Re: [PATCH RFC V1 net-next 3/4] net: Let the active time stamping layer be selectable.

From: Richard Cochran
Date: Fri Jan 21 2022 - 10:31:17 EST


On Fri, Jan 21, 2022 at 12:05:22PM +0100, Kurt Kanzenbach wrote:
> On Thu Jan 20 2022, Vladimir Oltean wrote:
> > Hi Richard,
> >
> > On Mon, Jan 03, 2022 at 03:25:54PM -0800, Richard Cochran wrote:
> >> Make the sysfs knob writable, and add checks in the ioctl and time
> >> stamping paths to respect the currently selected time stamping layer.
> >>
> >> Signed-off-by: Richard Cochran <richardcochran@xxxxxxxxx>
> >> ---
> >
> > Could we think of a more flexible solution? Your proposal would not
> > allow a packet to have multiple hwtstamps, and maybe that would be
> > interesting for some use cases (hardware testing, mostly).
>
> One use case i can think of for having multiple hwtimestamps per packet
> is crosstimestamping. Some devices such as hellcreek have multiple PHCs
> and allow generation of such crosstimestamps.

That may well be nice to have, but that is not in scope for this series.

Thanks,
Richard