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 <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Bjorn Helgaas 2012-01-17 17:41:21 -07:00 committed by Jesse Barnes
parent 1160831803
commit 316d86fe86

View File

@ -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);