On Mon, Oct 12, 2020 at 04:48:03PM +0100, Mark Brown wrote: > On Mon, Oct 12, 2020 at 04:55:27PM +0300, Andy Shevchenko wrote: > > > Currently those drivers need to do something like: > > > if (of_property_is_present("dma-names")) > > ret = try DMA mode; > > else > > ret = try PIO mode; > > > but this seems to me a bit stricter than needed. What if DMA mode fails, shall > > we fail the probe of the driver? > > They can also just try registering DMA and fall back to PIO. There is no possibility to do like this right now. > > If ASoC supports optional DMA resources, above can be simplified to something > > like: > > > ret = try DMA mode; > > if (ret != DMA mode ok) > > ret = try PIO mode; > > > which makes OF dependent parts gone along with relying on the properties rather > > than real resource availability. > > I don't understand the blocker to writing that code at the minute? Return code in both cases DMA okay, DMA is not okay is 0. -- With Best Regards, Andy Shevchenko