Bug 357749 (libinput-touchpad-kcm-accel-values)

Summary: [libinput] Pointer acceleration cannot be set below 0
Product: [Applications] systemsettings Reporter: Cyril Yab <cyril.yab>
Component: kcm_touchpadAssignee: Plasma Bugs List <plasma-bugs>
Status: RESOLVED FIXED    
Severity: normal CC: bugseforuns, kurmikon, nate, simonandric5
Priority: NOR Keywords: junior-jobs, usability
Version: 5.17.5   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In: 5.14
Bug Depends on:    
Bug Blocks: 383379    

Description Cyril Yab 2016-01-09 17:12:08 UTC
When setting the acceleration to the minimum, it is set to 0, whereas the minimum value accepted by libinput is -1. Since 0 is the default value anyway, I cannot actually decrease the mouse acceleration speed.

Reproducible: Always

Steps to Reproduce:
1. Go to System settings > Input devices > Touchpad > Pointer Motion.
2. Set the acceleration to the minimum (maximum left).

Actual Results:  
$ sudo xinput list-props "DLL0704:01 06CB:76AD Touchpad" |grep "274"
        libinput Accel Speed (274):     0.000000


Expected Results:  
$ sudo xinput list-props "DLL0704:01 06CB:76AD Touchpad" |grep "274"
        libinput Accel Speed (274):     -1.000000


Using Arch Linux (up-to-date), Touchpad KCM 5.5.3, libinput 1.1.4, xf86-input-libinput 0.16.0, Xorg server 1.18.0.
Comment 1 Giusy Digital 2017-01-27 10:18:02 UTC
Same problem to me.
https://bbs.archlinux.org/viewtopic.php?pid=1686729
https://forum.kde.org/viewtopic.php?f=66&t=138655

libinput is the default library for pointing devices. Please fix this bug.
Comment 2 Nate Graham 2017-08-10 20:32:40 UTC
As you have discovered, Libinput support here is poor to nonexistent. Fixing that is tracked with https://bugs.kde.org/show_bug.cgi?id=383379

As a workaround, you can either remove Libinput or configure it via .conf files if you're using Xorg: https://wiki.archlinux.org/index.php/Libinput#Configuration

*** This bug has been marked as a duplicate of bug 383379 ***
Comment 3 Nate Graham 2018-06-08 03:28:05 UTC
This was fixed for the Wayland version with https://cgit.kde.org/plasma-desktop.git/commit/?id=dd1244d6676620c06011b6c1db0c0ff3d5cdf0ab

The Xorg version is in progress and should be released in 5.14 as well.