Commit 9e8a4434 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'ethtool-introduce-phy-mse-diagnostics-uapi-and-drivers' 

Oleksij Rempel says:

====================
ethtool: introduce PHY MSE diagnostics UAPI and drivers

This series introduces a generic kernel-userspace API for retrieving PHY
Mean Square Error (MSE) diagnostics, together with netlink integration,
a fast-path reporting hook in LINKSTATE_GET, and initial driver
implementations for the KSZ9477 and DP83TD510E PHYs.

MSE is defined by the OPEN Alliance "Advanced diagnostic features for
100BASE-T1 automotive Ethernet PHYs" specification [1] as a measure of
slicer error rate, typically used internally to derive the Signal
Quality Indicator (SQI). While SQI is useful as a normalized quality
index, it hides raw measurement data, varies in scaling and thresholds
between vendors, and may not indicate certain failure modes - for
example, cases where autonegotiation would fail even though SQI reports
a good link. In practice, such scenarios can only be investigated in
fixed-link mode; here, MSE can provide an empirically estimated value
indicating conditions under which autonegotiation would not succeed.

Example output with current implementation:
root@DistroKit:~ ethtool lan1
Settings for lan1:
...
        Speed: 1000Mb/s
        Duplex: Full
...
        Link detected: yes
        SQI: 5/7
        MSE: 3/127 (channel: worst)

root@DistroKit:~ ethtool --show-mse lan1
MSE diagnostics for lan1:
MSE Configuration:
        Max Average MSE: 127
        Refresh Rate: 2000000 ps
        Symbols per Sample: 250
        Supported capabilities: average channel-a channel-b channel-c
                                channel-d worst

MSE Snapshot (Channel: a):
        Average MSE: 4

MSE Snapshot (Channel: b):
        Average MSE: 3

MSE Snapshot (Channel: c):
        Average MSE: 2

MSE Snapshot (Channel: d):
        Average MSE: 3

[1] https://opensig.org/wp-content/uploads/2024/01/Advanced_PHY_features_for_automotive_Ethernet_V1.0.pdf
====================

Link: https://patch.msgid.link/20251027122801.982364-1-o.rempel@pengutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents ff371a7e fd93ed77

Documentation/netlink/specs/ethtool.yaml

+86 −0
Original line number Diff line number Diff line
@@ -1823,6 +1823,73 @@ attribute-sets: 
        type: uint

        enum: pse-event

        doc: List of events reported by the PSE controller

  -

    name: mse-capabilities

    doc: MSE capabilities attribute set

    attr-cnt-name: --ethtool-a-mse-capabilities-cnt

    attributes:

      -

        name: max-average-mse

        type: uint

      -

        name: max-peak-mse

        type: uint

      -

        name: refresh-rate-ps

        type: uint

      -

        name: num-symbols

        type: uint

  -

    name: mse-snapshot

    doc: MSE snapshot attribute set

    attr-cnt-name: --ethtool-a-mse-snapshot-cnt

    attributes:

      -

        name: average-mse

        type: uint

      -

        name: peak-mse

        type: uint

      -

        name: worst-peak-mse

        type: uint

  -

    name: mse

    attr-cnt-name: --ethtool-a-mse-cnt

    attributes:

      -

        name: header

        type: nest

        nested-attributes: header

      -

        name: capabilities

        type: nest

        nested-attributes: mse-capabilities

      -

        name: channel-a

        type: nest

        nested-attributes: mse-snapshot

      -

        name: channel-b

        type: nest

        nested-attributes: mse-snapshot

      -

        name: channel-c

        type: nest

        nested-attributes: mse-snapshot

      -

        name: channel-d

        type: nest

        nested-attributes: mse-snapshot

      -

        name: worst-channel

        type: nest

        nested-attributes: mse-snapshot

      -

        name: link

        type: nest

        nested-attributes: mse-snapshot



operations:

  enum-model: directional
@@ -2756,6 +2823,25 @@ operations: 
        attributes:

