[PATCH net-next v1 0/3] net: phy: micrel: add extended PHY support for KSZ9477-class devices

[PATCH net-next v1 0/3] net: phy: micrel: add extended PHY support for KSZ9477-class devices

[Oleksij Rempel]

Hi all,

This patch series extends the PHY driver support for the Microchip
KSZ9477-class switch-integrated PHYs. These changes enhance ethtool
functionality and diagnostic capabilities by implementing the following
features:
- MDI/MDI-X configuration support
  All crossover modes (auto, MDI, MDI-X) are now configurable.

- RX error counter reporting
  The RXER counter (reg 0x15) is now accumulated and exported via
ethtool stats.

- Cable test support
  Reuses the KSZ9131 implementation to enable open/short fault
detection and approximate fault length reporting.

Oleksij Rempel (3):
  net: phy: micrel: add MDI/MDI-X control support for KSZ9477
    switch-integrated PHYs
  net: phy: micrel: Add RX error counter support for KSZ9477
    switch-integrated PHYs
  net: phy: micrel: add cable test support for KSZ9477-class PHYs

 drivers/net/phy/micrel.c | 111 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 109 insertions(+), 2 deletions(-)

--
2.39.5

[PATCH net-next v1 1/3] net: phy: micrel: add MDI/MDI-X control support for KSZ9477 switch-integrated PHYs

[Oleksij Rempel]

Add MDI/MDI-X configuration support for PHYs integrated in the KSZ9477
family of Ethernet switches.

All MDI/MDI-X configuration modes are supported:
  - Automatic MDI/MDI-X (ETH_TP_MDI_AUTO)
  - Forced MDI (ETH_TP_MDI)
  - Forced MDI-X (ETH_TP_MDI_X)

However, when operating in automatic mode, the PHY does not expose the
resolved crossover status (i.e., whether MDI or MDI-X is active).
Therefore, in auto mode, the driver reports ETH_TP_MDI_INVALID as
the current status.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/phy/micrel.c | 59 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 64aa03aed770..a51010e64444 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1948,6 +1948,56 @@ static int ksz886x_read_status(struct phy_device *phydev)
 	return genphy_read_status(phydev);
 }
 
+static int ksz9477_mdix_update(struct phy_device *phydev)
+{
+	if (phydev->mdix_ctrl != ETH_TP_MDI_AUTO)
+		phydev->mdix = phydev->mdix_ctrl;
+	else
+		phydev->mdix = ETH_TP_MDI_INVALID;
+
+	return 0;
+}
+
+static int ksz9477_read_mdix_ctrl(struct phy_device *phydev)
+{
+	int val;
+
+	val = phy_read(phydev, MII_KSZ9131_AUTO_MDIX);
+	if (val < 0)
+		return val;
+
+	if (!(val & MII_KSZ9131_AUTO_MDIX_SWAP_OFF))
+		phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
+	else if (val & MII_KSZ9131_AUTO_MDI_SET)
+		phydev->mdix_ctrl = ETH_TP_MDI;
+	else
+		phydev->mdix_ctrl = ETH_TP_MDI_X;
+
+	return 0;
+}
+
+static int ksz9477_read_status(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = ksz9477_mdix_update(phydev);
+	if (ret)
+		return ret;
+
+	return genphy_read_status(phydev);
+}
+
+static int ksz9477_config_aneg(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = ksz9131_config_mdix(phydev, phydev->mdix_ctrl);
+	if (ret)
+		return ret;
+
+	return genphy_config_aneg(phydev);
+}
+
 struct ksz9477_errata_write {
 	u8 dev_addr;
 	u8 reg_addr;
@@ -2029,6 +2079,13 @@ static int ksz9477_config_init(struct phy_device *phydev)
 			return err;
 	}
 
+	/* Read initial MDI-X config state. So, we do not need to poll it
+	 * later on.
+	 */
+	err = ksz9477_read_mdix_ctrl(phydev);
+	if (err)
+		return err;
+
 	return kszphy_config_init(phydev);
 }
 
