Messages in this thread |  | | | Subject | Re: [PATCH/RFC] dmaengine: add a slave parameter to __dma_request_channel() | | From | Vinod Koul <> | | Date | Thu, 08 Mar 2012 16:25:28 +0530 |
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On Thu, 2012-03-08 at 11:16 +0100, Guennadi Liakhovetski wrote: > I still have the impression, that my specific use-case (sh-mobile), where > channels can be freely configured for use by _ANY_ client on one of > _SEVERAL_ DMAC instances, is not fully understood or taken into account. > For this driver any kind of fixed mapping means, that we'd have to use > both virtual channels and controllers, adding _a lot_ of complexity to the > DMAC driver and making the dmaengine core just an "obfuscation layer." > Yes, I remember Russell proposing core helpers for this. They would help, > but (1) when would they be available, (2) how well would they be suitable > for us, (3) they'd take the coding / maintainance burden away, but > wouldn't reduce complexity and run-time overhead. Lets try to address you case as well. On a typical platform 1) how many dma controllers you have? 2) how many clients you have 3) which client can use what controller channel? How is mapping decided, do you have a mux, is it hard wired by soc designers,....? Can you pls give a description so that we ensure all models fit in the final solution?
-- ~Vinod
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