Re: [PATCH net-next v2 2/2] net: dsa: mv88e6xxx: embedded PTP timestamp support

On Sun, Jul 19, 2026 at 09:35:45PM +1000, Luke Howard wrote:

quoted

We try to keep the data path protocol between the switch and the host
API compatible, and identifiable by /sys/class/net/<conduit>/dsa/tagging.
I would argue that the protocol where PTP timestamps are in registers,
vs where they are in PTP header reserved fields, vs where they are
appended as trailers, are 3 different protocols and should not be
presented as "edsa".

For context: I added ArrTSMode support because even with the PTP
worker process priority bumped, ptp4l frequently missed RX timestamps.

I can add these as non-default tagging variants that can be selected
by the user. "edsa-arrts-trailer" and "edsa-arrts-ptp-reserved”?

I guess that would be fine, except:
- worth clarifying that you're talking about the Reserved2 field (rather
  than Reserved1 or Reserved3)
- any reason justifying the introduction of "edsa-arrts-trailed", or
  would it be just for completeness? As a user, what would make me
  decide between "edsa-arrts-trailer" and "edsa-arrts-ptp-reserved2"?