[alsa-devel] soc-dsp programming model for loopbacks

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Thu Jan 26 14:12:07 CET 2012

>> I can see how this would simplify the loopback part, but doesn't it make the
>> 'regular' playback/capture functionality more complex? If my DSP is seen as
>> a CODEC, how do I represent the CPU-DSP interface (DMA or shared memory)?
> You'd need a DAI for that interface but you'll need that no matter what
> you do, it'll just be a very simple DAI that needs no configuration for
> things like AIF format.  With the soc-pcm setup you also need the front
> and back end DAIs so it's about the same, the benefit comes at runtime.
> My primary focus for the CODEC<->CODEC links is actually things like
> basebands rather than on-SoC DSPs, it's just that if the hardware can be
> thought of in the same way it should simplify things a little.

Bear with me here, I am still somewhat confused.
- Liam suggested either a hard-coded DAI configuration or machine driver 
logic to remove the need for virtual front-ends
- Mark suggested to consider the DSP as a CODEC with some work to 
re-implement the host-dsp interface.
Is this CODEC<->CODEC solution on top of the Dynamic PCM patches? Or are 
we talking about two completely different approaches?
Thanks for your feedback

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