Hi, I seem to observe the exact same behavior on a machine with a different chipset
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) and using a Display Port connection. Gnome shell in use also. It doesn't depend on the particular DP device connected, and the behavior was introduced by (or co-occurred with) a recent package upgrade. If this package is responsible, the most recent upgrade in my system happened on 2016-03-11, upgrading from 2.99.917-2 to 2.99.917+git20160218-1. Thanks, Michael
