[alsa-devel] [PATCH 3/5] ALSA: pcm - fix page conversion on non-coherent MIPS arch
ralf at linux-mips.org
Fri Nov 27 09:46:35 CET 2009
On Thu, Nov 26, 2009 at 04:13:06PM +0100, Takashi Iwai wrote:
> The non-coherent MIPS arch doesn't give the correct address by a simple
> virt_to_page() for pages allocated via dma_alloc_coherent().
> Original patch by Wu Zhangjin <wuzj at lemote.com>. A proper check of the
> buffer allocation type was added to avoid the wrong conversion.
The origins of this patch go back far further. The oldest patch I could
find which is a superset of this was written by Atsushi Nemoto and
various incarnations of it have been sumitted to and reject by me
a number of times through the years.
> Note that this doesn't fix perfectly: the pages should be marked with
> proper pgprot value. This will be done in a future implementation like
> the conversion to dma_mmap_coherent().
> Signed-off-by: Takashi Iwai <tiwai at suse.de>
So while this is ugly I don't think this patch will actually make the
the situation worse for any MIPS platform. So with both eyes closed:
Acked-by: Ralf Baechle <ralf at linux-mips.org>
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