Re: [PATCH net-next v3 3/5] ethtool: netlink: add lightweight MSE reporting to LINKSTATE_GET

[Kory Maincent <kory.maincent@bootlin.com>]

Le Tue, 19 Aug 2025 09:12:54 +0200,
Oleksij Rempel <o.rempel@pengutronix.de> a écrit :

> Extend ETHTOOL_MSG_LINKSTATE_GET to optionally return a simplified
> Mean Square Error (MSE) reading alongside existing link status fields.
> 
> The new attributes are:
>   - ETHTOOL_A_LINKSTATE_MSE_VALUE: current average MSE value
>   - ETHTOOL_A_LINKSTATE_MSE_MAX: scale limit for the reported value
>   - ETHTOOL_A_LINKSTATE_MSE_CHANNEL: source channel selector
> 
> This path reuses the PHY MSE core API, but only retrieves a single
> value intended for quick link-health checks:
>   * If the PHY supports a WORST channel selector, report its current
>     average MSE.
>   * Otherwise, if LINK-wide measurements are supported, report those.
>   * If neither is available, omit the attributes.
> 
> Unlike the full MSE_GET interface, LINKSTATE_GET does not expose
> per-channel or peak/worst-peak values and incurs minimal overhead.
> Drivers that implement get_mse_config() / get_mse_snapshot() will
> automatically populate this data.
> 
> The intent is to provide tooling with a “fast path” health indicator
> without issuing a separate MSE_GET request, though the long-term
> overlap with the full interface may need reevaluation.

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>

Thank you!

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com