[PATCH AUTOSEL 5.6 320/606] ALSA: usb-audio: mixer: volume quirk for ESS Technology Asus USB DAC

Sasha Levin
2020-06-08T23:55:41Z

From: Chris Chiu <chiu@endlessm.com>

[ Upstream commit 4020d1ccbe55bdf67b31d718d2400506eaf4b43f ]

The Asus USB DAC is a USB type-C audio dongle for connecting to
the headset and headphone. The volume minimum value -23040 which
is 0xa600 in hexadecimal with the resolution value 1 indicates
this should be endianness issue caused by the firmware bug. Add
a volume quirk to fix the volume control problem.

Also fixes this warning:
Warning! Unlikely big volume range (=23040), cval->res is probably wrong.
[5] FU [Headset Capture Volume] ch = 1, val = -23040/0/1
Warning! Unlikely big volume range (=23040), cval->res is probably wrong.
[7] FU [Headset Playback Volume] ch = 1, val = -23040/0/1

Signed-off-by: Chris Chiu <chiu@endlessm.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200526062613.55401-1-chiu@endlessm.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/usb/mixer.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 7a2961ad60de..68fefe55e5c0 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1171,6 +1171,14 @@ static void volume_control_quirks(struct usb_mixer_elem_info *cval,
cval->res = 384;
}
break;
+ case USB_ID(0x0495, 0x3042): /* ESS Technology Asus USB DAC */
+ if ((strstr(kctl->id.name, "Playback Volume") != NULL) ||
+ strstr(kctl->id.name, "Capture Volume") != NULL) {
+ cval->min >>= 8;
+ cval->max = 0;
+ cval->res = 1;
+ }
+ break;
}
}

--
2.25.1