target/linux/brcm2708/patches-4.19/950-0388-Revert-bcm2835-interpolate-audio-delay.patch

   1 From 83251570f16ec848694dac016cbdb55b1d28496d Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Mon, 29 Apr 2019 19:16:14 +0100
   4 Subject: [PATCH] Revert "bcm2835: interpolate audio delay"
   5
   6 commit fb4b9f02986fcb5ae751106ef9b027806b5dd750 upstream.
   7
   8 This reverts commit fb8cc99f05687ca5565dc53a7ee0dd86aefad952.
   9 ---
  10  .../vc04_services/bcm2835-audio/bcm2835-pcm.c        | 12 +-----------
  11  .../staging/vc04_services/bcm2835-audio/bcm2835.h    |  1 -
  12  2 files changed, 1 insertion(+), 12 deletions(-)
  13
  14 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
  15 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
  16 @@ -11,7 +11,7 @@
  17  /* hardware definition */
  18  static const struct snd_pcm_hardware snd_bcm2835_playback_hw = {
  19         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  20 -       SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH),
  21 +       SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
  22         .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
  23         .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
  24         .rate_min = 8000,
  25 @@ -81,8 +81,6 @@ void bcm2835_playback_fifo(struct bcm283
  26                 alsa_stream->pos %= alsa_stream->buffer_size;
  27         }
  28
  29 -       alsa_stream->interpolate_start = ktime_get_ns();
  30 -
  31         if (alsa_stream->substream) {
  32                 if (new_period)
  33                         snd_pcm_period_elapsed(alsa_stream->substream);
  34 @@ -308,7 +306,6 @@ static int snd_bcm2835_pcm_prepare(struc
  35         alsa_stream->buffer_size = snd_pcm_lib_buffer_bytes(substream);
  36         alsa_stream->period_size = snd_pcm_lib_period_bytes(substream);
  37         alsa_stream->pos = 0;
  38 -       alsa_stream->interpolate_start = ktime_get_ns();
  39
  40         audio_debug("buffer_size=%d, period_size=%d pos=%d frame_bits=%d\n",
  41                 alsa_stream->buffer_size, alsa_stream->period_size,
  42 @@ -400,19 +397,12 @@ snd_bcm2835_pcm_pointer(struct snd_pcm_s
  43  {
  44         struct snd_pcm_runtime *runtime = substream->runtime;
  45         struct bcm2835_alsa_stream *alsa_stream = runtime->private_data;
  46 -       u64 now = ktime_get_ns();
  47
  48         audio_debug("pcm_pointer... (%d) hwptr=%d appl=%d pos=%d\n", 0,
  49                 frames_to_bytes(runtime, runtime->status->hw_ptr),
  50                 frames_to_bytes(runtime, runtime->control->appl_ptr),
  51                 alsa_stream->pos);
  52
  53 -       /* Give userspace better delay reporting by interpolating between GPU
  54 -        * notifications, assuming audio speed is close enough to the clock
  55 -        * used for ktime */
  56 -       if (alsa_stream->interpolate_start && alsa_stream->interpolate_start < now)
  57 -               runtime->delay = -(int)div_u64((now - alsa_stream->interpolate_start) * runtime->rate,  1000000000);
  58 -
  59         return snd_pcm_indirect_playback_pointer(substream,
  60                 &alsa_stream->pcm_indirect,
  61                 alsa_stream->pos);
  62 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h
  63 +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h
  64 @@ -133,7 +133,6 @@ struct bcm2835_alsa_stream {
  65         unsigned int pos;
  66         unsigned int buffer_size;
  67         unsigned int period_size;
  68 -       u64 interpolate_start;
  69
  70         atomic_t retrieved;
  71         struct bcm2835_audio_instance *instance;