cpuidle: coupled: disable interrupts after entering safe state

Calling cpuidle_enter_state is expected to return with interrupts
enabled, but interrupts must be disabled before starting the
ready loop synchronization stage.  Call local_irq_disable after
each call to cpuidle_enter_state for the safe state.

Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/coupled.c

@@ -460,6 +460,7 @@ int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
 		}
 		entered_state = cpuidle_enter_state(dev, drv,
 			dev->safe_state_index);
+		local_irq_disable();
 	}
 
 	/* Read barrier ensures online_count is read after prevent is cleared */
@@ -485,6 +486,7 @@ int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
 
 		entered_state = cpuidle_enter_state(dev, drv,
 			dev->safe_state_index);
+		local_irq_disable();
 	}
 
 	if (cpuidle_coupled_clear_pokes(dev->cpu)) {