Re: [PATCH 1/5] net: fec: properly support external PTP PHY for hardware time stamping

From: Richard Cochran
Date: Wed Jul 08 2020 - 06:55:11 EST


On Mon, Jul 06, 2020 at 09:33:30PM +0300, Sergey Organov wrote:
> Vladimir Oltean <olteanv@xxxxxxxxx> writes:
>
> > On Mon, Jul 06, 2020 at 06:21:59PM +0300, Sergey Organov wrote:
> > Both are finicky in their own ways. There is no real way for the user to
> > select which PHC they want to use. The assumption is that you'd always
> > want to use the outermost one, and that things in the kernel side always
> > collaborate towards that end.

+1

In addition, for PHY time stamping you must enable the costly
CONFIG_NETWORK_PHY_TIMESTAMPING option at compile time, and so the
user most definitely wants the "outer" function.

> Makes sense, -- thanks for clarification! Indeed, if somebody connected
> that external thingy, chances are high it was made for a purpose.

Yes, exactly.

Thanks,
Richard