Cubieboard, Qt 5 on Framebuffer and VSync

My personal goals with Qt 5 and Cubieboard have always been to try to get the most bang for my buck.

On cubieboard A20/cubietruck, using r3p2-01rel02 Mali libraries and some tweaking in the fex script it's actually possible to make use of all the power in the GPU and see the FPS go up.

On framebuffer though, going on 80+ FPS and above, it becomes noticeable that some animations display a sort of tearing effect: the vertical refresh rate of the screens is unable to keep up with the actual frame rate and the end result isn't that clean.

Following up on that same issue,which was posted on the cubieforums thread a while back, I managed to find the time to test one solution that popped up - a disabled function inside the framebuffer files in the sunxi kernel.

Enabling the function and re-compiling the kernel did the trick and I think it actually solved the issue.

While waiting to hear back from the user who reported the issue, I posted a couple of videos on youtube hoping to be able to demonstrate the issue (the sun orb going around), and the apparent solution:

Cubieboard A20 - Qt 5.3.0 - FB without vsync

Cubieboard A20 - Qt 5.3.0 - FB with vsync