External display not working at full resolution 1920x1080

[Ulrich Hobelmann]

This is a regression from Linux Mint 17.3 to 18.

I have a Thinkpad (x220) + Docking station, and an extra monitor plugged in.

With Linux Mint 18, the external display seems to work with lower resolutions, but not at the native 1920x1080. The picture will show for a fraction of a second, and show black for a long time. Sometimes the picture will return for a fraction of a second.

If I turn OFF the laptop display and only use the external one, I can sometimes convince it to run full resolution, but it will flicker sometimes or show a black screen for 10 seconds and then return the picture.

Graphics is internal Intel.

[Ulrich Hobelmann (ulrich-hobelmann)]

Desktop is MATE, by the way.