Merge tag 'pm+acpi-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
"These are: cpuidle fixes (including one fix for a recent regression),
cpufreq fixes (including fixes for two issues introduced during the
4.2 cycle), generic power domains framework fixes (two locking fixes
and one cleanup), one locking fix in the ACPI-based PCI hotplug
framework (ACPIPHP), removal of one ACPI backlight blacklist entry
that isn't necessary any more and a PM Kconfig cleanup.

Specifics:

- Fix a recent cpuidle core regression that broke suspend-to-idle on
all systems where cpuidle drivers don't provide ->enter_freeze
callbacks for any states (Sudeep Holla).

- Drop an unnecessary symbol definition from the cpuidle core code
handling coupled CPU cores (Anders Roxell).

- Fix a race condition related to governor initialization and removal
in the cpufreq core (Viresh Kumar).

- Clean up the cpufreq core to use list_is_last() for checking if the
given policy object is the last element of a list instead of open
coding that in a clumsy way (Gautham R Shenoy).

- Fix compiler warnings in the pxa2xx and cpufreq-dt cpufreq drivers
(Arnd Bergmann).

- Fix two locking issues and clean up a comment in the generic power
domains framework (Ulf Hansson, Marek Szyprowski, Moritz Fischer).

- Fix the error code path of one function in the ACPI-based PCI
hotplug framework (ACPIPHP) that forgets to release a lock acquired
previously (Insu Yun).

- Drop the ACPI backlight blacklist entry for Dell Inspiron 5737 that
is not necessary any more (Hans de Goede).

- Clean up the top-level PM Kconfig to stop requiring APM emulation
to depend on PM which in fact isn't necessary (Arnd Bergmann)"

* tag 'pm+acpi-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: cpufreq-dt: avoid uninitialized variable warnings:
cpufreq: pxa2xx: fix pxa_cpufreq_change_voltage prototype
PM: APM_EMULATION does not depend on PM
cpufreq: Use list_is_last() to check last entry of the policy list
cpufreq: Fix NULL reference crash while accessing policy->governor_data
cpuidle: coupled: remove unused define cpuidle_coupled_lock
PM / Domains: Fix typo in comment
PM / Domains: Fix potential deadlock while adding/removing subdomains
ACPI / PCI / hotplug: unlock in error path in acpiphp_enable_slot()
ACPI: Revert "ACPI / video: Add Dell Inspiron 5737 to the blacklist"
cpuidle: fix fallback mechanism for suspend to idle in absence of enter_freeze
PM / domains: fix lockdep issue for all subdomains

drivers/acpi/video_detect.c

···
 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
 		},
 	},
-	{
-	.callback = video_detect_force_vendor,
-	.ident = "Dell Inspiron 5737",
-	.matches = {
-		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-		DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"),
-		},
-	},
 
 	/*
 	 * These models have a working acpi_video backlight control, and using

drivers/base/power/domain.c

···
 
 /**
  * genpd_queue_power_off_work - Queue up the execution of genpd_poweroff().
- * @genpd: PM domait to power off.
+ * @genpd: PM domain to power off.
  *
  * Queue up the execution of genpd_poweroff() unless it's already been done
  * before.
···
 	queue_work(pm_wq, &genpd->power_off_work);
 }
 
-static int genpd_poweron(struct generic_pm_domain *genpd);
-
 /**
  * __genpd_poweron - Restore power to a given PM domain and its masters.
  * @genpd: PM domain to power up.
+ * @depth: nesting count for lockdep.
  *
  * Restore power to @genpd and all of its masters so that it is possible to
  * resume a device belonging to it.
  */
-static int __genpd_poweron(struct generic_pm_domain *genpd)
+static int __genpd_poweron(struct generic_pm_domain *genpd, unsigned int depth)
 {
 	struct gpd_link *link;
 	int ret = 0;
···
 	 * with it.
 	 */
 	list_for_each_entry(link, &genpd->slave_links, slave_node) {
-		genpd_sd_counter_inc(link->master);
+		struct generic_pm_domain *master = link->master;
 
-		ret = genpd_poweron(link->master);
+		genpd_sd_counter_inc(master);
+
+		mutex_lock_nested(&master->lock, depth + 1);
+		ret = __genpd_poweron(master, depth + 1);
+		mutex_unlock(&master->lock);
+
 		if (ret) {
-			genpd_sd_counter_dec(link->master);
+			genpd_sd_counter_dec(master);
 			goto err;
 		}
 	}
···
 	int ret;
 
 	mutex_lock(&genpd->lock);
-	ret = __genpd_poweron(genpd);
+	ret = __genpd_poweron(genpd, 0);
 	mutex_unlock(&genpd->lock);
 	return ret;
 }
+
 
 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 {
···
 	}
 
 	mutex_lock(&genpd->lock);
-	ret = __genpd_poweron(genpd);
+	ret = __genpd_poweron(genpd, 0);
 	mutex_unlock(&genpd->lock);
 
 	if (ret)
···
 	if (!link)
 		return -ENOMEM;
 
-	mutex_lock(&genpd->lock);
-	mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
+	mutex_lock(&subdomain->lock);
+	mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
 
 	if (genpd->status == GPD_STATE_POWER_OFF
 	    &&  subdomain->status != GPD_STATE_POWER_OFF) {
···
 		genpd_sd_counter_inc(genpd);
 
  out:
-	mutex_unlock(&subdomain->lock);
 	mutex_unlock(&genpd->lock);
+	mutex_unlock(&subdomain->lock);
 	if (ret)
 		kfree(link);
 	return ret;
···
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
 		return -EINVAL;
 
