Radeon Trinity 7400G fails with 4K UHD screen - atombios stuck executing BF64
Submitted by den..@..web.de
Assigned to Default DRI bug account
I have several issues trying to connect a 4k display to the radeon card via HDMI (@30Hz). If I boot with the screen connected, when trying to take over modesetting from EFI, the internal notebook display goes black as well as the external.
When I try to attach it during runtime, I can see the 3840 mode, but when I tryt to select it I get
[ 97.667521] [drm:atom_op_jump [radeon]] ERROR atombios stuck in loop for more than 5secs aborting
[ 97.667549] [drm:atom_execute_table_locked [radeon]] ERROR atombios stuck executing BF64 (len 962, WS 0, PS 0) @ 0xC1A1
Switching back to 1920 works fine, trying again simply causes the same error again. Tested Linux kernels 4.1.0 and 3.19. Ubuntu 15.04.
I might not be able to test for long, will probably send the screen back before long if I can't get it working in full resolution at all.