On Monday 26 August 2013 19:40:57 Vinod Koul wrote: > Why does DT need the fliter function in the first place. The DT enabled drivers > should not even have a filter function... > > The dmaengine core calls the optional filter function. This needs to be > implemented in driver in order for driver to check if the channel is what it > needs or not. You only just merged the dma_get_slave_channel() patch, which allows having no filter function. Up to Linux-3.11, the filter was always needed but could be 'static' and only called by the xlate function. Now the xlate function can pick a channel itself. > And the selection should be done for the cases where you dont have programmable > mux in dmac. For programmable ones passing slave_id in dma_slave_config should > be fine. I think passing a slave_id from the slave driver is never correct with DT, since the ID is a property of the system rather than the slave device, so the driver has no access to it. Drivers have to always take the settings from DT and ignore what dma_slave_config() sets later. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
