If you have the black screen of death when trying to get back from suspend mode, you might want to check out this bug description and possible resolutions: https://bugs.launchpad.net/ubuntu/+source/plasma-desktop/+bug/1849084
Otherwise disable compositor: qdbus org.kde.KWin /Compositor suspend
Check if compositor is enabled: qdbus org.kde.KWin /Compositor org.kde.kwin.Compositing.active
Or: qdbus org.kde.KWin /KWin supportInformation
Also an option: https://linuxconfig.org/amd-radeon-ubuntu-20-04-driver-installation
More info and troubleshooting: https://forums.linuxmint.com/viewtopic.php?t=293577
Might be worth investigating: https://github.com/Pergravis?tab=projects
Info: glxinfo | grep render
sudo lshw -c video
dmesg | grep -i amdgpu
inxi -G
Check performance: vblank_mode=0 glxgears
Started logging software installations:
xserver-xorg-hwe-18.04
Third party repository drivers: sudo add-apt-repository ppa:oibaf/graphics-drivers
Remove third party drivers: sudo ppa-purge ppa:oibaf/graphics-drivers
2021-08-16 Random notes
sudo aptitude purge libdrm-amdgpu1
https://ubuntuhandbook.org/index.php/2021/07/install-latest-mesa-ubuntu…
sudo apt install ppa-purge
Next purge the Ubuntu PPA which will downgrade all the installed packages:
sudo ppa-purge ppa:kisak/kisak-mesa
For Linux Mint 20, it’s recommended to add -d focal flag to work safely:
sudo ppa-purge -d focal ppa:kisak/kisak-mesa
glxinfo | grep "OpenGL version"
glxinfo | grep Mesa