From 40ab42ddca705bc0fedce6a933ef3b4787863445 Mon Sep 17 00:00:00 2001
From: oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Wed, 2 May 2012 20:04:42 +0000
Subject: [PATCH] EmbeddedPkg/SerialDxe: Do not block UART when no data is
 available on the port

Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13255 6f19259b-4bc3-4df7-8a09-765794883524
---
 ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c  | 31 +++++++++----------
 ArmPlatformPkg/Include/Drivers/PL011Uart.h    |  1 -
 .../PL011SerialPortLib/PL011SerialPortLib.c   |  3 +-
 EmbeddedPkg/SerialDxe/SerialIo.c              | 13 ++++----
 4 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c
index ca487ec98c..d728121b29 100644
--- a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c
+++ b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c
@@ -3,7 +3,7 @@
 
   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   Copyright (c) 2011 - 2012, ARM Ltd. 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
@@ -34,7 +34,6 @@ PL011UartInitializePort (
   IN UINTN               UartBase,
   IN UINT64              BaudRate,
   IN UINT32              ReceiveFifoDepth,
-  IN UINT32              Timeout,
   IN EFI_PARITY_TYPE     Parity,
   IN UINT8               DataBits,
   IN EFI_STOP_BITS_TYPE  StopBits
@@ -47,7 +46,7 @@ PL011UartInitializePort (
   if (BaudRate == 0) {
     return RETURN_INVALID_PARAMETER;
   }
-  
+
   LineControl = 0;
 
   // The PL011 supports a buffer of either 1 or 32 chars. Therefore we can accept
@@ -122,7 +121,7 @@ PL011UartInitializePort (
   default:
     return RETURN_INVALID_PARAMETER;
   }
-    
+
   // Don't send the LineControl value to the PL011 yet,
   // wait until after the Baud Rate setting.
   // This ensures we do not mess up the UART settings halfway through
@@ -134,7 +133,7 @@ PL011UartInitializePort (
   if (PcdGet32(PL011UartInteger) != 0) {
     // Integer and Factional part must be different of 0
     ASSERT(PcdGet32(PL011UartFractional) != 0);
-    
+
     MmioWrite32 (UartBase + UARTIBRD, PcdGet32(PL011UartInteger));
     MmioWrite32 (UartBase + UARTFBRD, PcdGet32(PL011UartFractional));
   } else {
@@ -305,14 +304,14 @@ PL011UartWrite (
   IN UINTN     NumberOfBytes
   )
 {
-	UINTN  Count;
+  UINTN  Count;
 
-	for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
-		while ((MmioRead32 (UartBase + UARTFR) & UART_TX_EMPTY_FLAG_MASK) == 0);
-		MmioWrite8 (UartBase + UARTDR, *Buffer);
-	}
+  for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
+    while ((MmioRead32 (UartBase + UARTFR) & UART_TX_EMPTY_FLAG_MASK) == 0);
+    MmioWrite8 (UartBase + UARTDR, *Buffer);
+  }
 
-	return NumberOfBytes;
+  return NumberOfBytes;
 }
 
 /**
@@ -335,12 +334,12 @@ PL011UartRead (
 {
   UINTN   Count;
 
-	for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
-		while ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) != 0);
-		*Buffer = MmioRead8 (UartBase + UARTDR);
-	}
+  for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
+    while ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) != 0);
+	*Buffer = MmioRead8 (UartBase + UARTDR);
+  }
 
-	return NumberOfBytes;
+  return NumberOfBytes;
 }
 
 /**
diff --git a/ArmPlatformPkg/Include/Drivers/PL011Uart.h b/ArmPlatformPkg/Include/Drivers/PL011Uart.h
index 518dab587f..354f111032 100644
--- a/ArmPlatformPkg/Include/Drivers/PL011Uart.h
+++ b/ArmPlatformPkg/Include/Drivers/PL011Uart.h
@@ -94,7 +94,6 @@ PL011UartInitializePort (
   IN UINTN               UartBase,
   IN UINT64              BaudRate,
   IN UINT32              ReceiveFifoDepth,
-  IN UINT32              Timeout,
   IN EFI_PARITY_TYPE     Parity,
   IN UINT8               DataBits,
   IN EFI_STOP_BITS_TYPE  StopBits
diff --git a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
index e3d8aabbc7..2395ffd6c8 100644
--- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
+++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
@@ -14,7 +14,7 @@
 
 **/
 
-#include <Include/Base.h>
+#include <Base.h>
 
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
@@ -40,7 +40,6 @@ SerialPortInitialize (
       (UINTN)PcdGet64 (PcdSerialRegisterBase),
       (UINTN)PcdGet64 (PcdUartDefaultBaudRate),
       0, // Use the default value for Fifo depth
-      0, // Use the default value for Timeout,
       (EFI_PARITY_TYPE)PcdGet8 (PcdUartDefaultParity),
       PcdGet8 (PcdUartDefaultDataBits),
       (EFI_STOP_BITS_TYPE) PcdGet8 (PcdUartDefaultStopBits));
diff --git a/EmbeddedPkg/SerialDxe/SerialIo.c b/EmbeddedPkg/SerialDxe/SerialIo.c
index 59d904c192..ef4e6a1910 100644
--- a/EmbeddedPkg/SerialDxe/SerialIo.c
+++ b/EmbeddedPkg/SerialDxe/SerialIo.c
@@ -167,7 +167,7 @@ SerialWrite (
 }
 
 /**
-  Writes data to a serial device.
+  Reads data from a serial device.
 
   @param  This              Protocol instance pointer.
   @param  BufferSize        On input, the size of the Buffer. On output, the amount of
@@ -189,15 +189,16 @@ SerialRead (
   )
 {
   UINTN Count = 0;
-  
+
   if (SerialPortPoll()) {
     Count = SerialPortRead (Buffer, *BufferSize);
+  }
+
+  if (Count != *BufferSize) {
     *BufferSize = Count;
-    return (Count == 0) ? EFI_DEVICE_ERROR : EFI_SUCCESS;
+    return EFI_TIMEOUT;
   }
-  
-  // No data to return
-  *BufferSize = 0;
+
   return EFI_SUCCESS;
 }
 
-- 
2.39.2