diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 159b16606f6c..44fcdd47ffb5 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -198,14 +198,14 @@ static u32 ethaddr_lo2_to_u32(const unsigned char *addr)
 
 static int yt921x_reg_read(struct yt921x_priv *priv, u32 reg, u32 *valp)
 {
-	WARN_ON(!mutex_is_locked(&priv->reg_lock));
+	lockdep_assert_held_once(&priv->reg_lock);
 
 	return priv->reg_ops->read(priv->reg_ctx, reg, valp);
 }
 
 static int yt921x_reg_write(struct yt921x_priv *priv, u32 reg, u32 val)
 {
-	WARN_ON(!mutex_is_locked(&priv->reg_lock));
+	lockdep_assert_held_once(&priv->reg_lock);
 
 	return priv->reg_ops->write(priv->reg_ctx, reg, val);
 }