drm/tests: managed: Add a simple test for drmm_managed_release

Add a simple test that checks whether the action is called when
drmm_managed_release is called.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240115171351.504264-6-michal.winiarski@intel.com

drivers/gpu/drm/tests/drm_managed_test.c

@@ -25,6 +25,30 @@ static void drm_action(struct drm_device *drm, void *ptr)
 	wake_up_interruptible(&priv->action_wq);
 }
 
+/*
+ * The test verifies that the release action is called when
+ * drmm_release_action is called.
+ */
+static void drm_test_managed_release_action(struct kunit *test)
+{
+	struct managed_test_priv *priv = test->priv;
+	int ret;
+
+	ret = drmm_add_action_or_reset(priv->drm, drm_action, priv);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	ret = drm_dev_register(priv->drm, 0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drmm_release_action(priv->drm, drm_action, priv);
+	ret = wait_event_interruptible_timeout(priv->action_wq, priv->action_done,
+					       msecs_to_jiffies(TEST_TIMEOUT_MS));
+	KUNIT_EXPECT_GT(test, ret, 0);
+
+	drm_dev_unregister(priv->drm);
+	drm_kunit_helper_free_device(test, priv->drm->dev);
+}
+
 /*
  * The test verifies that the release action is called automatically when the
  * device is released.
@@ -75,6 +99,7 @@ static int drm_managed_test_init(struct kunit *test)
 }
 
 static struct kunit_case drm_managed_tests[] = {
+	KUNIT_CASE(drm_test_managed_release_action),
 	KUNIT_CASE(drm_test_managed_run_action),
 	{}
 };