Re: [PATCH v21 27/39] ASoC: Introduce SND kcontrols to select sound card and PCM device

[Pierre-Louis Bossart]

On 5/7/24 14:51, Wesley Cheng wrote:
> Add SND kcontrol to SOC USB, which will allow for userpsace to determine
> which USB card number and PCM device to offload.  This allows for userspace
> to potentially tag an alternate path for a specific USB SND card and PCM
> device.  Previously, control was absent, and the offload path would be
> enabled on the last USB SND device which was connected.  This logic will
> continue to be applicable if no mixer input is received for specific device
> selection.
> 
> An example to configure the offload device using tinymix:
> tinymix -D 0 set 'USB Offload Playback Route Select' 1 0
> 
> The above command will configure the offload path to utilize card#1 and PCM
> stream#0.

I don't know how this is usable in practice. Using card indices is
really hard to do, it depends on the order in which devices are
plugged-in...