ASoC: check for substream not channels_min in pcm engines

This is a follow up on 53dea36c70c1857 which fixes the other affected
pcm engines.

Description from 53dea36c70c1857:
 Don't rely on the codec's channels_min information to decide wheter or
 not allocate a substream's DMA buffer. Rather check if the substream
 itself was allocated previously.

Without this patch I was seeing null-pointer dereferenc in atmel-pcm.

Signed-off-by: Joachim Eastwood <joachim.eastwood@jotron.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/sound/soc/ep93xx/ep93xx-pcm.c b/sound/soc/ep93xx/ep93xx-pcm.c
index a2de9c42b702..3fc96130d1a6 100644
--- a/sound/soc/ep93xx/ep93xx-pcm.c
+++ b/sound/soc/ep93xx/ep93xx-pcm.c
@@ -286,7 +286,6 @@ static u64 ep93xx_pcm_dmamask = 0xffffffff;
 static int ep93xx_pcm_new(struct snd_soc_pcm_runtime *rtd)
 {
         struct snd_card *card = rtd->card->snd_card;
-        struct snd_soc_dai *dai = rtd->cpu_dai;
         struct snd_pcm *pcm = rtd->pcm;
         int ret = 0;
 
@@ -295,14 +294,14 @@ static int ep93xx_pcm_new(struct snd_soc_pcm_runtime *rtd)
         if (!card->dev->coherent_dma_mask)
                 card->dev->coherent_dma_mask = 0xffffffff;
 
-        if (dai->driver->playback.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
                 ret = ep93xx_pcm_preallocate_dma_buffer(pcm,
                                         SNDRV_PCM_STREAM_PLAYBACK);
                 if (ret)
                         return ret;
         }
 
-        if (dai->driver->capture.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
                 ret = ep93xx_pcm_preallocate_dma_buffer(pcm,
                                         SNDRV_PCM_STREAM_CAPTURE);
                 if (ret)