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@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 levinale@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