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@xxxxxxxxx 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=79a8ec44d3dcf097f4a4492c506cbcf338324175 https://git.alsa-project.org/?p=alsa-ucm-conf.git;a=commitdiff;h=9ce9ddb4a84fb467602b716575ea1d8f2bab0c39 Regards, Hans
