ACPI / PM: Rework the handling of devices depending on power resources

Commit 0090def6 (ACPI: Add interface to register/unregister device
to/from power resources) made it possible to indicate to the ACPI
core that if the given device depends on any power resources, then
it should be resumed as soon as all of the power resources required
by it to transition to the D0 power state have been turned on.

Unfortunately, however, this was a mistake, because all devices
depending on power resources should be treated this way (i.e. they
should be resumed when all power resources required by their D0
state have been turned on) and for the majority of those devices
the ACPI core can figure out by itself which (physical) devices
depend on what power resources.

For this reason, replace the code added by commit 0090def6 with a
new, much more straightforward, mechanism that will be used
internally by the ACPI core and remove all references to that code
from kernel subsystems using ACPI.

For the cases when there are (physical) devices that should be
resumed whenever a not directly related ACPI device node goes into
D0 as a result of power resources configuration changes, like in
the SATA case, add two new routines, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), allowing subsystems to manage
such dependencies.  Convert the SATA subsystem to use the new
functions accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 567851b4f043..29a1badfca55 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -279,6 +279,7 @@ struct acpi_device {
         struct list_head physical_node_list;
         struct mutex physical_node_lock;
         DECLARE_BITMAP(physical_node_id_bitmap, ACPI_MAX_PHYSICAL_NODE);
+        struct list_head power_dependent;
 };
 
 static inline void *acpi_driver_data(struct acpi_device *d)
@@ -334,8 +335,6 @@ int acpi_device_set_power(struct acpi_device *device, int state);
 int acpi_bus_update_power(acpi_handle handle, int *state_p);
 bool acpi_bus_power_manageable(acpi_handle handle);
 bool acpi_bus_can_wakeup(acpi_handle handle);
-int acpi_power_resource_register_device(struct device *dev, acpi_handle handle);
-void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle);
 #ifdef CONFIG_ACPI_PROC_EVENT
 int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data);
 int acpi_bus_generate_proc_event4(const char *class, const char *bid, u8 type, int data);
@@ -414,6 +413,8 @@ acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
 int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
                             u32 target_state, int d_max_in, int *d_min_p);
 int acpi_pm_device_sleep_state(struct device *, int *, int);
+void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev);
+void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev);
 #else
 static inline acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
                                                acpi_notify_handler handler,
@@ -443,6 +444,10 @@ static inline int acpi_pm_device_sleep_state(struct device *d, int *p, int m)
 {
         return __acpi_device_power_state(m, p);
 }
+static inline void acpi_dev_pm_add_dependent(acpi_handle handle,
+                                             struct device *depdev) {}
+static inline void acpi_dev_pm_remove_dependent(acpi_handle handle,
+                                                struct device *depdev) {}
 #endif
 
 #ifdef CONFIG_PM_RUNTIME