On 27 Dec 2006, at 02:14, Chris Stones wrote:

I am strugling to find documentation, but from reading linux/fb.h  
it seems the only way to do this is with the FBIOGET_VBLANK  
ioctl.... however, for unknown reasons, this is always returning -1  
( ERROR ! )

That means that the framebuffer module used doesn't support that  
ioctl. It's not implemented for all framebuffer modules. The matrox  
framebuffer has it, and I have posted a patch in the past for the  
radeon framebuffer.

Which framebuffer module are you using?

-- 
Torgeir Veimo
torgeir@pobox.com