Date:   Fri, 26 Nov 2021 14:55:12 +0200
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Woojung Huh <woojung.huh@microchip.com>,
        UNGLinuxDriver@microchip.com, Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, kernel@pengutronix.de,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net v3 1/1] net: dsa: microchip: implement multi-bridge
 support
Message-ID: <20211126125512.qgld6r5a7ylcseot@skbuf>
References: <20211126123926.2981028-1-o.rempel@pengutronix.de>
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On Fri, Nov 26, 2021 at 01:39:26PM +0100, Oleksij Rempel wrote:
> Current driver version is able to handle only one bridge at time.
> Configuring two bridges on two different ports would end up shorting this
> bridges by HW. To reproduce it:
> 
> 	ip l a name br0 type bridge
> 	ip l a name br1 type bridge
> 	ip l s dev br0 up
> 	ip l s dev br1 up
> 	ip l s lan1 master br0
> 	ip l s dev lan1 up
> 	ip l s lan2 master br1
> 	ip l s dev lan2 up
> 
> 	Ping on lan1 and get response on lan2, which should not happen.
> 
> This happened, because current driver version is storing one global "Port VLAN
> Membership" and applying it to all ports which are members of any
> bridge.
> To solve this issue, we need to handle each port separately.
> 
> This patch is dropping the global port member storage and calculating
> membership dynamically depending on STP state and bridge participation.
> 
> Note: STP support was broken before this patch and should be fixed
> separately.
> 
> Fixes: c2e866911e25 ("net: dsa: microchip: break KSZ9477 DSA driver into two files")
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>