-	mutex_lock(&genpd->lock);
+	mutex_lock(&subdomain->lock);
+	mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
 
 	if (!list_empty(&subdomain->slave_links) || subdomain->device_count) {
 		pr_warn("%s: unable to remove subdomain %s\n", genpd->name,
···
 		if (link->slave != subdomain)
 			continue;
 
-		mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
-
 		list_del(&link->master_node);
 		list_del(&link->slave_node);
 		kfree(link);
 		if (subdomain->status != GPD_STATE_POWER_OFF)
 			genpd_sd_counter_dec(genpd);
-
-		mutex_unlock(&subdomain->lock);
 
 		ret = 0;
 		break;
···
 
 out:
 	mutex_unlock(&genpd->lock);
+	mutex_unlock(&subdomain->lock);
 
 	return ret;
 }

drivers/cpufreq/cpufreq-dt.c

···
 
 try_again:
 	cpu_reg = regulator_get_optional(cpu_dev, reg);
-	if (IS_ERR(cpu_reg)) {
+	ret = PTR_ERR_OR_ZERO(cpu_reg);
+	if (ret) {
 		/*
 		 * If cpu's regulator supply node is present, but regulator is
 		 * not yet registered, we should try defering probe.
 		 */
-		if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
+		if (ret == -EPROBE_DEFER) {
 			dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n",
 				cpu);
-			return -EPROBE_DEFER;
+			return ret;
 		}
 
 		/* Try with "cpu-supply" */
···
 			goto try_again;
 		}
 
-		dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n",
-			cpu, PTR_ERR(cpu_reg));
+		dev_dbg(cpu_dev, "no regulator for cpu%d: %d\n", cpu, ret);
 	}
 
 	cpu_clk = clk_get(cpu_dev, NULL);
-	if (IS_ERR(cpu_clk)) {
+	ret = PTR_ERR_OR_ZERO(cpu_clk);
+	if (ret) {
 		/* put regulator */
 		if (!IS_ERR(cpu_reg))
 			regulator_put(cpu_reg);
-
-		ret = PTR_ERR(cpu_clk);
 
 		/*
 		 * If cpu's clk node is present, but clock is not yet

drivers/cpufreq/cpufreq.c

···
 					  bool active)
 {
 	do {
-		policy = list_next_entry(policy, policy_list);
-
 		/* No more policies in the list */
-		if (&policy->policy_list == &cpufreq_policy_list)
+		if (list_is_last(&policy->policy_list, &cpufreq_policy_list))
 			return NULL;
+
+		policy = list_next_entry(policy, policy_list);
 	} while (!suitable_policy(policy, active));
 
 	return policy;

drivers/cpufreq/cpufreq_governor.c

···
 	if (!have_governor_per_policy())
 		cdata->gdbs_data = dbs_data;
 
+	policy->governor_data = dbs_data;
+
 	ret = sysfs_create_group(get_governor_parent_kobj(policy),
 				 get_sysfs_attr(dbs_data));
 	if (ret)
 		goto reset_gdbs_data;
 
-	policy->governor_data = dbs_data;
-
 	return 0;
 
 reset_gdbs_data:
+	policy->governor_data = NULL;
+
 	if (!have_governor_per_policy())
 		cdata->gdbs_data = NULL;
 	cdata->exit(dbs_data, !policy->governor->initialized);
···
 	if (!cdbs->shared || cdbs->shared->policy)
 		return -EBUSY;
 
-	policy->governor_data = NULL;
 	if (!--dbs_data->usage_count) {
 		sysfs_remove_group(get_governor_parent_kobj(policy),
 				   get_sysfs_attr(dbs_data));
+
+		policy->governor_data = NULL;
 
 		if (!have_governor_per_policy())
 			cdata->gdbs_data = NULL;
 
 		cdata->exit(dbs_data, policy->governor->initialized == 1);
 		kfree(dbs_data);
+	} else {
+		policy->governor_data = NULL;
 	}
 
 	free_common_dbs_info(policy, cdata);

drivers/cpufreq/pxa2xx-cpufreq.c

···
 	}
 }
 #else
-static int pxa_cpufreq_change_voltage(struct pxa_freqs *pxa_freq)
+static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq)
 {
 	return 0;
 }

drivers/cpuidle/coupled.c

···
 
 #define CPUIDLE_COUPLED_NOT_IDLE	(-1)
 
-static DEFINE_MUTEX(cpuidle_coupled_lock);
 static DEFINE_PER_CPU(struct call_single_data, cpuidle_coupled_poke_cb);
 
 /*

drivers/cpuidle/cpuidle.c

···
 	 * be frozen safely.
 	 */
 	index = find_deepest_state(drv, dev, UINT_MAX, 0, true);
-	if (index >= 0)
+	if (index > 0)
 		enter_freeze_proper(drv, dev, index);
 
 	return index;

drivers/pci/hotplug/acpiphp_glue.c

···
 {
 	pci_lock_rescan_remove();
 
-	if (slot->flags & SLOT_IS_GOING_AWAY)
+	if (slot->flags & SLOT_IS_GOING_AWAY) {
+		pci_unlock_rescan_remove();
 		return -ENODEV;
+	}
 
 	/* configure all functions */
 	if (!(slot->flags & SLOT_ENABLED))

kernel/power/Kconfig

···
 
 config APM_EMULATION
 	tristate "Advanced Power Management Emulation"
-	depends on PM && SYS_SUPPORTS_APM_EMULATION
+	depends on SYS_SUPPORTS_APM_EMULATION
 	help
 	  APM is a BIOS specification for saving power using several different
 	  techniques. This is mostly useful for battery powered laptops with

kernel/sched/idle.c

···
 	 */
 	if (idle_should_freeze()) {
 		entered_state = cpuidle_enter_freeze(drv, dev);
-		if (entered_state >= 0) {
+		if (entered_state > 0) {
 			local_irq_enable();
 			goto exit_idle;
 		}