On Thu, Mar 17, 2005 at 10:27:56AM +1100, Benjamin Herrenschmidt wrote:

On Wed, 2005-03-16 at 22:55 +0200, Ville Syrjälä wrote:

quoted

On Wed, Mar 16, 2005 at 10:49:11AM +1100, Benjamin Herrenschmidt wrote:

quoted

In the meantime, can you tell me more about your arbitration scheme ?

There is a lock associated with the graphics card. The lock is always 
taken before programming the hardware. Other things wanting access to the 
hardware wait until the lock is released.

Ok, so it would be easy to have directFB use an external arbiter without
breaking existing clients ? It will need at least to use the vga arbiter
that I'm about to finish, that should allow at least to have X on one
card and directFB on another without conflict.

Is the vga arbiter required for something else besides access to some 
legacy ports? DirectFB only uses legacy ports to wait for vsync if a 
better method is not available.

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