On Thu, Mar 17, 2005 at 12:12:58PM +1100, Benjamin Herrenschmidt wrote:

quoted

I understand you can't have userspace program the accelerator while 
someone else is doing the same thing. Oh and I now understand that the 
same really applies to direct framebuffer access due to the swapper.  

And you can't have someone program the accelerator while somebody does
direct access neither. It's basically all exclusive.

I haven't seen that happen on any hardware I own. Matrox specs explicitly 
mention that there is no need to synchronize accelerator and direct 
framebuffer access.

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/