[ 03/15] PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King <colin.king@canonical.com>

commit 9e16721498b0c3d3ebfa0b503c63d35c0a4c0642 upstream.

Right now using pcie_aspm=force will not enable ASPM if the FADT indicates
ASPM is unsupported.  However, the semantics of force should probably allow
for this, especially as they did before 3c076351c4 ("PCI: Rework ASPM
disable code")

This patch just skips the clearing of any ASPM setup that the firmware has
carried out on this bus if pcie_aspm=force is being used.

Reference: http://bugs.launchpad.net/bugs/962038
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pci/pcie/aspm.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -790,6 +790,9 @@ void pcie_clear_aspm(struct pci_bus *bus
 {
 	struct pci_dev *child;
 
+	if (aspm_force)
+		return;
+
 	/*
 	 * Clear any ASPM setup that the firmware has carried out on this bus
 	 */