[PATCH net-next 07/15] net: dsa: sja1105: exit sja1105_vlan_filtering when called multiple times

[Vladimir Oltean <olteanv@gmail.com>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

VLAN filtering is a global property for sja1105, and that means that we
rely on the DSA core to not call us more than once.

But we need to introduce some per-port state for the tagger, namely the
xmit_tpid, and the best place to do that is where the xmit_tpid changes,
namely in sja1105_vlan_filtering. So at the moment, exit early from the
function to avoid unnecessarily resetting the switch for each port call.
Then we'll change the xmit_tpid prior to the early exit in the next
patch.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/net/dsa/sja1105/sja1105_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index 15db37067bf1..8cf17238bc6a 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -2141,6 +2141,9 @@ static int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled)
 	else
 		state = SJA1105_VLAN_FILTERING_FULL;
 
+	if (priv->vlan_state == state)
+		return 0;
+
 	priv->vlan_state = state;
 
 	table = &priv->static_config.tables[BLK_IDX_GENERAL_PARAMS];
-- 
2.17.1