Re: Improved DRM support for cant_use_aperture platforms

["Michel Dänzer" <michel@daenzer.net>]

On Mit, 2003-05-14 at 11:41, Ivan Kokshaysky wrote:
> On Tue, May 13, 2003 at 09:20:09AM -0700, David Mosberger wrote:
> 
> > What's the nature of those "ugly and fragile" hacks?  Are you saying
> > that CPU accesses to AGP space aren't remapped in the "normal" (PC)
> > way?  Or is it something entirely different?
> 
> Ok, you asked for it... :-)
> As you know, Alpha architecture is entirely cache coherent
> by design, i.e. there are no such things as non-cacheable mappings
> or cache flushing in hardware. Native Alpha Titan/Marvel AGP controllers
> are also cache coherent (kind of AGP extension of traditional
> Alpha PCI IOMMU).
> However, the "normal" PC AGP implementation isn't - this applies
> to AMD-751/761 AGP controllers on Nautilus as well.
> The AGP window on these chipsets is accessible by CPU *only* in the
> system memory address space, i.e. it's always cacheable and thus
> totally useless on Alpha.

Set cant_use_aperture and use David's patch then? :)


-- 
Earthling Michel Dänzer   \  Debian (powerpc), XFree86 and DRI developer
Software libre enthusiast  \     http://svcs.affero.net/rm.php?r=daenzer