Re: [PATCH v4 1/4] Produce system time from correlated clocksource

Thomas Gleixner
2015-10-14T07:22:39Z

On Tue, 13 Oct 2015, Richard Cochran wrote:
> On Tue, Oct 13, 2015 at 09:15:51PM +0200, Thomas Gleixner wrote:
> > That's not working. The firmware is not going to change, no matter
> > what.
>
> Can we at least have a explanation of how the firmware operates? How
> are (ART,sys) pairs are generated, and how they are supposed to get
> into the DSP?

The firmware gives you an ART/audio timestamp pair. The firmware does
neither know about system time nor about PTP time.

So we have to do correlation in software.

Thanks,

tglx