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SubjectRe: [PATCHv3] DMAEngine: Define interleaved transfer request api
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On Tue, 2011-09-20 at 23:38 +0530, Jassi Brar wrote:
> On 20 September 2011 22:22, Vinod Koul <vinod.koul@intel.com> wrote:
> > Also for slave transfers, how do we infer direction?
> I already explained to Barry. Here's it again.
>
> At any time, the dmac driver knows if the channel, on which the xfer is
> prepared/submitted is Slave or not.
>
> SLAVE Transfer
> dmaxfer_template.src_inc && !dmaxfer_template.dst_inc => DMA_TO_DEVICE
> !dmaxfer_template.src_inc && dmaxfer_template.dst_inc => DMA_FROM_DEVICE
>
> Mem->Mem Transfer
> dmaxfer_template.src_inc && !dmaxfer_template.dst_inc => Meaningless
> !dmaxfer_template.src_inc && dmaxfer_template.dst_inc => MemSet
Rather than each driver adding this logic with good chance of screwing
up, care to add this as helper in dmaengine.h

Ideally, I would have preferred direction to be told explicitly, would
leave it you..

--
~Vinod



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