Re: [PATCH net-next 0/3] Document more PTP timestamping known quirks

Vladimir Oltean [off-list ref] writes:

I've tried to collect and summarize the conclusions of these discussions:
https://patchwork.ozlabs.org/project/netdev/patch/20200711120842.2631-1-sorganov@gmail.com/
https://patchwork.ozlabs.org/project/netdev/patch/20200710113611.3398-5-kurt@linutronix.de/
which were a bit surprising to me. Make sure they are present in the
documentation.

As one of participants of these discussions, I'm afraid I incline to
alternative approach to solving the issues current design has than the one
you advocate in these patch series.

I believe its upper-level that should enforce common policies like
handling hw time stamping at outermost capable device, not random MAC
driver out there.

I'd argue that it's then upper-level that should check PHY features, and
then do not bother MAC with ioctl() requests that MAC should not handle
in given configuration. This way, the checks for phy_has_hwtstamp()
won't be spread over multiple MAC drivers and will happily sit in the
upper-level ioctl() handler.

In other words, I mean that it's approach taken in ethtool that I tend
to consider being the right one.

Thanks,
-- Sergey