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Subject: Re: What is the reel purpose of in_beXX() and out_beXX() fonctions ?
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: David Laight <David.Laight@ACULAB.COM>
Date: Tue, 28 Oct 2014 08:11:26 +1100
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On Mon, 2014-10-27 at 15:05 +0000, David Laight wrote:
> 
> Unfortunately the functions sometimes contain additional (often
> unneeded) 
> sequencing instructions - the driver may be able to perform multiple 
> operations between the sequencing instructions.

That's in part why some folks are working on proper relaxed accessors
(see Will Deacon's stuff)

Cheers,
Ben.