3 files changed, 76 insertions, 6 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 8e5725b11ee8..959d6d5eb000 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2303,6 +2303,44 @@ out:
 EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
 
 /**
+ * of_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
+ * @parent_spec: OF phandle args to use for parent PM domain look-up
+ * @subdomain_spec: OF phandle args to use for subdomain look-up
+ *
+ * Looks-up a parent PM domain and subdomain based upon phandle args
+ * provided and removes the subdomain from the parent PM domain. Returns a
+ * negative error code on failure.
+ */
+int of_genpd_remove_subdomain(struct of_phandle_args *parent_spec,
+			      struct of_phandle_args *subdomain_spec)
+{
+	struct generic_pm_domain *parent, *subdomain;
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+
+	parent = genpd_get_from_provider(parent_spec);
+	if (IS_ERR(parent)) {
+		ret = PTR_ERR(parent);
+		goto out;
+	}
+
+	subdomain = genpd_get_from_provider(subdomain_spec);
+	if (IS_ERR(subdomain)) {
+		ret = PTR_ERR(subdomain);
+		goto out;
+	}
+
+	ret = pm_genpd_remove_subdomain(parent, subdomain);
+
+out:
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_genpd_remove_subdomain);
+
+/**
  * of_genpd_remove_last - Remove the last PM domain registered for a provider
  * @provider: Pointer to device structure associated with provider
  *
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 134a8af51511..0e99a760aebd 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -273,10 +273,38 @@ static void dpm_wait_for_suppliers(struct device *dev, bool async)
 	device_links_read_unlock(idx);
 }
 
-static void dpm_wait_for_superior(struct device *dev, bool async)
+static bool dpm_wait_for_superior(struct device *dev, bool async)
 {
-	dpm_wait(dev->parent, async);
+	struct device *parent;
+
+	/*
+	 * If the device is resumed asynchronously and the parent's callback
+	 * deletes both the device and the parent itself, the parent object may
+	 * be freed while this function is running, so avoid that by reference
+	 * counting the parent once more unless the device has been deleted
+	 * already (in which case return right away).
+	 */
+	mutex_lock(&dpm_list_mtx);
+
+	if (!device_pm_initialized(dev)) {
+		mutex_unlock(&dpm_list_mtx);
+		return false;
+	}
+
+	parent = get_device(dev->parent);
+
+	mutex_unlock(&dpm_list_mtx);
+
+	dpm_wait(parent, async);
+	put_device(parent);
+
 	dpm_wait_for_suppliers(dev, async);
+
+	/*
+	 * If the parent's callback has deleted the device, attempting to resume
+	 * it would be invalid, so avoid doing that then.
+	 */
+	return device_pm_initialized(dev);
 }
 
 static void dpm_wait_for_consumers(struct device *dev, bool async)
@@ -621,7 +649,8 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn
 	if (!dev->power.is_noirq_suspended)
 		goto Out;
 
-	dpm_wait_for_superior(dev, async);
+	if (!dpm_wait_for_superior(dev, async))
+		goto Out;
 
 	skip_resume = dev_pm_may_skip_resume(dev);
 
@@ -829,7 +858,8 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn
 	if (!dev->power.is_late_suspended)
 		goto Out;
 
-	dpm_wait_for_superior(dev, async);
+	if (!dpm_wait_for_superior(dev, async))
+		goto Out;
 
 	callback = dpm_subsys_resume_early_cb(dev, state, &info);
 
@@ -944,7 +974,9 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
 		goto Complete;
 	}
 
-	dpm_wait_for_superior(dev, async);
+	if (!dpm_wait_for_superior(dev, async))
+		goto Complete;
+
 	dpm_watchdog_set(&wd, dev);
 	device_lock(dev);
 
diff --git a/drivers/base/power/qos-test.c b/drivers/base/power/qos-test.c
index 3115db08d56b..79fc6c4418da 100644
--- a/drivers/base/power/qos-test.c
+++ b/drivers/base/power/qos-test.c
@@ -114,4 +114,4 @@ static struct kunit_suite pm_qos_test_module = {
 	.name = "qos-kunit-test",
 	.test_cases = pm_qos_test_cases,
 };
-kunit_test_suite(pm_qos_test_module);
+kunit_test_suites(&pm_qos_test_module);