ASoC: davinci-mcasp: Do not allow multiple streams in one direction

Make sure that the user can not start multiple streams with the same
direction.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index e1324989bd6b..020d8660e4e5 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -1230,11 +1230,15 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
         int i, dir;
         int tdm_slots = mcasp->tdm_slots;
 
-        if (mcasp->tdm_mask[substream->stream])
-                tdm_slots = hweight32(mcasp->tdm_mask[substream->stream]);
+        /* Do not allow more then one stream per direction */
+        if (mcasp->substreams[substream->stream])
+                return -EBUSY;
 
         mcasp->substreams[substream->stream] = substream;
 
+        if (mcasp->tdm_mask[substream->stream])
+                tdm_slots = hweight32(mcasp->tdm_mask[substream->stream]);
+
         if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
                 return 0;