On Thu, 2011-09-08 at 22:11 +0200, Arnd Bergmann wrote:
> On Thursday 08 September 2011 20:48:26 Linus Walleij wrote:
> > 2011/9/8 Arnd Bergmann <arnd@arndb.de>:
> > > On Thursday 08 September 2011, Barry Song wrote:
> > >>
> > >> this filter is used by all drivers with DMA since every dma channel is
> > >> fixed to be assigned to one device.
> > >
> > > Ok, I see now. I think it would be best to introduce a generic
> > > 'filter by device tree property' function or alternatively an
> > > dma_of_request_channel function like this:
> > 
> > You'd have to discuss that with Vinod, the thing is that x86 Atom
> > systems are using dmaengine for device slave transfers too, and
> > IIRC these things don't use devicetrees. I may be wrong...
> 
> Some of them use device tree, some don't.
> 
> I'm not saying that we have to convert all drivers to use this, but
> for platforms that always have device tree available, it seems by far
> the cleanest solution.
It maybe a clean solution but if it doesn't fit all needs, then it am
not sure...

One way as I said earlier to get the information of dmac-client
relationships from arch specific way (pci, device tree etc) and
dmacs/clients/platform presents them in arch-independent way to
dmaengine...

Thoughts?

--
~Vinod

-- 
~Vinod Koul
Intel Corp.