Browse Source

ACPI / PM: Add check preventing transitioning to non-D0 state from D3.

No power transitioning from D3 state up to a non-D0 state is allowed
so make acpi_device_set_power() fail and complain if such a transition
is attempted.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Lv Zheng 12 years ago
parent
commit
ddc150f7a3
1 changed files with 6 additions and 0 deletions
  1. 6 0
      drivers/acpi/bus.c

+ 6 - 0
drivers/acpi/bus.c

@@ -306,6 +306,12 @@ int acpi_device_set_power(struct acpi_device *device, int state)
 	 * a lower-powered state.
 	 */
 	if (state < device->power.state) {
+		if (device->power.state >= ACPI_STATE_D3_HOT &&
+		    state != ACPI_STATE_D0) {
+			printk(KERN_WARNING PREFIX
+			      "Cannot transition to non-D0 state from D3\n");
+			return -ENODEV;
+		}
 		if (device->power.flags.power_resources) {
 			result = acpi_power_transition(device, state);
 			if (result)