Re: [PATCH 08/14] net: vlan: remove invalid VLAN protocol warning

From: Felix Fietkau
Date: Tue Nov 08 2022 - 04:47:14 EST


On 08.11.22 10:40, Vladimir Oltean wrote:
On Tue, Nov 08, 2022 at 10:20:44AM +0100, Felix Fietkau wrote:
I need to look into how METADATA_HW_PORT_MUX works, but I think it could
work.

Could you please coordinate with Maxime to come up with something
common? Currently he proposes a generic "oob" tagger, while you propose
that we stay with the "mtk"/"qca" taggers, but they are taught to look
after offloaded metadata rather than in the packet. IMO your proposal
sounds better; the name of the tagging protocol is already exposed to
user space via /sys/class/net/<dsa-master>/dsa/tagging and therefore ABI.
It's just that we need a way to figure out how to make the flow
dissector and other layers not adjust for DSA header length if the DSA
tag is offloaded and not present in the packet.
I think it depends on the hardware. If you can rely on the hardware always reporting the port out-of-band, a generic "oob" tagger would be fine.
In my case, it depends on whether a second non-DSA ethernet MAC is active on the same device, so I do need to continue using the "mtk" tag driver.
The flow dissector part is already solved: I simply used the existing .flow_dissect() tag op.

- Felix