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<base href="https://bugs.freedesktop.org/" />
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<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [HSW DP MST] External monitors connected via Lenovo Ultra Dock turn off when logging into X"
href="https://bugs.freedesktop.org/show_bug.cgi?id=82153">82153</a>
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Summary</th>
<td>[HSW DP MST] External monitors connected via Lenovo Ultra Dock turn off when logging into X
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr>
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<th>OS</th>
<td>Linux (All)
</td>
</tr>
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<th>Reporter</th>
<td>thilo@ginkel.com
</td>
</tr>
<tr>
<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Version</th>
<td>XOrg CVS
</td>
</tr>
<tr>
<th>Component</th>
<td>DRM/Intel
</td>
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<th>Product</th>
<td>DRI
</td>
</tr></table>
<p>
<div>
<pre>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.</pre>
</div>
</p>
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