diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 9ada89355747554dc458c311f96333866cf7bc66..86a4aa72b3d4b3ca16aee15e0567036a6a2f6504 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -2,7 +2,7 @@
 /*
  * Broadcom GENET MDIO routines
  *
- * Copyright (c) 2014-2017 Broadcom
+ * Copyright (c) 2014-2024 Broadcom
  */
 
 #include <linux/acpi.h>
@@ -275,6 +275,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
 	 * block for the interface to work, unconditionally clear the
 	 * Out-of-band disable since we do not need it.
 	 */
+	mutex_lock(&phydev->lock);
 	reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
 	reg &= ~OOB_DISABLE;
 	if (priv->ext_phy) {
@@ -286,6 +287,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
 			reg |= RGMII_MODE_EN;
 	}
 	bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
+	mutex_unlock(&phydev->lock);
 
 	if (init)
 		dev_info(kdev, "configuring instance for %s\n", phy_name);