ALSA playback seems to be more reliable if the .pointer() hook reports a value slightly into the period, rather than right on the period boundary. This patch adds a fudge factor of 1/4 the period size to better estimate the actual position of the DMA engine in the audio buffer.
Signed-off-by: Grant Likely grant.likely@secretlab.ca ---
sound/soc/fsl/mpc5200_dma.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c index 9c88e15..ee5a606 100644 --- a/sound/soc/fsl/mpc5200_dma.c +++ b/sound/soc/fsl/mpc5200_dma.c @@ -297,7 +297,7 @@ psc_dma_pointer(struct snd_pcm_substream *substream) else s = &psc_dma->playback;
- count = s->period_current * s->period_bytes; + count = (s->period_current * s->period_bytes) + (s->period_bytes >> 2);
return bytes_to_frames(substream->runtime, count); }