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Date:   Fri, 18 Feb 2022 17:35:35 +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-next v3 1/1] net: dsa: microchip: ksz9477: export HW
 stats over stats64 interface
Message-ID: <20220218153535.optweu6jtzkerehe@skbuf>
References: <20220218121149.1430145-1-o.rempel@pengutronix.de>
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In-Reply-To: <20220218121149.1430145-1-o.rempel@pengutronix.de>
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On Fri, Feb 18, 2022 at 01:11:49PM +0100, Oleksij Rempel wrote:
> +static void ksz9477_r_mib_stats64(struct ksz_device *dev, int port)
> +{
> +	struct rtnl_link_stats64 *stats;
> +	struct ksz9477_stats_raw raw;
> +	struct ksz_port_mib *mib;
> +
> +	mib = &dev->ports[port].mib;
> +	stats = &mib->stats64;
> +
> +	memcpy(&raw, mib->counters, sizeof(raw));

I don't think you need an on-stack copy of mib->counters. If you're
concerned about line length just make "raw" point to mib->counters.

> +
> +	spin_lock(&mib->stats64_lock);
> +
> +	stats->rx_packets = raw.rx_bcast + raw.rx_mcast + raw.rx_ucast;
> +	stats->tx_packets = raw.tx_bcast + raw.tx_mcast + raw.tx_ucast;
> +
> +	/* HW counters are counting bytes + FCS which is not acceptable
> +	 * for rtnl_link_stats64 interface
> +	 */
> +	stats->rx_bytes = raw.rx_total - stats->rx_packets * ETH_FCS_LEN;
> +	stats->tx_bytes = raw.tx_total - stats->tx_packets * ETH_FCS_LEN;
> +
> +	stats->rx_length_errors = raw.rx_undersize + raw.rx_fragments +
> +		raw.rx_oversize;
> +
> +	stats->rx_crc_errors = raw.rx_crc_err;
> +	stats->rx_frame_errors = raw.rx_align_err;
> +	stats->rx_dropped = raw.rx_discards;
> +	stats->rx_errors = stats->rx_length_errors + stats->rx_crc_errors +
> +		stats->rx_frame_errors  + stats->rx_dropped;
> +
> +	stats->tx_window_errors = raw.tx_late_col;
> +	stats->tx_fifo_errors = raw.tx_discards;
> +	stats->tx_aborted_errors = raw.tx_exc_col;
> +	stats->tx_errors = stats->tx_window_errors + stats->tx_fifo_errors +
> +		stats->tx_aborted_errors;
> +
> +	stats->multicast = raw.rx_mcast;
> +	stats->collisions = raw.tx_total_col;
> +
> +	spin_unlock(&mib->stats64_lock);
> +}