Re: [PATCH v21 34/39] ALSA: usb-audio: Add USB offloading capable kcontrol

[Pierre-Louis Bossart]

On 5/7/24 14:51, Wesley Cheng wrote:
> In order to allow userspace/applications know about USB offloading status,
> expose a sound kcontrol that fetches information about which sound card
> index is associated with the ASoC platform card supporting offloading.  In
> the USB audio offloading framework, the ASoC BE DAI link is the entity
> responsible for registering to the SOC USB layer.  SOC USB will expose more
> details about the current offloading status, which includes the USB sound
> card and USB PCM device indexes currently being used.
> 
> It is expected for the USB offloading driver to add the kcontrol to the
> sound card associated with the USB audio device.  An example output would
> look like:
> 
> tinymix -D 1 get 'USB Offload Playback Capable Card'
> 0 (range -1->32)

You already gave the following examples in patch 29:

"
USB offloading idle:
tinymix -D 0 get 'USB Offload Playback Route Status'
-->-1, -1 (range -1->32)

USB offloading active(USB card#1 pcm#0):
tinymix -D 0 get 'USB Offload Playback Route Status'
-->1, 0 (range -1->32)
"

Can you clarify how many controls there would be in the end?
Also isn't tinymix -D N going to give you the controls for card N?