Bug 111400

Summary:	Prime offloading to iGPU leads to highly stretched window content
Product:	Mesa	Reporter:	tempel.julian
Component:	Drivers/Gallium/Iris	Assignee:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Status:	RESOLVED MOVED	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	normal
Priority:	medium
Version:	git
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	glxgears default window size with garbled content glxgears window content not garbled anymore by maximizing it

Description tempel.julian 2019-08-14 14:10:53 UTC

When I run "MESA_LOADER_DRIVER_OVERRIDE=iris DRI_PRIME=1 glxgears", the window content is highly stretched and thus looks garbled. This doesn't happen with some window sizes or aspect ratios though, and neither happens in maximized window or fullscreen mode.
The display has typical 16:9 AR and 1440p resolution, it's connected to a RX 570 card using amdgpu driver (and xf86-video-amdgpu).

Tested with latest xorg-git and mesa-aco-git with commit32cd9487f45372e0677603218a586ea99296d1d3. Happens with both xf86-video-intel and modesetting.

Comment 1 tempel.julian 2019-08-14 14:22:22 UTC

Forgot to mention: This is with Skylake IGP of an i7 6700k.

Comment 2 Denis 2019-08-14 14:34:31 UTC

hi, to me your command looks a bit weird, because iris is only for intel GPU's, or maybe I don't know something.

Here is output from my PC when I am running same command:


[den@den-pc Documents]$ MESA_LOADER_DRIVER_OVERRIDE=iris DRI_PRIME=1 glxgears
i965_dri.so does not support the 0xffffffff PCI ID.
libGL error: failed to create dri screen
libGL error: failed to load driver: iris
i965_dri.so does not support the 0xffffffff PCI ID.
libGL error: failed to create dri screen
libGL error: failed to load driver: iris
2197 frames in 5.0 seconds = 439.353 FPS
2432 frames in 5.0 seconds = 486.370 FPS

Also, if everything is valid, screenshots would be helpful I think.

Comment 3 tempel.julian 2019-08-14 15:05:20 UTC

You either need to adjust your xorg config to set up GPUs for prime offloading or you have to use xorg-server git-master which recently received a feature to do this automatically.

Of course the iris driver is only for Intel GPUs, but unlike i965, it supports offloading also from the dGPU to the iGPU, and not just from the iGPU to the dGPU. A good reason for doing this e.g. would be saving power in some circumstances where maximum performance is not required.

I'm attaching two images of glxgears in default window size (garbled) and maximized (correct).

Comment 4 tempel.julian 2019-08-14 15:06:24 UTC

Created attachment 145060 [details]
glxgears default window size with garbled content

Comment 5 tempel.julian 2019-08-14 15:07:15 UTC

Created attachment 145061 [details]
glxgears window content not garbled anymore by maximizing it

Comment 6 GitLab Migration User 2019-09-25 18:47:27 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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