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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 --- - [GM45] LCD waterfall effect on HP 2230s laptop"
href="https://bugs.freedesktop.org/show_bug.cgi?id=72289">72289</a>
</td>
</tr>
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<th>Assignee</th>
<td>chris@chris-wilson.co.uk
</td>
</tr>
<tr>
<th>Summary</th>
<td>[GM45] LCD waterfall effect on HP 2230s laptop
</td>
</tr>
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<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<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>jza@saunalahti.fi
</td>
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Version</th>
<td>7.7 (2011)
</td>
</tr>
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<th>Component</th>
<td>Driver/intel
</td>
</tr>
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<th>Product</th>
<td>xorg
</td>
</tr></table>
<p>
<div>
<pre>System environment:
-- chipset: GM45
-- system architecture: x86_64
-- xserver-xorg-video-intel: 2:2.99.904-0ubuntu2
-- xserver-xorg: 1:7.7+1ubuntu6
-- kernel: 3.11.0-12-generic
-- Linux distribution: Xubuntu 13.10
-- Machine or mobo model: Hewlett-Packard 2230s (FU312EA#AK8), BIOS: 68PHU Ver.
F20
-- Display connector: LVDS
Reproducing steps: Reproducable always by using the X.org desktop normally.
Additional info:
The display of the laptop has a waterfall interference effect when used with
the Linux Intel GPU driver. The effect is more pronounced the lower the display
brightness is set. On maximum brightness, the effect cannot be perceived.
The screen is completely calm on all brightness levels when the Windows driver
is used. Notice though that the bad effect is also present in BIOS menus and
when an operating system with a generic display driver is used. Maybe the
driver or LCD panel has to be configured in certain way to make the effect
disappear.
I captured a short video showing the effect:
<a href="http://users.metropolia.fi/~joonasms/waterfall.3gp">http://users.metropolia.fi/~joonasms/waterfall.3gp</a>
In the included dmesg with drm.debug=0x06 I have booted the machine with
maximum brightness, then adjusted it all the way down, and then back all the
way up.</pre>
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