Keyboard issues

seth · 2026-01-09 07:10:26

A "stuck" key can jam the bus?

If it keeps firing electric signals like crazy? Sure.

Fn+Space when keyboard is working normally, ctrl gets unpressed

This can either be a symptom of the defect or an https://en.wikipedia.org/wiki/Key_rollo … y_rollover limitation (oh, and look at the paragraph below)
It however doesn't do anything when the ctrl key is stuck?

Since reboot always helps, I assume you mean always using that parameter?

Yes.
If rebooting helps, does reloading atkbd?

tx · 2026-01-09 14:30:09

oh, and look at the paragraph below

You mean wikipedia one? (it's not below)

Fn+Space when keyboard is working normally, ctrl gets unpressed

Let me rewrite that: While Ctrl is pressed it is sending pressed events, on any other key press Ctrl stops sending pressed but properly sends key up when gets unpressed.

If rebooting helps, does reloading atkbd?

Unfortunately, at the time of the bug I had to reboot relatively quickly so I forgot to check this one.

It however doesn't do anything when the ctrl key is stuck?

No keybinding, even built-in and SysRq, worked when ctrl was stuck.

Ok, so I will try running with that kernel parameter, and if it occurs again:
1. Check SysRq and Fn+Space
2. Check evtest to determine whether keyboard stops working due to a stuck key which jams the bus, or if no events are sent at all (maybe there are multiple issues?)
3. Try to sleep & wake up
4. Try reloading atkbd (and i8042?)
Anything else?

seth · 2026-01-09 21:05:50

You mean wikipedia one?

Below in the wp article (the one talking about key jamming

No[t] even […] SysRq, worked when ctrl was stuck.

Sounds a lot like HW.

Anything else?

Do you still get input form an external keyboard? (Sorry if we had that before)

tx · 2026-01-09 21:19:56

Do you still get input form an external keyboard?

I still don't have one, so can't test.

Arch Linux

#26 2026-01-09 07:10:26

Re: Keyboard issues

#27 2026-01-09 14:30:09

Re: Keyboard issues

#28 2026-01-09 21:05:50

Re: Keyboard issues

#29 2026-01-09 21:19:56

Re: Keyboard issues

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