[PATCH] ASoC: qcom: use correct device pointer in dma allocation

[Srinivas Kandagatla]

dev pointer in struct snd_soc_pcm_runtime does not have dma_ops set. In 
v4.4 kernel dma_ops would end up pointing to dummy_dma_ops in such cases.
So attempting to use such device in allocating coherent memory on aarch64
would fail.

According to commit 1dccb598df549d892b6450c261da54cdd7af44b4 ("arm64:
simplify dma_get_ops") The current behavior of dma_get_ops is to fall
back to the global dma_ops when a device has not set its own dma_ops,
but only for DT based systems.

So, this patch fixes the driver to use correct device pointer while
allocating coherent memory, and also deletes un-necessary dma_mask setup
on soc_runtime->dev.

Without this patch lpass driver would fail with below log:
...
[    6.541542]  ADV7533: lpass_platform_alloc_buffer: Could not allocate DMA buffer
[    6.541914] apq8016-lpass-cpu 7708000.lpass-cpu: ASoC: pcm constructor failed: -12
[    6.548216] qcom-apq8016-sbc 7702000.sound: ASoC: can't create pcm ADV7533 :-12
[    6.555581] qcom-apq8016-sbc 7702000.sound: ASoC: failed to instantiate card -12
[    6.566072] qcom-apq8016-sbc: probe of 7702000.sound failed with error -12
...

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 sound/soc/qcom/lpass-platform.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
index 79688aa..4aeb8e1 100644
--- a/sound/soc/qcom/lpass-platform.c
+++ b/sound/soc/qcom/lpass-platform.c
@@ -440,18 +440,18 @@ static irqreturn_t lpass_platform_lpaif_irq(int irq, void *data)
 }
 
 static int lpass_platform_alloc_buffer(struct snd_pcm_substream *substream,
-		struct snd_soc_pcm_runtime *soc_runtime)
+		struct snd_soc_pcm_runtime *rt)
 {
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
 	size_t size = lpass_platform_pcm_hardware.buffer_bytes_max;
 
 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
-	buf->dev.dev = soc_runtime->dev;
+	buf->dev.dev = rt->platform->dev;
 	buf->private_data = NULL;
-	buf->area = dma_alloc_coherent(soc_runtime->dev, size, &buf->addr,
+	buf->area = dma_alloc_coherent(rt->platform->dev, size, &buf->addr,
 			GFP_KERNEL);
 	if (!buf->area) {
-		dev_err(soc_runtime->dev, "%s: Could not allocate DMA buffer\n",
+		dev_err(rt->platform->dev, "%s: Could not allocate DMA buffer\n",
 				__func__);
 		return -ENOMEM;
 	}
@@ -461,12 +461,12 @@ static int lpass_platform_alloc_buffer(struct snd_pcm_substream *substream,
 }
 
 static void lpass_platform_free_buffer(struct snd_pcm_substream *substream,
-		struct snd_soc_pcm_runtime *soc_runtime)
+		struct snd_soc_pcm_runtime *rt)
 {
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
 
 	if (buf->area) {
-		dma_free_coherent(soc_runtime->dev, buf->bytes, buf->area,
+		dma_free_coherent(rt->dev, buf->bytes, buf->area,
 				buf->addr);
 	}
 	buf->area = NULL;
@@ -499,9 +499,6 @@ static int lpass_platform_pcm_new(struct snd_soc_pcm_runtime *soc_runtime)
 
 	snd_soc_pcm_set_drvdata(soc_runtime, data);
 
-	soc_runtime->dev->coherent_dma_mask = DMA_BIT_MASK(32);
-	soc_runtime->dev->dma_mask = &soc_runtime->dev->coherent_dma_mask;
-
 	ret = lpass_platform_alloc_buffer(substream, soc_runtime);
 	if (ret)
 		return ret;
-- 
1.9.1