Re: [PATCH 2/8] dmaengine: mv_xor: add support for a38x command in descriptor mode

[Arnd Bergmann]

On Tuesday 12 May 2015 17:54:31 Thomas Petazzoni wrote:
> Dear Arnd Bergmann,
> 
> On Tue, 12 May 2015 17:49:08 +0200, Arnd Bergmann wrote:
> 
> > Using 
> > 
> >       if (IS_ENABLED(__BIG_ENDIAN))
> > 
> > here would make it more readable by avoiding the #if. 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.
> 
> Agreed on IS_ENABLED(). However, I don't understand the comment about
> the need to swap mmio accesses? We're using readl_relaxed() /
> writel_relaxed(), and they do the swapping already. Am I missing
> something?
> 

Sorry for being unclear. This was exactly my point: readl_relaxed()
has to do swaps internally, and you can also do swaps when accessing
the descriptor in memory.

	Arnd
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