[ibm-acpi-devel] Volume/Mic Mute Light Does Not Function on ThinkPad L420

[Mingcong B. <jef...@gm...>]

Greetings,

Thanks for all your great work for making ThinkPads usable on Linux!

I have recently acquired a ThinkPad L420, but I have been running into 
some issues - specifically, the Mic Mute button and the Volume Mute button:

- The Mic Mute button does not function, with no event registered on 
acpi_listen. However, if I turn down the input volume to 0 in a 
PulseAudio mixer, the Mic Mute LED lights up (red).
- The Volume Mute button *works*, but the LED does not light up/turn off 
with the volume mute event. It does register an event on acpi_listen, 
"button/mute MUTE 00000080 00000000 K".

In Windows, both mute LED only works when the Hot Key Integration driver 
is installed, much like other ThinkPad models of the same period (T420, 
X220, etc.).

I have attached acpidump and dmidecode outputs.

Best Regards,
Mingcong Bai