[PATCH 23/28] mpc82xx: Define CPU_FTR_NEED_COHERENT

[Scott Wood]

On Tue, Sep 18, 2007 at 09:34:31AM -0500, Rune Torgersen wrote:
> > -----Original Message-----
> > From: Scott Wood
> > Sent: Monday, September 17, 2007 11:58 AM
> > 
> > The 8272 (and presumably other PCI PQ2 chips) appear to have the
> > same issue as the 83xx regarding PCI streaming DMA.
> > 
> 
> Can you explain what this isssue is? We're using a 8280 and have had
> some PCI busmaster DMA problems, and wonder if it is related.

I'm not sure of the details, just that I get corrupted PCI DMA if I don't
set it.

BTW, if the problems you're seeing include lockups when using PCI DMA,
check out the end of the PCI initialization in
arch/powerpc/boot/cuboot-pq2.c; it requires certain non-default arbiter
settings.

-Scott