Hi,
On 12/19/22 10:17, Thorsten Leemhuis wrote:
Hi, this is your Linux kernel regression tracker speaking.
I noticed a regression report in bugzilla.kernel.org. As many (most?) kernel developer don't keep an eye on it, I decided to forward it by mail. Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=216818 :
sonic82003@gmail.com 2022-12-18 08:52:32 UTC
The mic mute led of my ThinkPad X1 Carbon Gen 9 doesn't work anymore after updating linux to version 6. I can still turn it on by running
echo 1 > /sys/class/leds/platform::micmute/brightness
With linux-lts it still works fine.
See the ticket for more details.
Note, I found a similar report that (despite my attempts to prevent things like this from happening) fell through the cracks here: https://bugzilla.kernel.org/show_bug.cgi?id=216355
plum 2022-08-13 02:11:01 UTC
I upgrade to kernel 5.19.1 but found my thinkpad x1 carbon 2021's mute led stop working.
Function is okay but LED won't light up.
Back to kernel 5.18 and it's normal and working again.
Fedora 36 64 bit Gnome-shell 42
From a quick research it looks to me like this is an issue for the sounds maintainers, as the LED itself apparently works. If that is something for the platform people instead please speak up.
Thanks for bringing this up, we recently hit this in Fedora too and we have a fix/workaround there. Let me copy and paste what I just added to bko216355 :
This is caused by a behavior change of the kernel code controlling the LED to only turn on the LED when all inputs, including e.g. the jack mic input are turned off in the alsa-mixer settings.
But most userspace code only turns the mic which it is actually using on/off when you hit the mic-mute hotkey.
Also see: https://bugzilla.redhat.com/show_bug.cgi?id=2134824
Which is the same bug.
There is a set of fixes available in the form of an alsa-ucm update which tells the kernel to ignore the state of the jack mic input restoring the old behavior:
https://git.alsa-project.org/?p=alsa-ucm-conf.git;a=commitdiff;h=79a8ec44d3d... https://git.alsa-project.org/?p=alsa-ucm-conf.git;a=commitdiff;h=9ce9ddb4a84...
Regards,
Hans