On 02/24/2015 04:28 PM, Russell King - ARM Linux wrote: > On Tue, Feb 24, 2015 at 04:21:22PM +0200, Peter Ujfalusi wrote: >> Do not direct map the virtual channels to sDMA request number. When the >> sDMA is behind of a crossbar this direct mapping can cause situations when >> certain channel can not be requested since the crossbar request number >> will no longer match with the sDMA request line. >> The direct mapping for virtual channels with HW request lines will make it >> harder to implement MEM_TO_MEM mode for the driver. > > I assume when you talk about MEM_TO_MEM, you're referring to a DMA_MEMCPY > driver. > > mem2mem should not be handled by the slave driver. This should be a > separate DMA engine driver structure which does not have DMA_SLAVE set. > > See how amba-pl08x handles this. Thanks for the pointer. I'm just planning to add the DMA_MEMCPY support for omap-dma. With that in place we can convert the remaining legacy API users to use dmaengine (as I recall all of them are using DMA for memcopy) -- Péter -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
