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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 - SKL: Display underruns"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92003">92003</a>
</td>
</tr>
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<th>Summary</th>
<td>SKL: Display underruns
</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>Other
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
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<th>Component</th>
<td>DRM/Intel
</td>
</tr>
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<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dan@reactivated.net
</td>
</tr>
<tr>
<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>Every now and then, the display momentarily blinks to black, and the following
message appears in the log:
[drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun
Reproduced on Linux 4.2 and 4.3-rc1, on a new Skylake laptop with quad-core i5
6200U. The laptop seems rather beefy so I have trouble believing this is a
general RAM bandwidth issue.
This is using just the internal laptop display, 1920x1080. Sometimes the
problem happens a lot, and sometimes it takes a while. However, I find that I
can't complete a grand prix in SuperTuxKart (about 20 mins gameplay) without
this happening at least once (usually more times).
I can't reproduce on intel-drm-nightly, however SuperTuxKart gameplay is not as
smooth there, every few minutes the display hangs for approximately 1 second,
with no messages in the log.
00:02.0 VGA compatible controller: Intel Corporation Device 1916 (rev 07)
(prog-if 00 [VGA controller])
Subsystem: ASUSTeK Computer Inc. Device 1c3d
Flags: bus master, fast devsel, latency 0, IRQ 123
Memory at de000000 (64-bit, non-prefetchable) [size=16M]
Memory at c0000000 (64-bit, prefetchable) [size=256M]
I/O ports at f000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: [40] Vendor Specific Information: Len=0c <?>
Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [100] #1b
Capabilities: [200] Address Translation Service (ATS)
Capabilities: [300] #13
Kernel driver in use: i915</pre>
</div>
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