diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 58 |
1 files changed, 37 insertions, 21 deletions
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; + } } /** |