ASUS Zenbook UX390

Volume increments do not work

Because of the "surround sound" audio hardware on the UX390, you have to tweak a Pulse configuration file to get volume incrementing to work. Otherwise, the volume will either be full or muted, despite appearing to increment.

Edit the analog output path config and add the Element Master and Element LFE parts below.

/usr/share/alsa-card-profile/mixer/paths/analog-output.conf.common

[Element Master]
switch = mute
volume = ignore

[Element PCM]
switch = mute
volume = merge
override-map.1 = all
override-map.2 = all-left,all-right

[Element LFE]
switch = mute
volume = ignore

Then, restart PulseAudio and changing the volume should work.

Headphone jack audio is always muted

See Advanced Linux Sound Architecture#Unmuting the channels.

Keyboard and Touchpad unusable in X and Wayland

Since kernel version v5.8, the asus-wmi driver gained the ability to detect "tablet mode" on convertible devices. However, at least on UX390UAK the asus-wmi driver believes that the device is always in tablet mode, although it is not a convertible (see [1] for a kernel bug report). Libinput automatically disables touchpad and keyboard when kernel reports tablet mode, so they only work in tty but not in X or wayland.

To workaround this, add a quirk file for libinput:

/etc/libinput/local-override.quirk

[test override 1]
MatchUdevType=touchpad
ModelTabletModeNoSuspend=1

[test override 2]
MatchUdevType=keyboard
ModelTabletModeNoSuspend=1