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Date: Fri, 2 Feb 2024 01:26:19 +0200
From: Vladimir Oltean <olteanv@gmail.com>
To: arinc.unal@arinc9.com
Cc: Daniel Golle <daniel@makrotopia.org>, DENG Qingfang <dqfext@gmail.com>,
	Sean Wang <sean.wang@mediatek.com>, Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
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	Alvin =?utf-8?Q?=C5=A0ipraga?= <ALSI@bang-olufsen.dk>,
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	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH net RFC] net: dsa: mt7530: fix link-local frames that
 ingress vlan filtering ports
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On Thu, Feb 01, 2024 at 10:13:39PM +0300, Arınç ÜNAL via B4 Relay wrote:
> One remaining limitation is that the ingress port must have a PVID assigned
> to it for the frame to be trapped to the CPU port. A PVID is set by default
> on vlan aware and vlan unaware ports. However, when the network interface
> that pertains to the ingress port is attached to a vlan_filtering enabled
> bridge, the user can remove the PVID assignment from it which would prevent
> the link-local frames from being trapped to the CPU port.
> 
> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
> ---
> I couldn't figure out a way to bypass VLAN table lookup for link-local
> frames to directly trap them to the CPU port. The CPU port is hardcoded for
> MT7530. For MT7531 and the switch on the MT7988 SoC, it depends on the port
> matrix to choose the CPU port to trap the frames to. Port matrix and VLAN
> table seem to go hand in hand so I don't know if this would even be
> possible.
> 
> If possible to implement, link-local frames must not be influenced by the
> VLAN table. They must always be trapped to the CPU port, and trapped
> untagged.

Isn't this, in effect, what the "Leaky VLAN Enable" bit does?