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/kirkwood/kirkwood-dma.c b/sound/soc/kirkwood/kirkwood-dma.c
index 210438261a49..d4a17780cef4 100644
--- a/sound/soc/kirkwood/kirkwood-dma.c
+++ b/sound/soc/kirkwood/kirkwood-dma.c
@@ -315,7 +315,6 @@ static int kirkwood_dma_preallocate_dma_buffer(struct snd_pcm *pcm,
 static int kirkwood_dma_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;
 
@@ -324,14 +323,14 @@ static int kirkwood_dma_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 = kirkwood_dma_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 = kirkwood_dma_preallocate_dma_buffer(pcm,
                                 SNDRV_PCM_STREAM_CAPTURE);
                 if (ret)