1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tests/drm_bridge_test.c b/drivers/gpu/drm/tests/drm_bridge_test.c
new file mode 100644
index 000000000000..887020141c7f
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_bridge_test.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kunit test for drm_bridge functions
+ */
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
+#include <drm/drm_bridge_helper.h>
+#include <drm/drm_kunit_helpers.h>
+
+#include <kunit/device.h>
+#include <kunit/test.h>
+
+/*
+ * Mimick the typical "private" struct defined by a bridge driver, which
+ * embeds a bridge plus other fields.
+ *
+ * Having at least one member before @bridge ensures we test non-zero
+ * @bridge offset.
+ */
+struct drm_bridge_priv {
+	unsigned int enable_count;
+	unsigned int disable_count;
+	struct drm_bridge bridge;
+	void *data;
+};
+
+struct drm_bridge_init_priv {
+	struct drm_device drm;
+	/** @dev: device, only for tests not needing a whole drm_device */
+	struct device *dev;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+	struct drm_encoder encoder;
+	struct drm_bridge_priv *test_bridge;
+	struct drm_connector *connector;
+	bool destroyed;
+};
+
+static struct drm_bridge_priv *bridge_to_priv(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct drm_bridge_priv, bridge);
+}
+
+static void drm_test_bridge_priv_destroy(struct drm_bridge *bridge)
+{
+	struct drm_bridge_priv *bridge_priv = bridge_to_priv(bridge);
+	struct drm_bridge_init_priv *priv = (struct drm_bridge_init_priv *)bridge_priv->data;
+
+	priv->destroyed = true;
+}
+
+static void drm_test_bridge_enable(struct drm_bridge *bridge)
+{
+	struct drm_bridge_priv *priv = bridge_to_priv(bridge);
+
+	priv->enable_count++;
+}
+
+static void drm_test_bridge_disable(struct drm_bridge *bridge)
+{
+	struct drm_bridge_priv *priv = bridge_to_priv(bridge);
+
+	priv->disable_count++;
+}
+
+static const struct drm_bridge_funcs drm_test_bridge_legacy_funcs = {
+	.destroy		= drm_test_bridge_priv_destroy,
+	.enable			= drm_test_bridge_enable,
+	.disable		= drm_test_bridge_disable,
+};
+
+static void drm_test_bridge_atomic_enable(struct drm_bridge *bridge,
+					  struct drm_atomic_state *state)
+{
+	struct drm_bridge_priv *priv = bridge_to_priv(bridge);
+
+	priv->enable_count++;
+}
+
+static void drm_test_bridge_atomic_disable(struct drm_bridge *bridge,
+					   struct drm_atomic_state *state)
+{
+	struct drm_bridge_priv *priv = bridge_to_priv(bridge);
+
+	priv->disable_count++;
+}
+
+static const struct drm_bridge_funcs drm_test_bridge_atomic_funcs = {
+	.destroy		= drm_test_bridge_priv_destroy,
+	.atomic_enable		= drm_test_bridge_atomic_enable,
+	.atomic_disable		= drm_test_bridge_atomic_disable,
+	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
+	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
+	.atomic_reset		= drm_atomic_helper_bridge_reset,
+};
+
+KUNIT_DEFINE_ACTION_WRAPPER(drm_bridge_remove_wrapper,
+			    drm_bridge_remove,
+			    struct drm_bridge *);
+
+static int drm_kunit_bridge_add(struct kunit *test,
+				struct drm_bridge *bridge)
+{
+	drm_bridge_add(bridge);
+
+	return kunit_add_action_or_reset(test,
+					 drm_bridge_remove_wrapper,
+					 bridge);
+}
+
+static struct drm_bridge_init_priv *
+drm_test_bridge_init(struct kunit *test, const struct drm_bridge_funcs *funcs)
+{
+	struct drm_bridge_init_priv *priv;
+	struct drm_encoder *enc;
+	struct drm_bridge *bridge;
+	struct drm_device *drm;
+	struct device *dev;
