PCI: disable ASPM per ACPI FADT setting
The ACPI FADT table includes an ASPM control bit. If the bit is set, do
not enable ASPM since it may indicate that the platform doesn't actually
support the feature.
Tested-by: Jack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 7764768b..89a2f0f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
+#include <linux/pci-aspm.h>
#include <acpi/acpi.h>
#include <acpi/acnamesp.h>
#include <acpi/acresrc.h>
@@ -372,6 +373,12 @@
printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
pci_no_msi();
}
+
+ if (acpi_gbl_FADT.boot_flags & BAF_PCIE_ASPM_CONTROL) {
+ printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
+ pcie_no_aspm();
+ }
+
ret = register_acpi_bus_type(&acpi_pci_bus);
if (ret)
return 0;
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index f824955..759c51a 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -808,6 +808,11 @@
__setup("pcie_noaspm", pcie_aspm_disable);
+void pcie_no_aspm(void)
+{
+ aspm_disabled = 1;
+}
+
#ifdef CONFIG_ACPI
#include <acpi/acpi_bus.h>
#include <linux/pci-acpi.h>