          - header

          - context

    -

      name: mse-get

      doc: Get PHY MSE measurement data and capabilities.

      attribute-set: mse

      do: &mse-get-op

        request:

          attributes:

            - header

        reply:

          attributes:

            - header

            - capabilities

            - channel-a

            - channel-b

            - channel-c

            - channel-d

            - worst-channel

            - link

      dump: *mse-get-op



mcast-groups:

  list:

Documentation/networking/ethtool-netlink.rst

+64 −0
Original line number Diff line number Diff line
@@ -242,6 +242,7 @@ Userspace to kernel: 
  ``ETHTOOL_MSG_RSS_SET``               set RSS settings

  ``ETHTOOL_MSG_RSS_CREATE_ACT``        create an additional RSS context

  ``ETHTOOL_MSG_RSS_DELETE_ACT``        delete an additional RSS context

  ``ETHTOOL_MSG_MSE_GET``               get MSE diagnostic data

  ===================================== =================================



Kernel to userspace:
@@ -299,6 +300,7 @@ Kernel to userspace: 
  ``ETHTOOL_MSG_RSS_CREATE_ACT_REPLY``     create an additional RSS context

  ``ETHTOOL_MSG_RSS_CREATE_NTF``           additional RSS context created

  ``ETHTOOL_MSG_RSS_DELETE_NTF``           additional RSS context deleted

  ``ETHTOOL_MSG_MSE_GET_REPLY``            MSE diagnostic data

  ======================================== =================================



``GET`` requests are sent by userspace applications to retrieve device
@@ -2458,6 +2460,68 @@ Kernel response contents: 


For a description of each attribute, see ``TSCONFIG_GET``.



MSE_GET

=======



Retrieves detailed Mean Square Error (MSE) diagnostic information from the PHY.



Request Contents:



  ====================================  ======  ============================

  ``ETHTOOL_A_MSE_HEADER``              nested  request header

  ====================================  ======  ============================



Kernel Response Contents:



  ====================================  ======  ================================

  ``ETHTOOL_A_MSE_HEADER``              nested  reply header

  ``ETHTOOL_A_MSE_CAPABILITIES``        nested  capability/scale info for MSE

                                                measurements

  ``ETHTOOL_A_MSE_CHANNEL_A``           nested  snapshot for Channel A

  ``ETHTOOL_A_MSE_CHANNEL_B``           nested  snapshot for Channel B

  ``ETHTOOL_A_MSE_CHANNEL_C``           nested  snapshot for Channel C

  ``ETHTOOL_A_MSE_CHANNEL_D``           nested  snapshot for Channel D

  ``ETHTOOL_A_MSE_WORST_CHANNEL``       nested  snapshot for worst channel

  ``ETHTOOL_A_MSE_LINK``                nested  snapshot for link-wide aggregate

  ====================================  ======  ================================



MSE Capabilities

----------------



This nested attribute reports the capability / scaling properties used to

interpret snapshot values.



  ============================================== ======  =========================

  ``ETHTOOL_A_MSE_CAPABILITIES_MAX_AVERAGE_MSE`` uint    max avg_mse scale

  ``ETHTOOL_A_MSE_CAPABILITIES_MAX_PEAK_MSE``    uint    max peak_mse scale

  ``ETHTOOL_A_MSE_CAPABILITIES_REFRESH_RATE_PS`` uint    sample rate (picoseconds)

  ``ETHTOOL_A_MSE_CAPABILITIES_NUM_SYMBOLS``     uint    symbols per HW sample

  ============================================== ======  =========================



The max-average/peak fields are included only if the corresponding metric

is supported by the PHY. Their absence indicates that the metric is not

available.



See ``struct phy_mse_capability`` kernel documentation in

``include/linux/phy.h``.



MSE Snapshot

------------



Each per-channel nest contains an atomic snapshot of MSE values for that

selector (channel A/B/C/D, worst channel, or link).



