From: Arnd Bergmann <arnd@arndb.de>
To: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org, Vinod Koul <vinod.koul@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Gregory Clement <gregory.clement@free-electrons.com>,
        Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
        Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
        Lior Amsalem <alior@marvell.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Thomas Petazzoni <thomas@free-electrons.com>,
        linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
        dmaengine@vger.kernel.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 2/8] dmaengine: mv_xor: add support for a38x command in descriptor mode
Date: Wed, 13 May 2015 10:46:45 +0200
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On Wednesday 13 May 2015 10:15:35 Maxime Ripard wrote:
> > Alternatively, you could leave the XOR_DESCRIPTOR_SWAP flag disabled
> > and just swap the descriptors manually like a lot of other drivers
> > do. You have to swap the mmio accesses anywya.
> 
> That won't be easily doable however.
> 
> Not only the endianness of the individual fields in the descriptor
> changes, but changing the endianness also swaps the fields themselves
> by pair of u32.
> 
> You can see that here:
> http://lxr.free-electrons.com/source/drivers/dma/mv_xor.h#L159
> 
> So I'm guessing that leaving it like it is was the more readable
> solution.

I see, yes that would get a bit ugly.

	Arnd
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