3 files changed, 27 insertions, 4 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9657abc..4534510 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -364,6 +364,31 @@ int acpi_bus_set_power(acpi_handle handle, int state)
 
 EXPORT_SYMBOL(acpi_bus_set_power);
 
+
+int acpi_bus_init_power(struct acpi_device *device)
+{
+	int state;
+	int result;
+
+	if (!device)
+		return -EINVAL;
+
+	device->power.state = ACPI_STATE_UNKNOWN;
+
+	result = __acpi_bus_get_power(device, &state);
+	if (result)
+		return result;
+
+	if (device->power.flags.power_resources)
+		result = acpi_power_on_resources(device, state);
+
+	if (!result)
+		device->power.state = state;
+
+	return result;
+}
+
+
 bool acpi_bus_power_manageable(acpi_handle handle)
 {
 	struct acpi_device *device;
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 433a8ee..7493e6c 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -44,6 +44,7 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
 int acpi_power_get_inferred_state(struct acpi_device *device, int *state);
 int acpi_power_on_resources(struct acpi_device *device, int state);
 int acpi_power_transition(struct acpi_device *device, int state);
+int acpi_bus_init_power(struct acpi_device *device);
 extern int acpi_power_nocheck;
 
 int acpi_wakeup_device_init(void);
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 29ef505..ef8e659 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -901,10 +901,7 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
 	device->power.states[ACPI_STATE_D3].power = 0;
 
-	/* TBD: System wake support and resource requirements. */
-
-	device->power.state = ACPI_STATE_UNKNOWN;
-	acpi_bus_get_power(device->handle, &(device->power.state));
+	acpi_bus_init_power(device);
 
 	return 0;
 }