Comment 19 for bug 1066883

lightdm is responsible for killing plymouth before starting X, so this can't be a plymouth bug. It may be a bug in the drm layer being triggered by plymouth.

If booting with plymouth-splash intact, after triggering the bug, is it possible to switch to a console and run 'sudo service lightdm restart'? Does X then start up correctly?

It may be useful to get the dmesg output of a failed boot with --verbose added to the kernel commandline, to get information about the ordering of the upstart jobs on boot.