Re: [net-next 4/4] gve: Add ethtool support

From: Andrew Lunn <andrew@lunn.ch>
To: Catherine Sullivan <csully@google.com>
Cc: netdev@vger.kernel.org, Sagi Shahar <sagis@google.com>,
	Jon Olson <jonolson@google.com>,
	Willem de Bruijn <willemb@google.com>,
	Luigi Rizzo <lrizzo@google.com>
Subject: Re: [net-next 4/4] gve: Add ethtool support
Date: Wed, 26 Jun 2019 21:48:05 +0200	[thread overview]
Message-ID: <20190626194805.GG27733@lunn.ch> (raw)
In-Reply-To: <20190626185251.205687-5-csully@google.com>

> +static int gve_get_sset_count(struct net_device *netdev, int sset)
> +{
> +	struct gve_priv *priv = netdev_priv(netdev);
> +
> +	if (!netif_carrier_ok(netdev))
> +		return 0;

That is pretty unusual. What goes wrong if there is no carrier and
statistics are returned?

> +static void
> +gve_get_ethtool_stats(struct net_device *netdev,
> +		      struct ethtool_stats *stats, u64 *data)
> +{
> +	struct gve_priv *priv = netdev_priv(netdev);
> +	u64 rx_pkts, rx_bytes, tx_pkts, tx_bytes;
> +	int ring;
> +	int i;
> +
> +	ASSERT_RTNL();
> +
> +	if (!netif_carrier_ok(netdev))
> +		return;
> +
> +	for (rx_pkts = 0, rx_bytes = 0, ring = 0;
> +	     ring < priv->rx_cfg.num_queues; ring++) {
> +		rx_pkts += priv->rx[ring].rpackets;
> +		rx_bytes += priv->rx[ring].rbytes;
> +	}
> +	for (tx_pkts = 0, tx_bytes = 0, ring = 0;
> +	     ring < priv->tx_cfg.num_queues; ring++) {
> +		tx_pkts += priv->tx[ring].pkt_done;
> +		tx_bytes += priv->tx[ring].bytes_done;
> +	}
> +	memset(data, 0, GVE_MAIN_STATS_LEN * sizeof(*data));

Maybe you should do this memset when the carrier is off?

      Andrew