ALSA: usb-audio: Add quirk for Redragon H510-PRO Wireless headset

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@gmail.com>
Link: https://patch.msgid.link/20260705184227.113588-1-agustinluzardo09@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

0 files changed, 0 insertions, 0 deletions