Re: [PATCH net-next v2 1/5] ethtool: introduce core UAPI and driver API for PHY MSE diagnostics
From: Andrew Lunn <andrew@lunn.ch>
Date: 2025-08-20 03:03:34
Also in:
linux-doc, lkml
Channel-to-pair mapping is normally straightforward, but in some cases (e.g. 100BASE-TX with MDI-X resolution unknown) the mapping is ambiguous. If hardware does not expose MDI-X status, the exact pair cannot be determined. To avoid returning misleading per-channel data in this case, a LINK selector is defined for aggregate MSE measurements.
This is the same with cable test. The API just labels the pairs using
ETHTOOL_A_CABLE_PAIR_A,
ETHTOOL_A_CABLE_PAIR_B,
ETHTOOL_A_CABLE_PAIR_C,
ETHTOOL_A_CABLE_PAIR_D,
It does not take into account MDI-X or anything.
quoted hunk ↗ jump to hunk
@@ -1174,6 +1246,60 @@ struct phy_driver { /** @get_sqi_max: Get the maximum signal quality indication */ int (*get_sqi_max)(struct phy_device *dev); + /** + * get_mse_config - Get configuration and scale of MSE measurement + * @dev: PHY device + * @config: Output (filled on success) + * + * Fill @config with the PHY's MSE configuration for the current + * link mode: scale limits (max_average_mse, max_peak_mse), update + * interval (refresh_rate_ps), sample length (num_symbols) and the + * capability bitmask (supported_caps). + * + * Implementations may defer configuration until hardware has + * converged; in that case they should return -EAGAIN and allow the + * caller to retry later. + * + * Return: + * * 0 - success, @config is valid + * * -EOPNOTSUPP - MSE configuration not implemented by the PHY + * or not supported in the current link mode + * * -ENETDOWN - link is down and configuration is not + * available in that state
This seems a bit odd. phylib knows the state of the link. If it is down, why would it even ask? Andrew