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>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 07a20ee3e690..1f0d457ecbcf 100644
--- a/drivers/acpi/bus.c
+++ b/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)