[forwarded from <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=816867>]

Mouse clicks and keyboard keys don't work at gdm when I first boot up. I
have to ssh into my machine and restart gdm to get it to work.

I am unable to even use Ctrl+Alt+F1 to switch to another virtual console
to log in. The only key sequence that responds is Ctrl+Alt+Delete, which
systemd picks up on as if I were at a virtual console that is not
running X, and duly reboots the system.

I have noticed that when gdm is in this state, /sys/class/tty/tty0/active
reads 'tty1', even though Xorg is launched with the 'vt7' argument.

I can ssh in and use chvt to change the current virtual terminal, and
the active tty status file changes to match, but the screen still shows
GDM's login prompt.

After restarting gdm, the active tty is changed to tty7 and at this
point everything works properly.