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>

3 files changed, 6 insertions, 9 deletions

diff --git a/sound/soc/blackfin/bf5xx-ac97-pcm.c b/sound/soc/blackfin/bf5xx-ac97-pcm.c
index fcff58390848..d7dc9bde0976 100644
--- a/sound/soc/blackfin/bf5xx-ac97-pcm.c
+++ b/sound/soc/blackfin/bf5xx-ac97-pcm.c
@@ -421,7 +421,6 @@ static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);
 static int bf5xx_pcm_ac97_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;
 
@@ -431,14 +430,14 @@ static int bf5xx_pcm_ac97_new(struct snd_soc_pcm_runtime *rtd)
         if (!card->dev->coherent_dma_mask)
                 card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 
-        if (dai->driver->playback.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_PLAYBACK);
                 if (ret)
                         goto out;
         }
 
-        if (dai->driver->capture.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_CAPTURE);
                 if (ret)
diff --git a/sound/soc/blackfin/bf5xx-i2s-pcm.c b/sound/soc/blackfin/bf5xx-i2s-pcm.c
index 6ec3d41b9b6d..63205d723eab 100644
--- a/sound/soc/blackfin/bf5xx-i2s-pcm.c
+++ b/sound/soc/blackfin/bf5xx-i2s-pcm.c
@@ -260,7 +260,6 @@ static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);
 static int bf5xx_pcm_i2s_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;
 
@@ -270,14 +269,14 @@ static int bf5xx_pcm_i2s_new(struct snd_soc_pcm_runtime *rtd)
         if (!card->dev->coherent_dma_mask)
                 card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 
-        if (dai->driver->playback.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_PLAYBACK);
                 if (ret)
                         goto out;
         }
 
-        if (dai->driver->capture.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_CAPTURE);
                 if (ret)
diff --git a/sound/soc/blackfin/bf5xx-tdm-pcm.c b/sound/soc/blackfin/bf5xx-tdm-pcm.c
index 4406f9a865ae..254490cf1876 100644
--- a/sound/soc/blackfin/bf5xx-tdm-pcm.c
+++ b/sound/soc/blackfin/bf5xx-tdm-pcm.c
@@ -286,7 +286,6 @@ static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);
 static int bf5xx_pcm_tdm_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 bf5xx_pcm_tdm_new(struct snd_soc_pcm_runtime *rtd)
         if (!card->dev->coherent_dma_mask)
                 card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 
-        if (dai->driver->playback.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_PLAYBACK);
                 if (ret)
                         goto out;
         }
 
-        if (dai->driver->capture.channels_min) {
+        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
                 ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                         SNDRV_PCM_STREAM_CAPTURE);
                 if (ret)