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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 - [i915] External monitors lose connection after suspend, or don't return from sleep"
href="https://bugs.freedesktop.org/show_bug.cgi?id=94103">94103</a>
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<th>Summary</th>
<td>[i915] External monitors lose connection after suspend, or don't return from sleep
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
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<th>OS</th>
<td>Linux (All)
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
</td>
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<th>Component</th>
<td>DRM/Intel
</td>
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<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
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<th>Reporter</th>
<td>dy@drexel.edu
</td>
</tr>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=121690" name="attach_121690" title="short">attachment 121690</a> <a href="attachment.cgi?id=121690&action=edit" title="short">[details]</a></span>
short
This is on a Dell XPS 9333 (Haswell) with a mini-displayport to dual HDMI hub.
Linux version 4.5.0-040500rc3-generic (kernel@gomeisa) (gcc version 5.2.1
20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201602071930 SMP Mon Feb 8 00:34:43 UTC
2016
Distro: Ubuntu 15.10
x86_64
Also affects mainline Ubuntu kernel 4.2.0-27-generic.
When entering display standby (either by timeout or xset dpms force off) , one
of three things happens:
1) After 30s, the monitors come back on by themselves, one monitor goes to
low-resolution or is disabled.
or, 2) Monitor configuration stays the same, but on resume, the two externals
fail to resume from standby state. Note that xrandr reports the same
configuration as before, and the mouse can be moved to the (still blank)
monitors.
or, 3) Resume from standby within 10 seconds and the issue doesn't occur.
The workaround is to unplug/replug the mini-DP. Sometimes this results in hang
or X restarting.
Additionally, one of the monitors occasionally (~30 minutes) blanks for a
half-second, and comes back.
This issue occurs regardless of one or two monitors on the hub, or two entirely
different monitors. It didn't occur with a non-MST, single miniDP to HDMI.
I have tested the hub with another XPS 9333 running windows, and the issue
doesn't occur.
Attached logs: short - for case (3) above
longresume-blanked - for case (2) above
what was left of the system log - freeze
all with drm.debug=14 switch
I'll test with drm-intel-nightly again in a few.</pre>
</div>
</p>
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