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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 - regression drm-next-5.2-wip: breaks vsync of new Compton xrender backend"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110417">110417</a>
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<th>Summary</th>
<td>regression drm-next-5.2-wip: breaks vsync of new Compton xrender backend
</td>
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<th>Product</th>
<td>DRI
</td>
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<th>Version</th>
<td>DRI git
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<th>Hardware</th>
<td>x86-64 (AMD64)
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<th>OS</th>
<td>Linux (All)
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>DRM/AMDgpu
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<th>Assignee</th>
<td>dri-devel@lists.freedesktop.org
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<th>Reporter</th>
<td>tempel.julian@gmail.com
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<pre>Created <span class=""><a href="attachment.cgi?id=143962" name="attach_143962" title="xorg log showing the pageflipping issue">attachment 143962</a> <a href="attachment.cgi?id=143962&action=edit" title="xorg log showing the pageflipping issue">[details]</a></span>
xorg log showing the pageflipping issue
Either build Compton from git "next" branch or use latest 6.2 release:
<a href="https://github.com/yshui/compton">https://github.com/yshui/compton</a>
Start Compton with new xrender vsync:
compton --config /dev/null --backend=xrender --vsync --experimental-backends
Result: There is tearing at the very top of the screen, can be easily verified
by playing this juddertest video in fullscreen:
<a href="https://youtu.be/_gBBz7IMz1Y">https://youtu.be/_gBBz7IMz1Y</a>
This is a regression that was introduced in drm-next-5.2-wip.
There is no tearing when:
-using linux-mainline 5.1-rc4 or stable 5.0 kernel
-There is also no tearing when using drm-next-5.2-wip branch, but append
amdgpu.dc=0 to kernel start parameters.
-There's also no tearing when using Compton's GLX backends, which use
MESA_swap_control for vsync.
The attached xorg log testifies that there is a problem with pageflipping, as
it is flooded with
[ 14.785] Failed to get FB for flip
[ 14.785] (WW) AMDGPU(0): Page flip failed: Resource temporarily
unavailable
[ 14.785] (EE) AMDGPU(0): present flip failed
Compton's new xrender backend uses the present extension to implement vsync,
which works well apart from that amdgpu driver regression.
It doesn't make a difference if modesetting or amdgpu DDX is used.
The problem wasn't introduced recently into drm-next-5.2-wip, it probably
existed from the start of that branch or shortly after.
Programs versions used:
Compton 6.2
drm-next-5.2-wip-git ce933436e554f76a41612c257a2e6eb1eb6ac759
xorg-server-git 6975807945d12c07f00e18df7fafeff43efa0267
xf86-video-amdgpu 19.0.1
mesa-git 19.1 109912.9e0c744f07a</pre>
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