[PATCH] ALSA: usb-audio: Add QUIRK_FLAG_MIXER_GET_CUR_BROKEN for Logitech PRO X 2 LIGHTSPEED

[Rong Zhang]

The UAC mixer of the Logitech PRO X 2 LIGHTSPEED has broken mixer
GET_CUR behavior but otherwise works fine.

Add a quirk table entry matching VID/PID=0x046d/0x0af7 and apply the
MIXER_GET_CUR_BROKEN quirk flag to make the mixer usable again.

Quirky device sample (after applying the quirk flag):

  usb 3-2.1: New USB device found, idVendor=046d, idProduct=0af7, bcdDevice= 1.00
  usb 3-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
  usb 3-2.1: Product: PRO X 2 LIGHTSPEED
  usb 3-2.1: Manufacturer: Logitech
  usb 3-2.1: SerialNumber: 0000000000000000
  usb 3-2.1: 2:0: broken mixer GET_CUR (-18944/0/256 => -2662)
  usb 3-2.1: 6:0: broken mixer GET_CUR (-18944/0/256 => 0)

Suggested-by: Brian van den Berg <faxuser@xxxxxxxxx>
Reported-by: Brian van den Berg <faxuser@xxxxxxxxx>
Link: https://lore.kernel.org/all/370007e6-b73b-4bfc-8410-a860781c7ad7@xxxxxxxxx/
Signed-off-by: Rong Zhang <i@xxxxxxxx>
---
 sound/usb/quirks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 0de7c9d94259..3bd66094863d 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2251,6 +2251,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 	DEVICE_FLG(0x046d, 0x0a8f, /* Logitech H390 headset */
 		   QUIRK_FLAG_CTL_MSG_DELAY_1M |
 		   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
+	DEVICE_FLG(0x046d, 0x0af7, /* Logitech PRO X 2 LIGHTSPEED */
+		   QUIRK_FLAG_MIXER_GET_CUR_BROKEN),
 	DEVICE_FLG(0x0499, 0x1506, /* Yamaha THR5 */
 		   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
 	DEVICE_FLG(0x0499, 0x1509, /* Steinberg UR22 */

---
base-commit: 8ba098e6b6ff0db8edf28528d1552be261af30d4
change-id: 41004393-uac-lg-pro-x-2-ls-a5ba4d779520

Thanks,
Rong