diff --git a/libcpu/arm/lm3s/serial.c b/libcpu/arm/lm3s/serial.c
index 79cb0ff4b4bab25786638afddba78e304dbf5f2c..4dd2bf306d5d63b8290a1ed5c060ddc4a7175d1c 100644
--- a/libcpu/arm/lm3s/serial.c
+++ b/libcpu/arm/lm3s/serial.c
@@ -15,18 +15,18 @@
 #include <rthw.h>
 #include <rtthread.h>
 
-#include <inc/hw_types.h>
+#include <inc/hw_types.h>
 #include <inc/hw_memmap.h>
-#include <inc/hw_uart.h>
-#include <inc/hw_ints.h>
-#include <driverlib/gpio.h>
-#include <driverlib/sysctl.h>
-#include <driverlib/interrupt.h>
+#include <inc/hw_uart.h>
+#include <inc/hw_ints.h>
+#include <driverlib/gpio.h>
+#include <driverlib/sysctl.h>
+#include <driverlib/interrupt.h>
 
 #include <uart.h>
-#include "board.h"
+#include "board.h"
 
-extern void rt_hw_interrupt_thread_switch(void);
+extern void rt_hw_interrupt_thread_switch(void);
 
 #define RT_UART_RX_BUFFER_SIZE 64
 
@@ -59,7 +59,7 @@ void rt_hw_uart_isr(struct rt_lm3s_serial* serial)
     rt_uint32_t status;
 
     device = (struct rt_device*)serial;
-    UARTIntStatus(serial->hw_base, true);
+    status = UARTIntStatus(serial->hw_base, true);
 
     /* clear interrupt status */
     UARTIntClear(serial->hw_base, status);
@@ -309,20 +309,20 @@ void rt_hw_serial_init(void)
 	serial->baudrate = 115200;
 
 	rt_memset(serial->rx_buffer, 0, sizeof(serial->rx_buffer));
-	serial->read_index = serial->save_index = 0;
+	serial->read_index = serial->save_index = 0;
 
 	/* enable UART0 clock */
-    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
-    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
-
+    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
+    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
+
 	/* set UART0 pinmux */
-    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
+    GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
+
+	/* Configure the UART for 115,200, 8-N-1 operation. */
+	UARTConfigSetExpClk(UART0_BASE, SysCtlClockGet(), serial->baudrate,
+                        (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
+                         UART_CONFIG_PAR_NONE));
 
-	/* Configure the UART for 115,200, 8-N-1 operation. */
-	UARTConfigSetExpClk(UART0_BASE, SysCtlClockGet(), serial->baudrate,
-                        (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
-                         UART_CONFIG_PAR_NONE));
-
 	serial->parent.init 	= rt_serial_init;
 	serial->parent.open 	= rt_serial_open;
 	serial->parent.close    = rt_serial_close;