Merge tag 'pm-4.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Three cpufreq fixes, one in the core (stable-candidate) and two in
  drivers (intel_pstate and cpufreq-dt).

  Specifics:

   - Fix a recent intel_pstate regression that caused the number of
     wakeups to increase significantly on an idle system in some cases
     due to excessive synchronize_sched() invocations (Rafael Wysocki).

   - Fix unnecessary invocations of WARN_ON() in the cpufreq core after
     cpufreq has been suspended introduced during the 4.6 cycla (Rafael
     Wysocki).

   - Fix an error code path in the cpufreq-dt-platdev driver that
     forgets to drop a reference to a DT node (Masahiro Yamada)"

* tag 'pm-4.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Avoid false-positive WARN_ON()s in cpufreq_update_policy()
  cpufreq: dt: call of_node_put() before error out
  intel_pstate: Do not clear utilization update hooks on policy changes

3 files changed, 11 insertions, 5 deletions

diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index 3646b143bbf5..0bb44d5b5df4 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -79,15 +79,16 @@ static const struct of_device_id machines[] __initconst = {
 static int __init cpufreq_dt_platdev_init(void)
 {
         struct device_node *np = of_find_node_by_path("/");
+        const struct of_device_id *match;
 
         if (!np)
                 return -ENODEV;
 
-        if (!of_match_node(machines, np))
+        match = of_match_node(machines, np);
+        of_node_put(np);
+        if (!match)
                 return -ENODEV;
 
-        of_node_put(of_root);
-
         return PTR_ERR_OR_ZERO(platform_device_register_simple("cpufreq-dt", -1,
                                                                NULL, 0));
 }
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 9009295f5134..5617c7087d77 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2261,6 +2261,10 @@ int cpufreq_update_policy(unsigned int cpu)
          * -> ask driver for current freq and notify governors about a change
          */
         if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
+                if (cpufreq_suspended) {
+                        ret = -EAGAIN;
+                        goto unlock;
+                }
                 new_policy.cur = cpufreq_update_current_freq(policy);
                 if (WARN_ON(!new_policy.cur)) {
                         ret = -EIO;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index fe9dc17ea873..1fa1a32928d7 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1400,6 +1400,9 @@ static void intel_pstate_set_update_util_hook(unsigned int cpu_num)
 {
         struct cpudata *cpu = all_cpu_data[cpu_num];
 
+        if (cpu->update_util_set)
+                return;
+
         /* Prevent intel_pstate_update_util() from using stale data. */
         cpu->sample.time = 0;
         cpufreq_add_update_util_hook(cpu_num, &cpu->update_util,
@@ -1440,8 +1443,6 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
         if (!policy->cpuinfo.max_freq)
                 return -ENODEV;
 
-        intel_pstate_clear_update_util_hook(policy->cpu);
-
         pr_debug("set_policy cpuinfo.max %u policy->max %u\n",
                  policy->cpuinfo.max_freq, policy->max);