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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. Frank > > > -- > ~Vinod