@@ -5691,6 +5748,8 @@ static struct phy_driver ksphy_driver[] = {
 	/* PHY_GBIT_FEATURES */
 	.config_init	= ksz9477_config_init,
 	.config_intr	= kszphy_config_intr,
+	.config_aneg	= ksz9477_config_aneg,
+	.read_status	= ksz9477_read_status,
 	.handle_interrupt = kszphy_handle_interrupt,
 	.suspend	= genphy_suspend,
 	.resume		= ksz9477_resume,
-- 
2.39.5

Re: [PATCH net-next v1 1/3] net: phy: micrel: add MDI/MDI-X control support for KSZ9477 switch-integrated PHYs

[Andrew Lunn]

On Tue, Jun 10, 2025 at 11:13:52AM +0200, Oleksij Rempel wrote:
> Add MDI/MDI-X configuration support for PHYs integrated in the KSZ9477
> family of Ethernet switches.
> 
> All MDI/MDI-X configuration modes are supported:
>   - Automatic MDI/MDI-X (ETH_TP_MDI_AUTO)
>   - Forced MDI (ETH_TP_MDI)
>   - Forced MDI-X (ETH_TP_MDI_X)
> 
> However, when operating in automatic mode, the PHY does not expose the
> resolved crossover status (i.e., whether MDI or MDI-X is active).
> Therefore, in auto mode, the driver reports ETH_TP_MDI_INVALID as
> the current status.

I assume you also considered returning ETH_TP_MDI_AUTO? What makes
INVALID better than AUTO?

	Andrew

Re: [PATCH net-next v1 1/3] net: phy: micrel: add MDI/MDI-X control support for KSZ9477 switch-integrated PHYs

[Oleksij Rempel]

On Tue, Jun 10, 2025 at 02:31:45PM +0200, Andrew Lunn wrote:
> On Tue, Jun 10, 2025 at 11:13:52AM +0200, Oleksij Rempel wrote:
> > Add MDI/MDI-X configuration support for PHYs integrated in the KSZ9477
> > family of Ethernet switches.
> > 
> > All MDI/MDI-X configuration modes are supported:
> >   - Automatic MDI/MDI-X (ETH_TP_MDI_AUTO)
> >   - Forced MDI (ETH_TP_MDI)
> >   - Forced MDI-X (ETH_TP_MDI_X)
> > 
> > However, when operating in automatic mode, the PHY does not expose the
> > resolved crossover status (i.e., whether MDI or MDI-X is active).
> > Therefore, in auto mode, the driver reports ETH_TP_MDI_INVALID as
> > the current status.
> 
> I assume you also considered returning ETH_TP_MDI_AUTO? What makes
> INVALID better than AUTO?

The phydev->mdix_ctrl returns configuration state, which cant be set to
ETH_TP_MDI_AUTO.
The phydev->mdix should return actual crossover state, which is
ETH_TP_MDI or ETH_TP_MDI_X. Setting it to ETH_TP_MDI_AUTO, would not
provide any usable information.

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Re: [PATCH net-next v1 1/3] net: phy: micrel: add MDI/MDI-X control support for KSZ9477 switch-integrated PHYs

[Andrew Lunn]