+	int ret;
+
+	dev = drm_kunit_helper_alloc_device(test);
+	if (IS_ERR(dev))
+		return ERR_CAST(dev);
+
+	priv = drm_kunit_helper_alloc_drm_device(test, dev,
+						 struct drm_bridge_init_priv, drm,
+						 DRIVER_MODESET | DRIVER_ATOMIC);
+	if (IS_ERR(priv))
+		return ERR_CAST(priv);
+
+	priv->test_bridge = devm_drm_bridge_alloc(dev, struct drm_bridge_priv, bridge, funcs);
+	if (IS_ERR(priv->test_bridge))
+		return ERR_CAST(priv->test_bridge);
+
+	priv->test_bridge->data = priv;
+
+	drm = &priv->drm;
+	priv->plane = drm_kunit_helper_create_primary_plane(test, drm,
+							    NULL,
+							    NULL,
+							    NULL, 0,
+							    NULL);
+	if (IS_ERR(priv->plane))
+		return ERR_CAST(priv->plane);
+
+	priv->crtc = drm_kunit_helper_create_crtc(test, drm,
+						  priv->plane, NULL,
+						  NULL,
+						  NULL);
+	if (IS_ERR(priv->crtc))
+		return ERR_CAST(priv->crtc);
+
+	enc = &priv->encoder;
+	ret = drmm_encoder_init(drm, enc, NULL, DRM_MODE_ENCODER_TMDS, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+
+	enc->possible_crtcs = drm_crtc_mask(priv->crtc);
+
+	bridge = &priv->test_bridge->bridge;
+	bridge->type = DRM_MODE_CONNECTOR_VIRTUAL;
+
+	ret = drm_kunit_bridge_add(test, bridge);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = drm_bridge_attach(enc, bridge, NULL, 0);
+	if (ret)
+		return ERR_PTR(ret);
+
+	priv->connector = drm_bridge_connector_init(drm, enc);
+	if (IS_ERR(priv->connector))
+		return ERR_CAST(priv->connector);
+
+	drm_connector_attach_encoder(priv->connector, enc);
+
+	drm_mode_config_reset(drm);
+
+	return priv;
+}
+
+/*
+ * Test that drm_bridge_get_current_state() returns the last committed
+ * state for an atomic bridge.
+ */
+static void drm_test_drm_bridge_get_current_state_atomic(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_bridge_init_priv *priv;
+	struct drm_bridge_state *curr_bridge_state;
+	struct drm_bridge_state *bridge_state;
+	struct drm_atomic_state *state;
+	struct drm_bridge *bridge;
+	struct drm_device *drm;
+	int ret;
+
+	priv = drm_test_bridge_init(test, &drm_test_bridge_atomic_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	drm = &priv->drm;
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+retry_commit:
+	bridge = &priv->test_bridge->bridge;
+	bridge_state = drm_atomic_get_bridge_state(state, bridge);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bridge_state);
+
+	ret = drm_atomic_commit(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry_commit;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_state:
+	ret = drm_modeset_lock(&bridge->base.lock, &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_state;
+	}
+
+	curr_bridge_state = drm_bridge_get_current_state(bridge);
+	KUNIT_EXPECT_PTR_EQ(test, curr_bridge_state, bridge_state);
+
+	drm_modeset_unlock(&bridge->base.lock);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+/*
+ * Test that drm_bridge_get_current_state() returns NULL for a
+ * non-atomic bridge.
+ */
+static void drm_test_drm_bridge_get_current_state_legacy(struct kunit *test)
+{
+	struct drm_bridge_init_priv *priv;
+	struct drm_bridge *bridge;
+
+	priv = drm_test_bridge_init(test, &drm_test_bridge_legacy_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	/*
+	 * NOTE: Strictly speaking, we should take the bridge->base.lock
+	 * before calling that function. However, bridge->base is only
+	 * initialized if the bridge is atomic, while we explicitly
+	 * initialize one that isn't there.