  ==========================================  ======  ===================

  ``ETHTOOL_A_MSE_SNAPSHOT_AVERAGE_MSE``      uint    average MSE value

  ``ETHTOOL_A_MSE_SNAPSHOT_PEAK_MSE``         uint    current peak MSE

  ``ETHTOOL_A_MSE_SNAPSHOT_WORST_PEAK_MSE``   uint    worst-case peak MSE

  ==========================================  ======  ===================



Within each channel nest, only the metrics supported by the PHY will be present.



See ``struct phy_mse_snapshot`` kernel documentation in

``include/linux/phy.h``.



Request translation

===================

drivers/net/phy/dp83td510.c

+62 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ 
#define DP83TD510E_MASTER_SLAVE_RESOL_FAIL	BIT(15)



#define DP83TD510E_MSE_DETECT			0xa85

#define DP83TD510E_MSE_MAX			U16_MAX



#define DP83TD510_SQI_MAX	7
@@ -249,6 +250,64 @@ struct dp83td510_priv { 
#define DP83TD510E_ALCD_COMPLETE			BIT(15)

#define DP83TD510E_ALCD_CABLE_LENGTH			GENMASK(10, 0)



static int dp83td510_get_mse_capability(struct phy_device *phydev,

					struct phy_mse_capability *cap)

{

	/* DP83TD510E documents only a single (average) MSE register

	 * (used to derive SQI); no peak or worst-peak counters are

	 * described. Advertise only PHY_MSE_CAP_AVG.

	 */

	cap->supported_caps = PHY_MSE_CAP_AVG;

	/* 10BASE-T1L is a single-pair medium, so there are no B/C/D channels.

	 * We still advertise PHY_MSE_CAP_CHANNEL_A to indicate that the PHY

	 * can attribute the measurement to a specific pair (the only one),

	 * rather than exposing it only as a link-aggregate.

	 *

	 * Rationale:

	 *  - Keeps the ethtool MSE_GET selection logic consistent: per-channel

	 *    (A/B/C/D) is preferred over WORST/LINK, so userspace receives a

	 *    CHANNEL_A nest instead of LINK.

	 *  - Signals to tools that "per-pair" data is available (even if there's

	 *    just one pair), avoiding the impression that only aggregate values

	 *    are supported.

	 *  - Remains compatible with multi-pair PHYs and uniform UI handling.

	 *

	 * Note: WORST and other channels are not advertised on 10BASE-T1L.

	 */

	cap->supported_caps |= PHY_MSE_CHANNEL_A | PHY_MSE_CAP_LINK;

	cap->max_average_mse = DP83TD510E_MSE_MAX;



	/* The datasheet does not specify the refresh rate or symbol count,

	 * but based on similar PHYs and standards, we can assume a common

	 * value. For 10BASE-T1L, the symbol rate is 7.5 MBd. A common

	 * diagnostic interval is around 1ms.

	 * 7.5e6 symbols/sec * 0.001 sec = 7500 symbols.

	 */

	cap->refresh_rate_ps = 1000000000; /* 1 ms */

	cap->num_symbols = 7500;



	return 0;

}



static int dp83td510_get_mse_snapshot(struct phy_device *phydev,

				      enum phy_mse_channel channel,

				      struct phy_mse_snapshot *snapshot)

{

	int ret;



	if (channel != PHY_MSE_CHANNEL_LINK &&

	    channel != PHY_MSE_CHANNEL_A)

		return -EOPNOTSUPP;



	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_MSE_DETECT);

	if (ret < 0)

		return ret;



	snapshot->average_mse = ret;



	return 0;

}



static int dp83td510_led_brightness_set(struct phy_device *phydev, u8 index,

					enum led_brightness brightness)

{
@@ -893,6 +952,9 @@ static struct phy_driver dp83td510_driver[] = { 
	.get_phy_stats	= dp83td510_get_phy_stats,

