ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes

acpi_power_get_inferred_state() should not update
device->power.state behind the back of its caller, so make it return
the state via a pointer instead.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 4 insertions, 8 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 4c9c2fb5d98..9bd1b6044b5 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -423,19 +423,16 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
                              Device Power Management
    -------------------------------------------------------------------------- */
 
-int acpi_power_get_inferred_state(struct acpi_device *device)
+int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 {
         int result = 0;
         struct acpi_handle_list *list = NULL;
         int list_state = 0;
         int i = 0;
 
-
-        if (!device)
+        if (!device || !state)
                 return -EINVAL;
 
-        device->power.state = ACPI_STATE_UNKNOWN;
-
         /*
          * We know a device's inferred power state when all the resources
          * required for a given D-state are 'on'.
@@ -450,13 +447,12 @@ int acpi_power_get_inferred_state(struct acpi_device *device)
                         return result;
 
                 if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
-                        device->power.state = i;
+                        *state = i;
                         return 0;
                 }
         }
 
-        device->power.state = ACPI_STATE_D3;
-
+        *state = ACPI_STATE_D3;
         return 0;
 }