Ok, I finally have some time to do this.
So here are all the logs.
Screen remained scrambled in all cases (I did ctrl+alt+backspace after each).
I put all logfiles (/etc/X11/xorg.conf, /var/log/Xorg.0.log and output of lspci -vvnn) together in a tar.gz.
case 0 = initial xorg.conf
case 1 = colortile false
case 2 = disable DRI
case 3 = colortile false+disable DRI
Ok, I finally have some time to do this.
So here are all the logs.
Screen remained scrambled in all cases (I did ctrl+alt+backspace after each).
I put all logfiles (/etc/X11/ xorg.conf, /var/log/Xorg.0.log and output of lspci -vvnn) together in a tar.gz.
case 0 = initial xorg.conf
case 1 = colortile false
case 2 = disable DRI
case 3 = colortile false+disable DRI