diff --git a/MdeModulePkg/Include/Ppi/SerialPortPei.h b/MdeModulePkg/Include/Ppi/SerialPortPei.h
index 88fcbf6e80..2b754f9cca 100644
--- a/MdeModulePkg/Include/Ppi/SerialPortPei.h
+++ b/MdeModulePkg/Include/Ppi/SerialPortPei.h
@@ -13,8 +13,8 @@
 
 **/
 
-#ifndef _PEI_SERIAL_PORT_PPI_H
-#define _PEI_SERIAL_PORT_PPI_H
+#ifndef __PEI_SERIAL_PORT_PPI_H__
+#define __PEI_SERIAL_PORT_PPI_H__
 
 #define PEI_SERIAL_PORT_PPI \
   { \
diff --git a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
index 190740c0bb..d21c00c5a4 100644
--- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
+++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
@@ -63,6 +63,7 @@ typedef struct {
   parameter Offset is added to the base address of the 16550 registers that is specified 
   by PcdSerialRegisterBase. 
   
+  @param  Base    The base address register of UART device.
   @param  Offset  The offset of the 16550 register to read.
 
   @return The value read from the 16550 register.
@@ -87,6 +88,7 @@ SerialPortReadRegister (
   parameter Offset is added to the base address of the 16550 registers that is specified 
   by PcdSerialRegisterBase. 
   
+  @param  Base    The base address register of UART device.
   @param  Offset  The offset of the 16550 register to write.
   @param  Value   The value to write to the 16550 register specified by Offset.
 
@@ -173,7 +175,7 @@ SerialPortLibUpdatePciRegister32 (
   This function assumes Root Bus Numer is Zero, and enables I/O and MMIO in PCI UART 
   Device if they are not already enabled. 
   
-  @return  The base address register of the PCI UART device.
+  @return  The base address register of the UART device.
 
 **/
 UINTN
@@ -411,6 +413,8 @@ GetSerialRegisterBase (
 /**
   Return whether the hardware flow control signal allows writing.
 
+  @param  SerialRegisterBase The base address register of UART device.
+
   @retval TRUE  The serial port is writable.
   @retval FALSE The serial port is not writable.
 **/