https://bugs.freedesktop.org/show_bug.cgi?id=73530
--- Comment #2 from Paul Menzel paulepanter@users.sourceforge.net --- Created attachment 91918 --> https://bugs.freedesktop.org/attachment.cgi?id=91918&action=edit Linux kernel ring buffer (`dmesg`)
Please note the Linux kernel command line, which has `radeon.modeset=0`, `drm.debug=14` and `acpi_osi=Linux`. Later the the Radeon module is removed with `sudo modprobe -r radeon` and reloaded with `sudo modprobe radeon modeset=1`.