Re: [PATCH] ALSA: usb-audio: Add iD14 MkI to monitor-mix volume quirk

On Sun, 23 Aug 2026 03:53:53 +0200,
Will Porter wrote:
> 
> Add the iD14 MkI USB ID to the existing audient_id14_map. This
> names feature unit 12 Monitor Mix Playback Volume.
> 
> Live meter A/B testing on MkI USB ID 2708:0002 reproduced the same
> asymmetric attenuation seen on MkII. At ALSA value 104, the right
> channel was 23.07 dB below the left. At 127, both channels were equal.
> 
> The misleading Speaker Playback Volume name causes PipeWire to adopt
> FU12 as the stream master. Reuse the existing map to keep the control
> available while preventing that selection.
> 
> Hardware-tested on Bazzite 7.2.0-ogc4.1.fc44.x86_64 with this change
> backported. ALSA exposed Monitor Mix Playback Volume after module load
> and USB reconnect. PipeWire volume changes from 100% to 35% and back
> left all four FU12 values at 127. Channel-isolated left/right playback
> remained balanced after reconnect.
> 
> Build-tested with CONFIG_SND_USB_AUDIO=m using the focused sound/usb
> target.
> 
> Assisted-by: Codex:gpt-5
> Signed-off-by: Will Porter <[email protected]>

Applied now.  Thanks.


Takashi