Ok, so I upgraded my 14.04 LTS headless server to 15.04 using ssh and cli. Had similar problem on boot (black screen) so I had thought "foolishly" that this would have been resolved in the latest release and did another upgrade to 15.10. Big mistake, I know.
Well, it's not completely bricked since I can boot into recovery mode and unlock my drive and proceed to boot but I am wondering if anyone knows if there is a known issue with this kernel and AMD drivers since it worked fine in 3.16.xx? I'm not doing anything graphics intensive so I'd rather not use any AMD proprietary drivers, it's a headless (no gui) server but I would like it to boot and get to the prompt for me to unlock the Luks encrypted drive at least.
Some data that may be helpful:
$ uname -r 4.2.0-18-generic $ dmesg | egrep 'drm|radeon' [ 2.039343] [drm] Initialized drm 1.1.0 20060810 [ 2.063777] [drm] VGACON disable radeon kernel modesetting. [ 2.063790] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module! [ 25.984146] [drm] VGACON disable radeon kernel modesetting. [ 25.984162] [drm:radeon_init [radeon]] *ERROR* No UMS support in radeon module! $ lspci | grep -i vga 01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS880 [Radeon HD 4250]
Saw this post here and Nephente commented that
The Wily kernel and the proprietary AMD drivers don't work together yet. – Nephente Oct 23 at 7:12
Well, I'm not using proprietary AMD drivers...that I know of.
I've tried setting 'nomodeset' in the /etc/default/grub to no avail. Can someone help get me to a point where I don't have to manually tell it to go to recovery mode every time I boot up? The only reason I upgraded is because my security scan found a TON of vulnerable out-of-date binaries in 14.04 even though it was fully patched (apt-get update && apt-get upgrade && apt-get dist-upgrade). That freaked me out so I upgraded to 15.X to get patched binaries without manually installing all of them.