ASoC: Tegra: tegra_pcm_deallocate_dma_buffer: Don't OOPS

Not all PCM devices have all sub-streams. Specifically, the SPDIF driver
only supports playback and hence has no capture substream. Check whether
a substream exists before dereferencing it, when de-allocating DMA
buffers in tegra_pcm_deallocate_dma_buffer.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
This commit is contained in:
Stephen Warren 2011-08-04 16:44:42 -06:00 committed by Mark Brown
parent 7cb0aa21a5
commit a96edd59b2

View File

@ -309,9 +309,14 @@ static int tegra_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
static void tegra_pcm_deallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
substream = pcm->streams[stream].substream;
if (!substream)
return;
buf = &substream->dma_buffer;
if (!buf->area)
return;