[Nouveau] [Bug 36416] New: External monitor connected to docking station gets no signal, although recognized

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=36416

           Summary: External monitor connected to docking station gets no
                    signal, although recognized
           Product: xorg
           Version: git
          Platform: x86-64 (AMD64)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Driver/nouveau
        AssignedTo: nouveau at lists.freedesktop.org
        ReportedBy: alex at diewald.cc
         QAContact: xorg-team at lists.x.org


Created an attachment (id=45851)
 --> (https://bugs.freedesktop.org/attachment.cgi?id=45851)
System Information (emerge --info)

Hello,

I'm running a gentoo amd64 installation on my Dell Precision M6300. It resides
in a docking station, so I don't have to connect 10 cables, when returning to
my desk. My external Monitor (HP LP2475w) is connected via the DVI-D connector
at the docking station.
"xrandr -q" lists the monitor. But if I enable it the monitor stays blank,
showing a "no signal" message and goes to sleep. Unplugging and replugging
doesn't improve it. The monitor is also listed in the Monitor section of the
system settings on my gnome 3 desktop, but it's the same game like with the
xrandr command line tool.
BUT, if I take my Laptop out of docking station and connect the monitor to the
DVI-D connector of the Laptop I immediately get a signal.