Elantech Touchpad only works right, if booted via 'System Recovery' option
Hello,
Issue Summary: Muttering(Stuttering, stucky) Touchpad. When I slide my finger over touchpad, it feels like it doesn't compute some events and stops for 0.1-0.5 seconds.(After some reboots, the touchpad worked by 'luck')
My solution: During reboot, I select 'F11 System Recovery' option. Visually, nothing happens and boots into OS, and the touchpad works like it supposed to. I tried 10 times with 'System Recovery option', and 10 times without. The solution works in everytime, and normal boot doesn't.
Hardware: HP Pavilion 15 EC0006NT, AMD 3550h, gtx 1650.
Touchpad: ELAN0718:01 04F3:30FD
Every OS I tried the touchpad with: Ubuntu 18.04, 19.10, 20.04, Fedora 32 Beta, Windows.
(I used Windows couple of days. Never encountered any issue with the touchpad)
The gentlemen from freedesktop said that my touchpad issue might be related to GNOME. Issue got closed, so no help from there. I am after this issue not only because i wish my touchpad worked, it's because i would like to help linux community. Maybe it is a critical bug for linux that a notice in time might help greatly.
That's his post:
The debounce timer is 12ms (iirc) but libinput isn't called until almost 3s later. There are heaps of these warnings in the log and in short - something is eating your CPU and libinput thus doesn't get to process events in time. This causes all sorts of issues but primarily: whenever this happens the cursor movement freezes because nothing is updating.
For more details see the docs and this post here.
This doesn't look like libinput bug, it looks like a GNOME shell/mutter bug. If you can figure out what applications or interactions trigger it then that'll help debug this further for the GNOME developers but for libinput right now there's nothing we can do here.
Easy way to verify this is indeed the (only) issue: at gdm click the gear icon in the bottom right and log in with a GNOME on Xorg session and it should disappear.
My Reply
There was two options on gear icon, "GNOME" and "GNOME Wayland". Both of them didn't make a change. I also disabled wayland: WaylandEnable=false And didn't work. What does that mean? Should I try out different kernels?
Then I discover 'System Recovery' boot option solution.
I made an important discovery that I had to share.
I discovered that the issue might not be related to the kernel as well. Because I selected 'F11 System Recovery' option during a boot, while I was desperate, and the touchpad worked.
When I press F11, it just regularly boots into Ubuntu without any 'visual' thing happening. But everytime I select System Recovery option, the touchpad works in every time.
I tried this out by 10 times booting normally, and by 10 times selecting 'System Recovery' option during boot. The touchpad didn't work during 10 normal boot trial, and It worked every single time when I selected 'System Recovery' option during boot.
Why that might be?