PCI: Don't clear ASPM bits when the FADT declares it's unsupported
authorMatthew Garrett <mjg59@coreos.com>
Tue, 7 Apr 2015 18:07:00 +0000 (11:07 -0700)
committerBjorn Helgaas <bhelgaas@google.com>
Thu, 9 Apr 2015 19:20:11 +0000 (14:20 -0500)
commit387d37577fdd05e9472c20885464c2a53b3c945f
tree5658630a603c2fa28fe5dc54502a0ac4c3bebe43
parent37a9c502c0af013aaae094556830100c2bb133ac
PCI: Don't clear ASPM bits when the FADT declares it's unsupported

Communications with a hardware vendor confirm that the expected behaviour
on systems that set the FADT ASPM disable bit but which still grant full
PCIe control is for the OS to leave any BIOS configuration intact and
refuse to touch the ASPM bits.  This mimics the behaviour of Windows.

Signed-off-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
drivers/acpi/pci_root.c
drivers/pci/pcie/aspm.c
include/linux/pci-aspm.h