Ubuntu
linux-meta-hwe package

Keyboard NumLock indicator turns off on connecting another keyboard

Bug #1845214 reported by Dmitry Lapshin
10
This bug affects 2 people
Affects Status Importance Assigned to Milestone
linux-meta-hwe (Ubuntu)
Confirmed
Undecided
Unassigned

Bug Description

My USB HID keyboard has NumLock LED. It usually works fine. However, when I plug in YubiKey (hardware security token, it is also identified as a USB HID keyboard) NumLock LED turns OFF, but the NumLock feature is still ON.

If I press NumLock, NumLock becomes disabled (it is displayed by DE and checked by typing). If I press NumLock again, NumLock turns back ON with LED.

I originally thought that issue could be related to the fact that YubiKey does not have a NumLock led, so it reports LED as nonexisting and stuff happens. However, today I tried attaching another USB keyboard: LED on first one still goes off; but LED on second goes ON immediately after plugging in. Pressing NumLock once disables NumLock and LED on first keyboard, as with YubiKey; pressing again enabled NumLock and both LEDs.

Seems like my user session (on vt2) is running Xorg while login screen (on vt1, the one that allows to choose a user and that you see before first login) is running Wayland; both are faulty. Because of this, I believe the issue is in the kernel.

However, I am not sure, so you can ask for way more reports to be added, I will add those. Reproducing should be pretty easy with any cheap USB keyboards, nothing special is used by me.

Operating system: Ubuntu 18.04 Bionic Beaver.
Linux kernel: 18.04 HWE, 5.0.0-25. However, I think I saw this blinking before upgrading to HWE.
DE: GNOME.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-generic-hwe-18.04 5.0.0.29.86
ProcVersionSignature: Ubuntu 5.0.0-25.26~18.04.1-generic 5.0.18
Uname: Linux 5.0.0-25-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Tue Sep 24 16:52:08 2019
SourcePackage: linux-meta-hwe
UpgradeStatus: Upgraded to bionic on 2018-09-03 (386 days ago)

Revision history for this message
Dmitry Lapshin (lapshin-dv) wrote :
Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in linux-meta-hwe (Ubuntu):
status: New → Confirmed
Revision history for this message
Stuart Longland (redhatter) wrote :

I've noticed the same thing… both on Ubuntu, and lately on Gentoo as well, so I'm thinking maybe something in udev / kernel has changed?

I use FVWM2 as my desktop on both OSes. My desktop runs Ubuntu 20.04 (AMD64).

On my laptop (Panasonic CF-53, which runs Gentoo) it's particularly insidious, plugging in the YubiKey (mine's a 5C which I use with a USB-A-C adaptor) causes NumLock to be turned on, and if your PIN code uses letters over the right-side of the keyboard, guess what? You're unwittingly typing numbers now! Cue confusion when the YubiKey rejects the PIN you just entered.

I've locked myself out of the YubiKey once because of that -- had to go in with the PUK and unlock it.

My desktop doesn't seem to secretly turn NumLock on; the state is retained, just the LED turns off.

If we can figure out what mechanism is doing it in Ubuntu, I'll chase up what's doing it Gentoo-side.

Revision history for this message
Dmitry Lapshin (lapshin-dv) wrote :

It's been several years since my report! Still reproducible on latest Ubuntu.

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