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Subject: Re: MMIO and gcc re-ordering (Was: [PATCH] [POWERPC]
	Improve	(in|out)_beXX() asm code)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Date: Fri, 23 May 2008 18:47:32 -0400
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Cc: linux-kernel@vger.kernel.org, David Miller <davem@davemloft.net>,
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On Fri, 2008-05-23 at 16:14 -0500, Scott Wood wrote:

> As Trent pointed out, if you change to eieio in the accessors, that'd 
> require drivers to also use mmiowb() before spin_unlock(), which fewer 
> drivers currently do.

No, this is a totally different issue. And we keep track of the need
for a sync in spin_unlock already.

Ben.