Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5e6d4fe4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Len Brown
Browse files

ACPI / PM: Introduce __acpi_bus_get_power() 



It sometimes is necessary to get the power state of an ACPI device
without updating its device->power.state field, for example to
avoid inconsistencies between device->power.state and the reference
counters of the device's power resources.  For this purpose introduce
__acpi_bus_get_power() that will return the given device's power
state via a pointer (instead of modifying device->power.state)
and make acpi_bus_get_power() use it.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 30d3df41

drivers/acpi/bus.c

+29 −19
Original line number Diff line number Diff line
@@ -196,34 +196,24 @@ EXPORT_SYMBOL(acpi_bus_get_private_data); 
                                 Power Management

   -------------------------------------------------------------------------- */



int acpi_bus_get_power(acpi_handle handle, int *state)

static int __acpi_bus_get_power(struct acpi_device *device, int *state)

{

	int result = 0;

	acpi_status status = 0;

	struct acpi_device *device = NULL;

	unsigned long long psc = 0;





	result = acpi_bus_get_device(handle, &device);

	if (result)

		return result;

	if (!device || !state)

		return -EINVAL;



	*state = ACPI_STATE_UNKNOWN;



	if (!device->flags.power_manageable) {

		/* TBD: Non-recursive algorithm for walking up hierarchy */

		if (device->parent)

			*state = device->parent->power.state;

		else

			*state = ACPI_STATE_D0;

	} else {

	if (device->flags.power_manageable) {

		/*

		 * Get the device's power state either directly (via _PSC) or

		 * indirectly (via power resources).

		 */

		if (device->power.flags.power_resources) {

			result = acpi_power_get_inferred_state(device,

							&device->power.state);

			result = acpi_power_get_inferred_state(device, state);

			if (result)

				return result;

		} else if (device->power.flags.explicit_get) {
@@ -231,20 +221,40 @@ int acpi_bus_get_power(acpi_handle handle, int *state) 
						       NULL, &psc);

			if (ACPI_FAILURE(status))

				return -ENODEV;

			device->power.state = (int)psc;

			*state = (int)psc;

		}



		*state = device->power.state;

	} else {

		/* TBD: Non-recursive algorithm for walking up hierarchy. */

		*state = device->parent ?

			device->parent->power.state : ACPI_STATE_D0;

	}



	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",

			  device->pnp.bus_id, device->power.state));

			  device->pnp.bus_id, *state));



	return 0;

}





int acpi_bus_get_power(acpi_handle handle, int *state)

{

	struct acpi_device *device;

	int result;



	result = acpi_bus_get_device(handle, &device);

	if (result)

		return result;



	result = __acpi_bus_get_power(device, state);

	if (result)

		return result;



	device->power.state = *state;

	return 0;

}

EXPORT_SYMBOL(acpi_bus_get_power);





int acpi_bus_set_power(acpi_handle handle, int state)

{

	int result = 0;