Subject: Re: [PATCH net-next 0/3] VLANs, DSA switches and multiple bridges

From: Russell King - ARM Linux admin <[email-masked]>
Date: Wed, 19 Feb 2020 00:17:37 +0000

On Tue, Feb 18, 2020 at 04:00:08PM -0800, Florian Fainelli wrote:
> On 2/18/20 3:45 AM, Russell King - ARM Linux admin wrote:
> > Hi,
> > 
> > This is a repost of the previously posted RFC back in December, which
> > did not get fully reviewed.  I've dropped the RFC tag this time as no
> > one really found anything too problematical in the RFC posting.
> > 
> > I've been trying to configure DSA for VLANs and not having much success.
> > The setup is quite simple:
> > 
> > - The main network is untagged
> > - The wifi network is a vlan tagged with id $VN running over the main
> >   network.
> > 
> > I have an Armada 388 Clearfog with a PCIe wifi card which I'm trying to
> > setup to provide wifi access to the vlan $VN network, while the switch
> > is also part of the main network.
> 
> Why not just revert 2ea7a679ca2abd251c1ec03f20508619707e1749 ("net: dsa:
> Don't add vlans when vlan filtering is disabled")? If a driver wants to
> veto the programming of VLANs while it has ports enslaved to a bridge
> that does not have VLAN filtering, it should have enough information to
> not do that operation.

I do not have the knowledge to know whether reverting that commit
would be appropriate; I do not know how the non-Marvell switches will
behave with such a revert - what was the reason for the commit in
the first place?

The commit says:

    This fixes at least one corner case. There are still issues in other
    corners, such as when vlan_filtering is later enabled.

but it doesn't say what that corner case was.  So, presumably reverting
it will cause a regression of whatever that corner case was...

-- 
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