On Tue, Jan 19, 2021 at 03:06:38PM +0100, Alban Bedel wrote:
> Multicast entries in the MAC table use the high bits of the MAC
> address to encode the ports that should get the packets. But this port
> mask does not work for the CPU port, to receive these packets on the
> CPU port the MAC_CPU_COPY flag must be set.
>
> Because of this IPv6 was effectively not working because neighbor
> solicitations were never received. This was not apparent before commit
> 9403c158 (net: mscc: ocelot: support IPv4, IPv6 and plain Ethernet mdb
> entries) as the IPv6 entries were broken so all incoming IPv6
> multicast was then treated as unknown and flooded on all ports.
>
> To fix this problem rework the ocelot_mact_learn() to set the
> MAC_CPU_COPY flag when a multicast entry that target the CPU port is
> added. For this we have to read back the ports endcoded in the pseudo
> MAC address by the caller. It is not a very nice design but that avoid
> changing the callers and should make backporting easier.
>
> Signed-off-by: Alban Bedel <alban.be...@aerq.com>
> Fixes: 9403c158b872 ("net: mscc: ocelot: support IPv4, IPv6 and plain
> Ethernet mdb entries")
>
> ---
Reviewed-by: Vladimir Oltean <vladimir.olt...@nxp.com>
Tested-by: Vladimir Oltean <vladimir.olt...@nxp.com>
Thanks!
