MS's doc defines aspm control bit in acpi FADT table. If the bit is set,
os should not enable aspm.
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
---
drivers/pci/pci-acpi.c | 7 +++++++
drivers/pci/pcie/aspm.c | 5 +++++
include/acpi/actbl.h | 1 +
include/linux/pci-aspm.h | 5 +++++
4 files changed, 18 insertions(+)
Index: linux/drivers/pci/pci-acpi.c
===================================================================
--- linux.orig/drivers/pci/pci-acpi.c 2008-07-21 10:40:29.000000000 +0800
+++ linux/drivers/pci/pci-acpi.c 2008-07-21 11:10:34.000000000 +0800
@@ -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 @@ static int __init acpi_pci_init(void)
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;
Index: linux/drivers/pci/pcie/aspm.c
===================================================================
--- linux.orig/drivers/pci/pcie/aspm.c 2008-07-21 10:44:55.000000000 +0800
+++ linux/drivers/pci/pcie/aspm.c 2008-07-21 14:55:51.000000000 +0800
@@ -808,6 +808,11 @@ static int __init pcie_aspm_disable(char
__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>
Index: linux/include/acpi/actbl.h
===================================================================
--- linux.orig/include/acpi/actbl.h 2008-07-21 10:40:42.000000000 +0800
+++ linux/include/acpi/actbl.h 2008-07-21 10:42:06.000000000 +0800
@@ -277,6 +277,7 @@ enum acpi_prefered_pm_profiles {
#define BAF_LEGACY_DEVICES 0x0001
#define BAF_8042_KEYBOARD_CONTROLLER 0x0002
#define BAF_MSI_NOT_SUPPORTED 0x0008
+#define BAF_PCIE_ASPM_CONTROL 0x0010
#define FADT2_REVISION_ID 3
#define FADT2_MINUS_REVISION_ID 2
Index: linux/include/linux/pci-aspm.h
===================================================================
--- linux.orig/include/linux/pci-aspm.h 2008-07-21 10:44:06.000000000 +0800
+++ linux/include/linux/pci-aspm.h 2008-07-21 10:46:15.000000000 +0800
@@ -27,6 +27,7 @@ extern void pcie_aspm_init_link_state(st
extern void pcie_aspm_exit_link_state(struct pci_dev *pdev);
extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
extern void pci_disable_link_state(struct pci_dev *pdev, int state);
+extern void pcie_no_aspm(void);
#else
static inline void pcie_aspm_init_link_state(struct pci_dev *pdev)
{
@@ -40,6 +41,10 @@ static inline void pcie_aspm_pm_state_ch
static inline void pci_disable_link_state(struct pci_dev *pdev, int state)
{
}
+
+static inline void pcie_no_aspm(void)
+{
+}
#endif
#ifdef CONFIG_PCIEASPM_DEBUG /* this depends on CONFIG_PCIEASPM */
--
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