Dear Maintainer,

I have laptop HP 650 with hybrid GPU Intel(R) HD Graphics 4600/Radeon HD 8730M.
When I use docking station, DVI(Display Ports) are not detected. Theese ports
are connected directly to radeon card. Ports connected to Intel card works
well.

I tried to test it in Ubuntu 14.04 beta live CD and it worked fine. When I
noticed they use 2.990 intel driver version I tried it to compile it by hand
from sources and try it, and it seems that newer driver works fine. Couldn't
you consider upgrade xserver-xorg-video-intel package at least in debian
experimental?
Please note that attached logs use newer combiled driver and no docking
station.

Thanks,

Jozef Hovan

Hi,

I am sorry for inaccurate information. Updated intel driver don't detect
DVI docking ports. It seems, ubuntu has patches in their driver. I am
going to try old version of ubuntu with driver 2:2.20.9-0ubuntu2.3. Do
you have any suggestion what other to try? Could it be intel or radeon
driver?

I am attaching xorg log booted ondocking station with debian testing
intel driver (2.21). There are detected laptop screen (eDP), VGA1 screen
and DVI dock port screen (DisplayPort-1-1) , but in xrandr is
Display-Port is hidden.

Jozef Hovan

You'll need to figure out exactly what ubuntu is doing differently,
either in the kernel or userspace drivers...

Cheers,
Julien

Hi,

It looks like I'm also experiencing same issue with Lenovo t440p machine
and Lenovo Ultra Dock.

This seems to be upsteam bug, one of:
https://bugs.freedesktop.org/show_bug.cgi?id=82153
https://bugs.freedesktop.org/show_bug.cgi?id=84718
https://bugs.freedesktop.org/show_bug.cgi?id=80355

Ok, I've created new bugreport for my case:

https://bugs.freedesktop.org/show_bug.cgi?id=86004

So it was mentioned that our xserver-xorg-video-intel package in unstable
is just too old to support DP MST.

Fortunately new version is available in experimental and it works for me!:

xserver-xorg-video-intel        2:2.99.916-1~exp1

It's a bit interesting. If I boot and load X11 while laptop is undocked,
xrandr will show only internal laptop connectors. Other ports will be
populated once laptop is docked. And they will stay forever

Not checked with multiple external displays. But internal laptop screen
plus one external monitor are working as expected.

So I'm considering this as fixed for me by using package from
experimental. But it'll be cool to have MST support in jessie. As far as I
understand it's pretty common now...