From 316d86fe8641abfad32702c77d9e62cf19e68b00 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 17 Jan 2012 17:41:21 -0700 Subject: [PATCH] x86/PCI: don't fall back to defaults if _CRS has no apertures Host bridges that lead to things like the Uncore need not have any I/O port or MMIO apertures. For example, in this case: ACPI: PCI Root Bridge [UNC1] (domain 0000 [bus ff]) PCI: root bus ff: using default resources PCI host bridge to bus 0000:ff pci_bus 0000:ff: root bus resource [io 0x0000-0xffff] pci_bus 0000:ff: root bus resource [mem 0x00000000-0x3fffffffffff] we should not pretend those default resources are available on bus ff. CC: Yinghai Lu Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes --- arch/x86/pci/acpi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index a312e76063a7..daa42490c1d9 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -404,7 +404,12 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root) kfree(sd); } else { get_current_resources(device, busnum, domain, &resources); - if (list_empty(&resources)) + + /* + * _CRS with no apertures is normal, so only fall back to + * defaults or native bridge info if we're ignoring _CRS. + */ + if (!pci_use_crs) x86_pci_root_bus_resources(busnum, &resources); bus = pci_create_root_bus(NULL, busnum, &pci_root_ops, sd, &resources); -- 2.20.1