[alsa-devel] [PATCH] ALSA: compress: Add DSP private metadata interface

[Tim Sheridan]

Hi Pierre-Louis,

> I am not too sure I understand what you refer to as synchronization or multi-
> device synchronization mechanisms. Since you mentioned you only need an
> initial time, I wonder if this is conceptually related to the
> start_at() functionality discussed last year for PCM?

Yup, it is related to the start_at() functionality. Before start_at() playback can happen, the AXD DSP must be switched into the start_at mode.

> If you have a set of implementation-defined mechanisms related to
> algorithms, why not use an ALSA binary control where you define you own
> syntax and content and use the alsa control layer as a 'dumb' pipe between
> user and kernel. That's what everyone does for DSP control.

Ah, thanks very much for that advice. This looks like a good option (looking how it's being done for filter parameters in sound/soc/intel/atom).

Cheers,
Tim