[PATCH 32/48] ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes

[Len Brown <lenb@xxxxxxxxxx>]

From: Rafael J. Wysocki <rjw@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
 drivers/acpi/bus.c      |    3 ++-
 drivers/acpi/internal.h |    2 +-
 drivers/acpi/power.c    |   12 ++++--------
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index d68bd61..a9fe8e6 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -222,7 +222,8 @@ int acpi_bus_get_power(acpi_handle handle, int *state)
 		 * indirectly (via power resources).
 		 */
 		if (device->power.flags.power_resources) {
-			result = acpi_power_get_inferred_state(device);
+			result = acpi_power_get_inferred_state(device,
+							&device->power.state);
 			if (result)
 				return result;
 		} else if (device->power.flags.explicit_get) {
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index a212bfe..2cc0148 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -41,7 +41,7 @@ static inline int acpi_debugfs_init(void) { return 0; }
 int acpi_power_init(void);
 int acpi_device_sleep_wake(struct acpi_device *dev,
                            int enable, int sleep_state, int dev_state);
-int acpi_power_get_inferred_state(struct acpi_device *device);
+int acpi_power_get_inferred_state(struct acpi_device *device, int *state);
 int acpi_power_transition(struct acpi_device *device, int state);
 extern int acpi_power_nocheck;
 
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 4c9c2fb..9bd1b60 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;
 }
 
-- 
1.7.4.rc1.7.g2cf08

--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html