Power management fixes for 5.9-rc7

- Export rcu_idle_{enter,exit} to modules to fix build issues
    introduced by recent RCU-lockdep fixes (Borislav Petkov).
 
  - Add missing return statement to a stub function in the ACPI
    processor driver to fix a build issue introduced by recent
    RCU-lockdep fixes (Rafael Wysocki).
 
  - Fix recently introduced suspicious RCU usage warnings in the PSCI
    cpuidle driver and drop stale comments regarding RCU_NONIDLE()
    usage from enter_s2idle_proper() (Ulf Hansson).
 
  - Fix error code path in the tegra30 devfreq driver (Dan Carpenter).
 
  - Add missing information to devfreq_summary debugfs (Chanwoo Choi).
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Merge tag 'pm-5.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix more fallout of recent RCU-lockdep changes in CPU idle code
  and two devfreq issues.

  Specifics:

   - Export rcu_idle_{enter,exit} to modules to fix build issues
     introduced by recent RCU-lockdep fixes (Borislav Petkov)

   - Add missing return statement to a stub function in the ACPI
     processor driver to fix a build issue introduced by recent
     RCU-lockdep fixes (Rafael Wysocki)

   - Fix recently introduced suspicious RCU usage warnings in the PSCI
     cpuidle driver and drop stale comments regarding RCU_NONIDLE()
     usage from enter_s2idle_proper() (Ulf Hansson)

   - Fix error code path in the tegra30 devfreq driver (Dan Carpenter)

   - Add missing information to devfreq_summary debugfs (Chanwoo Choi)"

* tag 'pm-5.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: processor: Fix build for ARCH_APICTIMER_STOPS_ON_C3 unset
  PM / devfreq: tegra30: Disable clock on error in probe
  PM / devfreq: Add timer type to devfreq_summary debugfs
  cpuidle: Drop misleading comments about RCU usage
  cpuidle: psci: Fix suspicious RCU usage
  rcu/tree: Export rcu_idle_{enter,exit} to modules

drivers/acpi/processor_idle.c

@@ -176,6 +176,7 @@ static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 					struct acpi_processor_cx *cx)
 {
+	return false;
 }
 
 #endif

drivers/cpuidle/cpuidle-psci.c

@@ -66,7 +66,7 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
 		return -1;
 
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
-	pm_runtime_put_sync_suspend(pd_dev);
+	RCU_NONIDLE(pm_runtime_put_sync_suspend(pd_dev));
 
 	state = psci_get_domain_state();
 	if (!state)
@@ -74,7 +74,7 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
 
 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
-	pm_runtime_get_sync(pd_dev);
+	RCU_NONIDLE(pm_runtime_get_sync(pd_dev));
 
 	cpu_pm_exit();
 

drivers/cpuidle/cpuidle.c

@@ -142,11 +142,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv,
 
 	time_start = ns_to_ktime(local_clock());
 
-	/*
-	 * trace_suspend_resume() called by tick_freeze() for the last CPU
-	 * executing it contains RCU usage regarded as invalid in the idle
-	 * context, so tell RCU about that.
-	 */
 	tick_freeze();
 	/*
 	 * The state used here cannot be a "coupled" one, because the "coupled"
@@ -159,11 +154,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv,
 	target_state->enter_s2idle(dev, drv, index);
 	if (WARN_ON_ONCE(!irqs_disabled()))
 		local_irq_disable();
-	/*
-	 * timekeeping_resume() that will be called by tick_unfreeze() for the
-	 * first CPU executing it calls functions containing RCU read-side
-	 * critical sections, so tell RCU about that.
-	 */
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		rcu_idle_exit();
 	tick_unfreeze();

drivers/devfreq/devfreq.c

@@ -1766,20 +1766,23 @@ static int devfreq_summary_show(struct seq_file *s, void *data)
 	struct devfreq *p_devfreq = NULL;
 	unsigned long cur_freq, min_freq, max_freq;
 	unsigned int polling_ms;
+	unsigned int timer;
 
-	seq_printf(s, "%-30s %-30s %-15s %10s %12s %12s %12s\n",
+	seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
 			"dev",
 			"parent_dev",
 			"governor",
+			"timer",
 			"polling_ms",
 			"cur_freq_Hz",
 			"min_freq_Hz",
 			"max_freq_Hz");
-	seq_printf(s, "%30s %30s %15s %10s %12s %12s %12s\n",
+	seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
 			"------------------------------",
 			"------------------------------",
 			"---------------",
 			"----------",
+			"----------",
 			"------------",
 			"------------",
 			"------------");
@@ -1803,13 +1806,15 @@ static int devfreq_summary_show(struct seq_file *s, void *data)
 		cur_freq = devfreq->previous_freq;
 		get_freq_range(devfreq, &min_freq, &max_freq);
 		polling_ms = devfreq->profile->polling_ms;
+		timer = devfreq->profile->timer;
 		mutex_unlock(&devfreq->lock);
 
 		seq_printf(s,
-			"%-30s %-30s %-15s %10d %12ld %12ld %12ld\n",
+			"%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
 			dev_name(&devfreq->dev),
 			p_devfreq ? dev_name(&p_devfreq->dev) : "null",
 			devfreq->governor_name,
+			polling_ms ? timer_name[timer] : "null",
 			polling_ms,
 			cur_freq,
 			min_freq,

drivers/devfreq/tegra30-devfreq.c

@@ -836,7 +836,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 	rate = clk_round_rate(tegra->emc_clock, ULONG_MAX);
 	if (rate < 0) {
 		dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", rate);
-		return rate;
+		err = rate;
+		goto disable_clk;
 	}
 
 	tegra->max_freq = rate / KHZ;
@@ -897,6 +898,7 @@ remove_opps:
 	dev_pm_opp_remove_all_dynamic(&pdev->dev);
 
 	reset_control_reset(tegra->reset);
+disable_clk:
 	clk_disable_unprepare(tegra->clock);
 
 	return err;

kernel/rcu/tree.c

@@ -673,6 +673,7 @@ void rcu_idle_enter(void)
 	lockdep_assert_irqs_disabled();
 	rcu_eqs_enter(false);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_enter);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**
@@ -886,6 +887,7 @@ void rcu_idle_exit(void)
 	rcu_eqs_exit(false);
 	local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_exit);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**