Bug 435247

Summary: KCM displays libinput-specific UI even when xorg config files specify the use of evdev instead
Product: [Applications] systemsettings Reporter: 2wxsy58236r3
Component: kcm_mouseAssignee: Plasma Bugs List <plasma-bugs>
Status: RESOLVED UNMAINTAINED    
Severity: normal CC: nate
Priority: NOR    
Version: 5.20.5   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description 2wxsy58236r3 2021-04-02 04:32:49 UTC
SUMMARY

I have switched to evdev for mouse by adding a configuration file in /etc/X11/xorg.conf.d/, but Mouse KCM still thinks I am using libinput.

I have to also switch to evdev for keyboard to make Mouse KCM displays the evdev set of options. 

STEPS TO REPRODUCE

1. Apply the following configuration:

Section "InputClass"
    Identifier "evdev-mouse"
    MatchIsPointer "yes"
    Driver "evdev"
EndSection

2. Log out and log in again
3. Mouse KCM still in libinput mode
4. Change the configuration to (add the keyboard section):

Section "InputClass"
    Identifier "evdev-keyboard"
    MatchIsKeyboard "yes"
    Driver "evdev"
EndSection

Section "InputClass"
    Identifier "evdev-mouse"
    MatchIsPointer "yes"
    Driver "evdev"
EndSection

5. Log out and log in again
6. Mouse KCM finally switches to evdev mode

ADDITIONAL INFORMATION

On Arch Linux, xorg-server depends on xf86-input-libinput, so it cannot be removed.
Comment 1 Nate Graham 2021-04-06 00:49:27 UTC
> On Arch Linux, xorg-server depends on xf86-input-libinput, so it cannot be removed.
Sounds like a packaging problem to me. :) This isn't a problem on other distros, so I would recommend that you get into contact with the Arch packagers about it.
Comment 2 2wxsy58236r3 2021-04-06 06:23:37 UTC
From /var/log/Xorg.0.log, I confirmed that it is possible to use evdev only for the mouse, but KDE incorrectly thinks that libinput is used, and settings like left-handed mode is not applied.

Arch Wiki also says that alternative drivers for Xorg#Input devices can generally be installed in parallel. [1]

[1] https://wiki.archlinux.org/index.php/Libinput#Via_Xorg_configuration_file
Comment 3 Nate Graham 2021-04-07 11:20:05 UTC
Ah, perhaps you're right.
Comment 4 Nate Graham 2024-03-25 01:40:33 UTC
Hello! This Bugzilla ticket concerns support for the non-Libinput version of the Mouse page, which is no longer supported in Plasma 6. As such, the ticket will be closed as fixing or implementing what's requested here is now out of scope.

Thanks for your understanding!