ASoC: intel: atom: Fix reference to PCM buffer address

PCM buffers might be allocated dynamically when the buffer
preallocation failed or a larger buffer is requested, and it's not
guaranteed that substream->dma_buffer points to the actually used
buffer.  The address should be retrieved from runtime->dma_addr,
instead of substream->dma_buffer (and shouldn't use virt_to_phys).

Also, remove the line overriding runtime->dma_area superfluously,
which was already set up at the PCM buffer allocation.

Cc: Cezary Rojewski <cezary.rojewski@intel.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20210728112353.6675-3-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/atom/sst-mfld-platform-pcm.c

@@ -127,7 +127,7 @@ static void sst_fill_alloc_params(struct snd_pcm_substream *substream,
 	snd_pcm_uframes_t period_size;
 	ssize_t periodbytes;
 	ssize_t buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
-	u32 buffer_addr = virt_to_phys(substream->dma_buffer.area);
+	u32 buffer_addr = substream->runtime->dma_addr;
 
 	channels = substream->runtime->channels;
 	period_size = substream->runtime->period_size;
@@ -233,7 +233,6 @@ static int sst_platform_alloc_stream(struct snd_pcm_substream *substream,
 	/* set codec params and inform SST driver the same */
 	sst_fill_pcm_params(substream, &param);
 	sst_fill_alloc_params(substream, &alloc_params);
-	substream->runtime->dma_area = substream->dma_buffer.area;
 	str_params.sparams = param;
 	str_params.aparams = alloc_params;
 	str_params.codec = SST_CODEC_TYPE_PCM;