Re: [PATCH 0/6] dmaengine: Add common dma_slave_config and split it into src and dst parts

[Vinod Koul <vkoul@kernel.org>]

On 09-03-26, 10:27, Frank Li wrote:
> On Mon, Mar 09, 2026 at 12:24:33PM +0100, Vinod Koul wrote:
> > On 14-01-26, 12:12, Frank Li wrote:
> > > Many DMA engine drivers store a dma_slave_config per channel. Propagate
> > > this configuration into struct dma_chan to avoid duplicating the same
> > > code in each driver.
> > >
> > > Much of dma_slave_config is identical for source and destination. Split
> > > the configuration into src and dst groups and use a union to preserve
> > > backward compatibility. This reduces the need for drivers to repeatedly
> > > check the DMA transfer direction.
> >
> > The reason why we had both the src/dstn sides was intended method to
> > allow upport ofr device to device dma. Some interest was shown for that
> > at that time.
> > I dont think we have such a user even now...
> 
> My means is the field name is identical, not value identical although most
> case is the identical. but it is possible, especial FIFO space windows,
> 
> sound/soc/fsl/fsl_asrc_dma.c use DEV_TO_DEV, at least src and addr use
> differece address.

Yeah so this would break if we go ahead. Thanks for looking this up

-- 
~Vinod