diff options
| -rw-r--r-- | drivers/acpi/power.c | 135 | ||||
| -rw-r--r-- | include/acpi/acpi_bus.h | 4 |
2 files changed, 139 insertions, 0 deletions
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index a916417b9e70..fe1e7bc91a5e 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -42,6 +42,11 @@ ACPI_MODULE_NAME("power"); #define ACPI_POWER_RESOURCE_STATE_ON 0x01 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF +struct acpi_power_dependent_device { + struct device *dev; + struct list_head node; +}; + struct acpi_power_resource { struct acpi_device device; struct list_head list_node; @@ -51,6 +56,7 @@ struct acpi_power_resource { unsigned int ref_count; bool wakeup_enabled; struct mutex resource_lock; + struct list_head dependents; }; struct acpi_power_resource_entry { @@ -232,8 +238,121 @@ static int acpi_power_get_list_state(struct list_head *list, int *state) return 0; } +static int +acpi_power_resource_add_dependent(struct acpi_power_resource *resource, + struct device *dev) +{ + struct acpi_power_dependent_device *dep; + int ret = 0; + + mutex_lock(&resource->resource_lock); + list_for_each_entry(dep, &resource->dependents, node) { + /* Only add it once */ + if (dep->dev == dev) + goto unlock; + } + + dep = kzalloc(sizeof(*dep), GFP_KERNEL); + if (!dep) { + ret = -ENOMEM; + goto unlock; + } + + dep->dev = dev; + list_add_tail(&dep->node, &resource->dependents); + dev_dbg(dev, "added power dependency to [%s]\n", resource->name); + +unlock: + mutex_unlock(&resource->resource_lock); + return ret; +} + +static void +acpi_power_resource_remove_dependent(struct acpi_power_resource *resource, + struct device *dev) +{ + struct acpi_power_dependent_device *dep; + + mutex_lock(&resource->resource_lock); + list_for_each_entry(dep, &resource->dependents, node) { + if (dep->dev == dev) { + list_del(&dep->node); + kfree(dep); + dev_dbg(dev, "removed power dependency to [%s]\n", + resource->name); + break; + } + } + mutex_unlock(&resource->resource_lock); +} + +/** + * acpi_device_power_add_dependent - Add dependent device of this ACPI device + * @adev: ACPI device pointer + * @dev: Dependent device + * + * If @adev has non-empty _PR0 the @dev is added as dependent device to all + * power resources returned by it. This means that whenever these power + * resources are turned _ON the dependent devices get runtime resumed. This + * is needed for devices such as PCI to allow its driver to re-initialize + * it after it went to D0uninitialized. + * + * If @adev does not have _PR0 this does nothing. + * + * Returns %0 in case of success and negative errno otherwise. + */ +int acpi_device_power_add_dependent(struct acpi_device *adev, + struct device *dev) +{ + struct acpi_power_resource_entry *entry; + struct list_head *resources; + int ret; + + if (!adev->flags.power_manageable) + return 0; + + resources = &adev->power.states[ACPI_STATE_D0].resources; + list_for_each_entry(entry, resources, node) { + ret = acpi_power_resource_add_dependent(entry->resource, dev); + if (ret) + goto err; + } + + return 0; + +err: + list_for_each_entry(entry, resources, node) + acpi_power_resource_remove_dependent(entry->resource, dev); + + return ret; +} + +/** + * acpi_device_power_remove_dependent - Remove dependent device + * @adev: ACPI device pointer + * @dev: Dependent device + * + * Does the opposite of acpi_device_power_add_dependent() and removes the + * dependent device if it is found. Can be called to @adev that does not + * have _PR0 as well. + */ +void acpi_device_power_remove_dependent(struct acpi_device *adev, + struct device *dev) +{ + struct acpi_power_resource_entry *entry; + struct list_head *resources; + + if (!adev->flags.power_manageable) + return; + + resources = &adev->power.states[ACPI_STATE_D0].resources; + list_for_each_entry_reverse(entry, resources, node) + acpi_power_resource_remove_dependent(entry->resource, dev); +} + static int __acpi_power_on(struct acpi_power_resource *resource) { + struct acpi_power_dependent_device *dep; acpi_status status = AE_OK; status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL); @@ -243,6 +362,21 @@ static int __acpi_power_on(struct acpi_power_resource *resource) ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n", resource->name)); + /* + * If there are other dependents on this power resource we need to + * resume them now so that their drivers can re-initialize the + * hardware properly after it went back to D0. + */ + if (list_empty(&resource->dependents) || + list_is_singular(&resource->dependents)) + return 0; + + list_for_each_entry(dep, &resource->dependents, node) { + dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n", + resource->name); + pm_request_resume(dep->dev); + } + return 0; } @@ -810,6 +944,7 @@ int acpi_add_power_resource(acpi_handle handle) ACPI_STA_DEFAULT); mutex_init(&resource->resource_lock); INIT_LIST_HEAD(&resource->list_node); + INIT_LIST_HEAD(&resource->dependents); resource->name = device->pnp.bus_id; strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_POWER_CLASS); diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 31b6c87d6240..4752ff0a9d9b 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -513,6 +513,10 @@ int acpi_device_fix_up_power(struct acpi_device *device); 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); +int acpi_device_power_add_dependent(struct acpi_device *adev, + struct device *dev); +void acpi_device_power_remove_dependent(struct acpi_device *adev, + struct device *dev); #ifdef CONFIG_PM bool acpi_bus_can_wakeup(acpi_handle handle); |