Sync to V-blank

[Eric Nelson <eric.nelson@boundarydevices.com>]

On Thu Apr 3 03:32:06 PDT 2014, Carlos Rafael Giani wrote:
 >
> This X11 vsync problem has been bugging several people, and to date,
> there is no proper solution (other than to use framebuffer directly
> instead, or switch to Wayland).
>
> Eric Nelson mentioned details about this, as well as a possible
> workaround. I appended his email here:
>
> =================================================

I haven't had much of a chance to look into this, but just found
this in "Freescale_XServer_Video_Driver_Users_Guide.pdf" in the
documents package of the documentation package of the 3.10.17-ga
release:

	https://community.freescale.com/docs/DOC-100787


	1.7 Tearing
	XServer (and early Microsoft Windows) does not support double
	buffering for the screen. There will be a copy from off-screen
	buffer to target on-screen area (or direct rendering to
	on-screen). The operation cannot be completed in the blank time
	of the display, and the IPU cannot provide an ideal VSYNC
	signal.
	Therefore, there will be tearing.

	To remove tearing, a GLES compositor is needed. This tearing
	free feature will be described in next release.

Regards,


Eric