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Message-ID: <1360271169.2650.31.camel@pasglop>
Subject: Re: [PATCH] drivers/block/xsysace - replace
 in(out)_8/in(out)_be16/in(out)_le16 with generic iowrite(read)8/16(be)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>, Michal Simek <monstr@monstr.eu>,
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Date: Fri, 08 Feb 2013 08:06:09 +1100
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On Thu, 2013-02-07 at 19:12 +0400, Alexey Brodkin wrote:
> not sure about items for "ace_datain/out_be16" - what about _rep
> options here?

Well, you have a backward wiring of an LE device so you can't use the
_rep variants, unless you ping pong, so you either use a loop of
ioread/write16 (le) and bite the bullet on extra barriers, or use _rep &
bounce buffer for a separate swap pass.

Point is, the backward wiring will require byteswap on both BE and LE
hosts for data (which is why it's so stupid).

Cheers,
Ben.