Re: Linux 2.6.39-rc3

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

On Don, 2011-04-14 at 23:09 +0200, Joerg Roedel wrote: 
> On Thu, Apr 14, 2011 at 10:28:43AM -0400, Alex Deucher wrote:
> > On Thu, Apr 14, 2011 at 4:56 AM, Joerg Roedel <joro@8bytes.org> wrote:
> > > And this makes a difference, with this change on-top of -rc3 the box boots
> > > fine. So there seems to be some dependency between the GART base and the GTT
> > > base even when they are in different address spaces.
> > >
> > > Alex, can you comment on this?
> > 
> > As Dave said, they are completely different addresses spaces.  You
> > could put the GPU aperture at 0 if you wanted (in fact we do on some
> > chips).  Perhaps there's some strange interaction with the nb gart
> > since the nb gart on that chipset was designed to be used for graphics
> > and the rs780/880 can be configured to use an agp aperture.
> > Unfortunately, I'm not that familiar with the nb gart.
> 
> Actually, the nb gart is part of the cpu. It is part of the cpu north
> bridge and can translate io and cpu accesses. In fact, it is a remapper
> of physical memory addresses.
> 
> The problem seems to be related to specific gpu chips. On another
> notebook with an hd3000 card gtt and the nb gart aperture are both on
> 0xa0000000 too but the box works fine.

Wasn't the working theory that the problem occurs if those two values
aren't the same?


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer