diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 6844106975a9..990ed3b07d3c 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -1937,6 +1937,7 @@ static int qca8k_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 
 	default:
 		WARN_ON(1);
+		return -EINVAL;
 	}
 
 	/* Enable/disable SerDes auto-negotiation as necessary */