Re: Memory-mapped I/O barriers, state of affairs?

[Andreas Bombe]

On Mon, Mar 22, 2010 at 08:18:49PM +0100, Leon Woestenberg wrote:
> What is the current solution for that particular problem, i.e. how
> should I make sure host memory writes are committed before I have an
> external DMA device act on it?

The dma_sync_* functions, if you reuse DMA buffers without unmapping,
take care of that.  Otherwise the process of mapping them handles it.

Documentation/DMA-API.txt and Documentation/PCI/PCI-DMA-mapping.txt
document those functions.
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