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>

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 1cb588691e16df2c3de9ab2f1263f6a584ca9ad0..2949a0d2d9619506d05a6b1180c3a523ea03c5ca 100644 (file)
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2210,6 +2210,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
                   QUIRK_FLAG_FORCE_IFACE_RESET | QUIRK_FLAG_IFACE_DELAY),
        DEVICE_FLG(0x03f0, 0x654a, /* HP 320 FHD Webcam */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
+       DEVICE_FLG(0x040b, 0x0897, /* Weltrend Semiconductor, sold as Redragon H510-PRO Wireless headset */
+                  QUIRK_FLAG_MIXER_GET_CUR_BROKEN),
        DEVICE_FLG(0x041e, 0x3000, /* Creative SB Extigy */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x041e, 0x4080, /* Creative Live Cam VF0610 */