[PATCH 0/7] DMAENGINE: fixes and PrimeCells

[jassi brar]

On Mon, May 10, 2010 at 2:26 AM, Dan Williams <dan.j.williams at intel.com> wrote:
> On Sun, May 9, 2010 at 3:06 AM, jassi brar <jassisinghbrar at gmail.com> wrote:
>> This discussion is purely about what the current DMA API misses and what
>> a generic DMA API should do. So, that the current DMA API fills up those
>> gap, if possible. I would love to get started implementing the generic
>> DMA API for reference but my priorities are decided by my employer.
>
> Well, the only significant miss that has been identified so far is
> dynamic channel allocation for the device-to-mem case.  Everything
> else can be done with small tweaks to the existing interface.  But
> some of this discussion reminds me of Section 2.4 of
> Documentaion/SubmittingPatches:
>
> 4) Don't over-design.
>
> Don't try to anticipate nebulous future cases which may or may not
> be useful:  "Make it as simple as you can, and no simpler."
There is a fine line between anticipating future requirements and
over-designing.

We already have Samsung's and STM's SoC sharing a DMAC IP.

Esp with PrimeCells, we are soon likely to see SoCs sharing a
peripheral IP with possibly different DMACs.

Some elements may be ideal-design at the cost of over-design, but not all.
Let us not simply brush aside all concerns as over-designing.