Jumpy touchpad input on Dell XPS 9370 when upgrading to 19.04 from 18.04

[Joseph Borg]

Quite hard to get meaningful errors / logs, but I'll try to explain the best I can.

I'm running on a Dell XPS 9370 (the developer edition).

I was running 18.04 on Wayland and have updated to 19.04 using the `do-release-upgrade` executable to 18.10 and then `do-release-upgrade -d`.

Still running on Wayland (although, as far as I can see, the issue is also on X), the pointer / touchpad has become very jumpy and has an odd acceleration profile. I had set the acceleration profile to "FLAT" on 18.04 and have tried to re-set that, but it doesn't seem to have changed anything.

When I move long distances, the pointer seems to suddenly x2 in speed (rather than linear acceleration that I'd be used to), making it difficult to accurately point.

The worst experience seems to be small adjustments, for example highlighting text. The cursor feels like it randomly jumps, some time it's fine, sometimes it jumps quite significant screen distance for a tiny movement of my finger and other times it is fine.

I'm more than happy to provide logs, videos etc.

Thanks all!

[Daniel van Vugt (vanvugt)]

To verify if the problem really is with libinput please try:

1. Install the old Xorg touchpad driver:

   sudo apt install xserver-xorg-input-synaptics

2. Reboot and then only log into Xorg sessions.

If that avoids the problem then please confirm by:

3. sudo apt remove xserver-xorg-input-synaptics

4. Reboot and verify the bug returns in Xorg sessions.

[Launchpad Janitor (janitor)]

[Expired for libinput (Ubuntu) because there has been no activity for 60 days.]