https://bugs.freedesktop.org/show_bug.cgi?id=92974
--- Comment #1 from Michel Dänzer michel@daenzer.net --- (In reply to charlie from comment #0)
With AMD Powerplay disabled in the kernel there are no startup issues.
Do you mean CONFIG_DRM_AMD_POWERPLAY=n in .config or amdgpu.powerplay=0 on the kernel command line?
Toggling or including/excluding these kernel boot, "lilo.conf" options have no effect on the bug: "amdgpu.enable_scheduler=0 ; radeon.modeset=1 ; radeon.hw_i2c=1 ; radeon.disp_priority=2 ; radeon.fastfb=1 ; radeon.backlight=1 ; radeon.pcie_gen2=-1 ; radeon.hard_reset=0"
radeon.* parameters don't have any effect with the amdgpu driver.