From 30a35388d12944e499642a0694c038a7e3ad6770 Mon Sep 17 00:00:00 2001 From: Joseph Shifflett Date: Tue, 6 Oct 2015 20:55:36 +0000 Subject: DuetPkg: exit pci function loops early if device is not multi-function When looping through all PCI functions, code should not look for functions 1-7 if function 0 is not present or if function 0 indicates the device is not multifunction. Prior to this fix the code would use stale data in a buffer to determine if a device is multifunction even if function 0 is not present. This fixes a code bug and provides very small performance improvements. PCI 2.3 Specification states: They [multifunction devices] are also required to always implement function 0 in the device. Implementing other functions is optional and may be assigned in any order. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Joseph Shifflett Reviewed-by: Ruiyu Ni git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18575 6f19259b-4bc3-4df7-8a09-765794883524 --- DuetPkg/PciBusNoEnumerationDxe/PciEnumeratorSupport.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'DuetPkg') diff --git a/DuetPkg/PciBusNoEnumerationDxe/PciEnumeratorSupport.c b/DuetPkg/PciBusNoEnumerationDxe/PciEnumeratorSupport.c index fb41727e7a..80b2b6b24d 100644 --- a/DuetPkg/PciBusNoEnumerationDxe/PciEnumeratorSupport.c +++ b/DuetPkg/PciBusNoEnumerationDxe/PciEnumeratorSupport.c @@ -1,6 +1,7 @@ /*++ Copyright (c) 2005 - 2014, Intel Corporation. All rights reserved.
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP
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 @@ -216,6 +217,13 @@ Returns: (UINT8) Func ); + if (EFI_ERROR (Status) && Func == 0) { + // + // go to next device if there is no Function 0 + // + break; + } + if (!EFI_ERROR (Status)) { // -- cgit v1.2.3