On Tue, Jul 9, 2019 at 4:45 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> 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.shevchenko@xxxxxxxxxxxxxxx>
>
> Though I'm not an expert in the area, Pierre and / or Liam should give
> their blessing.
>
Agreed, Liam or Pierre should also give their ok since this is one of
the closed source firmware drivers.
Reviewed-by: Curtis Malainey <cujomalainey@xxxxxxxxxxxx>
> >
> > Signed-off-by: Alex Levin <levinale@xxxxxxxxxxxx>
> > ---
> > 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
>
>
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