AMD GPU black screen after leaving computer idle

[David Aizenberg]

Hi, I have recently swapped out an NV card for AMD one and with no other changes this has started appearing.

After I leave my PC idle for +- 5-10 minutes I come back to a blank screen, and if I switch to VT/tty and back then it just opens lightdm/slim(whatever is set default at the time) and starts a new session, killing old one.

When I switch to VT/tty, I can see my old session/applications running if I run htop, but they disappear if I login in new session.

If I switch to VT/tty and back without leaving my machine idle, then it's working as expected.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.4.0-45-generic 5.4.0-45.49
ProcVersionSignature: Ubuntu 5.4.0-45.49-generic 5.4.55
Uname: Linux 5.4.0-45-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: david 5694 F.... pulseaudio
 /dev/snd/controlC2: david 5694 F.... pulseaudio
 /dev/snd/controlC1: david 5694 F.... pulseaudio
 /dev/snd/pcmC1D0p: david 5694 F...m pulseaudio
CasperMD5CheckResult: pass
CurrentDesktop: i3
Date: Tue Sep 8 23:01:57 2020
InstallationDate: Installed on 2020-07-22 (48 days ago)
InstallationMedia: Ubuntu-Server 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
MachineType: Dell Inc. Precision T5600
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-45-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro
RelatedPackageVersions:
 linux-restricted-modules-5.4.0-45-generic N/A
 linux-backports-modules-5.4.0-45-generic N/A
 linux-firmware 1.187.3
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/21/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A18
dmi.board.name: 0GN6JF
dmi.board.vendor: Dell Inc.
dmi.board.version: A02
dmi.chassis.type: 7
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA18:bd06/21/2018:svnDellInc.:pnPrecisionT5600:pvr01:rvnDellInc.:rn0GN6JF:rvrA02:cvnDellInc.:ct7:cvr:
dmi.product.name: Precision T5600
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

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

This change was made by a bot.

[David Aizenberg (pixelshuck)]

Workaround: https://medium.com/@strayobject/fix-displayport-monitor-not-waking-on-ubuntu-18-10-a1eced577f0a