[PATCH v7 13/16] drm/tests: atomic: Add tests for drm_atomic_commit_fill_with_defaults()

[Maxime Ripard <mripard@kernel.org>]

drm_atomic_commit_fill_with_defaults() is used by the
DRM_MODE_ATOMIC_RESET flag to bring all objects back to their pristine
state. However, it has no dedicated test coverage.

Add two tests that verify the reset cycle. The first enables a CRTC,
plane, and connector, then calls drm_atomic_commit_fill_with_defaults()
and verifies all objects return to their disabled state: CRTC inactive,
plane disabled with no framebuffer, and connector unbound. The second
goes further and commits the default-filled state to verify the
init -> enable -> reset -> commit sequence completes without errors.

Suggested-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/tests/drm_atomic_test.c | 313 +++++++++++++++++++++++++++++++-
 1 file changed, 311 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_atomic_test.c b/drivers/gpu/drm/tests/drm_atomic_test.c
index 5e156d09e56f..160de1aa3ec2 100644
--- a/drivers/gpu/drm/tests/drm_atomic_test.c
+++ b/drivers/gpu/drm/tests/drm_atomic_test.c
@@ -9,4 +9,5 @@
 #include <drm/drm_kunit_helpers.h>
 #include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_property.h>
 
 #include <kunit/test.h>
@@ -143,5 +144,4 @@ static struct kunit_case drm_atomic_get_connector_for_encoder_tests[] = {
 };
 
-
 static struct kunit_suite drm_atomic_get_connector_for_encoder_test_suite = {
 	.name = "drm_test_atomic_get_connector_for_encoder",
@@ -149,5 +149,314 @@ static struct kunit_suite drm_atomic_get_connector_for_encoder_test_suite = {
 };
 
-kunit_test_suite(drm_atomic_get_connector_for_encoder_test_suite);
+/*
+ * Test that after enabling a CRTC and connector, filling with defaults
+ * produces a state where all objects are disabled: CRTC is inactive,
+ * plane is disabled, and connector is unbound.
+ *
+ * This is done without any lease, so all objects are expected to be
+ * reset.
+ *
+ * The plane is not explicitly enabled with a framebuffer here, so
+ * this validates that fill_with_defaults produces a consistent
+ * disabled state rather than testing an active plane teardown.
+ */
+static void drm_test_check_fill_with_defaults(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_connector_state *new_conn_state;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_plane_state *new_plane_state;
+	struct drm_atomic_commit *state;
+	struct drm_display_mode *mode;
+	struct drm_device *drm;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm,
+						     priv->crtc,
+						     &priv->connector,
+						     mode, &ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+retry_fill:
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_fill;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, priv->crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_crtc_state);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->enable);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->active);
+
+	new_plane_state = drm_atomic_get_new_plane_state(state, priv->plane);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_plane_state);
+	KUNIT_EXPECT_NULL(test, new_plane_state->crtc);
+	KUNIT_EXPECT_NULL(test, new_plane_state->fb);
+
+	new_conn_state = drm_atomic_get_new_connector_state(state, &priv->connector);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_conn_state);
+	KUNIT_EXPECT_NULL(test, new_conn_state->crtc);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+/*
+ * Test that after enabling a CRTC and connector, fill_with_defaults
+ * produces a state that can be successfully committed.
+ *
+ * This is done without any lease, so all objects are reset.
+ *
+ * The plane is not explicitly enabled with a framebuffer, so this
+ * validates that fill_with_defaults produces a consistent disabled
+ * state rather than testing an active plane teardown.
+ */
+static void drm_test_check_fill_with_defaults_commit(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_commit *state;
+	struct drm_display_mode *mode;
+	struct drm_device *drm;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm,
+						     priv->crtc,
+						     &priv->connector,
+						     mode, &ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+retry_fill:
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_fill;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state->allow_modeset = true;
+
+	ret = drm_atomic_commit(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_fill;
+	}
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+/*
+ * Test that filling with defaults reports the color management changes
+ * on the new states through color_mgmt_changed, so that drivers
+ * reprogram the color management hardware when a LUT is being cleared
+ * by the reset.
+ */
+static void drm_test_check_fill_with_defaults_color_mgmt(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_plane_state *new_plane_state;
+	struct drm_atomic_commit *state;
+	struct drm_property_blob *gamma_lut;
+	struct drm_device *drm;
+	u32 lut = 0;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	gamma_lut = drm_property_create_blob(drm, sizeof(lut), &lut);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, gamma_lut);
+
+	/*
+	 * Attach a gamma LUT to the current CRTC state, like userspace
+	 * setting the GAMMA_LUT property would. The state takes ownership
+	 * of the blob reference.
+	 */
+	priv->crtc->state->gamma_lut = gamma_lut;
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+retry_fill:
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_fill;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, priv->crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_crtc_state);
+	KUNIT_EXPECT_NULL(test, new_crtc_state->gamma_lut);
+	KUNIT_EXPECT_TRUE(test, new_crtc_state->color_mgmt_changed);
+
+	new_plane_state = drm_atomic_get_new_plane_state(state, priv->plane);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_plane_state);
+	KUNIT_EXPECT_FALSE(test, new_plane_state->color_mgmt_changed);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+/*
+ * Test that a reset on which userspace re-applies the exact same
+ * configuration doesn't need a modeset, and thus doesn't require the
+ * DRM_MODE_ATOMIC_ALLOW_MODESET flag.
+ */
+static void drm_test_check_fill_with_defaults_no_modeset(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector_state *new_conn_state;
+	struct drm_atomic_commit *state;
+	struct drm_display_mode *mode;
+	struct drm_device *drm;
+	int ret;
+
+	priv = create_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+
+	drm = &priv->drm;
+
+	mode = drm_kunit_display_mode_from_cea_vic(test, drm, 16);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mode);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm,
+						     priv->crtc,
+						     &priv->connector,
+						     mode, &ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+retry:
+	ret = drm_atomic_commit_fill_with_defaults(NULL, state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	/* Re-apply the exact same configuration on top of the reset */
+	new_conn_state = drm_atomic_get_new_connector_state(state, &priv->connector);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_conn_state);
+
+	ret = drm_atomic_set_crtc_for_connector(new_conn_state, priv->crtc);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, priv->crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_crtc_state);
+
+	ret = drm_atomic_set_mode_for_crtc(new_crtc_state, mode);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_crtc_state->enable = true;
+	new_crtc_state->active = true;
+
+	/* Modesets aren't allowed and shouldn't be needed */
+	state->allow_modeset = false;
+
+	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->active_changed);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->connectors_changed);
+	KUNIT_EXPECT_FALSE(test, new_crtc_state->mode_changed);
+	KUNIT_EXPECT_FALSE(test, drm_atomic_crtc_needs_modeset(new_crtc_state));
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
+static struct kunit_case drm_atomic_fill_with_defaults_tests[] = {
+	KUNIT_CASE(drm_test_check_fill_with_defaults),
+	KUNIT_CASE(drm_test_check_fill_with_defaults_commit),
+	KUNIT_CASE(drm_test_check_fill_with_defaults_color_mgmt),
+	KUNIT_CASE(drm_test_check_fill_with_defaults_no_modeset),
+	{ }
+};
+
+static struct kunit_suite drm_atomic_fill_with_defaults_test_suite = {
+	.name = "drm_atomic_commit_fill_with_defaults",
+	.test_cases = drm_atomic_fill_with_defaults_tests,
+};
+
+kunit_test_suites(&drm_atomic_get_connector_for_encoder_test_suite,
+		  &drm_atomic_fill_with_defaults_test_suite);
 
 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");

-- 
2.55.0