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

@@ -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;
 }
 
 /**

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

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));

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);
-    *BufferSize = Count;
-    return (Count == 0) ? EFI_DEVICE_ERROR : EFI_SUCCESS;
   }
-  
-  // No data to return
-  *BufferSize = 0;
+
+  if (Count != *BufferSize) {
+    *BufferSize = Count;
+    return EFI_TIMEOUT;
+  }
+
   return EFI_SUCCESS;
 }