From 0d12e6a0033dd24c670446a7c685c6029d108e7e Mon Sep 17 00:00:00 2001
From: Hao Wu <hao.a.wu@intel.com>
Date: Fri, 11 Dec 2015 01:59:09 +0000
Subject: [PATCH] MdeModulePkg ScsiBusDxe: Fix caller event may nerver be
 signaled

For function ScsiExecuteSCSICommand(), when the 'Event' parameter is not
NULL but the target SCSI device does not support non-blocking I/O, it will
execute a blocking I/O operation instead.

However, after the SCSI operation is done, the 'Event' is not signaled to
inform the caller.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19217 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c | 46 +++++++++++++++++-----
 1 file changed, 37 insertions(+), 9 deletions(-)

diff --git a/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c b/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
index 3e49ffba68..8eb73e7673 100644
--- a/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
+++ b/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
@@ -2,7 +2,7 @@
   SCSI Bus driver that layers on every SCSI Pass Thru and
   Extended SCSI Pass Thru protocol in the system.
 
-Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2015, Intel Corporation. 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
@@ -986,13 +986,34 @@ ScsiExecuteSCSICommand (
 
   if (ScsiIoDevice->ExtScsiSupport) {
     ExtRequestPacket = (EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *) Packet;
-    Status = ScsiIoDevice->ExtScsiPassThru->PassThru (
-                                          ScsiIoDevice->ExtScsiPassThru,
-                                          Target,
-                                          ScsiIoDevice->Lun,
-                                          ExtRequestPacket,
-                                          Event
-                                          );
+
+    if (((ScsiIoDevice->ExtScsiPassThru->Mode->Attributes & EFI_SCSI_PASS_THRU_ATTRIBUTES_NONBLOCKIO) != 0) && (Event !=  NULL)) {
+      Status = ScsiIoDevice->ExtScsiPassThru->PassThru (
+                                                ScsiIoDevice->ExtScsiPassThru,
+                                                Target,
+                                                ScsiIoDevice->Lun,
+                                                ExtRequestPacket,
+                                                Event
+                                                );
+    } else {
+      //
+      // If there's no event or the SCSI Device doesn't support NON-BLOCKING,
+      // let the 'Event' parameter for PassThru() be NULL.
+      //
+      Status = ScsiIoDevice->ExtScsiPassThru->PassThru (
+                                                ScsiIoDevice->ExtScsiPassThru,
+                                                Target,
+                                                ScsiIoDevice->Lun,
+                                                ExtRequestPacket,
+                                                NULL
+                                                );
+      if (Event != NULL) {
+        //
+        // Signal Event to tell caller to pick up the SCSI IO Packet.
+        //
+        gBS->SignalEvent (Event);
+      }
+    }
   } else {
 
     mWorkingBuffer = AllocatePool (sizeof(EFI_SCSI_PASS_THRU_SCSI_REQUEST_PACKET));
@@ -1052,7 +1073,7 @@ ScsiExecuteSCSICommand (
                                           ScsiIoDevice->Pun.ScsiId.Scsi,
                                           ScsiIoDevice->Lun,
                                           mWorkingBuffer,
-                                          Event
+                                          NULL
                                           );
       if (EFI_ERROR(Status)) {
         FreePool(mWorkingBuffer);
@@ -1065,6 +1086,13 @@ ScsiExecuteSCSICommand (
       // free mWorkingBuffer.
       //
       FreePool(mWorkingBuffer);
+
+      //
+      // Signal Event to tell caller to pick up the SCSI IO Packet.
+      //
+      if (Event != NULL) {
+        gBS->SignalEvent (Event);
+      }
     }
   }
   return Status;
-- 
2.39.2