Arch Linux

polm23

Member

Registered: 2017-09-13

Posts: 15

[SOLVED] Keyboard doesn't work with kernel update

Around January my keyboard stopped responding after a kernel update. I assumed it was a temporary issue and held off on updating my kernel, but after trying a full update again today I had the same issue.

I have a desktop PC and have been using the keyboard for several years. It is an unremarkable USB keyboard. To rule out a hardware issue, I have tried alternate keyboards, or removing and reattaching the keyboard, without any change in results. I log in from the console, not any kind of graphical login manager, and the keyboard is unresponsive immediately - I can't even type my user name.

The kernel that is working for me is linux-6.6.7.arch1-1.

How can I go about debugging this? I believe I can log in to the machine using SSH even if the keyboard is unusable. If there is a log that persists between boots that would be helpful, as I can use Arch install media to downgrade the kernel after using the bad one.

Last edited by polm23 (2024-04-11 16:11:11)

kokoko3k

Member

Registered: 2008-11-14

Posts: 2,425

Re: [SOLVED] Keyboard doesn't work with kernel update

Unplug keyboard
Login via ssh
Connect the usb keyboard
Then type sudo dmesg in the ssh session
Post the output

Last edited by kokoko3k (2024-04-11 06:32:02)

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polm23

Member

Registered: 2017-09-13

Posts: 15

Re: [SOLVED] Keyboard doesn't work with kernel update

Unfortunately it turns out I was unable to SSH to the machine when the keyboard wasn't working - the connection timed out. However I was able to use journalctl to get previous dmesg records. Here's dmesg (~1000 lines):

https://gist.github.com/polm/7dfe453866 … f48f92df9e

There are a lot of USB disconnects. I think they match me physically disconnecting it to try different USB ports. I did see one error in there for the keyboard, but it was on a later connection, and usually there seems to be no interesting output.

There is one weird thing - the log says the kernel is 6.6.7, even though I upgraded it to 6.8 whatever the latest one is using

pacman -Syu

with no IgnorePkg or anything. Why would that happen? If the kernel version hadn't chagned I'd expect the keyboard to work. (When the keyboard doesn't work, I fix it by using the Arch install media to downgrade linux, linux-headers, nvidia, and nvidia-utils.)

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Keyboard doesn't work with kernel update

You're booting from a boot partition but none is mounted - so the kernel was updated into the wrong location (/boot mountpoint instead of the partition)

lsblk -f
cat /etc/fstab

Mount the boot partition into place and re-install the kernel (resp. run a general update, but you *have* to install the kernel)

Edit: another consequence of that is the missing network, therefore the ssh failure.

Last edited by seth (2024-04-11 13:52:48)

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polm23

Member

Registered: 2017-09-13

Posts: 15

Re: [SOLVED] Keyboard doesn't work with kernel update

Thanks, that was the issue! I remember my boot partition filled up due to some weird firmware includes, I must have made some bad fstab edits or something at the time.