Messages in this thread | | | Subject | Re: [PATCHv4] DMAEngine: Define interleaved transfer request api | From | Vinod Koul <> | Date | Mon, 10 Oct 2011 21:32:39 +0530 |
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On Mon, 2011-10-10 at 16:46 +0530, Jassi Brar wrote: > On 10 October 2011 16:15, Vinod Koul <vinod.koul@intel.com> wrote: > > > > But I am fine if we find a common ground and merge the two where dmac > > can cleanly identify direction and mode it is operating. > > > The client would set the xfer_direction and dmac would interpret as > > enum xfer_direction { > MEM_TO_MEM, -> Async/Memcpy mode > MEM_TO_DEV, -> Slave mode & From Memory to Device > DEV_TO_MEM, -> Slave mode & From Device to Memory > DEV_TO_DEV, -> Slave mode & From Device to Device > } > > How could it get any cleaner? Consider the case of a dmac driver which supports interleaved dma as well as memcpy and slave It needs to interpret dma_data_direction for later cases and xfer_direction for former ones. Not a clean way to convey same info. And only reason why we cannot use dma_data_direction here is because we don't know the "mode", by splitting we overcome that.
-- ~Vinod
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