Xorg 7.0-rc1 and EXA (radeon 9200)

[Michel Dänzer]

On Wed, 2005-10-26 at 16:00 +0200, Stephane Marchesin wrote:
> 
> Well, you see, about half of the issues with X are due to lack o
> arbitration. Think for example the radeon ddx using half the video ram
> for pixmaps, or the vt switch issues...
> 
> So using arbitration is actually the way to go, and drm is probably the
> right place to do that when it's available.
> 
> Now, for your surface, I suggest you just do tiled pixel acess, the
> tiling functions are in the radeon_span* files in the radeon dri driver.

It's not that simple because it's not the driver itself that touches the
framebuffer, so this approach would mean that fb would have to deal with
all kinds of tiling, endianness, ... Doesn't seem feasible.

> > I think the solution is to add something to the DRM for the server to
> > "reserve" some surfaces...
> >
> This is definitely not future-proof, just like when the ddx allocates
> half of the video memory for pixmaps even when it doesn't need them.

I'm afraid you're overreacting a little here. I agree with Ben that a
way for the X server to reserve a couple of physical surface registers
(as opposed to virtual surfaces, which can be merged by the DRM) would
be a good solution for this problem.


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer