[Bug 82153] New: [HSW DP MST] External monitors connected via Lenovo Ultra Dock turn off when logging into X

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=82153

          Priority: medium
            Bug ID: 82153
                CC: intel-gfx-bugs at lists.freedesktop.org
          Assignee: intel-gfx-bugs at lists.freedesktop.org
           Summary: [HSW DP MST] External monitors connected via Lenovo
                    Ultra Dock turn off when logging into X
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
          Severity: normal
    Classification: Unclassified
                OS: Linux (All)
          Reporter: thilo at ginkel.com
          Hardware: x86-64 (AMD64)
            Status: NEW
           Version: XOrg CVS
         Component: DRM/Intel
           Product: DRI

My Lenovo ThinkPad T440p is docked to a Lenovo ThinkPad Ultra Dock (40A20135EU,
firmware 2.17) with two external monitors attached via DVI / DisplayPort. The
current (as of 2014-08-04) DP MST patches are in place, but when initially
logging into my KDE session both external monitors turn off and only start
producing an image after briefly unplugging the dock's power adapter.

The dmesg output shows an error (but I do not know whether it is related):
"[drm:intel_uncore_check_errors] *ERROR* Unclaimed register before interrupt /
Unclaimed register detected before reading register 0x44018" (for details,
refer to attached dmesg output).

System environment:
-- chipset: QM87
-- system architecture: x86_64
-- xf86-video-intel/xserver/mesa/libdrm version:
   - xf86-video-intel: 2.99.914
   - xserver: 1.15.1
   - mesa: 10.1.3
   - libdrm: 2.4.52
-- kernel version: 3.16.0-rc6-tg+ (built from drm-next-nightly @ 2014-08-04)
-- Linux distribution: Kubuntu 14.04
-- Machine or mobo model: Lenovo ThinkPad T440p 20AN
-- Display connector: DVI, DisplayPort
3) Reproduce steps.

Boot system while docked. Log in to X session. External monitors attached to
dock will turn off.

Attachments will follow shortly (except for a VBIOS dump, which aborts with the
following error in dmesg: "i915 0000:00:02.0: Invalid ROM contents").

Please let me know if you need any further details or if I can help testing any
experimental patches.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20140804/9cd24c14/attachment.html>