Re: [PATCHv4] DMAEngine: Define interleaved transfer request api

From: Vinod Koul
Date: Tue Oct 11 2011 - 12:53:32 EST


On Tue, 2011-10-11 at 21:27 +0530, Jassi Brar wrote:
> On 11 October 2011 17:26, Vinod Koul <vinod.koul@xxxxxxxxx> wrote:
> >> >> >
> >> >> > But I am fine if we find a common ground and merge the two where dmac
> >> >> > can cleanly identify direction and mode it is operating.
> >> >> >
> >> >> The client would set the xfer_direction and dmac would interpret as
> >> >>
> >> >> enum xfer_direction {
> >> >> MEM_TO_MEM, -> Async/Memcpy mode
> >> >> MEM_TO_DEV, -> Slave mode & From Memory to Device
> >> >> DEV_TO_MEM, -> Slave mode & From Device to Memory
> >> >> DEV_TO_DEV, -> Slave mode & From Device to Device
> >> >> }
> >> >>
> >> >> How could it get any cleaner?
> >> > Consider the case of a dmac driver which supports interleaved dma as
> >> > well as memcpy and slave
> >> > It needs to interpret dma_data_direction for later cases and
> >> > xfer_direction for former ones.
> >> dma_data_direction is the mapping attribute of a buffer and is not meant to
> >> tell type of source and destination of a transfer.
> >> xfer_direction is meant for that purpose.
> >> So I'd rather convert device_prep_dma_cyclic and device_prep_slave_sg
> >> to use xfer_direction.
> >
> > If the conversion id done for all drivers, then it should be fine...
> >
> I already said that many days ago. Though I am not sure what blocks
> this patch if that conversion is done separately (which would touch many
> subsystems).
For this patchset, you need to remove frm_irq in template

--
~Vinod

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