Description of problem:
While my notebook is docked (i.e. with the lid closed, two external monitors connected), gdm shows the login dialog on the built-in display.

Version-Release number of selected component (if applicable):
gdm 3.22.3
kernel 4.10.10-200.fc25.x86_64


How reproducible:
I tested this using two notebooks, a Dell E6230 and a Dell E7240 in (two distinct) Dell E-Port Replicator Docking Stations, connected to two Dell monitors using displayport. Both notebooks are running fully updated Fedora 25 installations.


Steps to Reproduce:
1. Make sure notebook is turned off
2. Insert notebook in docking station
3. Power notebook on
4. Either automatically boot, or select kernel 4.10.10
5. Wait for the system to boot

Actual results:
The two external monitors show a gray screen (the gdm background). It is still possible to login while blindly typing the username and password. As soon as the desktop appears, the built-in display is turned off automatically.


Expected results:
Built-in display turned off, gdm login dialog on one of the external screens.


Additional info:
This problem does not occur while selecting the 4.10.9 kernel in grub.