From: Yotam Gigi <yotamg@mellanox.com>
Date: Wed, 27 Sep 2017 08:23:21 +0200
Subject: mlxsw: spectrum: Notify multicast router on RIF MTU changes
Patch-mainline: v4.15-rc1
Git-commit: fd890fe98f8b026642d39011d03d22fb4aa66b0f
References: bsc#1112374

Due to the fact that multicast routes hold the minimum MTU of all the
egress RIFs and trap packets that don't meet it, notify the mulitcast
router code on RIF MTU changes.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -5769,6 +5769,17 @@ int mlxsw_sp_netdevice_router_port_event
 	if (err)
 		goto err_rif_fdb_op;
 
+	if (rif->mtu != dev->mtu) {
+		struct mlxsw_sp_vr *vr;
+
+		/* The RIF is relevant only to its mr_table instance, as unlike
+		 * unicast routing, in multicast routing a RIF cannot be shared
+		 * between several multicast routing tables.
+		 */
+		vr = &mlxsw_sp->router->vrs[rif->vr_id];
+		mlxsw_sp_mr_rif_mtu_update(vr->mr4_table, rif, dev->mtu);
+	}
+
 	ether_addr_copy(rif->addr, dev->dev_addr);
 	rif->mtu = dev->mtu;