In case of _3LE/_3BE formats the samples are stored in 3 consecutive bytes without padding it to 4 bytes. This means that the DMA needs to be able to support 3 bytes word length in order to read/write the samples from memory correctly. Originally the code treated 24 bits physical length samples as they were 32 bits which leads to corruption when playing or recording audio.
The hw.formats field has already been prepared to exclude formats not supported by the DMA engine in use, which means that only on platforms where 3 bytes is supported by the DMA will be able to use this format.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com --- sound/core/pcm_dmaengine.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index d5611ec80381..6542c4083594 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -72,6 +72,8 @@ int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream, buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; else if (bits == 16) buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; + else if (bits == 24) + buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES; else if (bits <= 32) buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; else