RE: [PATCH net-next RFC 0/9] net: dsa: PTP timestamping for mv88e6xxx

Oops, I had "slaveOnly" set in my PC's configuration.  So layer2 seems
to work as expected.

Have you tested UDPv4?  It doesn't work.

I have not. Our usage has been focused on 802.1AS; the ptp4l settings we
use are the following:

transportSpecific    0x1
ptp_dst_mac          01:80:C2:00:00:0E
p2p_dst_mac          01:80:C2:00:00:0E
network_transport    L2
delay_mechanism      P2P
time_stamping        hardware

One thing that we're not doing (and probably should be) is configuring
multicast frames to 01:1B:19:00:00:00 to be destined to the CPU port.
(01:80:C2:00:00:0E is used for management, so the *_mgmt_rsvd2cpu()
functions give us that "for free".) That might be necessary to make 1588
L2 work properly. I don't know if that would affect 1588 L4, or if
there's anything else missing to make L4 timestamping work from the HW
perspective.

-- brandon