Re: radeon-pre-2

Keith Whitwell
2004-09-11T08:42:21Z

Dave Airlie wrote:
>>2D and 3D _are_ to most intents and purposes different functions. They
>>are as different as IDE CD and IDE disk if not more so.
>
>
> stop saying this, it isn't true and hasn't been for years, for the mach64
> type cards I'd agree, for something even like the i810 this isn't
> true, most cards have two paths (at least), an unaccelerated 2D path via
> programmed registers, and an accelerated path via some DMA mechanism, this
> isn't a 2d/3d split, you have to use the DMA mechanism for doing some 2d
> acceleration and you have to use it for all 3d acceleration normally,
>
> Lots of X DDX drivers use the accelerator for 2d stuff, some fbs use it
> for accelerating scrolling, the DRM uses it, this is wrong wrong wrong
> wrong...X/DRM at least lock each other out, but the fb just tramps in
> wearing its size nines.. so in summary the 2D/3D split exists in peoples
> minds (graphics cards designers excepted...)

Yes, it is closest to the truth to believe there is one acceleration engine
that does all drawing, and this should ideally have a single owner.

But that doesn't mean that mode-setting, etc, has to be moved into the DRM -
for my money that stuff can stay where it is, provided there are some sensible
interfaces put in place between the two components.

Keith