From: Yuval Mintz <yuvalm@mellanox.com>
Date: Wed, 24 Jan 2018 10:02:09 +0100
Subject: mlxsw: spectrum_router: Don't log an error on missing neighbor
Patch-mainline: v4.15
Git-commit: 1ecdaea02ca6bfacf2ecda500dc1af51e9780c42
References: bsc#1112374

Driver periodically samples all neighbors configured in device
in order to update the kernel regarding their state. When finding
an entry configured in HW that doesn't show in neigh_lookup()
driver logs an error message.
This introduces a race when removing multiple neighbors -
it's possible that a given entry would still be configured in HW
as its removal is still being processed but is already removed
from the kernel's neighbor tables.

Simply remove the error message and gracefully accept such events.

Fixes: c723c735fa6b ("mlxsw: spectrum_router: Periodically update the kernel's neigh table")
Fixes: 60f040ca11b9 ("mlxsw: spectrum_router: Periodically dump active IPv6 neighbours")
Signed-off-by: Yuval Mintz <yuvalm@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 |   10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -1942,11 +1942,8 @@ static void mlxsw_sp_router_neigh_ent_ip
 	dipn = htonl(dip);
 	dev = mlxsw_sp->router->rifs[rif]->dev;
 	n = neigh_lookup(&arp_tbl, &dipn, dev);
-	if (!n) {
-		netdev_err(dev, "Failed to find matching neighbour for IP=%pI4h\n",
-			   &dip);
+	if (!n)
 		return;
-	}
 
 	netdev_dbg(dev, "Updating neighbour with IP=%pI4h\n", &dip);
 	neigh_event_send(n, NULL);
@@ -1973,11 +1970,8 @@ static void mlxsw_sp_router_neigh_ent_ip
 
 	dev = mlxsw_sp->router->rifs[rif]->dev;
 	n = neigh_lookup(&nd_tbl, &dip, dev);
-	if (!n) {
-		netdev_err(dev, "Failed to find matching neighbour for IP=%pI6c\n",
-			   &dip);
+	if (!n)
 		return;
-	}
 
 	netdev_dbg(dev, "Updating neighbour with IP=%pI6c\n", &dip);
 	neigh_event_send(n, NULL);