Massive screen tearing using fractional scaling

[René Spies]

The tearing appears when fractional scaling is active and set to 125% (I only tested it with 125%) AND only when the mouse cursor is moved. The tearing does not appear, when the cursor is not moved. The tearing does also not appear when the display is scaled to 100 or 200% no matter if fractional scaling is active or the cursor is moved.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sun May 3 00:37:03 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 Intel Corporation UHD Graphics 620 (Whiskey Lake) [8086:3ea0] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. UHD Graphics 620 (Whiskey Lake) [1043:16a1]
InstallationDate: Installed on 2020-04-30 (2 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 04f3:0903 Elan Microelectronics Corp. ELAN:Fingerprint
 Bus 001 Device 002: ID 13d3:56dc IMC Networks USB2.0 HD UVC WebCam
 Bus 001 Device 004: ID 8087:0aaa Intel Corp.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: ASUSTeK COMPUTER INC. ZenBook UX392FA_UX392FA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-28-generic root=UUID=cbcf9a35-a5f8-429f-adad-ad8f21bff5df ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/17/2019
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: UX392FA.301
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: UX392FA
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX392FA.301:bd07/17/2019:svnASUSTeKCOMPUTERINC.:pnZenBookUX392FA_UX392FA:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX392FA:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: ZenBook
dmi.product.name: ZenBook UX392FA_UX392FA
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.101-2
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-2ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1846398, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.