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<base href="https://bugs.freedesktop.org/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Fedora 23 kernels lock up with Lenovo ThinkPad T440s in monitor connected Ultradock"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91476">91476</a>
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<th>Summary</th>
<td>Fedora 23 kernels lock up with Lenovo ThinkPad T440s in monitor connected Ultradock
</td>
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<th>Product</th>
<td>DRI
</td>
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<th>Version</th>
<td>XOrg git
</td>
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<th>Hardware</th>
<td>Other
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>DRM/Intel
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<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
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<th>Reporter</th>
<td>tcallawa@redhat.com
</td>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
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<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
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<p>
<div>
<pre>I'm using a Lenovo ThinkPad T440s with the latest BIOS installed (and the
latest firmware applied to the UltraDock). When I put the laptop in the
Ultradock with a monitor connected (DVI), the kernel starts to boot, but
freezes hard very early in the process. No errors are shown, even with
drm.debug=6. If I boot without the laptop in the dock, it boots up fine. If I
put the booted laptop in the dock, the system freezes and the laptop panel goes
dark. If I then undock the laptop, it resumes normal operation.
If I disconnect the external monitor from the UltraDock, then boot with the
laptop docked, it works properly.
I had this issue back in Fedora 20, until I updated the firmware on the
UltraDock. This all was working fine from then. through Fedora 21 and 22, but
stopped working with Fedora 23 (in fact, if I boot into the rescue kernel from
22, it works again). Kernels where I see this failure are:
kernel-4.2.0-0.rc2.git1.1.fc23.x86_64
kernel-4.2.0-0.rc3.git2.1.fc23.x86_64
kernel-4.2.0-0.rc3.git4.1.fc23.x86_64
Let me know what I can do to help debug this issue, it's really annoying.
Internal GPU:
0:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated
Graphics Controller (rev 0b)
External monitor is an Acer AL2223W.</pre>
</div>
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