1 files changed, 53 insertions, 16 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index d2c03239abcf..b6ff6ecf519d 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -366,7 +366,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 	not_suspended = 0;
 	list_for_each_entry(pdd, &genpd->dev_list, list_node)
 		if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
-		    || pdd->dev->power.irq_safe))
+		    || pdd->dev->power.irq_safe || to_gpd_data(pdd)->always_on))
 			not_suspended++;
 
 	if (not_suspended > genpd->in_progress)
@@ -503,6 +503,9 @@ static int pm_genpd_runtime_suspend(struct device *dev)
 
 	might_sleep_if(!genpd->dev_irq_safe);
 
+	if (dev_gpd_data(dev)->always_on)
+		return -EBUSY;
+
 	stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 	if (stop_ok && !stop_ok(dev))
 		return -EBUSY;
@@ -764,8 +767,10 @@ static int pm_genpd_prepare(struct device *dev)
 
 	genpd_acquire_lock(genpd);
 
-	if (genpd->prepared_count++ == 0)
+	if (genpd->prepared_count++ == 0) {
+		genpd->suspended_count = 0;
 		genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
+	}
 
 	genpd_release_lock(genpd);
 
@@ -857,7 +862,7 @@ static int pm_genpd_suspend_noirq(struct device *dev)
 	if (IS_ERR(genpd))
 		return -EINVAL;
 
-	if (genpd->suspend_power_off
+	if (genpd->suspend_power_off || dev_gpd_data(dev)->always_on
 	    || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
 		return 0;
 
@@ -890,7 +895,8 @@ static int pm_genpd_resume_noirq(struct device *dev)
 	if (IS_ERR(genpd))
 		return -EINVAL;
 
-	if (genpd->suspend_power_off)
+	if (genpd->suspend_power_off || dev_gpd_data(dev)->always_on
+	    || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
 		return 0;
 
 	/*
@@ -1009,7 +1015,8 @@ static int pm_genpd_freeze_noirq(struct device *dev)
 	if (IS_ERR(genpd))
 		return -EINVAL;
 
-	return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
+	return genpd->suspend_power_off || dev_gpd_data(dev)->always_on ?
+		0 : genpd_stop_dev(genpd, dev);
 }
 
 /**
@@ -1029,7 +1036,8 @@ static int pm_genpd_thaw_noirq(struct device *dev)
 	if (IS_ERR(genpd))
 		return -EINVAL;
 
-	return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
+	return genpd->suspend_power_off || dev_gpd_data(dev)->always_on ?
+		0 : genpd_start_dev(genpd, dev);
 }
 
 /**
@@ -1096,22 +1104,32 @@ static int pm_genpd_restore_noirq(struct device *dev)
 	 * Since all of the "noirq" callbacks are executed sequentially, it is
 	 * guaranteed that this function will never run twice in parallel for
 	 * the same PM domain, so it is not necessary to use locking here.
+	 *
+	 * At this point suspended_count == 0 means we are being run for the
+	 * first time for the given domain in the present cycle.
 	 */
-	genpd->status = GPD_STATE_POWER_OFF;
-	if (genpd->suspend_power_off) {
+	if (genpd->suspended_count++ == 0) {
 		/*
-		 * The boot kernel might put the domain into the power on state,
-		 * so make sure it really is powered off.
+		 * The boot kernel might put the domain into arbitrary state,
+		 * so make it appear as powered off to pm_genpd_poweron(), so
+		 * that it tries to power it on in case it was really off.
 		 */
-		if (genpd->power_off)
-			genpd->power_off(genpd);
-		return 0;
+		genpd->status = GPD_STATE_POWER_OFF;
+		if (genpd->suspend_power_off) {
+			/*
+			 * If the domain was off before the hibernation, make
+			 * sure it will be off going forward.
+			 */
+			if (genpd->power_off)
+				genpd->power_off(genpd);
+
+			return 0;
+		}
 	}
 
 	pm_genpd_poweron(genpd);
-	genpd->suspended_count--;
 
-	return genpd_start_dev(genpd, dev);
+	return dev_gpd_data(dev)->always_on ? 0 : genpd_start_dev(genpd, dev);
 }
 
 /**
@@ -1307,6 +1325,26 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 }
 
 /**
+ * pm_genpd_dev_always_on - Set/unset the "always on" flag for a given device.
+ * @dev: Device to set/unset the flag for.
+ * @val: The new value of the device's "always on" flag.
+ */
+void pm_genpd_dev_always_on(struct device *dev, bool val)
+{
+	struct pm_subsys_data *psd;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+
+	psd = dev_to_psd(dev);
+	if (psd && psd->domain_data)
+		to_gpd_data(psd->domain_data)->always_on = val;
+
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+EXPORT_SYMBOL_GPL(pm_genpd_dev_always_on);
+
+/**
  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
  * @genpd: Master PM domain to add the subdomain to.
  * @subdomain: Subdomain to be added.
@@ -1648,7 +1686,6 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
 	genpd->poweroff_task = NULL;
 	genpd->resume_count = 0;
 	genpd->device_count = 0;
-	genpd->suspended_count = 0;
 	genpd->max_off_time_ns = -1;
 	genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
 	genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;