	.update_stats	= dp83td510_update_stats,



	.get_mse_capability = dp83td510_get_mse_capability,

	.get_mse_snapshot = dp83td510_get_mse_snapshot,



	.led_brightness_set = dp83td510_led_brightness_set,

	.led_hw_is_supported = dp83td510_led_hw_is_supported,

	.led_hw_control_set = dp83td510_led_hw_control_set,

drivers/net/phy/micrel.c

+102 −0
Original line number Diff line number Diff line
@@ -2325,6 +2325,106 @@ static int kszphy_get_sqi_max(struct phy_device *phydev) 
	return KSZ9477_SQI_MAX;

}



static int kszphy_get_mse_capability(struct phy_device *phydev,

				     struct phy_mse_capability *cap)

{

	/* Capabilities depend on link mode:

	 * - 1000BASE-T: per-pair SQI registers exist => expose A..D

	 *   and a WORST selector.

	 * - 100BASE-TX: HW provides a single MSE/SQI reading in the "channel A"

	 *   register, but with auto MDI-X there is no MDI-X resolution bit,

	 *   so we cannot map that register to a specific wire pair reliably.

	 *   To avoid misleading per-channel data, advertise only LINK.

	 * Other speeds: no MSE exposure via this driver.

	 *

	 * Note: WORST is *not* a hardware selector on this family.

	 * We expose it because the driver computes it in software

	 * by scanning per-channel readouts (A..D) and picking the

	 * maximum average MSE.

	 */

	if (phydev->speed == SPEED_1000)

		cap->supported_caps = PHY_MSE_CAP_CHANNEL_A |

				      PHY_MSE_CAP_CHANNEL_B |

				      PHY_MSE_CAP_CHANNEL_C |

				      PHY_MSE_CAP_CHANNEL_D |

				      PHY_MSE_CAP_WORST_CHANNEL;

	else if (phydev->speed == SPEED_100)

		cap->supported_caps = PHY_MSE_CAP_LINK;

	else

		return -EOPNOTSUPP;



	cap->max_average_mse = FIELD_MAX(KSZ9477_MMD_SQI_MASK);

	cap->refresh_rate_ps = 2000000; /* 2 us */

	/* Estimated from link modulation (125 MBd per channel) and documented

	 * refresh rate of 2 us

	 */

	cap->num_symbols = 250;



	cap->supported_caps |= PHY_MSE_CAP_AVG;



	return 0;

}



static int kszphy_get_mse_snapshot(struct phy_device *phydev,

				   enum phy_mse_channel channel,

				   struct phy_mse_snapshot *snapshot)

{

	u8 num_channels;

	int ret;



	if (phydev->speed == SPEED_1000)

		num_channels = 4;

	else if (phydev->speed == SPEED_100)

		num_channels = 1;

	else

		return -EOPNOTSUPP;



	if (channel == PHY_MSE_CHANNEL_WORST) {

		u32 worst_val = 0;

		int i;



		/* WORST is implemented in software: select the maximum

		 * average MSE across the available per-channel registers.

		 * Only defined when multiple channels exist (1000BASE-T).

		 */

		if (num_channels < 2)

			return -EOPNOTSUPP;



		for (i = 0; i < num_channels; i++) {

			ret = phy_read_mmd(phydev, MDIO_MMD_PMAPMD,

					KSZ9477_MMD_SIGNAL_QUALITY_CHAN_A + i);

			if (ret < 0)

				return ret;



			ret = FIELD_GET(KSZ9477_MMD_SQI_MASK, ret);

			if (ret > worst_val)

				worst_val = ret;

		}

		snapshot->average_mse = worst_val;

	} else if (channel == PHY_MSE_CHANNEL_LINK && num_channels == 1) {

		ret = phy_read_mmd(phydev, MDIO_MMD_PMAPMD,

				   KSZ9477_MMD_SIGNAL_QUALITY_CHAN_A);

		if (ret < 0)

			return ret;

		snapshot->average_mse = FIELD_GET(KSZ9477_MMD_SQI_MASK, ret);

