[RFC/PATCH] remove gratuitous reads from maple pci config space methods
David Gibson
david at gibson.dropbear.id.au
Thu Aug 9 14:18:03 EST 2007
On Wed, Aug 08, 2007 at 11:16:32PM -0500, Nathan Lynch wrote:
> David Gibson wrote:
> > On Wed, Aug 08, 2007 at 07:50:44PM -0500, Nathan Lynch wrote:
> > > The maple pci configuration space write methods read the written
> > > location immediately after the write is performed, presumably in order
> > > to flush the write. However, configuration space writes are not
> > > allowed to be posted, making these reads gratuitous.
> >
> > It might be worth checking that there isn't a particular reason for
> > these. Just because posting writes are forbidden doesn't mean a
> > particular bridge won't screw it up...
>
> Well, I had already checked with Ben, who wrote the code, and my
> understanding is that the reads are intended to work around some
> misbehaving Apple bridges, but that a sync after the write (implied by
> releasing pci_lock in the generic pci code) should suffice for
> those.
Ah, ok then.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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