On Tue, Jun 10, 2025 at 02:46:11PM +0200, Oleksij Rempel wrote:
> On Tue, Jun 10, 2025 at 02:31:45PM +0200, Andrew Lunn wrote:
> > On Tue, Jun 10, 2025 at 11:13:52AM +0200, Oleksij Rempel wrote:
> > > Add MDI/MDI-X configuration support for PHYs integrated in the KSZ9477
> > > family of Ethernet switches.
> > > 
> > > All MDI/MDI-X configuration modes are supported:
> > >   - Automatic MDI/MDI-X (ETH_TP_MDI_AUTO)
> > >   - Forced MDI (ETH_TP_MDI)
> > >   - Forced MDI-X (ETH_TP_MDI_X)
> > > 
> > > However, when operating in automatic mode, the PHY does not expose the
> > > resolved crossover status (i.e., whether MDI or MDI-X is active).
> > > Therefore, in auto mode, the driver reports ETH_TP_MDI_INVALID as
> > > the current status.
> > 
> > I assume you also considered returning ETH_TP_MDI_AUTO? What makes
> > INVALID better than AUTO?
> 
> The phydev->mdix_ctrl returns configuration state, which cant be set to
> ETH_TP_MDI_AUTO.
> The phydev->mdix should return actual crossover state, which is
> ETH_TP_MDI or ETH_TP_MDI_X. Setting it to ETH_TP_MDI_AUTO, would not
> provide any usable information.

[Goes and looks at the code]

#define ETH_TP_MDI_INVALID	0x00 /* status: unknown; control: unsupported */
#define ETH_TP_MDI		0x01 /* status: MDI;     control: force MDI */
#define ETH_TP_MDI_X		0x02 /* status: MDI-X;   control: force MDI-X */
#define ETH_TP_MDI_AUTO		0x03 /*                  control: auto-select */

So _AUTO is not listed as being valid as a status. And _INVALID has
the comment unkown. So:

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

[PATCH net-next v1 2/3] net: phy: micrel: Add RX error counter support for KSZ9477 switch-integrated PHYs

[Oleksij Rempel]

Add support for tracking receive error statistics from PHYs integrated
into the KSZ9477 family of Ethernet switches.

The integrated PHYs expose a receive error (RXER) counter in register 0x15.
This counter increments when the PHY detects one or more symbol errors
on a received frame. The register is cleared upon reading.

Changes include:
- `kszphy_update_stats()` to accumulate the RX error count.
- `kszphy_get_phy_stats()` to expose this count via ethtool PHY stats.
- Addition of a private `rx_err_pkt_cnt` field in the driver.
- Registration of `.update_stats` and `.get_phy_stats` callbacks in the
  KSZ9477 PHY driver structure.

The functionality of this counter was confirmed by physically disturbing
the signal lines - specifically by wiggling exposed twisted pair wires and
intentionally shorting between pairs. These actions triggered RXER
increments, validating the counter's behavior.

This RXER counter is confirmed for KSZ9477 and likely applicable to
other related PHYs like those in KSZ9313.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/phy/micrel.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index a51010e64444..68d86383e6c7 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -431,6 +431,10 @@ struct kszphy_ptp_priv {
 	spinlock_t seconds_lock;
 };
 
+struct kszphy_phy_stats {
+	u64 rx_err_pkt_cnt;
+};
+
 struct kszphy_priv {
 	struct kszphy_ptp_priv ptp_priv;
 	const struct kszphy_type *type;
@@ -441,6 +445,7 @@ struct kszphy_priv {
 	bool rmii_ref_clk_sel_val;
 	bool clk_enable;
 	u64 stats[ARRAY_SIZE(kszphy_hw_stats)];
+	struct kszphy_phy_stats phy_stats;
 };
 
 static const struct kszphy_type lan8814_type = {
@@ -2130,6 +2135,35 @@ static void kszphy_get_stats(struct phy_device *phydev,
 		data[i] = kszphy_get_stat(phydev, i);
 }
 
