1 files changed, 19 insertions, 5 deletions

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 88561029cca8..1cc02ca2af2a 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;
 }
 #endif /* CONFIG_PM */