1 files changed, 22 insertions, 32 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 6ac9a7f33b64..301b785f9f56 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -162,7 +162,7 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 
 /**
  * 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.
@@ -172,16 +172,15 @@ static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 	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_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;
@@ -196,11 +195,16 @@ static int __genpd_poweron(struct generic_pm_domain *genpd)
 	 * 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;
+
+		genpd_sd_counter_inc(master);
+
+		mutex_lock_nested(&master->lock, depth + 1);
+		ret = genpd_poweron(master, depth + 1);
+		mutex_unlock(&master->lock);
 
-		ret = genpd_poweron(link->master);
 		if (ret) {
-			genpd_sd_counter_dec(link->master);
+			genpd_sd_counter_dec(master);
 			goto err;
 		}
 	}
@@ -223,20 +227,6 @@ static int __genpd_poweron(struct generic_pm_domain *genpd)
 	return ret;
 }
 
-/**
- * genpd_poweron - Restore power to a given PM domain and its masters.
- * @genpd: PM domain to power up.
- */
-static int genpd_poweron(struct generic_pm_domain *genpd)
-{
-	int ret;
-
-	mutex_lock(&genpd->lock);
-	ret = __genpd_poweron(genpd);
-	mutex_unlock(&genpd->lock);
-	return ret;
-}
-
 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 {
 	return GENPD_DEV_CALLBACK(genpd, int, save_state, dev);
@@ -484,7 +474,7 @@ static int pm_genpd_runtime_resume(struct device *dev)
 	}
 
 	mutex_lock(&genpd->lock);
-	ret = __genpd_poweron(genpd);
+	ret = genpd_poweron(genpd, 0);
 	mutex_unlock(&genpd->lock);
 
 	if (ret)
@@ -1339,8 +1329,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 	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) {
@@ -1363,8 +1353,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 		genpd_sd_counter_inc(genpd);
 
  out:
-	mutex_unlock(&subdomain->lock);
 	mutex_unlock(&genpd->lock);
+	mutex_unlock(&subdomain->lock);
 	if (ret)
 		kfree(link);
 	return ret;
@@ -1385,7 +1375,8 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 	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,
@@ -1398,22 +1389,19 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 		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;
 }
@@ -1818,8 +1806,10 @@ int genpd_dev_pm_attach(struct device *dev)
 
 	dev->pm_domain->detach = genpd_dev_pm_detach;
 	dev->pm_domain->sync = genpd_dev_pm_sync;
-	ret = genpd_poweron(pd);
 
+	mutex_lock(&pd->lock);
+	ret = genpd_poweron(pd, 0);
+	mutex_unlock(&pd->lock);
 out:
 	return ret ? -EPROBE_DEFER : 0;
 }