[PATCH 5.5 002/176] net: dsa: b53: Ensure the default VID is untagged

[Greg Kroah-Hartman]

From: Florian Fainelli <f.fainelli@xxxxxxxxx>

[ Upstream commit d965a5432d4c3e6b9c3d2bc1d4a800013bbf76f6 ]

We need to ensure that the default VID is untagged otherwise the switch
will be sending tagged frames and the results can be problematic. This
is especially true with b53 switches that use VID 0 as their default
VLAN since VID 0 has a special meaning.

Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/dsa/b53/b53_common.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1353,6 +1353,9 @@ void b53_vlan_add(struct dsa_switch *ds,
 
 		b53_get_vlan_entry(dev, vid, vl);
 
+		if (vid == 0 && vid == b53_default_pvid(dev))
+			untagged = true;
+
 		vl->members |= BIT(port);
 		if (untagged && !dsa_is_cpu_port(ds, port))
 			vl->untag |= BIT(port);