Re: [PATCH v2 net-next 01/15] net: dsa: provide an option for drivers to always receive bridge VLANs

From: Florian Fainelli
Date: Mon May 11 2020 - 18:58:15 EST




On 5/11/2020 6:53 AM, Vladimir Oltean wrote:
> From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
>
> DSA assumes that a bridge which has vlan filtering disabled is not
> vlan aware, and ignores all vlan configuration. However, the kernel
> software bridge code allows configuration in this state.
>
> This causes the kernel's idea of the bridge vlan state and the
> hardware state to disagree, so "bridge vlan show" indicates a correct
> configuration but the hardware lacks all configuration. Even worse,
> enabling vlan filtering on a DSA bridge immediately blocks all traffic
> which, given the output of "bridge vlan show", is very confusing.
>
> Provide an option that drivers can set to indicate they want to receive
> vlan configuration even when vlan filtering is disabled. At the very
> least, this is safe for Marvell DSA bridges, which do not look up
> ingress traffic in the VTU if the port is in 8021Q disabled state. It is
> also safe for the Ocelot switch family. Whether this change is suitable
> for all DSA bridges is not known.
>
> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

We may want to consolidate these checks in a helper function at some
point, and the name is still not super clear to me (not sure what
disabled refers to unless you read the comments), but this is as good as
it could be:

Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
--
Florian