[amdgpu] Scrumbled screen after standby on encrypted system

[snow]

I use Kubuntu 20.04 on an encrypted disk (LVM).

Problem:
After a standby when you wake up the system with the standby button again, the screen is for a short moment "scrambled" then the login dialog is presented and one can log in. This scrambled screen is only a cosmetic problem, but it does not fit the overall good design of the system. That's why I think it should be fixed.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-40.44-generic 5.4.44
Uname: Linux 5.4.0-40-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.3
Architecture: amd64
BootLog: Error: [Errno 13] Keine Berechtigung: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: KDE
Date: Wed Jul 15 23:50:54 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
ExtraDebuggingInterest: No
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] Picasso [1002:15d8] (rev d2) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Picasso [17aa:5125]
InstallationDate: Installed on 2020-07-14 (1 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
MachineType: LENOVO 20NKS01Y00
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-40-generic root=/dev/mapper/vgkubuntu-root ro quiet splash iommu=soft vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/19/2020
dmi.bios.vendor: LENOVO
dmi.bios.version: R12ET50W(1.20 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20NKS01Y00
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrR12ET50W(1.20):bd02/19/2020:svnLENOVO:pn20NKS01Y00:pvrThinkPadT495:rvnLENOVO:rn20NKS01Y00:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T495
dmi.product.name: 20NKS01Y00
dmi.product.sku: LENOVO_MT_20NK_BU_Think_FM_ThinkPad T495
dmi.product.version: ThinkPad T495
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.101-2
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.8-0ubuntu1~20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2.1
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)]

Can you attach a screenshot or photo of the problem?

[snow (mrauschert)]

s. screenshot. it canbe reproduced everytime after standby.

[Daniel van Vugt (vanvugt)]

Looks like a problem caused by the amdgpu driver. So first we need to see if the kernel part of the driver already has a fix for this. Please try installing a newer kernel like 5.8-rc5 or 5.7.9:

  https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=M;O=D

[snow (mrauschert)]

I installed kernel 5.7.9. The scramble screen did not change.

[snow (mrauschert)]

Remark: this problems only ocurrs in encrypted Kubuntu (LVM). Without encryption it was OK.

[Daniel van Vugt (vanvugt)]

Disk encryption should have no influence on display corruption. Most likely something else about the machine changed around the same time you enabled encryption.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Kai-Heng Feng (kaihengfeng)]

Do you see the issue on Ubuntu proper?

[snow (mrauschert)]

I installed Manjaro KDE and I saw the issue there either even if I tried 2 newer kernel versions there.
I installed today a fresh conpy of Kubuntu 20.04 again. The problem is the same.

[snow (mrauschert)]

I do not use standard Ubuntu at the moment. So, I cannot say for it.

[snow (mrauschert)]

Fyi: i booted from a Live USB stick on a HP EliteBok 745 G6 (also AMD-based) machine with Kubuntu 20.10. The scrambled screen was the same one, there.