	} else if (channel >= PHY_MSE_CHANNEL_A &&

		   channel <= PHY_MSE_CHANNEL_D) {

		/* Per-channel readouts are valid only for 1000BASE-T. */

		if (phydev->speed != SPEED_1000)

			return -EOPNOTSUPP;



		ret = phy_read_mmd(phydev, MDIO_MMD_PMAPMD,

				   KSZ9477_MMD_SIGNAL_QUALITY_CHAN_A + channel);

		if (ret < 0)

			return ret;

		snapshot->average_mse = FIELD_GET(KSZ9477_MMD_SQI_MASK, ret);

	} else {

		return -EOPNOTSUPP;

	}



	return 0;

}



static void kszphy_enable_clk(struct phy_device *phydev)

{

	struct kszphy_priv *priv = phydev->priv;
@@ -6497,6 +6597,8 @@ static struct phy_driver ksphy_driver[] = { 
	.cable_test_get_status	= ksz9x31_cable_test_get_status,

	.get_sqi	= kszphy_get_sqi,

	.get_sqi_max	= kszphy_get_sqi_max,

	.get_mse_capability = kszphy_get_mse_capability,

	.get_mse_snapshot = kszphy_get_mse_snapshot,

} };



module_phy_driver(ksphy_driver);

include/linux/phy.h

+206 −0
Original line number Diff line number Diff line
@@ -903,6 +903,165 @@ struct phy_led { 


#define to_phy_led(d) container_of(d, struct phy_led, led_cdev)



/*

 * PHY_MSE_CAP_* - Bitmask flags for Mean Square Error (MSE) capabilities

 *

 * These flags describe which MSE metrics and selectors are implemented

 * by the PHY for the current link mode. They are used in

 * struct phy_mse_capability.supported_caps.

 *

 * Standardization:

 *   The OPEN Alliance (OA) defines the presence of MSE/SQI/pMSE but not their

 *   numeric scaling, update intervals, or aggregation windows.  See:

 *     OA 100BASE-T1 TC1 v1.0, sections 6.1.1-6.1.3

 *     OA 1000BASE-T1 TC12 v2.2, sections 6.1.1-6.1.2

 *

 * Description of flags:

 *

 *   PHY_MSE_CAP_CHANNEL_A

 *     Per-pair diagnostics for Channel A are supported.  Mapping to the

 *     physical wire pair may depend on MDI/MDI-X polarity.

 *

 *   PHY_MSE_CAP_CHANNEL_B, _C, _D

 *     Same as above for channels B-D.

 *

 *   PHY_MSE_CAP_WORST_CHANNEL

 *     The PHY or driver can identify and report the single worst-performing

 *     channel without querying each one individually.

 *

 *   PHY_MSE_CAP_LINK

 *     The PHY provides only a link-wide aggregate measurement or cannot map

 *     results to a specific pair (for example 100BASE-TX with unknown

 *     MDI/MDI-X).

 *

 *   PHY_MSE_CAP_AVG

 *     Average MSE (mean DCQ metric) is supported.  For 100/1000BASE-T1 the OA

 *     recommends 2^16 symbols, scaled 0..511, but the exact scaling is

 *     vendor-specific.

 *

 *   PHY_MSE_CAP_PEAK

 *     Peak MSE (current peak within the measurement window) is supported.

 *     Defined as pMSE for 100BASE-T1; vendor-specific for others.

 *

 *   PHY_MSE_CAP_WORST_PEAK

 *     Latched worst-case peak MSE since the last read (read-to-clear if

 *     implemented).  Optional in OA 100BASE-T1 TC1 6.1.3.

