From: Sergei Shtylyov
Sent: Sunday, March 22, 2009 4:43 PM
>
> Hello.
>
> Subbrathnam, Swaminathan wrote:
>
> > CPPI4.1 is an evolution over CPPI3.0.
>
>    I would call the 3.0-to-4.1 changes rather revolutionary, than
> evolutionary...
>
> > As I see it the following features evolved compared to 3.0
> >
> > 1. List management functions are handled by the DMA engine in 4.1 compared 
> > to 3.0
> were the SW (driver) managed the same.
> >
>
>    True, descriptor queues are handled by the queue manager now.
>
> > 2. New performance modes (Generic RNDIS) got introduced.
> >
>
>    Those new modes don't have anything to do with CPPI 4.1 itself --
> they're part of USB XFER DMA. I think TI could well have kept using CPPI
> 3.0 and just added the new modes...
>
> > Beyond that the general processing of the DMA descriptors and functionality 
> > are
> very similar between CPPI3.0 and 4.1.
> >
>
>    There's nothing similar in the descriptor formats, there was no DMA
> controller, and neither queue nor buffer managers in CPPI 3.0.

DMA scheduler should be a configure once and leave. You should not need to use 
buffer manager as well. I am not sure if it is even supported on DA830.

Thanks,
Sekhar
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