Since my update from Ubuntu 14.04 -> 14.10 -> 15.04 it sems that i cannot boot my system anymore as i am stuck at the password prompt when ubuntu appempts to mount my encrypted root partition.
The funny thing is, all USB devices are powered down after i left GRUB2's menu. Additionally there were other creepy sympthoms like: At first this only occurred when booting kernel 3.19. After some reboots, it didn't matter wich kernel i tried, nor did it matter if i started with systemd or upstart.
The most recent kernel i installed was linux-image-3.19.0-15-generic (not sure if the 0 and 15 are in their right places).
Also, when booting a kernel without the splash and vt handoff flags, i get the following error message, printed multiple times:
usb 1-3 device descriptor read/all, error -110
usb 1-3 device descriptor read/8, error -110
As i just noticed, when booting into recovery mode, the usb devices are powered up after one minute or so, but no input is still beeing accepted, not even pressing CAD has any effect.
I've tried 3 different keyboards for now, all USB2 to USB2 connectors.
I don't really know how to proceed with this. Any advice is welcomed.