Hi guys,

I spent some time trying to figure out what's wrong with my shiny new system and 
it turned out that it is a problem somewhere between v4.5-rc[67] and DP 1.2 on 
Skylake.

With DP 1.2 enabled 'xrandr' reports half of the real monitor's (Dell UP2414Q) 
resolution, IOW 1920x2160.  Older kernels does not seem to work either.  
Disabling DP 1.2 seems to fix the problem, although in this mode it support 
3840x2160 @ 30Hz only.

Attached you'll find the 'dmesg' output.  Please let me know if i can help you 
with debugging the issue.


cheers,
Petko