mlxsw: spectrum: Don't emit errors when PFC is disabled

We can't have PAUSE frames and PFC both enabled on the same port, but
the fact that ieee_setpfc() was called doesn't necessarily mean PFC is
enabled.

Only emit errors when PAUSE frames and PFC are enabled simultaneously.

Fixes: d81a6bdb ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c

@@ -351,7 +351,8 @@ static int mlxsw_sp_dcbnl_ieee_setpfc(struct net_device *dev,
 	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
 	int err;
 
-	if (mlxsw_sp_port->link.tx_pause || mlxsw_sp_port->link.rx_pause) {
+	if ((mlxsw_sp_port->link.tx_pause || mlxsw_sp_port->link.rx_pause) &&
+	    pfc->pfc_en) {
 		netdev_err(dev, "PAUSE frames already enabled on port\n");
 		return -EINVAL;
 	}