Kubuntu on ThinkPad with TrackPoint and TouchPad Elantech Problem

Since I work at Dicoding, I use a ThinkPad (yeah, kind of bored of using Mac).

And, of course, I use Linux on that ThinkPad, as I am a fan of Kubuntu. 😂

After years of no problems at all, today I found that the touchpad was not moving while I was working. At some point, I used a USB mouse.

Okay, let’s get technical.

First, I thought that it was the device driver, so probably a new kernel caused the problem. I found that my Kubuntu has several kernels with versions 5.15.xx and 6.5.xx.

$ apt list --installed | grep linux-image

So, I tried to reboot several times with different kernel versions, manually selected via grub. But, the problem still exists. 😢

Let’s try a different perspective, check what happened on dmesg.

$ sudo dmesg | grep mouse

Now, we can see some kernel messages, “probably” related to the kernel module psmouse, or there’s a clue on the hardware name “probably” Elantech.

And then, of course, we move to ask Google. 😂

The quick fix that I got was to remove the kernel module psmouse and add it again. ¹

sudo modprobe -r psmouse && sudo modprobe psmouse proto=imps

But, um… yeah, still not perfect. I can’t use the scroll. 😕

On the other side, I found something with Elantech, information officially from Lenovo, the producer of ThinkPad. ² So there’s a trick regarding psmouse for Elantech by setting the kernel with the parameter psmouse.elantech_smbus=0.

Digging deeper regarding psmouse and Elantech, I found that it’s a bug in the Linux kernel ³, which comes from years ago. It made a wrong protocol detection in the kernel configuration: /sys/bus/serio/devices/serio1/protocol.

So, as mentioned in ², adjusting the kernel parameter fixed my problem. Then, I made it permanent by adding the parameter to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub ⁴.

Hope it helps.