FB model basic issues (WAS: radeon, apertures & memory mapping)

[Ville Syrjälä]

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:
> > On Wed, Mar 16, 2005 at 10:49:11AM +1100, Benjamin Herrenschmidt wrote:
> > > 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 at sci.fi
http://www.sci.fi/~syrjala/