[PATCH net-next] net: dsa: Do not configure VLAN ID 0

[Florian Fainelli]

Because we skip the prepare phase, we would not get a chance to have the
port_vlan_prepare() callback return -EOPNOTSUPP and tell us about that.
This causes problems with mv88e6xxx which specifically checks for VLAN
ID = 0. Turns out we do not actually need to program that VLAN ID since
it should be the default one for switches anyway.

Reported-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
 net/dsa/slave.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 1808a2cd6872..ec54d579645a 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -996,6 +996,9 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 	struct bridge_vlan_info info;
 	int ret;
 
+	if (vid == 0)
+		return 0;
+
 	/* Check for a possible bridge VLAN entry now since there is no
 	 * need to emulate the switchdev prepare + commit phase.
 	 */
@@ -1029,6 +1032,9 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 	struct bridge_vlan_info info;
 	int ret;
 
+	if (vid == 0)
+		return 0;
+
 	/* Check for a possible bridge VLAN entry now since there is no
 	 * need to emulate the switchdev prepare + commit phase.
 	 */
-- 
2.17.1