[PATCH v14 23/28] drm/tests: hdmi: Add tests for the color_format property

Nicolas Frattaroli
2026-04-23T19:07:45Z

Add some KUnit tests to check the color_format property is working as
expected with the HDMI state helper.

Existing tests are extended to also test the
DRM_CONNECTOR_COLOR_FORMAT_AUTO case, in order to avoid duplicating test
cases. For the explicitly selected color format cases, parameterized
tests are added.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 236 +++++++++++++++++++++
1 file changed, 236 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
index a4357efaa983..3444c93c615f 100644
--- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
@@ -60,6 +60,23 @@ static struct drm_display_mode *find_preferred_mode(struct drm_connector *connec
return preferred;
}

+static struct drm_display_mode *find_420_only_mode(struct drm_connector *connector)
+{
+ struct drm_device *drm = connector->dev;
+ struct drm_display_mode *mode;
+
+ mutex_lock(&drm->mode_config.mutex);
+ list_for_each_entry(mode, &connector->modes, head) {
+ if (drm_mode_is_420_only(&connector->display_info, mode)) {
+ mutex_unlock(&drm->mode_config.mutex);
+ return mode;
+ }
+ }
+ mutex_unlock(&drm->mode_config.mutex);
+
+ return NULL;
+}
+
static int set_connector_edid(struct kunit *test, struct drm_connector *connector,
const void *edid, size_t edid_len)
{
@@ -1547,6 +1564,7 @@ static void drm_test_check_max_tmds_rate_bpc_fallback_yuv420(struct kunit *test)
* RGB/10bpc
* - The chosen mode has a TMDS character rate lower than the display
* supports in YUV422/12bpc.
+ * - The HDMI connector state's color format property is unset (i.e. AUTO)
*
* Then we will prefer to keep the RGB format with a lower bpc over
* picking YUV422.
@@ -1609,6 +1627,7 @@ static void drm_test_check_max_tmds_rate_bpc_fallback_ignore_yuv422(struct kunit

conn_state = conn->state;
KUNIT_ASSERT_NOT_NULL(test, conn_state);
+ KUNIT_ASSERT_EQ(test, conn_state->color_format, DRM_CONNECTOR_COLOR_FORMAT_AUTO);

KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 10);
KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, DRM_OUTPUT_COLOR_FORMAT_RGB444);
@@ -1626,6 +1645,7 @@ static void drm_test_check_max_tmds_rate_bpc_fallback_ignore_yuv422(struct kunit
* RGB/8bpc
* - The chosen mode has a TMDS character rate lower than the display
* supports in YUV420/12bpc.
+ * - The HDMI connector state's color format property is unset (i.e. AUTO)
*
* Then we will prefer to keep the RGB format with a lower bpc over
* picking YUV420.
@@ -1687,6 +1707,7 @@ static void drm_test_check_max_tmds_rate_bpc_fallback_ignore_yuv420(struct kunit

conn_state = conn->state;
KUNIT_ASSERT_NOT_NULL(test, conn_state);
+ KUNIT_ASSERT_EQ(test, conn_state->color_format, DRM_CONNECTOR_COLOR_FORMAT_AUTO);

KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 8);
KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, DRM_OUTPUT_COLOR_FORMAT_RGB444);
@@ -2198,6 +2219,217 @@ static void drm_test_check_disable_connector(struct kunit *test)
drm_modeset_acquire_fini(&ctx);
}

