Re: [PATCH V4 2/3] dmaengine: tegra-adma: Add support for Tegra210 ADMA

Vinod Koul
2016-04-19T15:13:05Z

On Tue, Apr 19, 2016 at 03:54:27PM +0100, Jon Hunter wrote:
> >>>>> I can understand that you wish to consolidate the APIs for requesting a
> >>>>> channel, but it seems to me that you still need to have an API that DMA
> >>>>> controller drivers can call where they can pass their dma_device
> >>>>> structure to ensure you get a channel for the appropriate DMA controller.
> >>>
> >>> Yes but the idea was that xlate will help you to get the right channel. The
> >>> whole dmaengine property was supposed to help you with that
> >>
> >> Well it depends on the DMA controller. In the case of tegra the xlate
> >> helps you extract the slave request ID for a given device. However,
> >> because any channel can be used with any slave request ID, we don't care
> >> about the exact channel. So we request any available channel for the DMA
> >> controller in question and program it with the slave request we got from
> >> the xlate.
> >
> > Right. the cleanup was supposed to reduce the number of interfaces
> > that a slave driver can call and consolidate them as much as possible
> > into dma_request_chan(), but we still need dma_get_any_slave_channel()
> > as an interface for the dmaengine masters as you said.
>
> OK, great.
>
> Vinod, are you ok with this then? Any other items to fix-up?

Okay from me.

--
~Vinod