[PATCH v4 16/45] drm/connector: hdmi: Compute bpc and format automatically

Maxime Ripard
2023-11-28T10:26:52Z

Now that we have all the infrastructure needed, we can add some code
that will, for a given connector state and mode, compute the best output
format and bpc.

The algorithm is the same one than the one already found in i915 and
vc4.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 183 ++++++-
.../gpu/drm/tests/drm_atomic_state_helper_test.c | 529 ++++++++++++++++++++-
drivers/gpu/drm/tests/drm_kunit_edid.h | 160 +++++++
3 files changed, 860 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index af3ece136040..4b21422b0e3f 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -668,6 +668,96 @@ static bool hdmi_is_full_range(const struct drm_connector *connector,
return drm_default_rgb_quant_range(mode) == HDMI_QUANTIZATION_RANGE_FULL ? true : false;
}

+static bool
+sink_supports_format_bpc(const struct drm_connector *connector,
+ const struct drm_display_info *info,
+ const struct drm_display_mode *mode,
+ unsigned int format, unsigned int bpc)
+{
+ struct drm_device *dev = connector->dev;
+ u8 vic = drm_match_cea_mode(mode);
+
+ if (vic == 1 && bpc != 8) {
+ drm_dbg(dev, "VIC1 requires a bpc of 8, got %u\n", bpc);
+ return false;
+ }
+
+ if (!info->is_hdmi &&
+ (format != HDMI_COLORSPACE_RGB || bpc != 8)) {
+ drm_dbg(dev, "DVI Monitors require an RGB output at 8 bpc\n");
+ return false;
+ }
+
+ if (!(connector->hdmi.supported_formats & BIT(format))) {
+ drm_dbg(dev, "%s format unsupported by the connector.\n",
+ drm_hdmi_connector_get_output_format_name(format));
+ return false;
+ }
+
+ switch (format) {
+ case HDMI_COLORSPACE_RGB:
+ drm_dbg(dev, "RGB Format, checking the constraints.\n");
+
+ if (!(info->color_formats & DRM_COLOR_FORMAT_RGB444))
+ return false;
+
+ if (bpc == 10 && !(info->edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_30)) {
+ drm_dbg(dev, "10 BPC but sink doesn't support Deep Color 30.\n");
+ return false;
+ }
+
+ if (bpc == 12 && !(info->edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_36)) {
+ drm_dbg(dev, "12 BPC but sink doesn't support Deep Color 36.\n");
+ return false;
+ }
+
+ drm_dbg(dev, "RGB format supported in that configuration.\n");
+
+ return true;
+
+ case HDMI_COLORSPACE_YUV422:
+ drm_dbg(dev, "YUV422 format, checking the constraints.\n");
+
+ if (!(info->color_formats & DRM_COLOR_FORMAT_YCBCR422)) {
+ drm_dbg(dev, "Sink doesn't support YUV422.\n");
+ return false;
+ }
+
+ if (bpc != 12) {
+ drm_dbg(dev, "YUV422 only supports 12 bpc.\n");
+ return false;
+ }
+
+ drm_dbg(dev, "YUV422 format supported in that configuration.\n");
+
+ return true;
+
+ case HDMI_COLORSPACE_YUV444:
+ drm_dbg(dev, "YUV444 format, checking the constraints.\n");
+
+ if (!(info->color_formats & DRM_COLOR_FORMAT_YCBCR444)) {
+ drm_dbg(dev, "Sink doesn't support YUV444.\n");
+ return false;
+ }
+
+ if (bpc == 10 && !(info->edid_hdmi_ycbcr444_dc_modes & DRM_EDID_HDMI_DC_30)) {
+ drm_dbg(dev, "10 BPC but sink doesn't support Deep Color 30.\n");
+ return false;
+ }
+
+ if (bpc == 12 && !(info->edid_hdmi_ycbcr444_dc_modes & DRM_EDID_HDMI_DC_36)) {
+ drm_dbg(dev, "12 BPC but sink doesn't support Deep Color 36.\n");
+ return false;
+ }
+
+ drm_dbg(dev, "YUV444 format supported in that configuration.\n");
+
+ return true;
+ }
+
+ return false;
+}
+
static enum drm_mode_status
hdmi_clock_valid(const struct drm_connector *connector,
const struct drm_display_mode *mode,
@@ -712,6 +802,95 @@ hdmi_compute_clock(const struct drm_connector *connector,
return 0;
}

