From 12c22d6ef299ccf0955e5756eb57d90d7577ac68 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 26 Mar 2008 11:22:40 -0700 Subject: [PATCH] Revert "PCI: remove transparent bridge sizing" This reverts commit 8fa5913d54f3b1e09948e6a0db34da887e05ff1f, which caused various interesting problems for people, including wrong resource allocations. See for example bugzilla entry "2.6.25-rc2: ohci1394 problem (MMIO broken)" at http://bugzilla.kernel.org/show_bug.cgi?id=10080 And Gary Hade says: "The same change had also exposed an issue reported by Paul Martin that has been causing an Oops while hotplugging ThinkPads to a ThinkPad Dock II. See http://lkml.org/lkml/2008/2/19/405 http://bugzilla.kernel.org/show_bug.cgi?id=9961 I have a fix for the ThinkPad docking Oops but if the issue being discussed here is caused by the transparent bridge sizing removal change I totally agree that it should be reverted." The transparent bridge sizing removal change was motivated by insufficient PCI memory resource for a transparent bridge window that was being created as a result of expansion ROM(s) being included in the transparent bridge sizing calculations. A later "PCI: Remove default PCI expansion ROM memory allocation" change ( re: http://lkml.org/lkml/2007/12/11/361 ) removes the expansion ROM(s) from the transparent bridge sizing calculations which actually resolves the original issue in a different manner. So, even if the "PCI: remove transparent bridge sizing" is not problematic it is no longer needed anyway." Identified-by: Ivan Kokshaysky Tested-by: Thomas Meyer Acked-by: Gary Hade Acked-by: Ingo Molnar Cc: Stefan Richter Signed-off-by: Linus Torvalds --- drivers/pci/setup-bus.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 125e7b7f34ff..f7cb8e0758b4 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -486,12 +486,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus) break; case PCI_CLASS_BRIDGE_PCI: - /* don't size subtractive decoding (transparent) - * PCI-to-PCI bridges */ - if (bus->self->transparent) - break; pci_bridge_check_ranges(bus); - /* fall through */ default: pbus_size_io(bus); /* If the bridge supports prefetchable range, size it -- 2.20.1