after many repetitions of struggles with fglrx it is time to let it go – fglrx on linux is now officially dead. there were quite a few complaints about it not supporting latest X11 ABI 1 2 3. even though most of the time it worked nicely OotB, it had a long history of falling behind with changes in ABI.
from now on only official drivers for AMD/Radeon GP/GPUs are radeon (for older ones) and amdgpu (for newer ones).
after playing a bit with xorg.conf (years since i've done that manually the last time!) i managed to make it running with dual-screen setup, where one screen is rotated. here's the setup:
Section "ServerLayout" Identifier "X.org Configured" Screen 0 "Screen0" 0 0 InputDevice "Mouse0" "CorePointer" InputDevice "Keyboard0" "CoreKeyboard" EndSection Section "Files" ModulePath "/usr/lib/xorg/modules" FontPath "/usr/share/fonts/X11/misc" FontPath "/usr/share/fonts/X11/cyrillic" FontPath "/usr/share/fonts/X11/100dpi/:unscaled" FontPath "/usr/share/fonts/X11/75dpi/:unscaled" FontPath "/usr/share/fonts/X11/Type1" FontPath "/usr/share/fonts/X11/100dpi" FontPath "/usr/share/fonts/X11/75dpi" FontPath "built-ins" EndSection Section "Module" Load "glx" EndSection Section "InputDevice" Identifier "Keyboard0" Driver "kbd" EndSection Section "InputDevice" Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/input/mice" Option "ZAxisMapping" "4 5 6 7" EndSection Section "Monitor" Identifier "Monitor0" VendorName "Monitor Vendor" ModelName "Monitor Model" Option "Primary" "true" Option "DPMS" "true" Option "TargetRefresh" "60" Option "Position" "0 720" Option "Rotate" "normal" Option "Disable" "false" Option "PreferredMode" "1920x1200" EndSection Section "Monitor" Identifier "Monitor1" VendorName "Monitor Vendor" ModelName "Monitor Model" Option "Primary" "false" Option "DPMS" "true" Option "TargetRefresh" "60" Option "Position" "1920 0" Option "Rotate" "left" Option "Disable" "false" Option "PreferredMode" "1920x1200" EndSection Section "Device" Identifier "Card0" Driver "radeon" BusID "PCI:1:0:0" Option "Monitor-DVI-0" "Monitor0" Option "Monitor-DVI-1" "Monitor1" EndSection Section "Screen" Identifier "Screen0" Device "Card0" Monitor "Monitor0" SubSection "Display" Viewport 0 0 Virtual 3840 1920 Depth 24 EndSubSection EndSection
btw: abandoning fglrx fixed at least one game for me, namely talos principle.