From 297495f410228bed151dc767dfbbf5617323e378 Mon Sep 17 00:00:00 2001
From: Aaron Antone <aanton@microsoft.com>
Date: Thu, 11 Apr 2019 18:42:58 +0800
Subject: [PATCH] MdeModulePkg/ConSplitterDxe: Optimize the
 ConSplitterTextOutSetMode

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1412

For Console Out device, it would always set all present devices'
text out mode again through ConSplitterTextOutSetMode while adding
devices. That may cause the screen cleared for serval times.
So add a BOOLEAN to judge if it is adding device then we will not
set the same text mode again for same console out device.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
---
 .../Console/ConSplitterDxe/ConSplitter.c      | 33 ++++++++++++-------
 .../Console/ConSplitterDxe/ConSplitter.h      |  4 ++-
 2 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
index 6fc0e4796f..63c814ae18 100644
--- a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
+++ b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.c
@@ -16,7 +16,7 @@
   never removed. Such design ensures sytem function well during none console
   device situation.
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
 (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -180,7 +180,8 @@ GLOBAL_REMOVE_IF_UNREFERENCED TEXT_OUT_SPLITTER_PRIVATE_DATA mConOut = {
   0,
   (TEXT_OUT_SPLITTER_QUERY_DATA *) NULL,
   0,
-  (INT32 *) NULL
+  (INT32 *) NULL,
+  FALSE
 };
 
 //
@@ -235,7 +236,8 @@ GLOBAL_REMOVE_IF_UNREFERENCED TEXT_OUT_SPLITTER_PRIVATE_DATA mStdErr = {
   0,
   (TEXT_OUT_SPLITTER_QUERY_DATA *) NULL,
   0,
-  (INT32 *) NULL
+  (INT32 *) NULL,
+  FALSE
 };
 
 //
@@ -3132,8 +3134,9 @@ ConSplitterTextOutAddDevice (
   EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *Info;
   EFI_STATUS                           DeviceStatus;
 
-  Status                = EFI_SUCCESS;
-  CurrentNumOfConsoles  = Private->CurrentNumberOfConsoles;
+  Status                      = EFI_SUCCESS;
+  CurrentNumOfConsoles        = Private->CurrentNumberOfConsoles;
+  Private->AddingConOutDevice = TRUE;
 
   //
   // If the Text Out List is full, enlarge it by calling ConSplitterGrowBuffer().
@@ -3290,6 +3293,8 @@ ConSplitterTextOutAddDevice (
   //
   ConsplitterSetConsoleOutMode (Private);
 
+  Private->AddingConOutDevice = FALSE;
+
   return Status;
 }
 
@@ -4849,12 +4854,18 @@ ConSplitterTextOutSetMode (
   //
   TextOutModeMap = Private->TextOutModeMap + Private->TextOutListCount * ModeNumber;
   for (Index = 0, ReturnStatus = EFI_SUCCESS; Index < Private->CurrentNumberOfConsoles; Index++) {
-    Status = Private->TextOutList[Index].TextOut->SetMode (
-                                                    Private->TextOutList[Index].TextOut,
-                                                    TextOutModeMap[Index]
-                                                    );
-    if (EFI_ERROR (Status)) {
-      ReturnStatus = Status;
+    //
+    // While adding a console out device do not set same mode again for the same device.
+    //
+    if ((!Private->AddingConOutDevice) ||
+        (TextOutModeMap[Index] != Private->TextOutList[Index].TextOut->Mode->Mode)) {
+      Status = Private->TextOutList[Index].TextOut->SetMode (
+                                                      Private->TextOutList[Index].TextOut,
+                                                      TextOutModeMap[Index]
+                                                      );
+      if (EFI_ERROR (Status)) {
+        ReturnStatus = Status;
+      }
     }
   }
 
diff --git a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.h b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.h
index e9b68e58c6..419635c3f5 100644
--- a/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.h
+++ b/MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitter.h
@@ -1,7 +1,7 @@
 /** @file
   Private data structures for the Console Splitter driver
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -218,6 +218,8 @@ typedef struct {
   UINTN                                 TextOutQueryDataCount;
   INT32                                 *TextOutModeMap;
 
+  BOOLEAN                               AddingConOutDevice;
+
 } TEXT_OUT_SPLITTER_PRIVATE_DATA;
 
 #define TEXT_OUT_SPLITTER_PRIVATE_DATA_FROM_THIS(a) \
-- 
2.39.2