hp Spectre x360 Mute LED in Ubuntu

The LED in the mute key doesn’t work out of the box. To enable it, add a file /etc/modprobe.d/hp-spectre.conf with the following contents:

options snd-hda-intel model=mute-led-gpio

After a reboot, the LED should light up when the audio is muted.

(Source: wiki.archlinux.org)