On Mon, Jun 06, 2016 at 11:10:38PM -0700, Eric Anholt wrote: > >> >> - if (ret == DMA_COMPLETE || !txstate) > >> >> + if (ret == DMA_COMPLETE) > >> > > >> > Why do you change this? txstate can be NULL, so no point calculating reside > >> > for those cases > >> > >> The point was to go into the "Calculate where we're at in our current > >> DMA (if the current DMA is the one we're asking about status for)" path, > >> so that we could note when the DMA is complete even when there's no > >> txstate passed in. > > > > Can you explain what you mean by current DMA! > > > > The claulation is always done for 'descriptor' represnted by the cookie. So > > it doesnt not matter...! > > By current I mean the current descriptor that has been submitted to the > hardware, in bcm2835_chan->desc. As I said, you calculate for the descriptor respresnted by cookie and not the one getting processed! -- ~Vinod