I've got a new thinkpad laptop and I've been struggling with mouse acceleration on trackpoint, turns out disabling it isn't as straight-forward as you'd expect

To get rid of this abomination of a feature that is enabled by default we need xinput

The Fix

First you need to find the code or name of your trackpoint:

$ xinput list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=12   [slave  pointer  (2)]
⎜   ↳ TPPS/2 IBM TrackPoint                     id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Sleep Button                              id=8    [slave  keyboard (3)]
    ↳ Integrated Camera: Integrated C           id=10   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=11   [slave  keyboard (3)]
    ↳ ThinkPad Extra Buttons                    id=14   [slave  keyboard (3)]
    ↳ SteelSeries  SteelSeries Arctis 7         id=9    [slave  keyboard (3)]

Our guy is TPPS/2 IBM Trackpoint aka id 13. Next we can see the properties of this prop:

$ xinput list-props 13
Device 'TPPS/2 IBM TrackPoint':
        Device Enabled (140):   1
        Coordinate Transformation Matrix (142): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
        libinput Natural Scrolling Enabled (310):       0
        libinput Natural Scrolling Enabled Default (311):       0
        libinput Left Handed Enabled (312):     0
        libinput Left Handed Enabled Default (313):     0
        libinput Accel Speed (314):     0
        libinput Accel Speed Default (315):     0.000000
        libinput Accel Profiles Available (316):        1, 1
        libinput Accel Profile Enabled (317):   1, 0
        libinput Accel Profile Enabled Default (318):   1, 0
        libinput Scroll Methods Available (319):        0, 0, 1
        libinput Scroll Method Enabled (320):   0, 0, 1
        libinput Scroll Method Enabled Default (321):   0, 0, 1
        libinput Button Scrolling Button (322): 2
        libinput Button Scrolling Button Default (323): 2
        libinput Middle Emulation Enabled (324):        0
        libinput Middle Emulation Enabled Default (325):        0
        libinput Send Events Modes Available (260):     1, 0
        libinput Send Events Mode Enabled (261):        0, 0
        libinput Send Events Mode Enabled Default (262):        0, 0
        Device Node (263):      "/dev/input/event18"
        Device Product ID (264):        2, 10
        libinput Drag Lock Buttons (326):       <no items>
        libinput Horizontal Scroll Enabled (327):       1

To disable acceleration we are interested in one of these two settings:

        libinput Accel Speed (314):     0
        libinput Accel Profile Enabled (317):   1, 0

We can either diminish/change the acceleration speed by:

# to disable we can use negative acceleration
$ xinput set-prop 13 314 -1
# or we can disable acceleration profile entirely
$ xinput set-prop 13 317 0 1

Note, don't use both, -1 with disabled acceleration pretty much disables the devices.

Make It Persisntant

To make the change persist after restart simply add the config line it to your ~/.xsessionrc file, e.g.:

echo "xinput set-prop 13 317 0 1" >> ~/.xsessionrc