 -                                         rate_hw_constraint_rate, NULL,
 384 -                                         SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 385 -               err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
 386 -                                         rate_hw_constraint_channels, NULL,
 387 -                                         SNDRV_PCM_HW_PARAM_RATE, -1);
 388 -       }
 389 -
 390         chip->alsa_stream[idx] = alsa_stream;
 391
 392 -       if (!chip->opened)
 393 -               chip->cea_chmap = -1;
 394 -
 395         chip->opened |= (1 << idx);
 396         alsa_stream->open = 1;
 397         alsa_stream->draining = 1;
 398 @@ -344,7 +300,8 @@ static int snd_bcm2835_pcm_hw_free(struc
 399         return snd_pcm_lib_free_pages(substream);
 400  }
 401
 402 -int snd_bcm2835_pcm_prepare_again(struct snd_pcm_substream *substream)
 403 +/* prepare callback */
 404 +static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
 405  {
 406         bcm2835_chip_t *chip = snd_pcm_substream_chip(substream);
 407         struct snd_pcm_runtime *runtime = substream->runtime;
 408 @@ -352,6 +309,11 @@ int snd_bcm2835_pcm_prepare_again(struct
 409         int channels;
 410         int err;
 411
 412 +       audio_info(" .. IN\n");
 413 +
 414 +       if (mutex_lock_interruptible(&chip->audio_mutex))
 415 +               return -EINTR;
 416 +
 417         /* notify the vchiq that it should enter spdif passthrough mode by
 418          * setting channels=0 (see
 419          * https://github.com/raspberrypi/linux/issues/528) */
 420 @@ -367,23 +329,6 @@ int snd_bcm2835_pcm_prepare_again(struct
 421                 audio_error(" error setting hw params\n");
 422         }
 423
 424 -       return err;
 425 -}
 426 -
 427 -/* prepare callback */
 428 -static int snd_bcm2835_pcm_prepare(struct snd_pcm_substream *substream)
 429 -{
 430 -       bcm2835_chip_t *chip = snd_pcm_substream_chip(substream);
 431 -       struct snd_pcm_runtime *runtime = substream->runtime;
 432 -       bcm2835_alsa_stream_t *alsa_stream = runtime->private_data;
 433 -
 434 -       audio_info(" .. IN\n");
 435 -
 436 -       if (mutex_lock_interruptible(&chip->audio_mutex))
 437 -               return -EINTR;
 438 -
 439 -       snd_bcm2835_pcm_prepare_again(substream);
 440 -
 441         bcm2835_audio_setup(alsa_stream);
 442
 443         /* in preparation of the stream, set the controls (volume level) of the stream */
 444 --- a/sound/arm/bcm2835-vchiq.c
 445 +++ b/sound/arm/bcm2835-vchiq.c
 446 @@ -570,8 +570,6 @@ int bcm2835_audio_set_params(bcm2835_als
 447         VC_AUDIO_MSG_T m;
 448         AUDIO_INSTANCE_T *instance = alsa_stream->instance;
 449         int32_t success;
 450 -       uint32_t chmap_value;
 451 -       int i;
 452         int ret;
 453         LOG_DBG(" .. IN\n");
 454
 455 @@ -595,21 +593,10 @@ int bcm2835_audio_set_params(bcm2835_als
 456
 457         instance->result = -1;
 458
 459 -       if (alsa_stream->chip->cea_chmap >= 0) {
 460 -               chmap_value = (unsigned)alsa_stream->chip->cea_chmap << 24;
 461 -       } else {
 462 -               chmap_value = 0; /* force stereo */
 463 -               for (i = 0; i < 8; i++)
 464 -                       alsa_stream->chip->map_channels[i] = i;
 465 -       }
 466 -       for (i = 0; i < 8; i++)
 467 -               chmap_value |= alsa_stream->chip->map_channels[i] << (i * 3);
 468 -
 469         m.type = VC_AUDIO_MSG_TYPE_CONFIG;
 470         m.u.config.channels = channels;
 471         m.u.config.samplerate = samplerate;
 472         m.u.config.bps = bps;
 473 -       m.u.config.channelmap = chmap_value;
 474
 475         /* Create the message available completion */
 476         init_completion(&instance->msg_avail_comp);
 477 --- a/sound/arm/bcm2835.h
 478 +++ b/sound/arm/bcm2835.h
 479 @@ -107,8 +107,6 @@ typedef struct bcm2835_chip {
 480         int old_volume; /* stores the volume value whist muted */
 481         int dest;
 482         int mute;
 483 -       int cea_chmap; /* currently requested Audio InfoFrame Data Byte 4 */
 484 -       int map_channels[8];
 485
 486         unsigned int opened;
 487         unsigned int spdif_status;
 488 @@ -151,8 +149,6 @@ int snd_bcm2835_new_ctl(bcm2835_chip_t *
 489  int snd_bcm2835_new_pcm(bcm2835_chip_t * chip);
 490  int snd_bcm2835_new_spdif_pcm(bcm2835_chip_t * chip);
 491
 492 -int snd_bcm2835_pcm_prepare_again(struct snd_pcm_substream *substream);
 493 -
 494  int bcm2835_audio_open(bcm2835_alsa_stream_t * alsa_stream);
 495  int bcm2835_audio_close(bcm2835_alsa_stream_t * alsa_stream);
 496  int bcm2835_audio_set_params(bcm2835_alsa_stream_t * alsa_stream,