+/* KSZ9477 PHY RXER Counter. Probably supported by other PHYs like KSZ9313,
+ * etc. The counter is incremented when the PHY receives a frame with one or
+ * more symbol errors. The counter is cleared when the register is read.
+ */
+#define MII_KSZ9477_PHY_RXER_COUNTER	0x15
+
+static int kszphy_update_stats(struct phy_device *phydev)
+{
+	struct kszphy_priv *priv = phydev->priv;
+	int ret;
+
+	ret = phy_read(phydev, MII_KSZ9477_PHY_RXER_COUNTER);
+	if (ret < 0)
+		return ret;
+
+	priv->phy_stats.rx_err_pkt_cnt += ret;
+
+	return 0;
+}
+
+static void kszphy_get_phy_stats(struct phy_device *phydev,
+				 struct ethtool_eth_phy_stats *eth_stats,
+				 struct ethtool_phy_stats *stats)
+{
+	struct kszphy_priv *priv = phydev->priv;
+
+	stats->rx_errors = priv->phy_stats.rx_err_pkt_cnt;
+}
+
 static void kszphy_enable_clk(struct phy_device *phydev)
 {
 	struct kszphy_priv *priv = phydev->priv;
@@ -5745,6 +5779,7 @@ static struct phy_driver ksphy_driver[] = {
 	.phy_id		= PHY_ID_KSZ9477,
 	.phy_id_mask	= MICREL_PHY_ID_MASK,
 	.name		= "Microchip KSZ9477",
+	.probe		= kszphy_probe,
 	/* PHY_GBIT_FEATURES */
 	.config_init	= ksz9477_config_init,
 	.config_intr	= kszphy_config_intr,
@@ -5753,6 +5788,8 @@ static struct phy_driver ksphy_driver[] = {
 	.handle_interrupt = kszphy_handle_interrupt,
 	.suspend	= genphy_suspend,
 	.resume		= ksz9477_resume,
+	.get_phy_stats	= kszphy_get_phy_stats,
+	.update_stats	= kszphy_update_stats,
 } };
 
 module_phy_driver(ksphy_driver);
-- 
2.39.5

Re: [PATCH net-next v1 2/3] net: phy: micrel: Add RX error counter support for KSZ9477 switch-integrated PHYs

[Andrew Lunn]

On Tue, Jun 10, 2025 at 11:13:53AM +0200, Oleksij Rempel wrote:
> Add support for tracking receive error statistics from PHYs integrated
> into the KSZ9477 family of Ethernet switches.
> 
> The integrated PHYs expose a receive error (RXER) counter in register 0x15.
> This counter increments when the PHY detects one or more symbol errors
> on a received frame. The register is cleared upon reading.
> 
> Changes include:
> - `kszphy_update_stats()` to accumulate the RX error count.
> - `kszphy_get_phy_stats()` to expose this count via ethtool PHY stats.
> - Addition of a private `rx_err_pkt_cnt` field in the driver.
> - Registration of `.update_stats` and `.get_phy_stats` callbacks in the
>   KSZ9477 PHY driver structure.
> 
> The functionality of this counter was confirmed by physically disturbing
> the signal lines - specifically by wiggling exposed twisted pair wires and
> intentionally shorting between pairs. These actions triggered RXER
> increments, validating the counter's behavior.
> 
> This RXER counter is confirmed for KSZ9477 and likely applicable to
> other related PHYs like those in KSZ9313.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

[PATCH net-next v1 3/3] net: phy: micrel: add cable test support for KSZ9477-class PHYs

[Oleksij Rempel]

Enable cable test support for KSZ9477-class PHYs by reusing the
existing KSZ9131 implementation.

This also adds support for 100Mbit-only PHYs like KSZ8563, which are
identified as KSZ9477. For these PHYs, only two wire pairs (A and B)
are active, so the cable test logic limits the pair_mask accordingly.

Support for KSZ8563 is untested but added based on its register
compatibility and PHY ID match.

