Re: [RFC PATCH v3 3/4] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End

On Fri, Jun 12, 2020 at 03:37:50PM +0800, Shengjiu Wang wrote:

The dma channel has been requested by Back-End cpu dai driver already.
If fsl_asrc_dma requests dma chan with same dma:tx symlink, then
there will be below warning with SDMA.

[   48.174236] fsl-esai-dai 2024000.esai: Cannot create DMA dma:tx symlink

So if we can reuse the dma channel of Back-End, then the issue can be
fixed.

In order to get the dma channel which is already requested in Back-End.
we use the exported two functions (snd_soc_lookup_component_nolocked
and soc_component_to_pcm). If we can get the dma channel, then reuse it,
if can't, then request a new one.

Signed-off-by: Shengjiu Wang <redacted>

Reviewed-by: Nicolin Chen <nicoleotsuka@gmail.com>