+struct color_format_test_param {
+ enum drm_connector_color_format fmt;
+ enum drm_output_color_format expected;
+ int expected_ret;
+ const char *desc;
+};
+
+/* Test that if:
+ * - an HDMI connector supports RGB, YUV444, YUV422, and YUV420
+ * - the display supports RGB, YUV444, YUV422, and YUV420
+ * - the "color format" property is set
+ * then, for the preferred mode, for a given "color format" option:
+ * - DRM_CONNECTOR_COLOR_FORMAT_AUTO results in an output format of RGB
+ * - DRM_CONNECTOR_COLOR_FORMAT_YCBCR422 results in an output format of YUV422
+ * - DRM_CONNECTOR_COLOR_FORMAT_YCBCR420 results in an output format of YUV420
+ * - DRM_CONNECTOR_COLOR_FORMAT_YCBCR444 results in an output format of YUV444
+ * - DRM_CONNECTOR_COLOR_FORMAT_RGB results in an HDMI output format of RGB
+ */
+static void drm_test_check_hdmi_color_format(struct kunit *test)
+{
+ const struct color_format_test_param *param = test->param_value;
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_connector_state *conn_state;
+ struct drm_modeset_acquire_ctx ctx;
+ struct drm_crtc_state *crtc_state;
+ struct drm_atomic_state *state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ int ret;
+
+ priv = drm_kunit_helper_connector_hdmi_init_with_edid_funcs(test,
+ BIT(DRM_OUTPUT_COLOR_FORMAT_RGB444) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR422) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR420) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR444),
+ 12,
+ &dummy_connector_hdmi_funcs,
+ test_edid_hdmi_4k_rgb_yuv420_dc_max_340mhz);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ drm_modeset_acquire_init(&ctx, 0);
+
+ KUNIT_ASSERT_TRUE(test, priv->connector.ycbcr_420_allowed);
+
+ info = &priv->connector.display_info;
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, info);
+ preferred = find_preferred_mode(&priv->connector);
+ KUNIT_ASSERT_TRUE(test, drm_mode_is_420(info, preferred));
+
+ state = drm_kunit_helper_atomic_state_alloc(test, &priv->drm, &ctx);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+ conn_state = drm_atomic_get_connector_state(state, &priv->connector);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
+
+ conn_state->color_format = param->fmt;
+
+ ret = drm_atomic_set_crtc_for_connector(conn_state, priv->crtc);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ crtc_state = drm_atomic_get_crtc_state(state, priv->crtc);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);
+
+ ret = drm_atomic_set_mode_for_crtc(crtc_state, preferred);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ crtc_state->enable = true;
+ crtc_state->active = true;
+
+ ret = drm_atomic_check_only(state);
+ KUNIT_EXPECT_EQ(test, ret, param->expected_ret);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, param->expected);
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+}
+
+static const struct color_format_test_param hdmi_color_format_params[] = {
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_AUTO,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_RGB444,
+ .expected_ret = 0,
+ .desc = "AUTO -> RGB"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR422,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR422,
+ .expected_ret = 0,
+ .desc = "YCBCR422 -> YUV422"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR420,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR420,
+ .expected_ret = 0,
+ .desc = "YCBCR420 -> YUV420"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR444,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR444,
+ .expected_ret = 0,
+ .desc = "YCBCR444 -> YUV444"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_RGB444,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_RGB444,
+ .expected_ret = 0,
+ .desc = "RGB -> RGB"
+ },
+};
+
+KUNIT_ARRAY_PARAM_DESC(check_hdmi_color_format, hdmi_color_format_params, desc);
+
+/* Test that if:
+ * - the HDMI connector supports RGB, YUV422, YUV420, and YUV444
+ * - the display has a YUV420-only mode
+ * - the "color format" property is explicitly set (i.e. !AUTO)
+ * then:
