From 91cc526b15ffbbbdec5a57906596f37e059f80be Mon Sep 17 00:00:00 2001
From: Pankaj Bansal <pankaj.bansal@nxp.com>
Date: Mon, 18 Sep 2017 15:42:45 +0800
Subject: [PATCH] MdeModulePkg/SerialDxe: Fix not able to change serial
 attributes

Issue : When try to change serial attributes using sermode
command, the default values are set with the execute flow
as below.

The sermode command calls SerialSetAttributes, which sets H/W
attributes of Serial device. After that the SerialIo protocol is
reinstalled, which causes MdeModulePkg/Universal/Console/TerminalDxe
and MdeModulePkg/Universal/Console/ConPlatformDxe drivers' bindings
to stop and then start. This in turn calls SerialReset, which undoes
changes of SerialSetAttributes.

Cause : The SerialReset command resets the attributes' values
to default.
Fix : Serial Reset command should set the attributes which have
been changed by user after calling SerialSetAttributes.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
---
 MdeModulePkg/Universal/SerialDxe/SerialIo.c | 66 ++++++---------------
 1 file changed, 18 insertions(+), 48 deletions(-)

diff --git a/MdeModulePkg/Universal/SerialDxe/SerialIo.c b/MdeModulePkg/Universal/SerialDxe/SerialIo.c
index 43d33dba0c..ebcd927263 100644
--- a/MdeModulePkg/Universal/SerialDxe/SerialIo.c
+++ b/MdeModulePkg/Universal/SerialDxe/SerialIo.c
@@ -220,7 +220,6 @@ SerialReset (
   )
 {
   EFI_STATUS    Status;
-  EFI_TPL       Tpl;
 
   Status = SerialPortInitialize ();
   if (EFI_ERROR (Status)) {
@@ -228,49 +227,17 @@ SerialReset (
   }
 
   //
-  // Set the Serial I/O mode and update the device path
+  // Go set the current attributes
   //
-
-  Tpl = gBS->RaiseTPL (TPL_NOTIFY);
-
-  //
-  // Set the Serial I/O mode
-  //
-  This->Mode->ReceiveFifoDepth  = PcdGet16 (PcdUartDefaultReceiveFifoDepth);
-  This->Mode->Timeout           = 1000 * 1000;
-  This->Mode->BaudRate          = PcdGet64 (PcdUartDefaultBaudRate);
-  This->Mode->DataBits          = (UINT32) PcdGet8 (PcdUartDefaultDataBits);
-  This->Mode->Parity            = (UINT32) PcdGet8 (PcdUartDefaultParity);
-  This->Mode->StopBits          = (UINT32) PcdGet8 (PcdUartDefaultStopBits);
-
-  //
-  // Check if the device path has actually changed
-  //
-  if (mSerialDevicePath.Uart.BaudRate == This->Mode->BaudRate &&
-      mSerialDevicePath.Uart.DataBits == (UINT8) This->Mode->DataBits &&
-      mSerialDevicePath.Uart.Parity   == (UINT8) This->Mode->Parity &&
-      mSerialDevicePath.Uart.StopBits == (UINT8) This->Mode->StopBits
-     ) {
-    gBS->RestoreTPL (Tpl);
-    return EFI_SUCCESS;
-  }
-
-  //
-  // Update the device path
-  //
-  mSerialDevicePath.Uart.BaudRate = This->Mode->BaudRate;
-  mSerialDevicePath.Uart.DataBits = (UINT8) This->Mode->DataBits;
-  mSerialDevicePath.Uart.Parity   = (UINT8) This->Mode->Parity;
-  mSerialDevicePath.Uart.StopBits = (UINT8) This->Mode->StopBits;
-
-  Status = gBS->ReinstallProtocolInterface (
-                  mSerialHandle,
-                  &gEfiDevicePathProtocolGuid,
-                  &mSerialDevicePath,
-                  &mSerialDevicePath
-                  );
-
-  gBS->RestoreTPL (Tpl);
+  Status = This->SetAttributes (
+                   This,
+                   This->Mode->BaudRate,
+                   This->Mode->ReceiveFifoDepth,
+                   This->Mode->Timeout,
+                   (EFI_PARITY_TYPE) This->Mode->Parity,
+                   (UINT8) This->Mode->DataBits,
+                   (EFI_STOP_BITS_TYPE) This->Mode->StopBits
+                   );
 
   return Status;
 }
@@ -513,11 +480,6 @@ SerialDxeInitialize (
 {
   EFI_STATUS            Status;
 
-  Status = SerialPortInitialize ();
-  if (EFI_ERROR (Status)) {
-    return Status;
-  }
-
   mSerialIoMode.BaudRate = PcdGet64 (PcdUartDefaultBaudRate);
   mSerialIoMode.DataBits = (UINT32) PcdGet8 (PcdUartDefaultDataBits);
   mSerialIoMode.Parity   = (UINT32) PcdGet8 (PcdUartDefaultParity);
@@ -528,6 +490,14 @@ SerialDxeInitialize (
   mSerialDevicePath.Uart.Parity   = PcdGet8 (PcdUartDefaultParity);
   mSerialDevicePath.Uart.StopBits = PcdGet8 (PcdUartDefaultStopBits);
 
+  //
+  // Issue a reset to initialize the Serial Port
+  //
+  Status = mSerialIoTemplate.Reset (&mSerialIoTemplate);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
   //
   // Make a new handle with Serial IO protocol and its device path on it.
   //