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-rw-r--r--drivers/acpi/pci_root.c7
-rw-r--r--drivers/pci/pci-acpi.c1
-rw-r--r--drivers/pci/pcie/aspm.c58
-rw-r--r--include/linux/pci-aspm.h4
4 files changed, 46 insertions, 24 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 2672c798272f..7aff6312ce7c 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -596,6 +596,13 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
if (ACPI_SUCCESS(status)) {
dev_info(root->bus->bridge,
"ACPI _OSC control (0x%02x) granted\n", flags);
+ if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
+ /*
+ * We have ASPM control, but the FADT indicates
+ * that it's unsupported. Clear it.
+ */
+ pcie_clear_aspm(root->bus);
+ }
} else {
dev_info(root->bus->bridge,
"ACPI _OSC request failed (%s), "
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 4ecb6408b0d6..c8e75851a314 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -395,7 +395,6 @@ static int __init acpi_pci_init(void)
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
- pcie_clear_aspm();
pcie_no_aspm();
}
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index cbfbab18be91..1cfbf228fbb1 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -68,7 +68,7 @@ struct pcie_link_state {
struct aspm_latency acceptable[8];
};
-static int aspm_disabled, aspm_force, aspm_clear_state;
+static int aspm_disabled, aspm_force;
static bool aspm_support_enabled = true;
static DEFINE_MUTEX(aspm_lock);
static LIST_HEAD(link_list);
@@ -500,9 +500,6 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
int pos;
u32 reg32;
- if (aspm_clear_state)
- return -EINVAL;
-
/*
* Some functions in a slot might not all be PCIe functions,
* very strange. Disable ASPM for the whole slot
@@ -574,9 +571,6 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
return;
- if (aspm_disabled && !aspm_clear_state)
- return;
-
/* VIA has a strange chipset, root port is under a bridge */
if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT &&
pdev->bus->self)
@@ -608,7 +602,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
* the BIOS's expectation, we'll do so once pci_enable_device() is
* called.
*/
- if (aspm_policy != POLICY_POWERSAVE || aspm_clear_state) {
+ if (aspm_policy != POLICY_POWERSAVE) {
pcie_config_aspm_path(link);
pcie_set_clkpm(link, policy_to_clkpm_state(link));
}
@@ -649,8 +643,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
struct pci_dev *parent = pdev->bus->self;
struct pcie_link_state *link, *root, *parent_link;
- if ((aspm_disabled && !aspm_clear_state) || !pci_is_pcie(pdev) ||
- !parent || !parent->link_state)
+ if (!pci_is_pcie(pdev) || !parent || !parent->link_state)
return;
if ((parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT) &&
(parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM))
@@ -734,13 +727,18 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
* pci_disable_link_state - disable pci device's link state, so the link will
* never enter specific states
*/
-static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
+static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem,
+ bool force)
{
struct pci_dev *parent = pdev->bus->self;
struct pcie_link_state *link;
- if (aspm_disabled || !pci_is_pcie(pdev))
+ if (aspm_disabled && !force)
+ return;
+
+ if (!pci_is_pcie(pdev))
return;
+
if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
parent = pdev;
@@ -768,16 +766,31 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
void pci_disable_link_state_locked(struct pci_dev *pdev, int state)
{
- __pci_disable_link_state(pdev, state, false);
+ __pci_disable_link_state(pdev, state, false, false);
}
EXPORT_SYMBOL(pci_disable_link_state_locked);
void pci_disable_link_state(struct pci_dev *pdev, int state)
{
- __pci_disable_link_state(pdev, state, true);
+ __pci_disable_link_state(pdev, state, true, false);
}
EXPORT_SYMBOL(pci_disable_link_state);
+void pcie_clear_aspm(struct pci_bus *bus)
+{
+ struct pci_dev *child;
+
+ /*
+ * Clear any ASPM setup that the firmware has carried out on this bus
+ */
+ list_for_each_entry(child, &bus->devices, bus_list) {
+ __pci_disable_link_state(child, PCIE_LINK_STATE_L0S |
+ PCIE_LINK_STATE_L1 |
+ PCIE_LINK_STATE_CLKPM,
+ false, true);
+ }
+}
+
static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
{
int i;
@@ -935,6 +948,7 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
static int __init pcie_aspm_disable(char *str)
{
if (!strcmp(str, "off")) {
+ aspm_policy = POLICY_DEFAULT;
aspm_disabled = 1;
aspm_support_enabled = false;
printk(KERN_INFO "PCIe ASPM is disabled\n");
@@ -947,16 +961,18 @@ static int __init pcie_aspm_disable(char *str)
__setup("pcie_aspm=", pcie_aspm_disable);
-void pcie_clear_aspm(void)
-{
- if (!aspm_force)
- aspm_clear_state = 1;
-}
-
void pcie_no_aspm(void)
{
- if (!aspm_force)
+ /*
+ * Disabling ASPM is intended to prevent the kernel from modifying
+ * existing hardware state, not to clear existing state. To that end:
+ * (a) set policy to POLICY_DEFAULT in order to avoid changing state
+ * (b) prevent userspace from changing policy
+ */
+ if (!aspm_force) {
+ aspm_policy = POLICY_DEFAULT;
aspm_disabled = 1;
+ }
}
/**
diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h
index 7cea7b6c1413..c8320144fe79 100644
--- a/include/linux/pci-aspm.h
+++ b/include/linux/pci-aspm.h
@@ -29,7 +29,7 @@ extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
extern void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
extern void pci_disable_link_state(struct pci_dev *pdev, int state);
extern void pci_disable_link_state_locked(struct pci_dev *pdev, int state);
-extern void pcie_clear_aspm(void);
+extern void pcie_clear_aspm(struct pci_bus *bus);
extern void pcie_no_aspm(void);
#else
static inline void pcie_aspm_init_link_state(struct pci_dev *pdev)
@@ -47,7 +47,7 @@ static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
static inline void pci_disable_link_state(struct pci_dev *pdev, int state)
{
}
-static inline void pcie_clear_aspm(void)
+static inline void pcie_clear_aspm(struct pci_bus *bus)
{
}
static inline void pcie_no_aspm(void)
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-04 20:52:29 +0000