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Re: About MIPS specific dma_mmap_coherent()

To: Ralf Baechle <ralf@linux-mips.org>
Subject: Re: About MIPS specific dma_mmap_coherent()
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 12 May 2010 10:41:28 +0200
Cc: wuzhangjin@gmail.com, linux-mips <linux-mips@linux-mips.org>
In-reply-to: <20100511184844.GA7978@linux-mips.org>
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At Tue, 11 May 2010 19:48:44 +0100,
Ralf Baechle wrote:
> 
> On Wed, Apr 14, 2010 at 05:46:13PM +0200, Takashi Iwai wrote:
> 
> > But, I remember vaguely that calling pgprot_noncached()
> > unconditionally is dangerous.  It should be checked somehow, e.g. via
> > platform_device_is_coherent().  And, this found only in
> > dma-coherence.h, and adding it to pcm_native.c would become messy like
> > below...
> > 
> > So, it'd be really better to add dma_mmap_coherent(), indeed.
> 
> We agreed that this was only meant as a stop gap meassure.  As such I do
> agree with either of
> 
>   http://patchwork.linux-mips.org/patch/1117/
>   http://patchwork.linux-mips.org/patch/1118/
> 
> Wu has tested the 1117 patch so that might make it preferable especially
> for 2.6.34 if we should go for that.

OK, I merged the patch now as Wu confirmed it's working.
Will be included in the next pull request.


thanks,

Takashi

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