 */

#define PHY_MSE_CAP_CHANNEL_A BIT(0)

#define PHY_MSE_CAP_CHANNEL_B BIT(1)

#define PHY_MSE_CAP_CHANNEL_C BIT(2)

#define PHY_MSE_CAP_CHANNEL_D BIT(3)

#define PHY_MSE_CAP_WORST_CHANNEL BIT(4)

#define PHY_MSE_CAP_LINK BIT(5)

#define PHY_MSE_CAP_AVG BIT(6)

#define PHY_MSE_CAP_PEAK BIT(7)

#define PHY_MSE_CAP_WORST_PEAK BIT(8)



/*

 * enum phy_mse_channel - Identifiers for selecting MSE measurement channels

 *

 * PHY_MSE_CHANNEL_A - PHY_MSE_CHANNEL_D

 *   Select per-pair measurement for the corresponding channel.

 *

 * PHY_MSE_CHANNEL_WORST

 *   Select the single worst-performing channel reported by hardware.

 *

 * PHY_MSE_CHANNEL_LINK

 *   Select link-wide aggregate data (used when per-pair results are

 *   unavailable).

 */

enum phy_mse_channel {

	PHY_MSE_CHANNEL_A,

	PHY_MSE_CHANNEL_B,

	PHY_MSE_CHANNEL_C,

	PHY_MSE_CHANNEL_D,

	PHY_MSE_CHANNEL_WORST,

	PHY_MSE_CHANNEL_LINK,

};



/**

 * struct phy_mse_capability - Capabilities of Mean Square Error (MSE)

 *                             measurement interface

 *

 * Standardization notes:

 *

 * - Presence of MSE/SQI/pMSE is defined by OPEN Alliance specs, but numeric

 *   scaling, refresh/update rate and aggregation windows are not fixed and

 *   are vendor-/product-specific. (OA 100BASE-T1 TC1 v1.0 6.1.*;

 *   OA 1000BASE-T1 TC12 v2.2 6.1.*)

 *

 * - Typical recommendations: 2^16 symbols and 0..511 scaling for MSE; pMSE only

 *   defined for 100BASE-T1 (sliding window example), others are vendor

 *   extensions. Drivers must report actual scale/limits here.

 *

 * Describes the MSE measurement capabilities for the current link mode. These

 * properties are dynamic and may change when link settings are modified.

 * Callers should re-query this capability after any link state change to

 * ensure they have the most up-to-date information.

 *

 * Callers should only request measurements for channels and types that are

 * indicated as supported by the @supported_caps bitmask. If @supported_caps

 * is 0, the device provides no MSE diagnostics, and driver operations should

 * typically return -EOPNOTSUPP.

 *

 * Snapshot values for average and peak MSE can be normalized to a 0..1 ratio

 * by dividing the raw snapshot by the corresponding @max_average_mse or

 * @max_peak_mse value.

 *

 * @max_average_mse: The maximum value for an average MSE snapshot. This

 *   defines the scale for the measurement. If the PHY_MSE_CAP_AVG capability is

 *   supported, this value MUST be greater than 0. (vendor-specific units).

 * @max_peak_mse: The maximum value for a peak MSE snapshot. If either

 *   PHY_MSE_CAP_PEAK or PHY_MSE_CAP_WORST_PEAK is supported, this value MUST

 *   be greater than 0. (vendor-specific units).

 * @refresh_rate_ps: The typical interval, in picoseconds, between hardware

 *   updates of the MSE values. This is an estimate, and callers should not

 *   assume synchronous sampling. (vendor-specific units).

 * @num_symbols: The number of symbols aggregated per hardware sample to

 *   calculate the MSE. (vendor-specific units).

 * @supported_caps: A bitmask of PHY_MSE_CAP_* values indicating which

 *   measurement types (e.g., average, peak) and channels

 *   (e.g., per-pair or link-wide) are supported.

