Comment # 17 on bug 798308 from Koenraad Lelong

I let the machine boot to the graphical login.
No LVDS, when I select the VGA of the monitor I have the login-screen on it.
I log in.
LVDS appears, VGA disappears. Selecting DP-input gives no image.
xrandr --output DisplayPort-0 --auto does nothing I can see.
xrandr --output VGA-0 --auto gives :
xrandr: cannot find crtc for output VGA-0

I tried this several times.

After using System Settings ... and enabling VGA I get the following :
I let the machine boot to the graphical login.
No LVDS, when I select the VGA of the monitor I have the login-screen on it.
I log in.
LVDS appears, VGA remains. Selecting DP gives no image.
xrandr --output VGA-0 --auto does nothing I can see.
xrandr --output DisplayPort-0 --auto gives this :
xrandr: cannot find crtc for output DisplayPort-0

Every time I get three displays when I run xrandr.