Merge tag 'pm-reverts-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management commit reverts from Rafael Wysocki:
 "Since Geert reports additional problems with my PM QoS fix from the
  last week that have not been addressed by the most recent fixup on top
  of it, they both should better be reverted now and let's fix the
  original issue properly in 4.15.

  This reverts two recent PM QoS commits one of which introduced
  multiple problems and the other one fixed some, but not all of them
  (Rafael Wysocki)"

* tag 'pm-reverts-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "PM / QoS: Fix device resume latency PM QoS"
  Revert "PM / QoS: Fix default runtime_pm device resume latency"

6 files changed, 32 insertions, 57 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 227bac5f1191..321cd7b4d817 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -377,8 +377,7 @@ int register_cpu(struct cpu *cpu, int num)
 
 	per_cpu(cpu_sys_devices, num) = &cpu->dev;
 	register_cpu_under_node(num, cpu_to_node(num));
-	dev_pm_qos_expose_latency_limit(&cpu->dev,
-					PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
+	dev_pm_qos_expose_latency_limit(&cpu->dev, 0);
 
 	return 0;
 }
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index 51751cc8c9e6..281f949c5ffe 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -14,20 +14,23 @@
 static int dev_update_qos_constraint(struct device *dev, void *data)
 {
 	s64 *constraint_ns_p = data;
-	s64 constraint_ns = -1;
+	s32 constraint_ns = -1;
 
 	if (dev->power.subsys_data && dev->power.subsys_data->domain_data)
 		constraint_ns = dev_gpd_data(dev)->td.effective_constraint_ns;
 
-	if (constraint_ns < 0)
+	if (constraint_ns < 0) {
 		constraint_ns = dev_pm_qos_read_value(dev);
-
-	if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+		constraint_ns *= NSEC_PER_USEC;
+	}
+	if (constraint_ns == 0)
 		return 0;
 
-	constraint_ns *= NSEC_PER_USEC;
-
-	if (constraint_ns < *constraint_ns_p || *constraint_ns_p < 0)
+	/*
+	 * constraint_ns cannot be negative here, because the device has been
+	 * suspended.
+	 */
+	if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0)
 		*constraint_ns_p = constraint_ns;
 
 	return 0;
@@ -60,14 +63,10 @@ static bool default_suspend_ok(struct device *dev)
 
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
-	if (constraint_ns == 0)
+	if (constraint_ns < 0)
 		return false;
 
-	if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
-		constraint_ns = -1;
-	else
-		constraint_ns *= NSEC_PER_USEC;
-
+	constraint_ns *= NSEC_PER_USEC;
 	/*
 	 * We can walk the children without any additional locking, because
 	 * they all have been suspended at this point and their
@@ -77,19 +76,14 @@ static bool default_suspend_ok(struct device *dev)
 		device_for_each_child(dev, &constraint_ns,
 				      dev_update_qos_constraint);
 
-	if (constraint_ns < 0) {
-		/* The children have no constraints. */
-		td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
-		td->cached_suspend_ok = true;
-	} else {
-		constraint_ns -= td->suspend_latency_ns + td->resume_latency_ns;
-		if (constraint_ns > 0) {
-			td->effective_constraint_ns = constraint_ns;
-			td->cached_suspend_ok = true;
-		} else {
-			td->effective_constraint_ns = 0;
-		}
+	if (constraint_ns > 0) {
+		constraint_ns -= td->suspend_latency_ns +
+				td->resume_latency_ns;
+		if (constraint_ns == 0)
+			return false;
 	}
+	td->effective_constraint_ns = constraint_ns;
+	td->cached_suspend_ok = constraint_ns >= 0;
 
 	/*
 	 * The children have been suspended already, so we don't need to take
@@ -151,14 +145,13 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd,
 		td = &to_gpd_data(pdd)->td;
 		constraint_ns = td->effective_constraint_ns;
 		/* default_suspend_ok() need not be called before us. */
-		if (constraint_ns < 0)
+		if (constraint_ns < 0) {
 			constraint_ns = dev_pm_qos_read_value(pdd->dev);
-
-		if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+			constraint_ns *= NSEC_PER_USEC;
+		}
+		if (constraint_ns == 0)
 			continue;
 
-		constraint_ns *= NSEC_PER_USEC;
-
 		/*
 		 * constraint_ns cannot be negative here, because the device has
 		 * been suspended.
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 7d29286d9313..277d43a83f53 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -189,7 +189,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
 	plist_head_init(&c->list);
 	c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
 	c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
-	c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+	c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
 	c->type = PM_QOS_MIN;
 	c->notifiers = n;
 
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 13e015905543..7bcf80fa9ada 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -253,7 +253,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
 	    || (dev->power.request_pending
 			&& dev->power.request == RPM_REQ_RESUME))
 		retval = -EAGAIN;
-	else if (__dev_pm_qos_read_value(dev) == 0)
+	else if (__dev_pm_qos_read_value(dev) < 0)
 		retval = -EPERM;
 	else if (dev->power.runtime_status == RPM_SUSPENDED)
 		retval = 1;
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 632077f05c57..156ab57bca77 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -218,14 +218,7 @@ static ssize_t pm_qos_resume_latency_show(struct device *dev,
 					  struct device_attribute *attr,
 					  char *buf)
 {
-	s32 value = dev_pm_qos_requested_resume_latency(dev);
-
-	if (value == 0)
-		return sprintf(buf, "n/a\n");
-	else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
-		value = 0;
-
-	return sprintf(buf, "%d\n", value);
+	return sprintf(buf, "%d\n", dev_pm_qos_requested_resume_latency(dev));
 }
 
 static ssize_t pm_qos_resume_latency_store(struct device *dev,
@@ -235,21 +228,11 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev,
 	s32 value;
 	int ret;
 
-	if (!kstrtos32(buf, 0, &value)) {
-		/*
-		 * Prevent users from writing negative or "no constraint" values
-		 * directly.
-		 */
-		if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
-			return -EINVAL;
+	if (kstrtos32(buf, 0, &value))
+		return -EINVAL;
 
-		if (value == 0)
-			value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
-	} else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) {
-		value = 0;
-	} else {
+	if (value < 0)
 		return -EINVAL;
-	}
 
 	ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
 					value);
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index aa390404e85f..48eaf2879228 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -298,8 +298,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		data->needs_update = 0;
 	}
 
-	if (resume_latency < latency_req &&
-	    resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+	/* resume_latency is 0 means no restriction */
+	if (resume_latency && resume_latency < latency_req)
 		latency_req = resume_latency;
 
 	/* Special case when user has set very strict latency requirement */