From: Ruiyu Ni Subject: [PATCH] MdeModulePkg/PciBus: Fix bug that PCI BUS claims too much resource Date: Thu, 16 Nov 2017 18:15:14 +0100 The bug was caused by 728d74973c9262b6c7b7ef4be213223d55affec3 "MdeModulePkg/PciBus: Count multiple hotplug resource paddings". The patch firstly updated the Bridge->Alignment to the maximum alignment of all devices under the bridge, then aligned the Bridge->Length to Bridge->Alignment. It caused too much resources were claimed. The new patch firstly aligns Bridge->Length to Bridge->Alignment, then updates the Bridge->Alignment to the maximum alignment of all devices under the bridge. Because the step to update the Bridge->Alignment is to make sure the resource allocated to the bus under the Bridge meets all devices alignment. But the Bridge->Length doesn't have to align to the maximum alignment. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni Reviewed-by: Eric Dong (cherry picked from commit 6e3287442774c1a4bc83f127694700eeb07c18dc) --- MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c | 24 ++++++++++---------- 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c index 8dbe9a00380f..2f713fcee95e 100644 --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciResourceSupport.c @@ -389,18 +389,7 @@ CalculateResourceAperture ( } // - // Adjust the bridge's alignment to the MAX (first) alignment of all children. - // - CurrentLink = Bridge->ChildList.ForwardLink; - if (CurrentLink != &Bridge->ChildList) { - Node = RESOURCE_NODE_FROM_LINK (CurrentLink); - if (Node->Alignment > Bridge->Alignment) { - Bridge->Alignment = Node->Alignment; - } - } - - // - // At last, adjust the aperture with the bridge's alignment + // Adjust the aperture with the bridge's alignment // Aperture[PciResUsageTypical] = ALIGN_VALUE (Aperture[PciResUsageTypical], Bridge->Alignment + 1); Aperture[PciResUsagePadding] = ALIGN_VALUE (Aperture[PciResUsagePadding], Bridge->Alignment + 1); @@ -410,6 +399,17 @@ CalculateResourceAperture ( // Use the larger one between the padding resource and actual occupied resource. // Bridge->Length = MAX (Aperture[PciResUsageTypical], Aperture[PciResUsagePadding]); + + // + // Adjust the bridge's alignment to the MAX (first) alignment of all children. + // + CurrentLink = Bridge->ChildList.ForwardLink; + if (CurrentLink != &Bridge->ChildList) { + Node = RESOURCE_NODE_FROM_LINK (CurrentLink); + if (Node->Alignment > Bridge->Alignment) { + Bridge->Alignment = Node->Alignment; + } + } } /** -- 2.14.1.3.gb7cf6e02401b