diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
index 6331464d9101..de11ab8ffd91 100644
--- a/drivers/tty/serial/apbuart.c
+++ b/drivers/tty/serial/apbuart.c
@@ -125,7 +125,9 @@ static void apbuart_rx_chars(struct uart_port *port)
 		status = UART_GET_STATUS(port);
 	}
 
+	spin_unlock(&port->lock);
 	tty_flip_buffer_push(&port->state->port);
+	spin_lock(&port->lock);
 }
 
 static void apbuart_tx_chars(struct uart_port *port)