x86/PCI: ignore Consumer/Producer bit in ACPI window descriptions
authorBjorn Helgaas <bjorn.helgaas@hp.com>
Tue, 6 Apr 2010 19:24:08 +0000 (13:24 -0600)
committerJesse Barnes <jbarnes@virtuousgeek.org>
Thu, 8 Apr 2010 16:23:42 +0000 (09:23 -0700)
ACPI Address Space Descriptors (used in _CRS) have a Consumer/Producer
bit that is supposed to distinguish regions that are consumed directly
by a device from those that are forwarded ("produced") by a bridge.
But BIOSes have apparently not used this consistently, and Windows
seems to ignore it, so I think Linux should ignore it as well.

I can't point to any of these supposed broken BIOSes, but since we
now rely on _CRS by default, I think it's safer to ignore this bit
from the start.

Here are details of my experiments with how Windows handles it:
    https://bugzilla.kernel.org/show_bug.cgi?id=15701

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
arch/x86/pci/acpi.c

index c7b1ebfb7da79b3ee0f7b3cdaad17ba760b9e05e..334153ca4c301770850949e384f4feac60d4015f 100644 (file)
@@ -71,8 +71,7 @@ resource_to_addr(struct acpi_resource *resource,
        if (ACPI_SUCCESS(status) &&
            (addr->resource_type == ACPI_MEMORY_RANGE ||
            addr->resource_type == ACPI_IO_RANGE) &&
-           addr->address_length > 0 &&
-           addr->producer_consumer == ACPI_PRODUCER) {
+           addr->address_length > 0) {
                return AE_OK;
        }
        return AE_ERROR;