Re: [PATCH v2 net] net: dsa: vsc73xx: fix reception from VLAN-unaware bridges

From: Florian Fainelli
Date: Mon Oct 14 2024 - 13:12:09 EST


On 10/14/24 08:30, Vladimir Oltean wrote:
Similar to the situation described for sja1105 in commit 1f9fc48fd302
("net: dsa: sja1105: fix reception from VLAN-unaware bridges"), the
vsc73xx driver uses tag_8021q and doesn't need the ds->untag_bridge_pvid
request. In fact, this option breaks packet reception.

The ds->untag_bridge_pvid option strips VLANs from packets received on
VLAN-unaware bridge ports. But those VLANs should already be stripped
by tag_vsc73xx_8021q.c as part of vsc73xx_rcv() - they are not VLANs in
VLAN-unaware mode, but DSA tags. Thus, dsa_software_vlan_untag() tries
to untag a VLAN that doesn't exist, corrupting the packet.

Fixes: 93e4649efa96 ("net: dsa: provide a software untagging function on RX for VLAN-aware bridges")
Tested-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
--
Florian