Comment 7 for bug 799069

Ok I think I got it.

I'm not using "active" vt, I always put it on vt7. I'm not too sure where plymouth is running but it might be on vt7, which means they'll both compete for the display and, as I don't chose to run on "active" vt, it'll be only deactivated and not quitted, which doesn't seem enough.

Running only plymouth (no lightdm) and then running:

plymouth deactivate
X vt7

leads to X not starting because of the non returning ioctl. I guess that quitting plymouth unconditionally would work, no idea if that's a problem in the general case though. As far as we (Debian) are concerned, we quit plymouth anyway so it shouldn't break anything.