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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [i915][SNB] black screen in X when resuming from suspend or hibernate"
href="https://bugs.freedesktop.org/show_bug.cgi?id=98516">98516</a>
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<th>Summary</th>
<td>[i915][SNB] black screen in X when resuming from suspend or hibernate
</td>
</tr>
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<th>Product</th>
<td>DRI
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
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<th>OS</th>
<td>Linux (All)
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>major
</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>
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<th>Reporter</th>
<td>freedesktop@equaeghe.nospammail.net
</td>
</tr>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
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<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
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<pre>Created <span class=""><a href="attachment.cgi?id=127639" name="attach_127639" title="dmesg output after issue occurred">attachment 127639</a> <a href="attachment.cgi?id=127639&action=edit" title="dmesg output after issue occurred">[details]</a></span>
dmesg output after issue occurred
# System Information
Linux <hostname> 4.8.5-gentoo #1 SMP <datetime> 2016 x86_64 Intel(R) Core(TM)
i7-2620M CPU @ 2.70GHz GenuineIntel GNU/Linux
Manufacturer: LENOVO
Product Name: 4290W4H
Version: ThinkPad X220
Internal connector: LVDS
Connection to external displays: often DP (via docking station), sometimes VGA
(directly)
# Problem description
Often, but not always (about half of the time, say), when resuming from suspend
(to RAM) or hibernate (to disk), I get a black screen instead of the lock
screen (X 1.18.4, SDDM 0.13.0, KWin 5.7.5). The mouse cursor is visible and can
be moved and often I get a brief flash of the lock screen (or desktop?) before
the screen turns black. Such brief flashes also sometimes occur when switching
to a VT. VTs do work.
My impression is that it happens more often after I've disconnected from the DP
display, if not upon the first sleep thereafter, then a subsequent one (without
intermediate reboot).
I used to be able to reliably resume in the past, but since I upgraded from
KDE4 to KDE5, many i915-related issues appeared. I'd read that this was known.
After a number of updates both to KDE and the kernel version, many issues went
away. This issue is the only remaining major one.
# Some information gathered
When switching to the console, a kernel message sometimes appears:
kernel: [drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* failed to
enable link training
kernel: [drm:intel_dp_start_link_train [i915]] *ERROR* failed to start channel
equalization
I started following the guide at
<a href="https://01.org/linuxgraphics/documentation/how-report-bugs">https://01.org/linuxgraphics/documentation/how-report-bugs</a>, so enabled the
drm.debug=0x1e log_buf_len=1M options. I attach a resulting dmesg output; my
impression is that due to the options, my dmesg is ‘filled’ with stuff that may
not be relevant.
Also important to note is that since I activated the kernel options, I've had a
different type of issue, which I think essentially locked my computer. The X
screen had also turned black and drm-related messages appeared on a VT console
I could change to (only one change was possible, I think, before thinks locked
up even further).
# Request
I realize that I haven't followed all instructions at
<a href="https://01.org/linuxgraphics/documentation/how-report-bugs">https://01.org/linuxgraphics/documentation/how-report-bugs</a>, but I hope the
information I provided is enough to get feedback on how to diagnose further.</pre>
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