Re: [PATCHv3] DMAEngine: Define interleaved transfer request api

[Vinod Koul]

On Tue, 2011-09-20 at 23:38 +0530, Jassi Brar wrote:
> On 20 September 2011 22:22, Vinod Koul <vinod.koul@xxxxxxxxx> 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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