 */

struct phy_mse_capability {

	u64 max_average_mse;

	u64 max_peak_mse;

	u64 refresh_rate_ps;

	u64 num_symbols;

	u32 supported_caps;

};



/**

 * struct phy_mse_snapshot - A snapshot of Mean Square Error (MSE) diagnostics

 *

 * Holds a set of MSE diagnostic values that were all captured from a single

 * measurement window.

 *

 * Values are raw, device-scaled and not normalized. Use struct

 * phy_mse_capability to interpret the scale and sampling window.

 *

 * @average_mse: The average MSE value over the measurement window.

 *   OPEN Alliance references MSE as a DCQ metric; recommends 2^16 symbols and

 *   0..511 scaling. Exact scale and refresh are vendor-specific.

 *   (100BASE-T1 TC1 v1.0 6.1.1; 1000BASE-T1 TC12 v2.2 6.1.1).

 *

 * @peak_mse: The peak MSE value observed within the measurement window.

 *   For 100BASE-T1, "pMSE" is optional and may be implemented via a sliding

 *   128-symbol window with periodic capture; not standardized for 1000BASE-T1.

 *   (100BASE-T1 TC1 v1.0 6.1.3, Table "DCQ.peakMSE").

 *

 * @worst_peak_mse: A latched high-water mark of the peak MSE since last read

 *   (read-to-clear if implemented). OPEN Alliance shows a latched "worst case

 *   peak MSE" for 100BASE-T1 pMSE; availability/semantics outside that are

 *   vendor-specific. (100BASE-T1 TC1 v1.0 6.1.3, DCQ.peakMSE high byte;

 *   1000BASE-T1 TC12 v2.2 treats DCQ details as vendor-specific.)

 */

struct phy_mse_snapshot {

	u64 average_mse;

	u64 peak_mse;

	u64 worst_peak_mse;

};



/**

 * struct phy_driver - Driver structure for a particular PHY type

 *
@@ -1184,6 +1343,53 @@ struct phy_driver { 
	/** @get_sqi_max: Get the maximum signal quality indication */

	int (*get_sqi_max)(struct phy_device *dev);



	/**

	 * @get_mse_capability: Get capabilities and scale of MSE measurement

	 * @dev:    PHY device

	 * @cap: Output (filled on success)

	 *

	 * Fill @cap with the PHY's MSE capability 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 capability report until hardware has

	 * converged; in that case they should return -EAGAIN and allow the

	 * caller to retry later.

	 *

	 * Return: 0 on success. On failure, returns a negative errno code, such

	 * as -EOPNOTSUPP if MSE measurement is not supported by the PHY or in

	 * the current link mode, or -EAGAIN if the capability information is

	 * not yet available.

	 */

	int (*get_mse_capability)(struct phy_device *dev,

				  struct phy_mse_capability *cap);



	/**

	 * @get_mse_snapshot: Retrieve a snapshot of MSE diagnostic values

	 * @dev:      PHY device

	 * @channel:  Channel identifier (PHY_MSE_CHANNEL_*)

	 * @snapshot: Output (filled on success)

	 *

	 * Fill @snapshot with a correlated set of MSE values from the most

	 * recent measurement window.

	 *

	 * Callers must validate @channel against supported_caps returned by

	 * get_mse_capability(). Drivers must not coerce @channel; if the

	 * requested selector is not implemented by the device or current link

	 * mode, the operation must fail.

	 *

	 * worst_peak_mse is latched and must be treated as read-to-clear.

	 *

	 * Return: 0 on success. On failure, returns a negative errno code, such

	 * as -EOPNOTSUPP if MSE measurement is not supported by the PHY or in

	 * the current link mode, or -EAGAIN if measurements are not yet

	 * available.

	 */

	int (*get_mse_snapshot)(struct phy_device *dev,

				enum phy_mse_channel channel,

				struct phy_mse_snapshot *snapshot);



	/* PLCA RS interface */

	/** @get_plca_cfg: Return the current PLCA configuration */

	int (*get_plca_cfg)(struct phy_device *dev,