Touchpad click&drag no longer works after suspend

[Frederik TIlmann]

Normally I use click-hold-and-move to e.g. move windows around on the screen. This action works fine with the touchpad also directly after booting, but after Suspend and reawakening, I can only move the window (or other item) a few pixels. The hold is still recognised but any movements on the touchpad are not.
If I click and then use the Lenovo pointing stick, it works, likewise if I use the buttons above the touchpad, it also works. In spite of the relatively straightforward workaround this is very annoying and prevents (for me) one-handed use of the touchpad.
Also, this is a kernel-based regression: on 4.15.0.36 it is broken but for 4.15.0.34 it works fin,

My hardware: Lenovo X1-Carbon, 5th generation

Description: Ubuntu 16.04.5 LTS
Release: 16.04

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.15.0-36-generic 4.15.0-36.39~16.04.1
ProcVersionSignature: Ubuntu 4.15.0-36.39~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-36-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CurrentDesktop: MATE
Date: Sun Oct 21 16:35:18 2018
InstallationDate: Installed on 2018-01-23 (271 days ago)
InstallationMedia: Ubuntu-MATE 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
SourcePackage: linux-signed-hwe
UpgradeStatus: No upgrade log present (probably fresh install)

[Po-Hsu Lin (cypressyew)]

Hello,

can you still reproduce this now with the latest kernel? (If yes, please attach the "lsb_release -a ; uname -a" output from a terminal here)

Thanks

[Frederik TIlmann (tilmann)]

I actually figured out it's a duplicate of https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1722478 .

The work-around suggested there to add "psmouse.synaptics_intertouch=0" to the boot parameters worked for me as well, so I am not really sure if the very latest kernel would have fixed this.
If required I can test when I get home.

[Frederik TIlmann (tilmann)]

Maybe the title of #1722478 should be changed to reflect that this bug does not only affect two-finger scrolling but also click-and-drag but I don't have the authority to do this I think.