+	 *
+	 * In order to avoid unnecessary warnings, let's skip the
+	 * locking. The function would return NULL in all cases anyway,
+	 * so we don't really have any concurrency to worry about.
+	 */
+	bridge = &priv->test_bridge->bridge;
+	KUNIT_EXPECT_NULL(test, drm_bridge_get_current_state(bridge));
+}
+
+static struct kunit_case drm_bridge_get_current_state_tests[] = {
+	KUNIT_CASE(drm_test_drm_bridge_get_current_state_atomic),
+	KUNIT_CASE(drm_test_drm_bridge_get_current_state_legacy),
+	{ }
+};
+
+
+static struct kunit_suite drm_bridge_get_current_state_test_suite = {
+	.name = "drm_test_bridge_get_current_state",
+	.test_cases = drm_bridge_get_current_state_tests,
+};
+
+/*
+ * Test that an atomic bridge is properly power-cycled when calling
+ * drm_bridge_helper_reset_crtc().
+ */
+static void drm_test_drm_bridge_helper_reset_crtc_atomic(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_bridge_init_priv *priv;
+	struct drm_display_mode *mode;
+	struct drm_bridge_priv *bridge_priv;
+	int ret;
+
+	priv = drm_test_bridge_init(test, &drm_test_bridge_atomic_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, &priv->drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_commit:
+	ret = drm_kunit_helper_enable_crtc_connector(test,
+						     &priv->drm, priv->crtc,
+						     priv->connector,
+						     mode,
+						     &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_commit;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	bridge_priv = priv->test_bridge;
+	KUNIT_ASSERT_EQ(test, bridge_priv->enable_count, 1);
+	KUNIT_ASSERT_EQ(test, bridge_priv->disable_count, 0);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_reset:
+	ret = drm_bridge_helper_reset_crtc(&bridge_priv->bridge, &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_reset;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	KUNIT_EXPECT_EQ(test, bridge_priv->enable_count, 2);
+	KUNIT_EXPECT_EQ(test, bridge_priv->disable_count, 1);
+}
+
+/*
+ * Test that calling drm_bridge_helper_reset_crtc() on a disabled atomic
+ * bridge will fail and not call the enable / disable callbacks
+ */
+static void drm_test_drm_bridge_helper_reset_crtc_atomic_disabled(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_bridge_init_priv *priv;
+	struct drm_display_mode *mode;
+	struct drm_bridge_priv *bridge_priv;
+	int ret;
+
+	priv = drm_test_bridge_init(test, &drm_test_bridge_atomic_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, &priv->drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	bridge_priv = priv->test_bridge;
+	KUNIT_ASSERT_EQ(test, bridge_priv->enable_count, 0);
+	KUNIT_ASSERT_EQ(test, bridge_priv->disable_count, 0);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_reset:
+	ret = drm_bridge_helper_reset_crtc(&bridge_priv->bridge, &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_reset;
+	}
+	KUNIT_EXPECT_LT(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	KUNIT_EXPECT_EQ(test, bridge_priv->enable_count, 0);
+	KUNIT_EXPECT_EQ(test, bridge_priv->disable_count, 0);
+}
+
+/*
+ * Test that a non-atomic bridge is properly power-cycled when calling
+ * drm_bridge_helper_reset_crtc().
