1 files changed, 51 insertions, 33 deletions
diff --git a/ArmVirtPkg/Library/FdtPL011SerialPortLib/FdtPL011SerialPortLib.c b/ArmVirtPkg/Library/FdtPL011SerialPortLib/FdtPL011SerialPortLib.c
index 614ea5a860..9d71f36957 100644
--- a/ArmVirtPkg/Library/FdtPL011SerialPortLib/FdtPL011SerialPortLib.c
+++ b/ArmVirtPkg/Library/FdtPL011SerialPortLib/FdtPL011SerialPortLib.c
@@ -23,49 +23,57 @@
 #include <Library/HobLib.h>
 #include <Guid/EarlyPL011BaseAddress.h>
 
-STATIC UINTN  mSerialBaseAddress;
-
-RETURN_STATUS
-EFIAPI
-SerialPortInitialize (
-  VOID
-  )
-{
-  return RETURN_SUCCESS;
-}
+STATIC UINTN          mSerialBaseAddress;
+STATIC RETURN_STATUS  mPermanentStatus = RETURN_SUCCESS;
 
 /**
-
   Program hardware of Serial port
 
-  @return    RETURN_NOT_FOUND if no PL011 base address could be found
-             Otherwise, result of PL011UartInitializePort () is returned
+  @retval RETURN_SUCCESS    If the serial port was initialized successfully by
+                            this call, or an earlier call, to
+                            SerialPortInitialize().
 
+  @retval RETURN_NOT_FOUND  If no PL011 base address could be found.
+
+  @return                   Error codes forwarded from
+                            PL011UartInitializePort().
 **/
 RETURN_STATUS
 EFIAPI
-FdtPL011SerialPortLibInitialize (
+SerialPortInitialize (
   VOID
   )
 {
   VOID                *Hob;
+  RETURN_STATUS       Status;
   CONST UINT64        *UartBase;
+  UINTN               SerialBaseAddress;
   UINT64              BaudRate;
   UINT32              ReceiveFifoDepth;
   EFI_PARITY_TYPE     Parity;
   UINT8               DataBits;
   EFI_STOP_BITS_TYPE  StopBits;
 
+  if (mSerialBaseAddress != 0) {
+    return RETURN_SUCCESS;
+  }
+
+  if (RETURN_ERROR (mPermanentStatus)) {
+    return mPermanentStatus;
+  }
+
   Hob = GetFirstGuidHob (&gEarlyPL011BaseAddressGuid);
   if ((Hob == NULL) || (GET_GUID_HOB_DATA_SIZE (Hob) != sizeof *UartBase)) {
-    return RETURN_NOT_FOUND;
+    Status = RETURN_NOT_FOUND;
+    goto Failed;
   }
 
   UartBase = GET_GUID_HOB_DATA (Hob);
 
-  mSerialBaseAddress = (UINTN)*UartBase;
-  if (mSerialBaseAddress == 0) {
-    return RETURN_NOT_FOUND;
+  SerialBaseAddress = (UINTN)*UartBase;
+  if (SerialBaseAddress == 0) {
+    Status = RETURN_NOT_FOUND;
+    goto Failed;
   }
 
   BaudRate         = (UINTN)PcdGet64 (PcdUartDefaultBaudRate);
@@ -74,15 +82,25 @@ FdtPL011SerialPortLibInitialize (
   DataBits         = PcdGet8 (PcdUartDefaultDataBits);
   StopBits         = (EFI_STOP_BITS_TYPE)PcdGet8 (PcdUartDefaultStopBits);
 
-  return PL011UartInitializePort (
-           mSerialBaseAddress,
-           FixedPcdGet32 (PL011UartClkInHz),
-           &BaudRate,
-           &ReceiveFifoDepth,
-           &Parity,
-           &DataBits,
-           &StopBits
-           );
+  Status = PL011UartInitializePort (
+             SerialBaseAddress,
+             FixedPcdGet32 (PL011UartClkInHz),
+             &BaudRate,
+             &ReceiveFifoDepth,
+             &Parity,
+             &DataBits,
+             &StopBits
+             );
+  if (RETURN_ERROR (Status)) {
+    goto Failed;
+  }
+
+  mSerialBaseAddress = SerialBaseAddress;
+  return RETURN_SUCCESS;
+
+Failed:
+  mPermanentStatus = Status;
+  return Status;
 }
 
 /**
@@ -102,7 +120,7 @@ SerialPortWrite (
   IN UINTN  NumberOfBytes
   )
 {
-  if (mSerialBaseAddress != 0) {
+  if (!RETURN_ERROR (SerialPortInitialize ())) {
     return PL011UartWrite (mSerialBaseAddress, Buffer, NumberOfBytes);
   }
 
@@ -126,7 +144,7 @@ SerialPortRead (
   IN  UINTN  NumberOfBytes
   )
 {
-  if (mSerialBaseAddress != 0) {
+  if (!RETURN_ERROR (SerialPortInitialize ())) {
     return PL011UartRead (mSerialBaseAddress, Buffer, NumberOfBytes);
   }
 
@@ -146,7 +164,7 @@ SerialPortPoll (
   VOID
   )
 {
-  if (mSerialBaseAddress != 0) {
+  if (!RETURN_ERROR (SerialPortInitialize ())) {
     return PL011UartPoll (mSerialBaseAddress);
   }
 
@@ -199,7 +217,7 @@ SerialPortSetAttributes (
 {
   RETURN_STATUS  Status;
 
-  if (mSerialBaseAddress == 0) {
+  if (RETURN_ERROR (SerialPortInitialize ())) {
     Status = RETURN_UNSUPPORTED;
   } else {
     Status = PL011UartInitializePort (
@@ -234,7 +252,7 @@ SerialPortSetControl (
 {
   RETURN_STATUS  Status;
 
-  if (mSerialBaseAddress == 0) {
+  if (RETURN_ERROR (SerialPortInitialize ())) {
     Status = RETURN_UNSUPPORTED;
   } else {
     Status = PL011UartSetControl (mSerialBaseAddress, Control);
@@ -261,7 +279,7 @@ SerialPortGetControl (
 {
   RETURN_STATUS  Status;
 
-  if (mSerialBaseAddress == 0) {
+  if (RETURN_ERROR (SerialPortInitialize ())) {
     Status = RETURN_UNSUPPORTED;
   } else {
     Status = PL011UartGetControl (mSerialBaseAddress, Control);