On Tue, Aug 19, 2014 at 03:44:23PM +0100, Russell King - ARM Linux wrote: > On Tue, Aug 19, 2014 at 07:15:07PM +0530, Vinod Koul wrote: > > On Thu, Aug 14, 2014 at 09:57:53AM +0100, Russell King - ARM Linux wrote: > > > It's got something to do with the async engine API, and seems to be > > > something to do with whether a descriptor can have other transactions > > > added to it, and whether a descriptor can be re-used (async-tx engines > > > typically allocate a fixed set of descriptors and recycle them.) > > Yes this is my understanding too. Async API IIUC can reuse descriptors and > > if engine doesnt support this is a way to tell them please do use that. > > > > For slave dmanegine API we need to ignore it. > > We shouldn't ignore it - ignoring it makes it harder to implement a DMA > engine driver which supports both the slave and async APIs, because > we then need to know the reason for the channel being requested. Do you have such usage coming up near future :) > > Ignoring it until it can be understood and documented is an approach I > would agree with though. Certainly, I am asking Dan to add more clarity on these bits to help improve. -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
