I feel silly even writing this.
I just installed the 5.13.4-200 kernel update on my venerable Thinkpad W520. This old battle tank'd keyboard has a button that mutes the built-in microphone. It has a tiny orange LED that's lit when the mike is muted. I don't remember ever having to use it in the last decade, but it's there and that's what it does.
Booting the 5.13 kernel: the orange LED gets turned on during the boot, and it stays lit. The mute button itself is fully functional. Audio mixer dutifully reports the ambient noise level gets muted on/off.
There's also the built-in speaker mute button that works the same way, and its behavior is unchanged under 5.13, its orange LED is on only when it mutes the audio out.
Rebooting 5.12: both mute buttons' LED indicators work as advertised.
Can anyone think of an even more meaningless kernel bug?
On Sat, 24 Jul 2021 10:14:47 -0400 Sam Varshavchik wrote:
Can anyone think of an even more meaningless kernel bug?
I've had my numlock light turned on at boot forever, so I've got an /etc/X11/xinit script to turn it off with xset. Maybe xset could turn off this light too :-). [The numlock state isn't set, just the light is turned on].
(For all I know numlock doesn't turn on at boot any longer, it has been years since I last checked after writing the script).