Re: net: dsa: mv88e6xxx: no multicasts rx'd after enabling hw time stamping

From: Andrew Lunn <andrew@lunn.ch>
To: George McCollister <george.mccollister@gmail.com>
Cc: netdev <netdev@vger.kernel.org>,
	Richard Cochran <richardcochran@gmail.com>
Subject: Re: net: dsa: mv88e6xxx: no multicasts rx'd after enabling hw time stamping
Date: Wed, 28 Jul 2021 23:04:59 +0200	[thread overview]
Message-ID: <YQHGe6Rv9T4+E3AG@lunn.ch> (raw)
In-Reply-To: <CAFSKS=Pv4qjfikHcvyycneAkQWTXQkKS_0oEVQ3JyE5UL6H=MQ@mail.gmail.com>

On Wed, Jul 28, 2021 at 03:44:24PM -0500, George McCollister wrote:
> If I do the following on one of my mv88e6390 switch ports I stop
> receiving multicast frames.
> hwstamp_ctl -i lan0 -t 1 -r 12
> 
> Has anyone seen anything like this or have any ideas what might be
> going on? Does anyone have PTP working on the mv88e6390?
> 
> I tried this but it doesn't help:
> ip maddr add 01:xx:xx:xx:xx:xx dev lan0
> 
> I've tried sending 01:1B:19:00:00:00, 01:80:C2:00:00:0E as well as
> other random ll multicast addresses. Nothing gets through once
> hardware timestamping is switched on. The switch counters indicate
> they're making it into the outward facing switch port but are not
> being sent out the CPU facing switch port. I ran into this while
> trying to get ptp4l to work.

Hi George

All my testing was i think on 6352.

I assume you get multicast before using hwstamp_ctl?

Maybe use:

https://github.com/lunn/mv88e6xxx_dump

and dump the ATU before and afterwards.

The 6390 family introduced a new way to configured which reserved
management addresses get forwarded to the CPU. Maybe take a look at
mv88e6390_g1_mgmt_rsvd2cpu() and see if you can spot anything odd
going on.

You might also want to check if mv88e6352_port_set_mcast_flood() is
being called.

      Andrew