---

yaml
---
r: 328705
b: refs/heads/master
c: 6bf9af4
h: refs/heads/master
i:
  328703: 45eabca
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5b41147ceae44350f43f9b8124687d22bed2bbb9
+refs/heads/master: 6bf9af464c4894e613567c0fb6559be67f31c88a

trunk/Documentation/cpuidle/sysfs.txt

@@ -76,9 +76,17 @@ total 0
 
 
 * desc : Small description about the idle state (string)
-* disable : Option to disable this idle state (bool)
+* disable : Option to disable this idle state (bool) -> see note below
 * latency : Latency to exit out of this idle state (in microseconds)
 * name : Name of the idle state (string)
 * power : Power consumed while in this idle state (in milliwatts)
 * time : Total time spent in this idle state (in microseconds)
 * usage : Number of times this state was entered (count)
+
+Note:
+The behavior and the effect of the disable variable depends on the
+implementation of a particular governor. In the ladder governor, for
+example, it is not coherent, i.e. if one is disabling a light state,
+then all deeper states are disabled as well, but the disable variable
+does not reflect it. Likewise, if one enables a deep state but a lighter
+state still is disabled, then this has no effect.

trunk/drivers/cpuidle/governors/ladder.c

@@ -88,6 +88,8 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 
 	/* consider promotion */
 	if (last_idx < drv->state_count - 1 &&
+	    !drv->states[last_idx + 1].disabled &&
+	    !dev->states_usage[last_idx + 1].disable &&
 	    last_residency > last_state->threshold.promotion_time &&
 	    drv->states[last_idx + 1].exit_latency <= latency_req) {
 		last_state->stats.promotion_count++;
@@ -100,7 +102,9 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 
 	/* consider demotion */
 	if (last_idx > CPUIDLE_DRIVER_STATE_START &&
-	    drv->states[last_idx].exit_latency > latency_req) {
+	    (drv->states[last_idx].disabled ||
+	    dev->states_usage[last_idx].disable ||
+	    drv->states[last_idx].exit_latency > latency_req)) {
 		int i;
 
 		for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) {