README.md

Fix microphone mute LED on ThinkPad T14s Gen 2 AMD (Linux)

On this model, the indicator of micphone mute is not working properly in Linux due to how the device is implemented in ALSA and pulseuaio. The microphone device is suplex and has its micrphone LED event set to the wrong one.

Use the following script to fix this:

#!/bin/bash

echo -n 7 > /sys/class/sound/card1/controlC1/led-mic/detach

To run this at startup, use a systemd unit similiar to this:

[Unit]
Description=Fix ThinkPad T14s AMD Microphone Led

[Service]
ExecStart=/usr/bin/fix-tp-mic-led.sh

[Install]
WantedBy=multi-user.target

Caveats

The microphone mute LED only tracks the status of internal microphone. More testing is needed to determine correct behavior under Windows and mimic it back in Linux.

Thanks @evanslify ! This also fixes my F4-Mic_Mute led in my T14s Gen3 (Intel), running kernel 6.1.0/Debian.
I tested muting all possible Mic/Capture inputs i could find in the KDE audio settings and pavucontrol, but still could not get the F4 led to turn on.

In my case /sys/class/sound/ctl-led/mic/card0/ has associated the controls 7 and 42:

• control.7 is "Capture switch" with MIXER interface,
• control.42 is "Dmic0 Capture Switch" also with MIXER interface,

Control 7 is what i had to remove from the ctrl-led to get it working....