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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [RFC/PATCH] remove gratuitous reads from maple pci config space
	methods
Date: Thu, 9 Aug 2007 12:40:52 +0200
To: Nathan Lynch <ntl@pobox.com>
Cc: linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>,
	David Gibson <david@gibson.dropbear.id.au>
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>> 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,

None of the PCI interfaces on the U3 or U4 bridges have that
problem as far as I know.  I think the workaround was copied
from code for older Apple bridges?

> but that a sync after the write (implied by
> releasing pci_lock in the generic pci code) should suffice for those.

I don't see how a sync could help here at all, not more than
an eieio anyway?


Segher