https://bugs.freedesktop.org/show_bug.cgi?id=95298
--- Comment #3 from Yaroslav Halchenko debian@onerussian.com --- prev kernel: 4.4.2-3 -- yes it connected/light up no problem. I had 1 more issue though (may be relevant). When I come to work, and drop laptop into docking station, if then external monitor immediately lights up in 'clone' mode, I had to turn it off in xrandr/Displays, since otherwise whenever I run my stock "enable external monitor, disable laptop" xrandr line the whole display would go black without any signs of life from the laptop and I had to reboot. I have forgot if/where I had report on that issue. If I turned it off first in Gnome Display and then run xrandr to enable external in Primary mode -- it worked fine.
runpm: I will try whenever free time emerges (later today/or monday)
bisection: if only nothing left for poor me. This is the main workhorse machine for me