[meta-freescale] imx6q gpu performance lower than expected

[Dmitriy B.]

2015-03-23 17:10 GMT+03:00 Nikita Yushchenko <nyushchenko at dev.rtsoft.ru>:

> Following up myself.
>
> We have tested master + qt 5.3.2 and master + qt 5.4.1 combinations, with
> LVDS 1280x800 screen and eglfs backend.
>
> Overall results are:
>   dizzy, qt 5.3.2, imx6s => 22 fps  [this is poor hw, included just for
> reference]
>   dizzy, qt 5.3.2, imx6q => 37 fps
>   master, qt 5.3.2, imx6q => 49 fps
>   master, qt 5.4.1, imx6q => 59 fps
>
> Thus "memory bandwidth" is *not* the limiting factor on original setup.


You can't assume that without finding the culprit (read below). Memory
usage might have been optimized, knowing Vivante, they can leave various
bugs for years.


> Pure software update resulted into significant fps improvement.


Don't forget that when you change bracnhes, you also checkout meta-qt5
master branch, which might have latest things from qt5 developers, like
GLES3 support or bugfixes pulled from original qt5 repos.

Many thanks to Heikki Sarkanen for information that master branch shows
> better graphics performance.


Any info about at what exact point it did happen and what was the problem?
Relying on master is not a good way to go, master/master-next can be
broken, so you can't use that in your production all the time.

dizzy uses imx_3.10.17_1.0.0_ga as it seems
https://github.com/Freescale/meta-fsl-arm/blob/dizzy/recipes-kernel/linux/linux-imx_3.10.17.bb#L14
Vivante commits are there
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/drivers/mxc/gpu-viv?h=imx_3.10.17_1.0.0_ga
While master uses imx_3.10.53_1.1.0_ga
https://github.com/Freescale/meta-fsl-arm/blob/master/recipes-kernel/linux/linux-imx_3.10.53.bb#L13
Vivante at
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/log/drivers/mxc/gpu-viv?h=imx_3.10.53_1.1.0_ga

Best Regards,
Dmitriy Beykun
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