cpuidle / menu: Return (-1) if there are no suitable states

If there is a PM QoS latency limit and all of the sufficiently shallow
C-states are disabled, the cpuidle menu governor returns 0 which on
some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned
if that C-state has been disabled.

Fix the issue by modifying the menu governor to return (-1) in such
situations.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 71b523293354..3ca15a8cbaa8 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -296,7 +296,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
                 data->needs_update = 0;
         }
 
-        data->last_state_idx = 0;
+        data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1;
 
         /* Special case when user has set very strict latency requirement */
         if (unlikely(latency_req == 0))