ACPI: PM: Check states of power resources during initialization

To avoid situations in which the actual states of certain ACPI power
resources are not known just because they have never been referenced
by any device configuration objects, check the initial states of all
power resources as soon as they are found in the ACPI namespace (and
fall back to turning them on if the state check fails).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Andreas K. Huettel <andreas.huettel@ur.de>

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index f0ed441..bb03fb0 100644 (file)
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -943,6 +943,7 @@ struct acpi_device *acpi_add_power_resource(acpi_handle handle)
        union acpi_object acpi_object;
        struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
        acpi_status status;
+       u8 state_dummy;
        int result;
 
        acpi_bus_get_device(handle, &device);
@@ -971,6 +972,10 @@ struct acpi_device *acpi_add_power_resource(acpi_handle handle)
        resource->order = acpi_object.power_resource.resource_order;
        resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 
+       /* Get the initial state or just flip it on if that fails. */
+       if (acpi_power_get_state(resource, &state_dummy))
+               __acpi_power_on(resource);
+
        pr_info("%s [%s]\n", acpi_device_name(device), acpi_device_bid(device));
 
        device->flags.match_driver = true;