[PATCH 3.10 17/51] drivers: net: cpsw: discard dual emac default vlan configuration

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mugunthan V N <mugunthanvnm@ti.com>

commit 02a54164c52ed6eca3089a0d402170fbf34d6cf5 upstream.

In Dual EMAC, the default VLANs are used to segregate Rx packets between
the ports, so adding the same default VLAN to the switch will affect the
normal packet transfers. So returning error on addition of dual EMAC
default VLANs.

Even if EMAC 0 default port VLAN is added to EMAC 1, it will lead to
break dual EMAC port separations.

Fixes: d9ba8f9e6298 (driver: net: ethernet: cpsw: dual emac interface implementation)
Reported-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/ethernet/ti/cpsw.c |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1293,6 +1293,19 @@ static int cpsw_ndo_vlan_rx_add_vid(stru
 	if (vid == priv->data.default_vlan)
 		return 0;
 
+	if (priv->data.dual_emac) {
+		/* In dual EMAC, reserved VLAN id should not be used for
+		 * creating VLAN interfaces as this can break the dual
+		 * EMAC port separation
+		 */
+		int i;
+
+		for (i = 0; i < priv->data.slaves; i++) {
+			if (vid == priv->slaves[i].port_vlan)
+				return -EINVAL;
+		}
+	}
+
 	dev_info(priv->dev, "Adding vlanid %d to vlan filter\n", vid);
 	return cpsw_add_vlan_ale_entry(priv, vid);
 }
@@ -1306,6 +1319,15 @@ static int cpsw_ndo_vlan_rx_kill_vid(str
 	if (vid == priv->data.default_vlan)
 		return 0;
 
+	if (priv->data.dual_emac) {
+		int i;
+
+		for (i = 0; i < priv->data.slaves; i++) {
+			if (vid == priv->slaves[i].port_vlan)
+				return -EINVAL;
+		}
+	}
+
 	dev_info(priv->dev, "removing vlanid %d from vlan filter\n", vid);
 	ret = cpsw_ale_del_vlan(priv->ale, vid, 0);
 	if (ret != 0)