From: Arnd Bergmann <arnd@arndb.de>
To: tom.leiming@gmail.com
Subject: Re: [PATCH 0/3] dma-mapping:remove CONFIG_HAVE_DMA_ATTRS
Date: Sun, 5 Jul 2009 13:19:36 +0200
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On Saturday 04 July 2009, tom.leiming@gmail.com wrote:
> 2,Disabling CONFIG_HAVE_DMA_ATTRS may lead to a compile failure;

I'm not sure I understand this point. CONFIG_HAVE_DMA_ATTRS tells
the common code whether the architecture understands dma attributes.
If you enable it on all architectures, you will get new compile
failures on all those that don't understand them, while the current
code correctly falls back on the standard functions.

I think it makes sense to combine CONFIG_HAVE_DMA_ATTRS with the
use of dma-mapping-common.h, but the majority of the architectures
just uses a static mapping, where attributes make no sense.

You also missed powerpc64, which selects CONFIG_HAVE_DMA_ATTRS
but does not (yet) use dma-mapping-common.h.

	Arnd <><
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