[PATCH v1] cpuidle: Do not return from cpuidle_play_dead() on callback failures

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If the :enter_dead() idle state callback fails for a certain state,
there may be still a shallower state for which it will work.

Because the only caller of cpuidle_play_dead(), native_play_dead(),
falls back to hlt_play_dead() if it returns an error, it should
better try all of the idle states for which :enter_dead() is present
before failing, so change it accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpuidle/cpuidle.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/cpuidle.c
+++ linux-pm/drivers/cpuidle/cpuidle.c
@@ -70,9 +70,10 @@ int cpuidle_play_dead(void)
 		return -ENODEV;
 
 	/* Find lowest-power state that supports long-term idle */
-	for (i = drv->state_count - 1; i >= 0; i--)
-		if (drv->states[i].enter_dead)
-			return drv->states[i].enter_dead(dev, i);
+	for (i = drv->state_count - 1; i >= 0; i--) {
+		if (drv->states[i].enter_dead && !drv->states[i].enter_dead(dev, i))
+			return 0;
+	}
 
 	return -ENODEV;
 }