ethtool: Move n-tuple capability check into set_flags

set_flags should check if the underlying device supports
n-tuple filter programming before setting the device flags
on the netdevice.
Signed-off-by: NPeter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/ethtool.c

@@ -134,15 +134,21 @@ u32 ethtool_op_get_flags(struct net_device *dev)
 
 int ethtool_op_set_flags(struct net_device *dev, u32 data)
 {
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+
 	if (data & ETH_FLAG_LRO)
 		dev->features |= NETIF_F_LRO;
 	else
 		dev->features &= ~NETIF_F_LRO;
 
-	if (data & ETH_FLAG_NTUPLE)
+	if (data & ETH_FLAG_NTUPLE) {
+		if (!ops->set_rx_ntuple)
+			return -EOPNOTSUPP;
 		dev->features |= NETIF_F_NTUPLE;
-	else
+	} else {
+		/* safe to clear regardless */
 		dev->features &= ~NETIF_F_NTUPLE;
+	}
 
 	return 0;
 }
@@ -318,9 +324,6 @@ static int ethtool_set_rx_ntuple(struct net_device *dev, void __user *useraddr)
 	struct ethtool_rx_ntuple_flow_spec_container *fsc = NULL;
 	int ret;
 
-	if (!ops->set_rx_ntuple)
-		return -EOPNOTSUPP;
-
 	if (!(dev->features & NETIF_F_NTUPLE))
 		return -EINVAL;