Commit 73a0e614 authored Apr 06, 2010 by Bjorn Helgaas Committed by Jesse Barnes Apr 08, 2010

x86/PCI: ignore Consumer/Producer bit in ACPI window descriptions

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>

parent cf90bfe2

arch/x86/pci/acpi.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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;

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