From: Vladimir Oltean <vladimir.oltean@xxxxxxx> Since commit 4cf35a2b627a ("net: mscc: ocelot: fix broken IP multicast flooding") from v5.12, unregistered IP multicast flooding is configurable in the ocelot driver for bridged ports. However, by writing 0 to the PGID_MCIPV4 and PGID_MCIPV6 port masks at initialization time, the CPU port module, for which ocelot_port_set_mcast_flood() is not called, will have unknown IP multicast flooding disabled. This makes it impossible for an application such as smcroute to work properly, since all IP multicast traffic received on a standalone port is treated as unregistered (and dropped). Starting with commit 7569459a52c9 ("net: dsa: manage flooding on the CPU ports"), the limitation above has been lifted, because when standalone ports become IFF_PROMISC or IFF_ALLMULTI, ocelot_port_set_mcast_flood() would be called on the CPU port module, so unregistered multicast is flooded to the CPU on an as-needed basis. But between v5.12 and v5.18, IP multicast flooding to the CPU has remained broken, promiscuous or not. Delete the inexplicable premature optimization of clearing PGID_MCIPV4 and PGID_MCIPV6 as part of the init sequence, and allow unregistered IP multicast to be flooded freely to the CPU port module. Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support") Cc: stable@xxxxxxxxxx Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mscc/ocelot.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -2208,9 +2208,13 @@ int ocelot_init(struct ocelot *ocelot) ANA_PGID_PGID, PGID_MC); ocelot_rmw_rix(ocelot, ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), + ANA_PGID_PGID, PGID_MCIPV4); + ocelot_rmw_rix(ocelot, ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), + ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), + ANA_PGID_PGID, PGID_MCIPV6); + ocelot_rmw_rix(ocelot, ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), + ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports)), ANA_PGID_PGID, PGID_BC); - ocelot_write_rix(ocelot, 0, ANA_PGID_PGID, PGID_MCIPV4); - ocelot_write_rix(ocelot, 0, ANA_PGID_PGID, PGID_MCIPV6); /* Allow manual injection via DEVCPU_QS registers, and byte swap these * registers endianness.