diff options
| author | Ben Gardiner <bengardiner@nanometrics.ca> | 2011-05-24 14:50:18 -0400 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-05-25 19:14:30 +0800 |
| commit | ef39eb6f212996ede8da47ef45e6dffff1121ec7 (patch) | |
| tree | 5cb3b33659f4e7e280af765124cd8bc2a7175f96 /sound/soc/davinci | |
| parent | acb8e2666eba7417e2fab783f86dbe067c3e815f (diff) | |
ASoC: davinci-pcm: fix audible glitch on 2nd ping-pong playback
The release of the dma channels was being performed in prepare and there was a
edma_resume call for the asp-channel only being executed on START, RESUME and
PAUSE_RELEASE.
The mcasp on da850evm with ping-pong buffers enabled was exhibiting an audible
glitch on every playback after the first. It was determined through trial and
error that the following two changes fix this problem:
1) Move the edma_start calls from prepare to trigger and 2) reverse the order
of starting the asp and ram channels.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Steven Faludi <stevenfaludi@nanometrics.ca>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound/soc/davinci')
| -rw-r--r-- | sound/soc/davinci/davinci-pcm.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/sound/soc/davinci/davinci-pcm.c b/sound/soc/davinci/davinci-pcm.c index 9b5a9bf9393a..5d9269a51761 100644 --- a/sound/soc/davinci/davinci-pcm.c +++ b/sound/soc/davinci/davinci-pcm.c @@ -544,6 +544,13 @@ static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd) switch (cmd) { case SNDRV_PCM_TRIGGER_START: + edma_start(prtd->asp_channel); + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && + prtd->ram_channel >= 0) { + /* copy 1st iram buffer */ + edma_start(prtd->ram_channel); + } + break; case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: edma_resume(prtd->asp_channel); @@ -582,11 +589,6 @@ static int davinci_pcm_prepare(struct snd_pcm_substream *substream) print_buf_info(prtd->asp_link[0], "asp_link[0]"); print_buf_info(prtd->asp_link[1], "asp_link[1]"); - if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { - /* copy 1st iram buffer */ - edma_start(prtd->ram_channel); - } - edma_start(prtd->asp_channel); return 0; } prtd->period = 0; @@ -596,7 +598,6 @@ static int davinci_pcm_prepare(struct snd_pcm_substream *substream) edma_read_slot(prtd->asp_link[0], &prtd->asp_params); edma_write_slot(prtd->asp_channel, &prtd->asp_params); davinci_pcm_enqueue_dma(substream); - edma_start(prtd->asp_channel); return 0; } |