* @dev: Device whose preferred target power state to return.
* @adev: ACPI device node corresponding to @dev.
* @target_state: System state to match the resultant device state.
- * @d_max_in: Deepest low-power state to take into consideration.
- * @d_min_p: Location to store the upper limit of the allowed states range.
- * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * @d_min_p: Location to store the highest power state available to the device.
+ * @d_max_p: Location to store the lowest power state available to the device.
*
- * Find the lowest power (highest number) ACPI device power state that the
- * device can be in while the system is in the state represented by
- * @target_state. If @d_min_p is set, the highest power (lowest number) device
- * power state that @dev can be in for the given system sleep state is stored
- * at the location pointed to by it.
+ * Find the lowest power (highest number) and highest power (lowest number) ACPI
+ * device power states that the device can be in while the system is in the
+ * state represented by @target_state. Store the integer numbers representing
+ * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
+ * respectively.
*
* Callers must ensure that @dev and @adev are valid pointers and that @adev
* actually corresponds to @dev before using this function.
+ *
+ * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
+ * returns a value that doesn't make sense. The memory locations pointed to by
+ * @d_max_p and @d_min_p are only modified on success.
*/
static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
- u32 target_state, int d_max_in, int *d_min_p)
+ u32 target_state, int *d_min_p, int *d_max_p)
{
- char acpi_method[] = "_SxD";
- unsigned long long d_min, d_max;
+ char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
+ acpi_handle handle = adev->handle;
+ unsigned long long ret;
+ int d_min, d_max;
bool wakeup = false;
+ acpi_status status;
- if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
- return -EINVAL;
-
- if (d_max_in > ACPI_STATE_D3_HOT) {
- enum pm_qos_flags_status stat;
-
- stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
- if (stat == PM_QOS_FLAGS_ALL)
- d_max_in = ACPI_STATE_D3_HOT;
- }
-
- acpi_method[2] = '0' + target_state;
/*
- * If the sleep state is S0, the lowest limit from ACPI is D3,
- * but if the device has _S0W, we will use the value from _S0W
- * as the lowest limit from ACPI. Finally, we will constrain
- * the lowest limit with the specified one.
+ * If the system state is S0, the lowest power state the device can be
+ * in is D3cold, unless the device has _S0W and is supposed to signal
+ * wakeup, in which case the return value of _S0W has to be used as the
+ * lowest power state available to the device.
*/
d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3_COLD;
* If present, _SxD methods return the minimum D-state (highest power
* state) we can use for the corresponding S-states. Otherwise, the
* minimum D-state is D0 (ACPI 3.x).
- *
- * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
- * provided -- that's our fault recovery, we ignore retval.
*/
if (target_state > ACPI_STATE_S0) {
- acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
+ /*
+ * We rely on acpi_evaluate_integer() not clobbering the integer
+ * provided if AE_NOT_FOUND is returned.
+ */
+ ret = d_min;
+ status = acpi_evaluate_integer(handle, method, NULL, &ret);
+ if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
+ || ret > ACPI_STATE_D3_COLD)
+ return -ENODATA;
+
+ /*
+ * We need to handle legacy systems where D3hot and D3cold are
+ * the same and 3 is returned in both cases, so fall back to
+ * D3cold if D3hot is not a valid state.
+ */
+ if (!adev->power.states[ret].flags.valid) {
+ if (ret == ACPI_STATE_D3_HOT)
+ ret = ACPI_STATE_D3_COLD;
+ else
+ return -ENODATA;
+ }
+ d_min = ret;
wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
&& adev->wakeup.sleep_state >= target_state;
} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
* can wake the system. _S0W may be valid, too.
*/
if (wakeup) {
- acpi_status status;
-
- acpi_method[3] = 'W';
- status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
- &d_max);
- if (ACPI_FAILURE(status)) {
- if (target_state != ACPI_STATE_S0 ||
- status != AE_NOT_FOUND)
+ method[3] = 'W';
+ status = acpi_evaluate_integer(handle, method, NULL, &ret);
+ if (status == AE_NOT_FOUND) {
+ if (target_state > ACPI_STATE_S0)
d_max = d_min;
- } else if (d_max < d_min) {
- /* Warn the user of the broken DSDT */
- printk(KERN_WARNING "ACPI: Wrong value from %s\n",
- acpi_method);
- /* Sanitize it */
- d_min = d_max;
+ } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
+ /* Fall back to D3cold if ret is not a valid state. */
+ if (!adev->power.states[ret].flags.valid)
+ ret = ACPI_STATE_D3_COLD;
+
+ d_max = ret > d_min ? ret : d_min;
+ } else {
+ return -ENODATA;
}
}
- if (d_max_in < d_min)
- return -EINVAL;
if (d_min_p)
*d_min_p = d_min;
- /* constrain d_max with specified lowest limit (max number) */
- if (d_max > d_max_in) {
- for (d_max = d_max_in; d_max > d_min; d_max--) {
- if (adev->power.states[d_max].flags.valid)
- break;
- }
- }
- return d_max;
+
+ if (d_max_p)
+ *d_max_p = d_max;
+
+ return 0;
}
/**
* @d_min_p: Location to store the upper limit of the allowed states range.
* @d_max_in: Deepest low-power state to take into consideration.
* Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
+ * incorrect, or -ENODATA on ACPI method failure.
*
* The caller must ensure that @dev is valid before using this function.
*/
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
+ int ret, d_max;
+
+ if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
+ return -EINVAL;
+
+ if (d_max_in > ACPI_STATE_D3_HOT) {
+ enum pm_qos_flags_status stat;
+
+ stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
+ if (stat == PM_QOS_FLAGS_ALL)
+ d_max_in = ACPI_STATE_D3_HOT;
+ }
if (!handle || acpi_bus_get_device(handle, &adev)) {
dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
return -ENODEV;
}
- return acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
- d_max_in, d_min_p);
+ ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
+ d_min_p, &d_max);
+ if (ret)
+ return ret;
+
+ if (d_max_in < *d_min_p)
+ return -EINVAL;
+
+ if (d_max > d_max_in) {
+ for (d_max = d_max_in; d_max > *d_min_p; d_max--) {
+ if (adev->power.states[d_max].flags.valid)
+ break;
+ }
+ }
+ return d_max;
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);
static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
u32 system_state)
{
- int power_state;
+ int ret, state;
if (!acpi_device_power_manageable(adev))
return 0;
- power_state = acpi_dev_pm_get_state(dev, adev, system_state,
- ACPI_STATE_D3_COLD, NULL);
- if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3_COLD)
- return -EIO;
-
- return acpi_device_set_power(adev, power_state);
+ ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
+ return ret ? ret : acpi_device_set_power(adev, state);
}
/**
projects / karo-tx-linux.git / commitdiff