On Mon, Oct 07, 2013 at 10:39:34AM +0900, Chanho Park wrote: > > > Why didn't you use a cookie value to track the request? > > > The cookie is assigned when each transfer is submitted. > > > If you save the value in the desc, we can find the request easily. > > > > If there are several cyclic desc in the work list, is there a better way > > to find the "current" one? The chan struct tracks the last completed and > > last submitted cookies, but these will be the first and last > > respectively as long as the cyclic transfer is active. Is there an > > "active" cookie stored somewhere that I missed? > > Assume there are three cookies. If you want to get the second cookie not > latest cookie, your way can be also correct in such case? > I think tx_status API is to get dma status of the given cookie. > You are only considering a cyclic case. For cyclic case you would have possible same descriptor running till you terminate.
For non cyclic, if you have 3 descriptors submitted, the cookie value can be, say 7, 8 and 9. If you query the status of any descriptor and pass the last optional txstate arg then you will know the last cookie completed. so if txstate->last is 7, then 7th was completed and 8 should be running and 9 in queue! > > Looking for the first buffer with status == BUSY is an improvement I'll > > make. Any way to avoid looking through the list? Its already there :) -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
