ACPI / PM: Add function for updating device power state consistently

Add function acpi_bus_update_power() for reading the actual power
state of an ACPI device and updating its device->power.state field
in such a way that its power resources' reference counters will
remain consistent with that field.

For this purpose introduce __acpi_bus_set_power() setting the
power state of an ACPI device without updating its
device->power.state field and make acpi_bus_set_power() and
acpi_bus_update_power() use it (acpi_bus_set_power() retains the
current behavior for now).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 359ef11725a6..5d2c4c540063 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -330,6 +330,7 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle,
 int acpi_bus_get_status(struct acpi_device *device);
 int acpi_bus_get_power(acpi_handle handle, int *state);
 int acpi_bus_set_power(acpi_handle handle, 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);
 #ifdef CONFIG_ACPI_PROC_EVENT