MdeModulePkg/PciBus: Should reserve enough bus number for HPC

When there is no bridge before the HPC (hot plug controller),
the issue cannot be seen.
But when there are bridges before the HPC, the PciBus will only
use the value (= <CurrentBusNumber> + <ReservedBusNumber>) as the
sub-ordinary bus number for HPC.
The correct sub-ordinary bus number should be:
<CurrentBusNumber> + <OccupiedBusNumber>(by earlier bridges) +
<ReservedBusNumber>.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
index 12647be85f..f3407bcb63 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
@@ -1,7 +1,7 @@
 /** @file

   Internal library implementation for PCI Bus module.

 

-Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>

+Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>

 (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>

 This program and the accompanying materials

 are licensed and made available under the terms and conditions of the BSD License

@@ -1232,7 +1232,7 @@ PciScanBus (
             //

             // Reserve the larger one between the actual occupied bus number and padded bus number

             //

-            Status = PciAllocateBusNumber (PciDevice, StartBusNumber, (UINT8) (BusRange), &PaddedSubBus);

+            Status = PciAllocateBusNumber (PciDevice, SecondBus, (UINT8) (BusRange), &PaddedSubBus);

             if (EFI_ERROR (Status)) {

               return Status;

             }