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Date: Tue, 28 Nov 2006 21:56:21 +0000
From: Alan <alan@lxorguk.ukuu.org.uk>
To: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: [rfc PATCH] ieee1394: ohci1394: delete bogus spinlock, flush
 MMIO writes
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On Tue, 28 Nov 2006 22:24:11 +0100 (CET)
Stefan Richter <stefanr@s5r6.in-berlin.de> wrote:

> All MMIO writes which were surrounded by the spinlock as well as the
> very last MMIO write of the IRQ handler are now explicitly flushed by
> MMIO reads of the respective register.

MMIO is ordered anyway on the bus, you just need mmiowb() to force
ordering to the bus controller in case you are on a big numa box.