Re: [PATCH] net: dsa: mv88e6xxx: avoid error message on remove from VLAN 0

From: Andrew Lunn <andrew@lunn.ch>
To: Vivien Didelot <vivien.didelot@gmail.com>
Cc: "Nikita Yushchenko" <nikita.yoush@cogentembedded.com>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Heiner Kallweit" <hkallweit1@gmail.com>,
	"Marek Behún" <marek.behun@nic.cz>,
	"Russell King" <rmk+kernel@armlinux.org.uk>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Chris Healy" <cphealy@gmail.com>
Subject: Re: [PATCH] net: dsa: mv88e6xxx: avoid error message on remove from VLAN 0
Date: Fri, 31 May 2019 16:37:58 +0200	[thread overview]
Message-ID: <20190531143758.GB23821@lunn.ch> (raw)
In-Reply-To: <20190531103105.GE23464@t480s.localdomain>

> I'm not sure that I like the semantic of it, because the driver can actually
> support VID 0 per-se, only the kernel does not use VLAN 0. Thus I would avoid
> calling the port_vlan_del() ops for VID 0, directly into the upper DSA layer.
> 
> Florian, Andrew, wouldn't the following patch be more adequate?
> 
>     diff --git a/net/dsa/slave.c b/net/dsa/slave.c
>     index 1e2ae9d59b88..80f228258a92 100644
>     --- a/net/dsa/slave.c
>     +++ b/net/dsa/slave.c
>     @@ -1063,6 +1063,10 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
>             struct bridge_vlan_info info;
>             int ret;
>      
>     +       /* VID 0 has a special meaning and is never programmed in hardware */
>     +       if (!vid)
>     +               return 0;
>     +
>             /* Check for a possible bridge VLAN entry now since there is no
>              * need to emulate the switchdev prepare + commit phase.
>              */

Hi Vivien

If we put this in rx_kill_vid, we should probably have something
similar in rx_add_vid, just in case the kernel does start using VID 0.

	Andrew