Created attachment 122231 [details]
Oops.

I've seen this once before but couldn't reproduce at the time - maybe some luck
needed or maybe I didn't replicate well enough.

Currently running agd5f drm-fixes-4.5 on R9285.

PC booted from cold and running X with one display (DVI).

Someone else turns on/starts using HDMI TV.

I switch VT from X and start wayland (weston-launch) - works OK.

Quit weston with ctrl/alt/bs I see fbcon prompt but display is hung.

Sysrq works, log snip showing Oops attached.

I left in the trace an earlier edid error from when TV powered on in case
relevant.

Ever since I changed mobo before putting in tonga I've seen this with the TV.
It never fails to work so I guess something just tries again  - xrandr
--verbose will show correct/complete edid.