When my update failed going from 14.04 to 15.10, I tried formatting and doing a fresh install of 15.10
That didn't work (I'll explain now) so I tried Ubuntu-MATE 15.04 fresh install, coz I thought if I'm gonna resintall linux, might aswell try a different desktop, and maybe an older version will work. Anyway what's been happening is that when I choose ubuntu from GRUB menu, most of the time I just get a black screen with no backlight, but sometimes it boots. (And when I have the black screen I can change the volume on the keyboard and hear a sound. Strange isn't it?)
When I boot in recovery mode I found an error message that I think I managed to replicate with
dmesg | egrep "drm|radeon"
Here is the output:
[ 12.519822] [drm] Initialized drm 1.1.0 20060810
[ 12.980446] [drm] VGACON disable radeon kernel modesetting.
[ 12.980478] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module!
[ 13.007473] [drm] VGACON disable radeon kernel modesetting.
[ 13.007502] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module!
I have no idea what this means.
P.S, I Already tried removing the proprietary drivers, and installing the open source radeon drivers, and reinstalling the desktop and changing from lightdm to gdm incase it was lightdm not working.