+ */
+static void drm_test_drm_bridge_helper_reset_crtc_legacy(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_bridge_init_priv *priv;
+	struct drm_display_mode *mode;
+	struct drm_bridge_priv *bridge_priv;
+	int ret;
+
+	priv = drm_test_bridge_init(test, &drm_test_bridge_legacy_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, &priv->drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_commit:
+	ret = drm_kunit_helper_enable_crtc_connector(test,
+						     &priv->drm, priv->crtc,
+						     priv->connector,
+						     mode,
+						     &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_commit;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	bridge_priv = priv->test_bridge;
+	KUNIT_ASSERT_EQ(test, bridge_priv->enable_count, 1);
+	KUNIT_ASSERT_EQ(test, bridge_priv->disable_count, 0);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_reset:
+	ret = drm_bridge_helper_reset_crtc(&bridge_priv->bridge, &ctx);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry_reset;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	KUNIT_EXPECT_EQ(test, bridge_priv->enable_count, 2);
+	KUNIT_EXPECT_EQ(test, bridge_priv->disable_count, 1);
+}
+
+static struct kunit_case drm_bridge_helper_reset_crtc_tests[] = {
+	KUNIT_CASE(drm_test_drm_bridge_helper_reset_crtc_atomic),
+	KUNIT_CASE(drm_test_drm_bridge_helper_reset_crtc_atomic_disabled),
+	KUNIT_CASE(drm_test_drm_bridge_helper_reset_crtc_legacy),
+	{ }
+};
+
+static struct kunit_suite drm_bridge_helper_reset_crtc_test_suite = {
+	.name = "drm_test_bridge_helper_reset_crtc",
+	.test_cases = drm_bridge_helper_reset_crtc_tests,
+};
+
+static int drm_test_bridge_alloc_init(struct kunit *test)
+{
+	struct drm_bridge_init_priv *priv;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	priv->dev = kunit_device_register(test, "drm-bridge-dev");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
+
+	test->priv = priv;
+
+	priv->test_bridge = devm_drm_bridge_alloc(priv->dev, struct drm_bridge_priv, bridge,
+						  &drm_test_bridge_atomic_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->test_bridge);
+
+	priv->test_bridge->data = priv;
+
+	KUNIT_ASSERT_FALSE(test, priv->destroyed);
+
+	return 0;
+}
+
+/*
+ * Test that a bridge is freed when the device is destroyed in lack of
+ * other drm_bridge_get/put() operations.
+ */
+static void drm_test_drm_bridge_alloc_basic(struct kunit *test)
+{
+	struct drm_bridge_init_priv *priv = test->priv;
+
+	KUNIT_ASSERT_FALSE(test, priv->destroyed);
+
+	kunit_device_unregister(test, priv->dev);
+	KUNIT_EXPECT_TRUE(test, priv->destroyed);
+}
+
+/*
+ * Test that a bridge is not freed when the device is destroyed when there
+ * is still a reference to it, and freed when that reference is put.
+ */
+static void drm_test_drm_bridge_alloc_get_put(struct kunit *test)
+{
+	struct drm_bridge_init_priv *priv = test->priv;
+
+	KUNIT_ASSERT_FALSE(test, priv->destroyed);
+
+	drm_bridge_get(&priv->test_bridge->bridge);
+	KUNIT_EXPECT_FALSE(test, priv->destroyed);
+
+	kunit_device_unregister(test, priv->dev);
+	KUNIT_EXPECT_FALSE(test, priv->destroyed);
+
+	drm_bridge_put(&priv->test_bridge->bridge);
+	KUNIT_EXPECT_TRUE(test, priv->destroyed);
+}
+
+static struct kunit_case drm_bridge_alloc_tests[] = {
+	KUNIT_CASE(drm_test_drm_bridge_alloc_basic),
+	KUNIT_CASE(drm_test_drm_bridge_alloc_get_put),
+	{ }
+};
+
+static struct kunit_suite drm_bridge_alloc_test_suite = {
+	.name = "drm_bridge_alloc",
+	.init = drm_test_bridge_alloc_init,
+	.test_cases = drm_bridge_alloc_tests,
+};
+
+kunit_test_suites(
+	&drm_bridge_get_current_state_test_suite,
+	&drm_bridge_helper_reset_crtc_test_suite,
+	&drm_bridge_alloc_test_suite,
+);
+
+MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
+MODULE_AUTHOR("Luca Ceresoli <luca.ceresoli@bootlin.com>");
+
+MODULE_DESCRIPTION("Kunit test for drm_bridge functions");
+MODULE_LICENSE("GPL");