On Wed, Jan 30, 2013 at 03:36:48PM -0600, Steve Wise wrote:
> I wonder, then, what the correct service is to get the cpu physical
> address from a kernel virtual address returned from
> dma_alloc_coherent()?  I think this is correct as-is, since I think
> dma_alloc_coherent() falls under the "directly mapped" addresses in
> the virt_to_phys() prototype comment.
> 

Here is another relevant comment I should have included.

commit ae6a5d37725853325a2b3460165fbc5613ce2916
Author: Russell King <[email protected]>
Date:   Tue Nov 20 12:17:51 2012 +0000

    ASoC: kirkwood-dma: fix use of virt_to_phys()

    This is part of a patch found in Rabeeh Khoury's git tree for the
    cubox.

    You can not use virt_to_phys() on the address returned from
    dma_alloc_coherent(); it may not be part of the kernel direct-mapped
    memory.  Fix this to use the DMA address instead.

    Signed-off-by: Russell King <[email protected]>
    Signed-off-by: Mark Brown <[email protected]>

I don't know the details though, and I certainly don't know how
someone would fix this.  ;)

regards,
dan carpenter
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