On Mon, 2012-09-17 at 09:36 +0100, Russell King - ARM Linux wrote: > > > I'm not saying take the slave_id out of the map. I'm saying, let the > > > DMA engine driver itself figure out what dma_chan to return. > > But wont that assume the dma controller knows which channel to allocate. > > And how would it know this information? This can be problematic for hard > > wired muxes, but can be easily done for controller which have > > programmable mux. > > Well, as I have already said, at the moment you're returning the _first_ > _free_ _channel_ on a DMA device, which almost certainly will always be > the wrong one. Yes I overlooked, the continue is wrong. It needs to move to next available channel. I have fixed it.
Now on the question if we should allow dmaengine to select channel or let dma engine driver do that, I don't see how that helps for hard wired muxes where dma engine driver doesn't know anything of mapping. For your OMAP dma this wont matter as I think you have a programmable mux so you maybe able to use any channel with rightly programmed mux, right? -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