+ * - color format DRM_CONNECTOR_COLOR_FORMAT_RGB444 will fail
+ * drm_atomic_check_only for the YUV420-only mode with -EINVAL
+ * - color format DRM_CONNECTOR_COLOR_FORMAT_YCBCR444 will fail
+ * drm_atomic_check_only for the YUV420-only mode with -EINVAL
+ * - color format DRM_CONNECTOR_COLOR_FORMAT_YCBCR422 will fail
+ * drm_atomic_check_only for the YUV420-only mode with -EINVAL
+ * - color format DRM_CONNECTOR_COLOR_FORMAT_YCBCR420 passes
+ * drm_atomic_check_only for the YUV420-only mode
+ */
+static void drm_test_check_hdmi_color_format_420_only(struct kunit *test)
+{
+ const struct color_format_test_param *param = test->param_value;
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_connector_state *conn_state;
+ struct drm_modeset_acquire_ctx ctx;
+ struct drm_crtc_state *crtc_state;
+ struct drm_atomic_state *state;
+ struct drm_display_mode *dank;
+ int ret;
+
+ priv = drm_kunit_helper_connector_hdmi_init_with_edid_funcs(test,
+ BIT(DRM_OUTPUT_COLOR_FORMAT_RGB444) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR422) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR420) |
+ BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR444),
+ 12,
+ &dummy_connector_hdmi_funcs,
+ test_edid_hdmi_1080p_rgb_yuv_4k_yuv420_dc_max_200mhz);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ drm_modeset_acquire_init(&ctx, 0);
+
+ dank = find_420_only_mode(&priv->connector);
+ KUNIT_ASSERT_NOT_NULL(test, dank);
+
+ state = drm_kunit_helper_atomic_state_alloc(test, &priv->drm, &ctx);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+ conn_state = drm_atomic_get_connector_state(state, &priv->connector);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
+
+ conn_state->color_format = param->fmt;
+
+ ret = drm_atomic_set_crtc_for_connector(conn_state, priv->crtc);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ crtc_state = drm_atomic_get_crtc_state(state, priv->crtc);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);
+
+ ret = drm_atomic_set_mode_for_crtc(crtc_state, dank);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ crtc_state->enable = true;
+ crtc_state->active = true;
+
+ ret = drm_atomic_check_only(state);
+ KUNIT_EXPECT_EQ(test, ret, param->expected_ret);
+ if (!param->expected_ret)
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, param->expected);
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+};
+
+static const struct color_format_test_param hdmi_color_format_420_only_params[] = {
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_RGB444,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_RGB444,
+ .expected_ret = -EINVAL,
+ .desc = "RGB should fail"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR444,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR444,
+ .expected_ret = -EINVAL,
+ .desc = "YUV444 should fail"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR422,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR422,
+ .expected_ret = -EINVAL,
+ .desc = "YUV422 should fail"
+ },
+ {
+ .fmt = DRM_CONNECTOR_COLOR_FORMAT_YCBCR420,
+ .expected = DRM_OUTPUT_COLOR_FORMAT_YCBCR420,
+ .expected_ret = 0,
+ .desc = "YUV420 should work"
+ },
+};
+
+KUNIT_ARRAY_PARAM_DESC(check_hdmi_color_format_420_only,
+ hdmi_color_format_420_only_params, desc);
+
static struct kunit_case drm_atomic_helper_connector_hdmi_check_tests[] = {
KUNIT_CASE(drm_test_check_broadcast_rgb_auto_cea_mode),
KUNIT_CASE(drm_test_check_broadcast_rgb_auto_cea_mode_vic_1),
@@ -2227,6 +2459,10 @@ static struct kunit_case drm_atomic_helper_connector_hdmi_check_tests[] = {
KUNIT_CASE(drm_test_check_tmds_char_rate_rgb_8bpc),
KUNIT_CASE(drm_test_check_tmds_char_rate_rgb_10bpc),
KUNIT_CASE(drm_test_check_tmds_char_rate_rgb_12bpc),
+ KUNIT_CASE_PARAM(drm_test_check_hdmi_color_format,
+ check_hdmi_color_format_gen_params),
+ KUNIT_CASE_PARAM(drm_test_check_hdmi_color_format_420_only,
+ check_hdmi_color_format_420_only_gen_params),
/*
* TODO: We should have tests to check that a change in the
* format triggers a CRTC mode change just like we do for the

--
2.53.0