Note that DisplayPort is not yet implemented in the master branch of the xf86-video-intel driver. That is surely the cause of these problems.
There is a display-port branch which I am using now and seems to be quite stable: http://cgit.freedesktop.org/xorg/driver/xf86-video-intel/log/?h=display-port
You will have to git-clone that and bootstrap the build by running autogen.sh
Note that DisplayPort is not yet implemented in the master branch of the xf86-video-intel driver. That is surely the cause of these problems.
There is a display-port branch which I am using now and seems to be quite stable: cgit.freedeskto p.org/xorg/ driver/ xf86-video- intel/log/ ?h=display- port
http://
You will have to git-clone that and bootstrap the build by running autogen.sh