Problem: Wait for VSync on pipe A and Wake up on pipe B

Nicolas Cadio nicolas.cadio at
Thu Aug 20 02:41:28 PDT 2009


I have an application which must to synchronize with the vertical synchronisation of my display. 
To do this synchronization, I use a function of GLX (glXWaitVideoSyncSGI).

This function call the function DRM to wait the vertical synchronization (drmWaitVBlank) and the driver (drm.ko) does a wait on the pipe A of my Xserver.

But my output  (LVDS) of my Xserver is connected to the pipe B and so the driver (drm.ko) does a wake up on the pipe B.

So my applicaton is not synchronized with my display.

I would like to know how to configure my application for it uses the pipe B when it does a wait for the vertical synchronization.
Where I can configure my application for it uses the pipe B for the VSync ?
Is it in the xorg.conf or elsewhere?

Thanks, Nicolas

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