Re: [RFC] arm: DMA-API contiguous cacheable memory

From: Russell King - ARM Linux
Date: Tue May 19 2015 - 18:09:56 EST


On Wed, May 20, 2015 at 12:05:54AM +0200, Lorenzo Nava wrote:
> Maybe my interpretation of dma_alloc_coherent() is not correct, and
> the coherency can be managed using the dma_sync_single_for_* functions
> and it doesn't require hardware mechanism.

dma_sync_single_for_* are only for use with the streaming DMA API,
where you must have already mapped the buffer using one of the
dma_map_* functions. Anything other than that is abusing the API.

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