Broken TrackPoint in recent Tumbleweed update

English Hardware
#1

Hello,
a few days ago, I’ve updated to a new version of openSUSE Tumbleweed on my Thinkpad T440p and my TrackPoint has started acting very strange. If I move the pointing stick up or to the right, it behaves correctly but as soon as it tilts even slightly in the other two directions, it shoots to the top or right side of the screen respectively. This seems to me like an unsigned integer is used in place where a signed one should clearly be used. The mouse and TrackPad both work normally. I will add that this install of Tumbleweed is a few years old with many different packages and enabled repos, but I checked and the xinput package is the one from the main Tumbleweed repository.

xinput --list 14
AlpsPS/2 ALPS DualPoint Stick           	id=14	[slave  pointer  (2)]
	Reporting 7 classes:
		Class originated from: 14. Type: XIButtonClass
		Buttons supported: 7
		Button labels: "Button Left" "Button Middle" "Button Right" "Button Wheel Up" "Button Wheel Down" "Button Horiz Wheel Left" "Button Horiz Wheel Right"
		Button state:
		Class originated from: 14. Type: XIValuatorClass
		Detail for Valuator 0:
		  Label: Rel X
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: relative
		Class originated from: 14. Type: XIValuatorClass
		Detail for Valuator 1:
		  Label: Rel Y
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: relative
		Class originated from: 14. Type: XIValuatorClass
		Detail for Valuator 2:
		  Label: Rel Horiz Scroll
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: relative
		Class originated from: 14. Type: XIValuatorClass
		Detail for Valuator 3:
		  Label: Rel Vert Scroll
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: relative
		Class originated from: 14. Type: XIScrollClass
		Scroll info for Valuator 2
		  type: 2 (horizontal)
		  increment: 120.000000
		  flags: 0x0
		Class originated from: 14. Type: XIScrollClass
		Scroll info for Valuator 3
		  type: 1 (vertical)
		  increment: 120.000000
		  flags: 0x0
#2

I’ve tried downgrading libinput10 and xf86-input-libinput to the version available in the Leap repositories, but to no avail.

Also, then I use xinput test-xi2 and slightly nudge the Trackpoint downwards, I can consistently see this:
image

Which supports my hypothesis about the unsigned integer underflow.

I’m thinking of filing a bug report, but I’m still not sure if it isn’t some super special configuration collision that is only specific to my case.

I’ll also add that the TouchPad on this machine has been replaced to the one from ThinkPad T450, this has however worked fine for years and on top of that is a very common mod.

I’ll appreciate any kind of help since using my computer and working has become very cumbersome.

#3

Was a bug in kernel, should be fixed in the next update. See Bug 1209805 – Kernel regression: Possible integer underflow in input pipeline of ThinkPad trackpoint.