diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c
index 5efb2b593be333483afd79b52678e1e177cb9acf..45022f2909f0af0a0a60478c901e263609a829a8 100644
--- a/drivers/tty/serial/max3100.c
+++ b/drivers/tty/serial/max3100.c
@@ -213,7 +213,7 @@ static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
 	return 0;
 }
 
-static int max3100_handlerx(struct max3100_port *s, u16 rx)
+static int max3100_handlerx_unlocked(struct max3100_port *s, u16 rx)
 {
 	unsigned int status = 0;
 	int ret = 0, cts;
@@ -254,6 +254,17 @@ static int max3100_handlerx(struct max3100_port *s, u16 rx)
 	return ret;
 }
 
+static int max3100_handlerx(struct max3100_port *s, u16 rx)
+{
+	unsigned long flags;
+	int ret;
+
+	uart_port_lock_irqsave(&s->port, &flags);
+	ret = max3100_handlerx_unlocked(s, rx);
+	uart_port_unlock_irqrestore(&s->port, flags);
+	return ret;
+}
+
 static void max3100_work(struct work_struct *w)
 {
 	struct max3100_port *s = container_of(w, struct max3100_port, work);