Bug#651227: Compositing unuseable with Radeon r300

[David Smith <sidicas2@gmail.com>]

> I retried with 4:4.8.4-3 but got similar bad results than a year ago:
>> glxgears
> Running synchronized to the vertical refresh.  The framerate should be
> approximately the same as the monitor refresh rate.
> 62 frames in 5.0 seconds = 12.369 FPS
> 64 frames in 5.0 seconds = 12.778 FPS
> ...
>
> from glxinfo:
> OpenGL vendor string: X.Org R300 Project
> OpenGL renderer string: Gallium 0.4 on ATI RS690
> OpenGL version string: 2.1 Mesa 8.0.4
> OpenGL shading language version string: 1.20

>From glxinfo, is direct rendering enabled?
Do you have a /etc/X11/xorg.conf file? If so, can you try moving it
out of the way or renaming it?

My RV410 hardware is older than the RS690 and I'm getting a solid
60FPS synched to the refresh rate of the display.