Commit 38c92fff authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI / PM: Make __acpi_bus_get_power() cover D3cold correctly 



After recent changes of the ACPI device power states definitions, if
power resources are not used for the device's power management, the
state returned by __acpi_bus_get_power() cannot exceed D3hot, because
the return values of _PSC are 0 through 3.  However, if the _PR3
method is not present for the device and _PS3 returns 3, we have to
assume that the device is in D3cold, so the value returned by
__acpi_bus_get_power() in that case should be 4.

Similarly, acpi_power_get_inferred_state() should take the power
resources for the D3hot state into account in general, so that it
can return 3 if those resources are "on" or 4 (D3cold) otherwise.

Fix the the above two issues and make sure that if both _PSC and
_PR3 are present for the device, the power resources listed by _PR3
will be used to determine if the number 3 returned by _PSC is meant
to represent D3cold or D3hot.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 63a1a765

drivers/acpi/bus.c

+29 −22
Original line number Diff line number Diff line
@@ -202,37 +202,44 @@ static const char *state_string(int state) 


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

{

	int result = 0;

	acpi_status status = 0;

	unsigned long long psc = 0;

	int result = ACPI_STATE_UNKNOWN;



	if (!device || !state)

		return -EINVAL;



	*state = ACPI_STATE_UNKNOWN;

	if (!device->flags.power_manageable) {

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

		*state = device->parent ?

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

		goto out;

	}



	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, state);

			if (result)

				return result;

		} else if (device->power.flags.explicit_get) {

			status = acpi_evaluate_integer(device->handle, "_PSC",

						       NULL, &psc);

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

		unsigned long long psc;

		acpi_status status = acpi_evaluate_integer(device->handle,

							   "_PSC", NULL, &psc);

		if (ACPI_FAILURE(status))

			return -ENODEV;

			*state = (int)psc;



		result = psc;

	}

	} else {

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

		*state = device->parent ?

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

	/* The test below covers ACPI_STATE_UNKNOWN too. */

	if (result <= ACPI_STATE_D2) {

	  ; /* Do nothing. */

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

		int error = acpi_power_get_inferred_state(device, &result);

		if (error)

			return error;

	} else if (result == ACPI_STATE_D3_HOT) {

		result = ACPI_STATE_D3;

	}

	*state = result;



 out:

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

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

drivers/acpi/power.c

+1 −1
Original line number Diff line number Diff line
@@ -631,7 +631,7 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state) 
	 * We know a device's inferred power state when all the resources

	 * required for a given D-state are 'on'.

	 */

	for (i = ACPI_STATE_D0; i < ACPI_STATE_D3_HOT; i++) {

	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {

		list = &device->power.states[i].resources;

		if (list->count < 1)

			continue;

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