[PATCH] x86/PCI: ignore Consumer/Producer bit in ACPI windowdescriptions

From: Bjorn Helgaas
Date: Tue Apr 06 2010 - 15:24:20 EST

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:

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>

arch/x86/pci/acpi.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index c7b1ebf..334153c 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -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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