FAILED: patch "[PATCH] net: phy: dp83867: Disable EEE support as not implemented" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 84a905290cb4c3d9a71a9e3b2f2e02e031e7512f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025110212-wavy-support-eaec@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 84a905290cb4c3d9a71a9e3b2f2e02e031e7512f Mon Sep 17 00:00:00 2001
From: Emanuele Ghidoli <[email protected]>
Date: Thu, 23 Oct 2025 16:48:53 +0200
Subject: [PATCH] net: phy: dp83867: Disable EEE support as not implemented

While the DP83867 PHYs report EEE capability through their feature registers, the actual hardware does not support EEE (see Links). When the connected MAC enables EEE, it causes link instability and communication failures.

The issue is reproducible with a iMX8MP and relevant stmmac ethernet port. Since the introduction of phylink-managed EEE support in the stmmac driver, EEE is now enabled by default, leading to issues on systems using the DP83867 PHY.

Call phy_disable_eee during phy initialization to prevent EEE from being enabled on DP83867 PHYs.

index deeefb962566..36a0c1b7f59c 100644
@@ -738,6 +738,12 @@ static int dp83867_config_init(struct phy_device *phydev)
 			return ret;
 	}
 
+	/* Although the DP83867 reports EEE capability through the
+	 * MDIO_PCS_EEE_ABLE and MDIO_AN_EEE_ADV registers, the feature
+	 * is not actually implemented in hardware.
+	 */
+	phy_disable_eee(phydev);
+
 	if (phy_interface_is_rgmii(phydev) ||
 	    phydev->interface == PHY_INTERFACE_MODE_SGMII) {
 		val = phy_read(phydev, MII_DP83867_PHYCTRL);

From: Heiner Kallweit <[email protected]>

[ Upstream commit b55498ff14bd14860d48dc8d2a0b6889b218c408 ]

If a MAC driver doesn't support EEE, then the PHY shouldn't advertise it. Add phy_disable_eee() for this purpose.

Stable-dep-of: 84a905290cb4 ("net: phy: dp83867: Disable EEE support as not implemented")

---
 drivers/net/phy/phy_device.c | 16 ++++++++++++++++
 include/linux/phy.h          |  1 +
 2 files changed, 17 insertions(+)

index 834624a61060e..1a0c51a7702e5 100644
@@ -3045,6 +3045,22 @@ void phy_support_eee(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_support_eee);
 
+/**
+ * phy_disable_eee - Disable EEE for the PHY
+ * @phydev: Target phy_device struct
+ *
+ * This function is used by MAC drivers for MAC's which don't support EEE.
+ * It disables EEE on the PHY layer.
+ */
+void phy_disable_eee(struct phy_device *phydev)
+{
+	linkmode_zero(phydev->supported_eee);
+	linkmode_zero(phydev->advertising_eee);
+	phydev->eee_cfg.tx_lpi_enabled = false;
+	phydev->eee_cfg.eee_enabled = false;
+}
+EXPORT_SYMBOL_GPL(phy_disable_eee);
+
 /**
  * phy_support_sym_pause - Enable support of symmetrical pause
  * @phydev: target phy_device struct

index dfc7b97f9648d..1888924bca77d 100644
@@ -2030,6 +2030,7 @@ void phy_advertise_eee_all(struct phy_device *phydev);
 void phy_support_sym_pause(struct phy_device *phydev);
 void phy_support_asym_pause(struct phy_device *phydev);
 void phy_support_eee(struct phy_device *phydev);
+void phy_disable_eee(struct phy_device *phydev);
 void phy_set_sym_pause(struct phy_device *phydev, bool rx, bool tx,
 		       bool autoneg);
 void phy_set_asym_pause(struct phy_device *phydev, bool rx, bool tx);

2.51.0

From: Emanuele Ghidoli <[email protected]>

[ Upstream commit 84a905290cb4c3d9a71a9e3b2f2e02e031e7512f ]

While the DP83867 PHYs report EEE capability through their feature registers, the actual hardware does not support EEE (see Links). When the connected MAC enables EEE, it causes link instability and communication failures.

The issue is reproducible with a iMX8MP and relevant stmmac ethernet port. Since the introduction of phylink-managed EEE support in the stmmac driver, EEE is now enabled by default, leading to issues on systems using the DP83867 PHY.

Call phy_disable_eee during phy initialization to prevent EEE from being enabled on DP83867 PHYs.

---
 drivers/net/phy/dp83867.c | 6 ++++++
 1 file changed, 6 insertions(+)

index 4120385c5a79d..e02e3479e1c7a 100644
@@ -792,6 +792,12 @@ static int dp83867_config_init(struct phy_device *phydev)
 			return ret;
 	}
 
+	/* Although the DP83867 reports EEE capability through the
+	 * MDIO_PCS_EEE_ABLE and MDIO_AN_EEE_ADV registers, the feature
+	 * is not actually implemented in hardware.
+	 */
+	phy_disable_eee(phydev);
+
 	if (phy_interface_is_rgmii(phydev) ||
 	    phydev->interface == PHY_INTERFACE_MODE_SGMII) {
 		val = phy_read(phydev, MII_DP83867_PHYCTRL);

2.51.0