Merge tag 'pm-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Fix a recent regression in the timer events oriented (TEO) cpuidle
  governor causing it to misbehave when idle state 0 is disabled and
  rename two local variables for improved clarity on top of that"

* tag 'pm-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: teo: Rename two local variables in teo_select()
  cpuidle: teo: Fix alternative idle state lookup

1 files changed, 31 insertions, 17 deletions

diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c
index 7b91060e82f6..d9262db79cae 100644
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -382,8 +382,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	alt_intercepts = 2 * idx_intercept_sum > cpu_data->total - idx_hit_sum;
 	alt_recent = idx_recent_sum > NR_RECENT / 2;
 	if (alt_recent || alt_intercepts) {
-		s64 last_enabled_span_ns = duration_ns;
-		int last_enabled_idx = idx;
+		s64 first_suitable_span_ns = duration_ns;
+		int first_suitable_idx = idx;
 
 		/*
 		 * Look for the deepest idle state whose target residency had
@@ -397,37 +397,51 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		intercept_sum = 0;
 		recent_sum = 0;
 
-		for (i = idx - 1; i >= idx0; i--) {
+		for (i = idx - 1; i >= 0; i--) {
 			struct teo_bin *bin = &cpu_data->state_bins[i];
 			s64 span_ns;
 
 			intercept_sum += bin->intercepts;
 			recent_sum += bin->recent;
 
+			span_ns = teo_middle_of_bin(i, drv);
+
+			if ((!alt_recent || 2 * recent_sum > idx_recent_sum) &&
+			    (!alt_intercepts ||
+			     2 * intercept_sum > idx_intercept_sum)) {
+				if (teo_time_ok(span_ns) &&
+				    !dev->states_usage[i].disable) {
+					idx = i;
+					duration_ns = span_ns;
+				} else {
+					/*
+					 * The current state is too shallow or
+					 * disabled, so take the first enabled
+					 * deeper state with suitable time span.
+					 */
+					idx = first_suitable_idx;
+					duration_ns = first_suitable_span_ns;
+				}
+				break;
+			}
+
 			if (dev->states_usage[i].disable)
 				continue;
 
-			span_ns = teo_middle_of_bin(i, drv);
 			if (!teo_time_ok(span_ns)) {
 				/*
-				 * The current state is too shallow, so select
-				 * the first enabled deeper state.
+				 * The current state is too shallow, but if an
+				 * alternative candidate state has been found,
+				 * it may still turn out to be a better choice.
 				 */
-				duration_ns = last_enabled_span_ns;
-				idx = last_enabled_idx;
-				break;
-			}
+				if (first_suitable_idx != idx)
+					continue;
 
-			if ((!alt_recent || 2 * recent_sum > idx_recent_sum) &&
-			    (!alt_intercepts ||
-			     2 * intercept_sum > idx_intercept_sum)) {
-				idx = i;
-				duration_ns = span_ns;
 				break;
 			}
 
-			last_enabled_span_ns = span_ns;
-			last_enabled_idx = i;
+			first_suitable_span_ns = span_ns;
+			first_suitable_idx = i;
 		}
 	}