Hello, I've been noticing what sounds like the same issue as the original post. This is brand new install of Ubuntu 20.04 after running all updates and restarting. A clean boot show has no display problems but after I suspend my system I get a lot of tearing/flashing. If I drop the rate on the larger monitor from 144Hz to 59.95Hz the problem goes away. I have also tried the other supported rates of 120.00 and 99.95 which still have tearing.
If I try the same process but with just my larger screen enabled, the resume doesn't have the flickering. This does not seem to be happening in Fedora 32 in the same system. Since that runs 5.6 and 3.36 on Wayland maybe the issue is in the kernel. I am mostly a user so I can't really draw better conclusions. I can provide a video and logs as needed. My setup: AMD® Ryzen 5 2600x six-core processor × 12 AMD® Radeon rx 5600 xt GNOME version 3.36.3 Kernel: 5.4.0-40-generic #44-Ubuntu SMP Tue Jun 23 00:01:04 UTC 2020 Windowing System X11 (also happens when using Wayland) 2 monitors: Samsung 32" with resolution 3840x2160 @ 144.00 Hz Asus 24" 1920x1080 at 60Hz -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1874588 Title: Flickering screen after waking up from Suspend Status in linux package in Ubuntu: Incomplete Bug description: Just did a fresh install of Ubuntu 20.04 LTS and everything was fine, display worked perfect. Then I put the machine in Suspend mode (by clicking on GUI button), left for 5 minutes, came back, woke up the machine (by clicking a key on the keyboard), and upon waking up, the display started flickering heavily. Relevant Specs (Sorry if I missed anything): AMD® Ryzen 9 3900x 12-core processor × 24 AMD® Radeon rx 5700 xt GNOME version 3.36.1 Windowing System X11 I am running 3 monitors: Samsung with resolution 3840x2160 and 2 LG monitors with resolution 1920x1080, all at 60Hz Most of the flickering is happening on Samsung, although once in a while, other monitors flicker a little bit as well. Things to note: When I switch Samsung to lower resolution, the flickering goes away. When I come back to 3840x2160, it comes back. When I switch to lower resolution, suspend and come back, everything is fine. If I reboot the machine, the display is fine until I suspend and wake up again (if I am in higher resolution). I tried changing the refresh rate of Samsung to 30.00 and 29.97 (the only two available when I turn off FreeSync), and the issue still persists. Turning FreeSync on and off does nothing. Thank you, Pavel. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-26-generic 5.4.0-26.30 ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30 Uname: Linux 5.4.0-26-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: pavel 1870 F.... pulseaudio /dev/snd/controlC0: pavel 1870 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Apr 23 21:14:00 2020 InstallationDate: Installed on 2020-04-23 (0 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) MachineType: System manufacturer System Product Name ProcEnviron: LANGUAGE=en_CA:en PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_CA.UTF-8 SHELL=/bin/bash ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-26-generic root=UUID=02f6301e-c22b-462d-a4e5-71a78b7eb203 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-26-generic N/A linux-backports-modules-5.4.0-26-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/19/2019 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1405 dmi.board.asset.tag: Default string dmi.board.name: TUF GAMING X570-PLUS (WI-FI) dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev X.0x dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1405:bd11/19/2019:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnTUFGAMINGX570-PLUS(WI-FI):rvrRevX.0x:cvnDefaultstring:ct3:cvrDefaultstring: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1874588/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
