EmbeddedPkg/SerialDxe: Only read Serial Port if data available

[mirror_edk2.git] / EmbeddedPkg / SerialDxe / SerialIo.c

diff --git a/EmbeddedPkg/SerialDxe/SerialIo.c b/EmbeddedPkg/SerialDxe/SerialIo.c
index 612543be14abff3d51cae457ec868ee59533d1fb..b9ea4b9c423c001d647eb054b695e620295b6d10 100644 (file)
--- a/EmbeddedPkg/SerialDxe/SerialIo.c
+++ b/EmbeddedPkg/SerialDxe/SerialIo.c
@@ -188,10 +188,12 @@ SerialRead (
   OUT VOID                   *Buffer\r
   )\r
 {\r
-  UINTN Count;\r
+  UINTN Count = 0;\r
   \r
-  Count = SerialPortRead (Buffer, *BufferSize);\r
-  *BufferSize = Count;\r
+  if (SerialPortPoll()) {\r
+    Count = SerialPortRead (Buffer, *BufferSize);\r
+    *BufferSize = Count;\r
+  }\r
   return (Count == 0) ? EFI_DEVICE_ERROR : EFI_SUCCESS;\r
 }\r
 \r