RE: [PATCH] net: lan743x_ptp: convert to ktime_get_clocktai_ts64

From: Bryan.Whitehead
Date: Wed Aug 15 2018 - 16:41:26 EST


> > > Question: this is the only ptp driver that sets the hardware time to
> > > the current system time in TAI. Why does it do that?
> >
> > This is done when the driver starts up after reset. Otherwise the clock is off
> by 48 years.
> > It seemed to me that the system time was the most appropriate clock to
> sync to.
> > If my reasoning is incorrect, please enlighten me.
>
> I've never worked with PTP, but my understanding from looking at the other
> drivers is that the time normally gets set either from another host through
> the PTP protocol, or using clock_settime() from user space with the current
> time.

Those methods will still work. But if it's not set by those methods, I thought the clock should at least be set once on driver startup to align with the system clock. After that, other methods are free to reset it again.

Bryan