Re: vlan_filtering=1 breaks all traffic

From: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>,
	Network Development <netdev@vger.kernel.org>,
	Florian Fainelli <f.fainelli@gmail.com>
Subject: Re: vlan_filtering=1 breaks all traffic
Date: Sat, 5 Dec 2020 17:02:26 +0100	[thread overview]
Message-ID: <5edbf8fb-f5f3-b3b6-7b96-6a41f25cbfc8@prevas.dk> (raw)
In-Reply-To: <20201205154529.GO1551@shell.armlinux.org.uk>

On 05/12/2020 16.45, Russell King - ARM Linux admin wrote:
> On Sat, Dec 05, 2020 at 03:49:02PM +0100, Rasmus Villemoes wrote:
>> So, I found out that the problem disappers when I disable
>> vlan_filtering, and googling then led me to Russell's patches from
>> around March
>> (https://patchwork.ozlabs.org/project/netdev/cover/20200218114515.GL18808@shell.armlinux.org.uk/).
>>
>> But, unlike from what I gather from Russell's description, the problem
>> is there whether or not the bridge is created with vlan_filtering
>> enabled from the outset or not.
> 
> No. My problem is where the bridge is created _without_ vlan_filtering
> enabled, and is subsequently enabled. That caused traffic to stop as
> soon as vlan_filtering was enabled.
> 
> Note that if the bridge were created with vlan_filtering enabled from
> the start, there would be no problem.

That was what I was trying to say: I see the problem whether or not
vlan_filtering is enabled from the beginning (hence the "unlike..."). So
since disabling vlan_filtering (or never enabling it in the first place)
makes traffic flow, the symptoms look similar to the problem you
described (and that was what led me to those patches).

>> Also, cherry-picking 517648c8d1 to
>> 5.9.12 doesn't help. The problem also exists on 5.4.80, and (somewhat
>> naively) backporting 54a0ed0df496 as well as 517648c8d1 doesn't change that.
> 
> I'm not sure what 517648c8d1 is - this isn't a mainline or net-next
> commit ID.

Sorry, I mistakenly took the sha1 from the 5.4 branch I cherry-picked it
to - I did indeed mean your subsequent 1fb74191988f setting the flag for
mv88e6xxxx.

> You will, however, find that the problem was subsequently fixed by
> 1fb74191988f on top of 54a0ed0df496, 

Unfortunately not. So either it's simply some completely different
underlying issue, or there's something else going on in my setup that
prevents the configure_vlan_while_not_filtering patches from fixing it.

Thanks,
Rasmus