[Linaro-mm-sig] [RFC] ARM DMA mapping TODO, v1

Arnd Bergmann arnd at arndb.de
Fri Apr 29 07:21:16 EDT 2011


On Friday 29 April 2011, Benjamin Herrenschmidt wrote:
> 
> > However, dma_alloc_coherent() memory can't be used with the dma_sync_*
> > API as its return address (unlike other architectures) is not in the
> > kernel direct mapped memory range.
> 
> Well, on non-coherent architectures, dma_sync_* are cache flushes, I
> don't see the point of doing those on a non-cachable mapping anyways.
> 
The point was that you cannot do

#define dma_alloc_coherent dma_alloc_noncoherent

on ARM, as some other architectures do.

	Arnd



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