diff options
| -rw-r--r-- | drivers/acpi/device_pm.c | 19 | ||||
| -rw-r--r-- | drivers/pci/pci-acpi.c | 45 | ||||
| -rw-r--r-- | include/acpi/acpi_bus.h | 1 |
3 files changed, 51 insertions, 14 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 97450f4003cc..f007116a8427 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -484,6 +484,25 @@ void acpi_dev_power_up_children_with_adr(struct acpi_device *adev) acpi_dev_for_each_child(adev, acpi_power_up_if_adr_present, NULL); } +/** + * acpi_dev_power_state_for_wake - Deepest power state for wakeup signaling + * @adev: ACPI companion of the target device. + * + * Evaluate _S0W for @adev and return the value produced by it or return + * ACPI_STATE_UNKNOWN on errors (including _S0W not present). + */ +u8 acpi_dev_power_state_for_wake(struct acpi_device *adev) +{ + unsigned long long state; + acpi_status status; + + status = acpi_evaluate_integer(adev->handle, "_S0W", NULL, &state); + if (ACPI_FAILURE(status)) + return ACPI_STATE_UNKNOWN; + + return state; +} + #ifdef CONFIG_PM static DEFINE_MUTEX(acpi_pm_notifier_lock); static DEFINE_MUTEX(acpi_pm_notifier_install_lock); diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 068d6745bf98..052a611081ec 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -976,24 +976,41 @@ bool acpi_pci_power_manageable(struct pci_dev *dev) bool acpi_pci_bridge_d3(struct pci_dev *dev) { struct pci_dev *rpdev; - struct acpi_device *adev; - acpi_status status; - unsigned long long state; + struct acpi_device *adev, *rpadev; const union acpi_object *obj; if (acpi_pci_disabled || !dev->is_hotplug_bridge) return false; - /* Assume D3 support if the bridge is power-manageable by ACPI. */ - if (acpi_pci_power_manageable(dev)) - return true; + adev = ACPI_COMPANION(&dev->dev); + if (adev) { + /* + * If the bridge has _S0W, whether or not it can go into D3 + * depends on what is returned by that object. In particular, + * if the power state returned by _S0W is D2 or shallower, + * entering D3 should not be allowed. + */ + if (acpi_dev_power_state_for_wake(adev) <= ACPI_STATE_D2) + return false; + + /* + * Otherwise, assume that the bridge can enter D3 so long as it + * is power-manageable via ACPI. + */ + if (acpi_device_power_manageable(adev)) + return true; + } rpdev = pcie_find_root_port(dev); if (!rpdev) return false; - adev = ACPI_COMPANION(&rpdev->dev); - if (!adev) + if (rpdev == dev) + rpadev = adev; + else + rpadev = ACPI_COMPANION(&rpdev->dev); + + if (!rpadev) return false; /* @@ -1001,15 +1018,15 @@ bool acpi_pci_bridge_d3(struct pci_dev *dev) * doesn't supply a wakeup GPE via _PRW, it cannot signal hotplug * events from low-power states including D3hot and D3cold. */ - if (!adev->wakeup.flags.valid) + if (!rpadev->wakeup.flags.valid) return false; /* - * If the Root Port cannot wake itself from D3hot or D3cold, we - * can't use D3. + * In the bridge-below-a-Root-Port case, evaluate _S0W for the Root Port + * to verify whether or not it can signal wakeup from D3. */ - status = acpi_evaluate_integer(adev->handle, "_S0W", NULL, &state); - if (ACPI_SUCCESS(status) && state < ACPI_STATE_D3_HOT) + if (rpadev != adev && + acpi_dev_power_state_for_wake(rpadev) <= ACPI_STATE_D2) return false; /* @@ -1018,7 +1035,7 @@ bool acpi_pci_bridge_d3(struct pci_dev *dev) * bridges *below* that Root Port can also signal hotplug events * while in D3. */ - if (!acpi_dev_get_property(adev, "HotPlugSupportInD3", + if (!acpi_dev_get_property(rpadev, "HotPlugSupportInD3", ACPI_TYPE_INTEGER, &obj) && obj->integer.value == 1) return true; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index cd3b75e08ec3..3412297a6b8b 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -533,6 +533,7 @@ int acpi_bus_update_power(acpi_handle handle, int *state_p); int acpi_device_update_power(struct acpi_device *device, int *state_p); bool acpi_bus_power_manageable(acpi_handle handle); void acpi_dev_power_up_children_with_adr(struct acpi_device *adev); +u8 acpi_dev_power_state_for_wake(struct acpi_device *adev); int acpi_device_power_add_dependent(struct acpi_device *adev, struct device *dev); void acpi_device_power_remove_dependent(struct acpi_device *adev, |