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)
commit73a0e614580fb650846be1e9315f6b7b6069b9cc
tree058e95bd3c0f88eee83f9b1f39afdcdd355392d5
parentcf90bfe2ebaf9d32f37acbebb7425c280fd6cd30
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>
arch/x86/pci/acpi.c