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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 - External screens connected through a daisy-chained Display Port are randomly flickering"
href="https://bugs.freedesktop.org/show_bug.cgi?id=97311">97311</a>
</td>
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<th>Summary</th>
<td>External screens connected through a daisy-chained Display Port are randomly flickering
</td>
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<th>Product</th>
<td>DRI
</td>
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<th>Version</th>
<td>XOrg git
</td>
</tr>
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
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<th>OS</th>
<td>Linux (All)
</td>
</tr>
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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>cristi.magherusan@gmail.com
</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>
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<div>
<pre>At work I recently bought a new primary monitor for my laptop's external
dual-screen setup. After a bit of research it turned out I need to connect it
in a daisy-chain DisplayPort setup, otherwise the resolution of my older second
screen would be limited to 1024x768.
As soon as figured out what I needed to do and I set everything up, all the
monitors started working in their native resolution, but the external screens
started to randomly turn black for like half a second, but not both at the same
time, then again work well for a while until the next half-second blackout.
With the same kernel, the same monitors as well as the previous monitors
configured to use both my video outputs didn't have this flockering issue, nor
did I see it on the other external monitor that I connect at home.
These are my system specs:
OS: Ubuntu Xenial x86_64
Kernel: 4.7.0-040700rc5-lowlatency from
<a href="http://kernel.ubuntu.com/~kernel-ppa/mainline/">http://kernel.ubuntu.com/~kernel-ppa/mainline/</a>, installed before because of a
similar <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - LCD flickering on Thinkpad T440p (Haswell) with kernel 4.6-rc4 (PSR enabled)"
href="show_bug.cgi?id=95176">bug #95176</a>, which used to manifest on my laptop's screen.
lspci output:
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated
Graphics Controller (rev 0b)
00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev
0b)
00:14.0 USB controller: Intel Corporation 8 Series USB xHCI HC (rev 04)
00:16.0 Communication controller: Intel Corporation 8 Series HECI #0 (rev 04)
00:16.3 Serial controller: Intel Corporation 8 Series HECI KT (rev 04)
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I218-LM (rev
04)
00:1b.0 Audio device: Intel Corporation 8 Series HD Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 1 (rev e4)
00:1c.3 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 4 (rev e4)
00:1c.4 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 5 (rev e4)
00:1d.0 USB controller: Intel Corporation 8 Series USB EHCI #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation 8 Series LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 8 Series SATA Controller 1 [AHCI
mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 8 Series SMBus Controller (rev 04)
02:00.0 Network controller: Intel Corporation Wireless 7260 (rev 73)
03:00.0 SD Host controller: O2 Micro, Inc. SD/MMC Card Reader Controller (rev
01)
The dmesg output doesn't show any messages related to the intel driver, so
that's why I didn't attach it, but if this information is not enough I can
produce more logs upon request.</pre>
</div>
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