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 --- sound/usb/mixer.c | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 81b2db0edd5f..0b568a9fdab3 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; } }