Re: [PATCH] ALSA: usb-audio: Add quirk for Redragon H510-PRO Wireless headset

[Takashi Iwai]

On Sun, 05 Jul 2026 20:42:27 +0200,
Agustin Luzardo wrote:
> 
> The device with USB ID 040b:0897 (Weltrend Semiconductor chipset,
> sold rebranded as the Redragon H510-PRO Wireless headset, reporting
> "XiiSound Technology Corporation" in its USB string descriptors)
> reports a constant value on GET_CUR for its PCM Playback Volume
> control while still supporting an actually tunable volume. This
> trips the sticky-value detection in check_sticky_volume_control(),
> which disables the mixer control entirely:
> 
>   usb 1-4: 5:0: sticky mixer values (0/100/1 => 80), disabling
> 
> As a result, the device boots with playback volume effectively muted
> and provides no way to raise it through the normal ALSA/PipeWire
> mixer path.
> 
> Apply QUIRK_FLAG_MIXER_GET_CUR_BROKEN so the sticky check marks the
> control as get_cur_broken and relies on the cached value instead of
> disabling the mixer control outright.
> 
> Tested by backporting this quirk flag and the supporting
> get_cur_broken logic onto a Linux 7.1.2-zen kernel build that does
> not yet carry it, and confirming that after applying the flag the
> kernel log changes from:
> 
>   usb 1-4: 5:0: sticky mixer values (0/100/1 => 80), disabling
> 
> to:
> 
>   usb 1-4: 5:0: broken mixer GET_CUR (0/100/1 => 80)
> 
> with the control usable via the driver's cached value afterward.
> 
> Signed-off-by: Agustin Luzardo <agustinluzardo09@xxxxxxxxx>

Applied this one now.  Thanks.


Takashi