Linux ubuntu 5.4.0-1025-raspi introduces cursor lag especially for tablets
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-raspi (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned | ||
Focal |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
By returning my raspberry Pi4 to Linux ubuntu 5.4.0-1022-raspi, I was able to verify that the lag is introduced between that version and Linux ubuntu 5.4.0-1025-raspi. I do not appear to have anything intermediate on my system. I also noted that under Wayland the neither the separate cursor for the tablet or the mouse cursor shows lag in the newer kernel. Unfortunately, I have no other clue as to what is going on.
The system report will show Linux ubuntu 5.4.0-1022-raspi as I have rolled back to that to avoid the problem for now.
ubuntu 20.04.1 LTS
ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-
ProcVersionSign
Uname: Linux 5.4.0-1022-raspi aarch64
ApportVersion: 2.20.11-
Architecture: arm64
CasperMD5CheckR
CurrentDesktop: LXQt
Date: Sat Dec 12 16:27:02 2020
ImageMediaBuild: 20200731
SourcePackage: linux-raspi
UpgradeStatus: No upgrade log present (probably fresh install)
A little more information that may help:
1) Same issue seen with a complete new install of ubuntu-server-20.04 for pi 4 + Lubuntu. vc4-fkms- v3d` in \boot\firmware\ usercfg. txt the lag goes away. However this introduces random screen flashing and other screen update artifacts such as blank regions.
2) If I do not include `dtoverlay=