diff --git a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
index 04d8ca1949..a6c990dee6 100644
--- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
+++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.c
@@ -38,6 +38,7 @@
 #define   B_UART_LSR_TEMT     BIT6
 #define R_UART_MSR            6
 #define   B_UART_MSR_CTS      BIT4
+#define   B_UART_MSR_DSR      BIT5
 
 /**
   Read an 8-bit 16550 register.  If PcdSerialUseMmio is TRUE, then the value is read from 
@@ -226,10 +227,35 @@ SerialPortWrite (
     //
     for (Index = 0; Index < FifoSize && NumberOfBytes != 0; Index++, NumberOfBytes--, Buffer++) {
       if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
-        //
-        // Wait for notification from peer to send data
-        //
-        while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_CTS)) == 0);
+        if (PcdGetBool (PcdSerialDetectCable)) {
+          //
+          // Wait for both DSR and CTS to be set
+          //   DSR is set if a cable is connected.
+          //   CTS is set if it is ok to transmit data
+          //
+          //   DSR  CTS  Description                               Action
+          //   ===  ===  ========================================  ========
+          //    0    0   No cable connected.                       Wait
+          //    0    1   No cable connected.                       Wait
+          //    1    0   Cable connected, but not clear to send.   Wait
+          //    1    1   Cable connected, and clear to send.       Transmit
+          //
+          while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) != (B_UART_MSR_DSR | B_UART_MSR_CTS));
+        } else {
+          //
+          // Wait for both DSR and CTS to be set OR for DSR to be clear.  
+          //   DSR is set if a cable is connected.
+          //   CTS is set if it is ok to transmit data
+          //
+          //   DSR  CTS  Description                               Action
+          //   ===  ===  ========================================  ========
+          //    0    0   No cable connected.                       Transmit
+          //    0    1   No cable connected.                       Transmit
+          //    1    0   Cable connected, but not clear to send.   Wait
+          //    1    1   Cable connected, and clar to send.        Transmit
+          //
+          while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) == (B_UART_MSR_DSR));
+        }
       }
       
       //
diff --git a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
index 251f353884..3f223667c7 100644
--- a/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
+++ b/MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf
@@ -1,7 +1,7 @@
 ## @file
 #   SerialPortLib instance for 16550 UART
 #
-#  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
 #  This program and the accompanying materials
 #  are licensed and made available under the terms and conditions of the BSD License
 #  which accompanies this distribution.  The full text of the license may be found at
@@ -35,6 +35,7 @@
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialDetectCable
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterBase
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialBaudRate
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialLineControl
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 63297bb11b..093eeae180 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -4,7 +4,7 @@
 # It also provides the defintions(including PPIs/PROTOCOLs/GUIDs and library classes)
 # and libraries instances, which are used for those modules.
 #
-# Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.<BR>
 # This program and the accompanying materials are licensed and made available under 
 # the terms and conditions of the BSD License that accompanies this distribution.  
 # The full text of the license may be found at
@@ -402,6 +402,11 @@
   #  If FALSE, then the 16550 serial port hardware flow control is disabled.  Default value.
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseHardwareFlowControl|FALSE|BOOLEAN|0x00020001
 
+  ## If TRUE, then 16550 serial Tx operations will block if DSR is not asserted (no cable).
+  #  If FALSE, then the 16550 serial Tx operations will not be blocked if DSR is not asserted. Default value.
+  #  This PCD is ignored if PcdSerialUseHardwareFlowControl is FALSE.
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialDetectCable|FALSE|BOOLEAN|0x00020006
+    
   ## Base address of 16550 serial port registers in MMIO or I/O space.  Default is 0x3F8.
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterBase|0x03F8|UINT64|0x00020002