Apple M9179LL/A 30" Widescreen LCD with rv280

[Alex Deucher]

On Sun, 27 Feb 2005 23:59:09 -0500 (EST), Vladimir Dergachev
<volodya at mindspring.com> wrote:
> >
> >> Also note you will get trouble with 3d, since the radeon driver can
> >> only handle 2048x2048 resolution.
> >
> > Wow, this I didn't know; it should be noted on the wiki. I absolutely
> > need to run 3d. You mean the radeon dri driver won't support
> > widescreen modes?. How will this appear though?. Will I get black
> > borders or will it not display at all?. Does the radeon framebuffer
> > device have such a problem too?. I wonder how the bios would
> > initialize this card when I power up the computer.
> >
> 
> It appears as only the square 0-2047x0-2047 can be rendered into, if a
> window moves out of it the part that is outside will not get any
> rendering.
> 
> AFAIK, Mesa CVS has just received a patch to enable tiling support which
> cures this problem, so you might want to try newer drivers.

actually not so.  the rendering engine only has 11 bit coordinates. 
whether the framebuffer is tiled or not is irrelevant.  actually,
tiling further adds to the 2048 limit since the max width of a tiled
surface is 2048.  The real fix could be to iterate over the buffer in
chunks of 2048 or to adjust the offset of the 3d engine for every 3d
window.  for tiled surfaces you'd have to either only use tiling for
full screen 3d within 2048x2048 or use more than one tiled surface.

Alex

> 
>                    best
> 
>                       Vladimir Dergachev