On Wed, May 07, 2014 at 03:37:45PM -0700, Christopher Freeman wrote: > On Wed, May 07, 2014 at 09:37:25AM -0700, Stephen Warren wrote: > > On 05/06/2014 03:22 PM, Christopher Freeman wrote: > > > Get word-level granularity from hardware for calculating > > > the transfer count remaining. > > > > > diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c > > > > > +static int tegra_dma_wcount_in_bytes(struct dma_chan *dc) > > > > A lot of the code in this function is identical to the code in > > tegra_dma_terminate_all() which does the same thing. Can this be pulled > > out into a shared utility function? > > > I'll look at making utility functions for ISR handling and the calculations for the byte counts. > > > > + tegra_dma_pause(tdc, true); > > > > Is this continual pausing/resuming of the DMA operation going to > > negatively affect performance? > > > I tried testing the performance impact and each call took about 20 uS. And of > course, the client would have to be calling this constantly. But why do we need to pause, cant we read the status form HW and report..? -- ~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
