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Date:   Wed, 2 Dec 2020 15:04:38 +0200
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@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 v2 2/2] net: dsa: qca: ar9331: export stats64
Message-ID: <20201202130438.vuhujicfcg2n2ih7@skbuf>
References: <20201202120712.6212-1-o.rempel@pengutronix.de>
 <20201202120712.6212-3-o.rempel@pengutronix.de>
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In-Reply-To: <20201202120712.6212-3-o.rempel@pengutronix.de>
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On Wed, Dec 02, 2020 at 01:07:12PM +0100, Oleksij Rempel wrote:
> Add stats support for the ar9331 switch.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  /* Warning: switch reset will reset last AR9331_SW_MDIO_PHY_MODE_PAGE request
> @@ -422,6 +527,7 @@ static void ar9331_sw_phylink_mac_link_down(struct dsa_switch *ds, int port,
>  					    phy_interface_t interface)
>  {
>  	struct ar9331_sw_priv *priv = (struct ar9331_sw_priv *)ds->priv;
> +	struct ar9331_sw_port *p = &priv->port[port];
>  	struct regmap *regmap = priv->regmap;
>  	int ret;
>  
> @@ -429,6 +535,8 @@ static void ar9331_sw_phylink_mac_link_down(struct dsa_switch *ds, int port,
>  				 AR9331_SW_PORT_STATUS_MAC_MASK, 0);
>  	if (ret)
>  		dev_err_ratelimited(priv->dev, "%s: %i\n", __func__, ret);
> +
> +	cancel_delayed_work_sync(&p->mib_read);

Is this sufficient? Do you get a guaranteed .phylink_mac_link_down event
on unbind? How do you ensure you don't race with the stats worker there?

> +static void ar9331_stats_update(struct ar9331_sw_port *port,
> +				struct rtnl_link_stats64 *stats)
> +{
> +	struct ar9331_sw_stats *s = &port->stats;
> +
> +	stats->rx_packets = s->rxbroad + s->rxmulti + s->rx64byte +
> +		s->rx128byte + s->rx256byte + s->rx512byte + s->rx1024byte +
> +		s->rx1518byte + s->rxmaxbyte;
> +	stats->tx_packets = s->txbroad + s->txmulti + s->tx64byte +
> +		s->tx128byte + s->tx256byte + s->tx512byte + s->tx1024byte +
> +		s->tx1518byte + s->txmaxbyte;
> +	stats->rx_bytes = s->rxgoodbyte;
> +	stats->tx_bytes = s->txbyte;
> +	stats->rx_errors = s->rxfcserr + s->rxalignerr + s->rxrunt +
> +		s->rxfragment + s->rxoverflow;
> +	stats->tx_errors = s->txoversize;
> +	stats->multicast = s->rxmulti;
> +	stats->collisions = s->txcollision;
> +	stats->rx_length_errors = s->rxrunt * s->rxfragment + s->rxtoolong;

Multiplication? Is this right?

> +	stats->rx_crc_errors = s->rxfcserr + s->rxalignerr + s->rxfragment;
> +	stats->rx_frame_errors = s->rxalignerr;
> +	stats->rx_missed_errors = s->rxoverflow;
> +	stats->tx_aborted_errors = s->txabortcol;
> +	stats->tx_fifo_errors = s->txunderrun;
> +	stats->tx_window_errors = s->txlatecol;
> +	stats->rx_nohandler = s->filtered;
> +}
> +
> +static void ar9331_do_stats_poll(struct work_struct *work)
> +{
> +

Could you remove this empty line.