From 3a2f9cce7d2a393c6655c6cf2cde8539e75aa3ea Mon Sep 17 00:00:00 2001
From: erictian <erictian@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Thu, 4 Mar 2010 09:29:34 +0000
Subject: [PATCH] uniform the sw and hw expression to avoid confusing. it does
 not effect hw function.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10186 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c | 7 ++++---
 MdeModulePkg/Bus/Pci/EhciDxe/UsbHcMem.c  | 4 ++++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
index d2e53300af..58d4a303dc 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/EhciSched.c
@@ -74,6 +74,7 @@ EhcCreateHelpQ (
   QhHw->HorizonLink = QH_LINK (PciAddr + OFFSET_OF(EHC_QH, QhHw), EHC_TYPE_QH, FALSE);
   QhHw->Status      = QTD_STAT_HALTED;
   QhHw->ReclaimHead = 1;
+  Qh->NextQh        = Qh;
   Ehc->ReclaimHead  = Qh;
 
   //
@@ -335,9 +336,9 @@ EhcLinkQhToAsync (
   Qh->NextQh              = Head->NextQh;
   Head->NextQh            = Qh;
 
-  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Head, sizeof (EHC_QH));
+  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Qh->NextQh, sizeof (EHC_QH));
   Qh->QhHw.HorizonLink    = QH_LINK (PciAddr, EHC_TYPE_QH, FALSE);
-  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Qh, sizeof (EHC_QH));
+  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Head->NextQh, sizeof (EHC_QH));
   Head->QhHw.HorizonLink  = QH_LINK (PciAddr, EHC_TYPE_QH, FALSE);
 }
 
@@ -372,7 +373,7 @@ EhcUnlinkQhFromAsync (
   Head->NextQh            = Qh->NextQh;
   Qh->NextQh              = NULL;
 
-  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Head, sizeof (EHC_QH));
+  PciAddr = UsbHcGetPciAddressForHostMem (Ehc->MemPool, Head->NextQh, sizeof (EHC_QH));
   Head->QhHw.HorizonLink  = QH_LINK (PciAddr, EHC_TYPE_QH, FALSE);
 
   //
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/UsbHcMem.c b/MdeModulePkg/Bus/Pci/EhciDxe/UsbHcMem.c
index 5194d540a7..536d8ad8e6 100644
--- a/MdeModulePkg/Bus/Pci/EhciDxe/UsbHcMem.c
+++ b/MdeModulePkg/Bus/Pci/EhciDxe/UsbHcMem.c
@@ -246,6 +246,10 @@ UsbHcGetPciAddressForHostMem (
   Head      = Pool->Head;
   AllocSize = USBHC_MEM_ROUND (Size);
 
+  if (Mem == NULL) {
+    return 0;
+  }
+
   for (Block = Head; Block != NULL; Block = Block->Next) {
     //
     // scan the memory block list for the memory block that