Re: [PATCH net-next v1 2/9] net: dsa: tag_ar9331: detect IGMP and MLD packets

From: Andrew Lunn <andrew@lunn.ch>
To: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mips@vger.kernel.org
Subject: Re: [PATCH net-next v1 2/9] net: dsa: tag_ar9331: detect IGMP and MLD packets
Date: Sat, 3 Apr 2021 16:49:50 +0200	[thread overview]
Message-ID: <YGiAjngOfDVWz/D7@lunn.ch> (raw)
In-Reply-To: <20210403114848.30528-3-o.rempel@pengutronix.de>

> @@ -31,6 +96,13 @@ static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb,
>  	__le16 *phdr;
>  	u16 hdr;
>  
> +	if (dp->stp_state == BR_STATE_BLOCKING) {
> +		/* TODO: should we reflect it in the stats? */
> +		netdev_warn_once(dev, "%s:%i dropping blocking packet\n",
> +				 __func__, __LINE__);
> +		return NULL;
> +	}
> +
>  	phdr = skb_push(skb, AR9331_HDR_LEN);
>  
>  	hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION);

Hi Oleksij

This change does not seem to fit with what this patch is doing.

I also think it is wrong. You still need BPDU to pass through a
blocked port, otherwise spanning tree protocol will be unstable.

	Andrew