Hi,
Debian rebooted infinitely and randomly when radeon was enabled.
But Xorg works fine by startx.
I had this normal setting in /etc/X11/xorg.conf.d/50dimensions.conf:
Section "Monitor"
Identifier "HDMI-0"
DisplaySize 477 268
Option "Primary" "true"
EndSection
The aim was to adjust with accuracy to the real screen dimensions.
If I removed these settings, all work fine. No more reboots.
I do not understand why these legitimate settings do reboot
the kernel and not xorg when the kernel does not crash.
-- Rpnpif