Power management fixes for v4.12-rc6

- Revert a recent cpufreq schedutil governor change that caused some
    systems to behave undesirably (Rafael Wysocki).
 
  - Fix a cpufreq conservative governor issue introduced during the
    3.10 cycle that prevents it from working as expected in some
    situations (Tomasz Wilczyński).
 
  - Fix an error code path in the generic cpuidle driver for DT-based
    systems (Christophe Jaillet).
 
  - Fix three minor issues in devfreq drivers for Exynos (Arvind Yadav,
    Krzysztof Kozlowski).
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Merge tag 'pm-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These revert a recent cpufreq schedutil governor change that turned
  out to be problematic and fix a few minor issues in cpufreq, cpuidle
  and the Exynos devfreq drivers.

  Specifics:

   - Revert a recent cpufreq schedutil governor change that caused some
     systems to behave undesirably (Rafael Wysocki).

   - Fix a cpufreq conservative governor issue introduced during the
     3.10 cycle that prevents it from working as expected in some
     situations (Tomasz Wilczyński).

   - Fix an error code path in the generic cpuidle driver for DT-based
     systems (Christophe Jaillet).

   - Fix three minor issues in devfreq drivers for Exynos (Arvind Yadav,
     Krzysztof Kozlowski)"

* tag 'pm-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: dt: Add missing 'of_node_put()'
  cpufreq: conservative: Allow down_threshold to take values from 1 to 10
  Revert "cpufreq: schedutil: Reduce frequencies slower"
  PM / devfreq: exynos-ppmu: Staticize event list
  PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable
  PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable

drivers/cpufreq/cpufreq_conservative.c

@@ -185,8 +185,8 @@ static ssize_t store_down_threshold(struct gov_attr_set *attr_set,
 	int ret;
 	ret = sscanf(buf, "%u", &input);
 
-	/* cannot be lower than 11 otherwise freq will not fall */
-	if (ret != 1 || input < 11 || input > 100 ||
+	/* cannot be lower than 1 otherwise freq will not fall */
+	if (ret != 1 || input < 1 || input > 100 ||
 			input >= dbs_data->up_threshold)
 		return -EINVAL;
 

drivers/cpuidle/dt_idle_states.c

@@ -180,8 +180,10 @@ int dt_init_idle_driver(struct cpuidle_driver *drv,
 		if (!state_node)
 			break;
 
-		if (!of_device_is_available(state_node))
+		if (!of_device_is_available(state_node)) {
+			of_node_put(state_node);
 			continue;
+		}
 
 		if (!idle_state_valid(state_node, i, cpumask)) {
 			pr_warn("%s idle state not valid, bailing out\n",

drivers/devfreq/event/exynos-nocp.c

@@ -267,7 +267,11 @@ static int exynos_nocp_probe(struct platform_device *pdev)
 	}
 	platform_set_drvdata(pdev, nocp);
 
-	clk_prepare_enable(nocp->clk);
+	ret = clk_prepare_enable(nocp->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
+		return ret;
+	}
 
 	pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
 			dev_name(dev));

drivers/devfreq/event/exynos-ppmu.c

@@ -44,7 +44,7 @@ struct exynos_ppmu {
 	{ "ppmu-event2-"#name, PPMU_PMNCNT2 },	\
 	{ "ppmu-event3-"#name, PPMU_PMNCNT3 }
 
-struct __exynos_ppmu_events {
+static struct __exynos_ppmu_events {
 	char *name;
 	int id;
 } ppmu_events[] = {
@@ -648,7 +648,11 @@ static int exynos_ppmu_probe(struct platform_device *pdev)
 			dev_name(&pdev->dev), desc[i].name);
 	}
 
-	clk_prepare_enable(info->ppmu.clk);
+	ret = clk_prepare_enable(info->ppmu.clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
+		return ret;
+	}
 
 	return 0;
 }

kernel/sched/cpufreq_schedutil.c

@@ -101,9 +101,6 @@ static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time,
 	if (sg_policy->next_freq == next_freq)
 		return;
 
-	if (sg_policy->next_freq > next_freq)
-		next_freq = (sg_policy->next_freq + next_freq) >> 1;
-
 	sg_policy->next_freq = next_freq;
 	sg_policy->last_freq_update_time = time;