Created attachment 133368 [details]
Output of "dmesg -w" (full)

Full output of "dmesg -w", recorded by running "dmesg -w > filename.txt". The
previous one was incomplete as it was subject to console line limitations,
cutting off the moment when the crash actually occurs. I left the command
running in a different runlevel; This time the crash didn't shut down the
monitor after switching to it (Control + Alt + F1) so I was able to cleanly
shut down dmesg then issue a normal reboot. I waited there for about 5 minutes
before doing so, to give dmesg time to record as much information as possible.
The crash appears to start at the following lines:

[112873.658950] radeon 0000:03:00.0: ring 4 stalled for more than 10024msec
[112873.658953] radeon 0000:03:00.0: GPU lockup (current fence id
0x000000000072f6bd last fence id 0x000000000072f6c1 on ring 4)