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path: root/drivers/acpi/sleep.c
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Diffstat (limited to 'drivers/acpi/sleep.c')
-rw-r--r--drivers/acpi/sleep.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 1784cb30e7cf..028dd425702c 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -716,8 +716,9 @@ int acpi_suspend(u32 acpi_state)
* @dev: device to examine; its driver model wakeup flags control
* whether it should be able to wake up the system
* @d_min_p: used to store the upper limit of allowed states range
- * Return value: preferred power state of the device on success, -ENODEV on
- * failure (ie. if there's no 'struct acpi_device' for @dev)
+ * @d_max_in: specify the lowest allowed states
+ * Return value: preferred power state of the device on success, -ENODEV
+ * (ie. if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
*
* Find the lowest power (highest number) ACPI device power state that
* device @dev can be in while the system is in the sleep state represented
@@ -732,13 +733,15 @@ int acpi_suspend(u32 acpi_state)
* via @wake.
*/
-int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
+int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
char acpi_method[] = "_SxD";
unsigned long long d_min, d_max;
+ if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
+ return -EINVAL;
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
printk(KERN_DEBUG "ACPI handle has no context!\n");
return -ENODEV;
@@ -746,8 +749,10 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
acpi_method[2] = '0' + acpi_target_sleep_state;
/*
- * If the sleep state is S0, we will return D3, but if the device has
- * _S0W, we will use the value from _S0W
+ * 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.
*/
d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3;
@@ -791,8 +796,17 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
}
}
+ 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;
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);