Re: [RFC/PATCH] remove gratuitous reads from maple pci config space methods

David Gibson wrote:

On Wed, Aug 08, 2007 at 07:50:44PM -0500, Nathan Lynch wrote:

quoted

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.