Tested on KSZ9893 (Gigabit): open and short conditions were correctly
detected on all four pairs. Fault length reporting is functional and
varies by pair. For example:
- 2m cable: open faults reported ~1.2m (pairs B–D), 0.0m (pair A)
- No cable: all pairs report 0.0m fault length

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/phy/micrel.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 68d86383e6c7..d0429dc8f561 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1723,7 +1723,8 @@ static int ksz9x31_cable_test_fault_length(struct phy_device *phydev, u16 stat)
 	 *
 	 * distance to fault = (VCT_DATA - 22) * 4 / cable propagation velocity
 	 */
-	if (phydev_id_compare(phydev, PHY_ID_KSZ9131))
+	if (phydev_id_compare(phydev, PHY_ID_KSZ9131) ||
+	    phydev_id_compare(phydev, PHY_ID_KSZ9477))
 		dt = clamp(dt - 22, 0, 255);
 
 	return (dt * 400) / 10;
@@ -1797,12 +1798,20 @@ static int ksz9x31_cable_test_get_status(struct phy_device *phydev,
 					 bool *finished)
 {
 	struct kszphy_priv *priv = phydev->priv;
-	unsigned long pair_mask = 0xf;
+	unsigned long pair_mask;
 	int retries = 20;
 	int pair, ret, rv;
 
 	*finished = false;
 
+	if (linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
+			      phydev->supported) ||
+	    linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
+			      phydev->supported))
+		pair_mask = 0xf; /* All pairs */
+	else
+		pair_mask = 0x3; /* Pairs A and B only */
+
 	/* Try harder if link partner is active */
 	while (pair_mask && retries--) {
 		for_each_set_bit(pair, &pair_mask, 4) {
@@ -5790,6 +5799,8 @@ static struct phy_driver ksphy_driver[] = {
 	.resume		= ksz9477_resume,
 	.get_phy_stats	= kszphy_get_phy_stats,
 	.update_stats	= kszphy_update_stats,
+	.cable_test_start	= ksz9x31_cable_test_start,
+	.cable_test_get_status	= ksz9x31_cable_test_get_status,
 } };
 
 module_phy_driver(ksphy_driver);
-- 
2.39.5

Re: [PATCH net-next v1 3/3] net: phy: micrel: add cable test support for KSZ9477-class PHYs

[Andrew Lunn]

On Tue, Jun 10, 2025 at 11:13:54AM +0200, Oleksij Rempel wrote:
> Enable cable test support for KSZ9477-class PHYs by reusing the
> existing KSZ9131 implementation.
> 
> This also adds support for 100Mbit-only PHYs like KSZ8563, which are
> identified as KSZ9477. For these PHYs, only two wire pairs (A and B)
> are active, so the cable test logic limits the pair_mask accordingly.
> 
> Support for KSZ8563 is untested but added based on its register
> compatibility and PHY ID match.
> 
> Tested on KSZ9893 (Gigabit): open and short conditions were correctly
> detected on all four pairs. Fault length reporting is functional and
> varies by pair. For example:
> - 2m cable: open faults reported ~1.2m (pairs B–D), 0.0m (pair A)
> - No cable: all pairs report 0.0m fault length
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH net-next v1 0/3] net: phy: micrel: add extended PHY support for KSZ9477-class devices

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 10 Jun 2025 11:13:51 +0200 you wrote:
> Hi all,
> 
> This patch series extends the PHY driver support for the Microchip
> KSZ9477-class switch-integrated PHYs. These changes enhance ethtool
> functionality and diagnostic capabilities by implementing the following
> features:
> - MDI/MDI-X configuration support
>   All crossover modes (auto, MDI, MDI-X) are now configurable.
> 
> [...]

Here is the summary with links:
  - [net-next,v1,1/3] net: phy: micrel: add MDI/MDI-X control support for KSZ9477 switch-integrated PHYs
    https://git.kernel.org/netdev/net-next/c/ee868127170c
  - [net-next,v1,2/3] net: phy: micrel: Add RX error counter support for KSZ9477 switch-integrated PHYs
    https://git.kernel.org/netdev/net-next/c/597ebdf37222
  - [net-next,v1,3/3] net: phy: micrel: add cable test support for KSZ9477-class PHYs
    https://git.kernel.org/netdev/net-next/c/b2f96c3c9631

You are awesome, thank you!
-- 
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