Rotating one of my monitors makes it garbled and/or logs me out (causing endless login loop).
Mesa 17.1 (padoka PPA).
Linux Kernel 4.10.
Xubuntu 16.10. (XFCE).
Radeon RX 480.
A) Dell U2410 (1920x1080) via HDMI.
B) QNIX QX2710LED (2560x1440) via DVI.
Disabling #B doesn't help.
Not sure if this is a Mesa bug, but it's my best guess.
Note, this doesn't occur when using Unity, so it might be specific to X11?
I wonder if the unusual combo of HDMI + DVI might also be important - I did find one related thread somewhere (lost it, sorry) mentioning they fixed rotation issues by using different ports (Unfortunately, the QNIX only has DVI).
This has been bugging me for a while, but I always rotated the monitor before upgrading kernel/mesa etc so I didn't click that it was rotation until today.
Unfortunately I can't get a screenshot as it's too unstable. If it displays anything before logging out it looks like strips of actual rotated desktop plus strips of unintelligible data.
*** This bug has been marked as a duplicate of bug 99916 ***