diff --git a/drivers/net/ethernet/ti/cpsw-phy-sel.c b/drivers/net/ethernet/ti/cpsw-phy-sel.c
index e9cc61e1ec742090157db6b792b1a6a9168e6635..c3e85acfdc70233a628f939477b208e3dd28121b 100644
--- a/drivers/net/ethernet/ti/cpsw-phy-sel.c
+++ b/drivers/net/ethernet/ti/cpsw-phy-sel.c
@@ -63,8 +63,12 @@ static void cpsw_gmii_sel_am3352(struct cpsw_phy_sel_priv *priv,
 		mode = AM33XX_GMII_SEL_MODE_RGMII;
 		break;
 
-	case PHY_INTERFACE_MODE_MII:
 	default:
+		dev_warn(priv->dev,
+			 "Unsupported PHY mode: \"%s\". Defaulting to MII.\n",
+			phy_modes(phy_mode));
+		/* fallthrough */
+	case PHY_INTERFACE_MODE_MII:
 		mode = AM33XX_GMII_SEL_MODE_MII;
 		break;
 	};
@@ -106,8 +110,12 @@ static void cpsw_gmii_sel_dra7xx(struct cpsw_phy_sel_priv *priv,
 		mode = AM33XX_GMII_SEL_MODE_RGMII;
 		break;
 
-	case PHY_INTERFACE_MODE_MII:
 	default:
+		dev_warn(priv->dev,
+			 "Unsupported PHY mode: \"%s\". Defaulting to MII.\n",
+			phy_modes(phy_mode));
+		/* fallthrough */
+	case PHY_INTERFACE_MODE_MII:
 		mode = AM33XX_GMII_SEL_MODE_MII;
 		break;
 	};