On Mon, Jul 08, 2019 at 09:01:47PM -0700, Alex Levin wrote:
> sst_platform_pcm_pointer is called from both snd_pcm_period_elapsed and
> from snd_pcm_ioctl. Calling read timestamp results in recalculating
> pcm_delay and buffer_ptr (sst_calc_tstamp) which consumes buffers in a
> faster rate than intended.
> In a tested BSW system with chtrt5650, for a rate of 48000, the
> measured rate was sometimes 10 times more than that.
> After moving the timestamp read to period elapsed, buffer consumption is
> as expected.
>From code prospective it looks good. You may take mine
Reviewed-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Though I'm not an expert in the area, Pierre and / or Liam should give
their blessing.
>
> Signed-off-by: Alex Levin <levin...@chromium.org>
> ---
> sound/soc/intel/atom/sst-mfld-platform-pcm.c | 23 +++++++++++++-------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> index 0e8b1c5eec88..196af0b30b41 100644
> --- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> +++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> @@ -265,16 +265,28 @@ static void sst_period_elapsed(void *arg)
> {
> struct snd_pcm_substream *substream = arg;
> struct sst_runtime_stream *stream;
> - int status;
> + struct snd_soc_pcm_runtime *rtd;
> + int status, ret_val;
>
> if (!substream || !substream->runtime)
> return;
> stream = substream->runtime->private_data;
> if (!stream)
> return;
> +
> + rtd = substream->private_data;
> + if (!rtd)
> + return;
> +
> status = sst_get_stream_status(stream);
> if (status != SST_PLATFORM_RUNNING)
> return;
> +
> + ret_val = stream->ops->stream_read_tstamp(sst->dev,
> &stream->stream_info);
> + if (ret_val) {
> + dev_err(rtd->dev, "stream_read_tstamp err code = %d\n",
> ret_val);
> + return;
> + }
> snd_pcm_period_elapsed(substream);
> }
>
> @@ -658,20 +670,15 @@ static snd_pcm_uframes_t sst_platform_pcm_pointer
> (struct snd_pcm_substream *substream)
> {
> struct sst_runtime_stream *stream;
> - int ret_val, status;
> + int status;
> struct pcm_stream_info *str_info;
> - struct snd_soc_pcm_runtime *rtd = substream->private_data;
>
> stream = substream->runtime->private_data;
> status = sst_get_stream_status(stream);
> if (status == SST_PLATFORM_INIT)
> return 0;
> +
> str_info = &stream->stream_info;
> - ret_val = stream->ops->stream_read_tstamp(sst->dev, str_info);
> - if (ret_val) {
> - dev_err(rtd->dev, "sst: error code = %d\n", ret_val);
> - return ret_val;
> - }
> substream->runtime->delay = str_info->pcm_delay;
> return str_info->buffer_ptr;
> }
> --
> 2.22.0.410.gd8fdbe21b5-goog
>
--
With Best Regards,
Andy Shevchenko
