Re: [PATCH net-next v2 3/3] phy: dp83tg720: Add statistics support

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hello Oleksij,

On Tue, 20 Aug 2024 14:29:14 +0200
Oleksij Rempel <o.rempel@pengutronix.de> wrote:

> Introduce statistics support for the DP83TG720 PHY driver, enabling
> detailed monitoring and reporting of link quality and packet-related
> metrics.
> 
> To avoid double reading of certain registers, the implementation caches
> all relevant register values in a single operation. This approach
> ensures accurate and consistent data retrieval, particularly for
> registers that clear upon reading or require special handling.
> 
> Some of the statistics, such as link training times, do not increment
> and therefore require special handling during the extraction process.

This all looks good to me, I do have one small nit bellow :

> +/**
> + * dp83tg720_get_stats - Get the statistics values.
> + * @phydev: Pointer to the phy_device structure.
> + * @stats: Pointer to the ethtool_stats structure.
> + * @data: Pointer to the buffer where the statistics values will be stored.
> + *
> + * Fills the buffer with the statistics values, filtering out those that are
> + * not applicable based on the PHY's operating mode (e.g., RGMII).

I don't see how this filtering is actually implemented, is this comment
correct ?

> + */
> +static void dp83tg720_get_stats(struct phy_device *phydev,
> +				struct ethtool_stats *stats, u64 *data)
> +{
> +	int i, j = 0;
> +
> +	dp83tg720_cache_reg_values(phydev);
> +
> +	for (i = 0; i < ARRAY_SIZE(dp83tg720_hw_stats); i++) {
> +		data[j] = dp83tg720_extract_stat_value(phydev, i);
> +		j++;
> +	}
> +}

Thanks,

Maxime