Comment 158 for bug 1275794

(In reply to comment #124)
> (In reply to comment #122)
> > I also get a mirrored output on VGA, however I could not extend to that
> > adapter. (it seems to be a hardware mirror, I only see one external display,
> > DP2, in XrandR...)
>
> Same here. Switching to one external DP display now works like a charm. Gets
> identified as DP2 in xrandr.
>
> Connecting a second DP display result in a mirrored output. Both external
> displays are identified as DP2.
>
> There seems to be still a problem enumerating the devices connected to the
> DP hub

Same on a Thinkpad W540 with Ultra Dock. Ubuntu 13.10 3.14.0-031400rc1-generic