On Tue, Oct 08, 2013 at 09:00:24PM +0530, Vinod Koul wrote:
On Tue, Oct 08, 2013 at 06:13:56PM +0200, Lars-Peter Clausen wrote:
And second question for Takakshi or Mark. I see that this value ends up in usermode, what is the intented usage of this?
I think it is supposed to help to calculate the audio delay, but I don't think it is actually that widely used at the moment. And yes, in order to make this more accurate we should probably add support for incorporating also the fifo size of the DMA channel.
But then why dont add to delay field, why report to usermode
It's only really useful if the buffer is large enough to start causing an issue with A/V sync and similar - it's there to help account for delays introduced after things have gone from DMA. Most hardware has relatively small buffers so it's not a big deal. I don't know why the two are expressed differently, though the fact that one is in units of time and the other is in units of data suggests it's just about making it easier to express.