device drm with PCIe?

Jung-uk Kim jkim at
Fri Dec 16 10:59:08 PST 2005

On Friday 16 December 2005 01:27 pm, Eric Anholt wrote:
> On Fri, 2005-12-16 at 12:30 -0500, Jung-uk Kim wrote:
> > On Thursday 15 December 2005 07:36 am, O. Hartmann wrote:
> > > Normally 'device drm' is only useable in conjunction with
> > > 'device agp'. A lot of amd64 based boxes now use PEG slots for
> > > their graphics accelerators. Is it possible to utilize 'drm'
> > > with PCIe devices?
> >
> > Yes.  It should work, at least in theory. ;-)
> >
> > > Does device agp has any effect on PCIe graphics accelerators?
> >
> > No.  You don't need it for PCI-Express controller.
> Now, this is stuff I don't 100% understand, but what I've figured
> out so far is that for graphics, you're going to need a GART
> somewhere.  For their PCIE cards, ATI deals with this by doing
> essentially the old PCIGART method but tweaked, in lieu of AGP. 
> Intel's PCIE graphics, on the other hand, has a GART on their chips
> that is basically the same thing as their previous AGP GARTs, at
> least in terms of programming.  So we expose their gart through the
> agp device still, even though the chipset may be PCIE.

Ah, Eric is correct about the Intel part.  But it was amd64 thread, so 
I just assumed... :-(

Jung-uk Kim

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