[PATCH net-next v2] net: dsa: b53: Create default VLAN entry explicitly

[Florian Fainelli <f.fainelli@gmail.com>]

In case CONFIG_VLAN_8021Q is not set, there will be no call down to the
b53 driver to ensure that the default PVID VLAN entry will be configured
with the appropriate untagged attribute towards the CPU port. We were
implicitly relying on dsa_slave_vlan_rx_add_vid() to do that for us,
instead make it explicit.

Reported-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v2:

- use b53_vlan_port_needs_forced_tagged() as suggested by Vladimir in
  his review

 drivers/net/dsa/b53/b53_common.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 6e199454e41d..b23e3488695b 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -728,6 +728,13 @@ static u16 b53_default_pvid(struct b53_device *dev)
 		return 0;
 }
 
+static bool b53_vlan_port_needs_forced_tagged(struct dsa_switch *ds, int port)
+{
+	struct b53_device *dev = ds->priv;
+
+	return dev->tag_protocol == DSA_TAG_PROTO_NONE && dsa_is_cpu_port(ds, port);
+}
+
 int b53_configure_vlan(struct dsa_switch *ds)
 {
 	struct b53_device *dev = ds->priv;
@@ -748,9 +755,20 @@ int b53_configure_vlan(struct dsa_switch *ds)
 
 	b53_enable_vlan(dev, -1, dev->vlan_enabled, ds->vlan_filtering);
 
-	b53_for_each_port(dev, i)
+	/* Create an untagged VLAN entry for the default PVID in case
+	 * CONFIG_VLAN_8021Q is disabled and there are no calls to
+	 * dsa_slave_vlan_rx_add_vid() to create the default VLAN
+	 * entry. Do this only when the tagging protocol is not
+	 * DSA_TAG_PROTO_NONE
+	 */
+	b53_for_each_port(dev, i) {
+		v = &dev->vlans[def_vid];
+		v->members |= BIT(i);
+		if (!b53_vlan_port_needs_forced_tagged(ds, i))
+			v->untag = v->members;
 		b53_write16(dev, B53_VLAN_PAGE,
 			    B53_VLAN_PORT_DEF_TAG(i), def_vid);
+	}
 
 	/* Upon initial call we have not set-up any VLANs, but upon
 	 * system resume, we need to restore all VLAN entries.
@@ -1460,13 +1478,6 @@ static int b53_vlan_prepare(struct dsa_switch *ds, int port,
 	return 0;
 }
 
-static bool b53_vlan_port_needs_forced_tagged(struct dsa_switch *ds, int port)
-{
-	struct b53_device *dev = ds->priv;
-
-	return dev->tag_protocol == DSA_TAG_PROTO_NONE && dsa_is_cpu_port(ds, port);
-}
-
 int b53_vlan_add(struct dsa_switch *ds, int port,
 		 const struct switchdev_obj_port_vlan *vlan,
 		 struct netlink_ext_ack *extack)
-- 
2.25.1