+static bool
+hdmi_try_format_bpc(const struct drm_connector *connector,
+ struct drm_connector_state *state,
+ const struct drm_display_mode *mode,
+ unsigned int bpc, enum hdmi_colorspace fmt)
+{
+ const struct drm_display_info *info = &connector->display_info;
+ struct drm_device *dev = connector->dev;
+ int ret;
+
+ drm_dbg(dev, "Trying %s output format\n",
+ drm_hdmi_connector_get_output_format_name(fmt));
+
+ if (!sink_supports_format_bpc(connector, info, mode, fmt, bpc)) {
+ drm_dbg(dev, "%s output format not supported with %u bpc\n",
+ drm_hdmi_connector_get_output_format_name(fmt), bpc);
+ return false;
+ }
+
+ ret = hdmi_compute_clock(connector, state, mode, bpc, fmt);
+ if (ret) {
+ drm_dbg(dev, "Couldn't compute clock for %s output format and %u bpc\n",
+ drm_hdmi_connector_get_output_format_name(fmt), bpc);
+ return false;
+ }
+
+ drm_dbg(dev, "%s output format supported with %u (TMDS char rate: %llu Hz)\n",
+ drm_hdmi_connector_get_output_format_name(fmt), bpc, state->hdmi.tmds_char_rate);
+
+ return true;
+}
+
+static int
+hdmi_compute_format(const struct drm_connector *connector,
+ struct drm_connector_state *state,
+ const struct drm_display_mode *mode,
+ unsigned int bpc)
+{
+ struct drm_device *dev = connector->dev;
+
+ if (hdmi_try_format_bpc(connector, state, mode, bpc, HDMI_COLORSPACE_RGB)) {
+ state->hdmi.output_format = HDMI_COLORSPACE_RGB;
+ return 0;
+ }
+
+ if (hdmi_try_format_bpc(connector, state, mode, bpc, HDMI_COLORSPACE_YUV422)) {
+ state->hdmi.output_format = HDMI_COLORSPACE_YUV422;
+ return 0;
+ }
+
+ drm_dbg(dev, "Failed. No Format Supported for that bpc count.\n");
+
+ return -EINVAL;
+}
+
+static int
+hdmi_compute_config(const struct drm_connector *connector,
+ struct drm_connector_state *state,
+ const struct drm_display_mode *mode)
+{
+ struct drm_device *dev = connector->dev;
+ unsigned int max_bpc = clamp_t(unsigned int,
+ state->max_bpc,
+ 8, connector->max_bpc);
+ unsigned int bpc;
+ int ret;
+
+ for (bpc = max_bpc; bpc >= 8; bpc -= 2) {
+ drm_dbg(dev, "Trying with a %d bpc output\n", bpc);
+
+ ret = hdmi_compute_format(connector, state, mode, bpc);
+ if (ret)
+ continue;
+
+ state->hdmi.output_bpc = bpc;
+
+ drm_dbg(dev,
+ "Mode %ux%u @ %uHz: Found configuration: bpc: %u, fmt: %s, clock: %llu\n",
+ mode->hdisplay, mode->vdisplay, drm_mode_vrefresh(mode),
+ state->hdmi.output_bpc,
+ drm_hdmi_connector_get_output_format_name(state->hdmi.output_format),
+ state->hdmi.tmds_char_rate);
+
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
/**
* drm_atomic_helper_connector_hdmi_check() - Helper to check HDMI connector atomic state
* @connector: DRM Connector
@@ -737,9 +916,7 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector,

new_state->hdmi.is_full_range = hdmi_is_full_range(connector, new_state);

- ret = hdmi_compute_clock(connector, new_state, mode,
- new_state->hdmi.output_bpc,
- new_state->hdmi.output_format);
+ ret = hdmi_compute_config(connector, new_state, mode);
if (ret)
return ret;

diff --git a/drivers/gpu/drm/tests/drm_atomic_state_helper_test.c b/drivers/gpu/drm/tests/drm_atomic_state_helper_test.c
index e7dbdd4a4e7f..860e34b00fee 100644
--- a/drivers/gpu/drm/tests/drm_atomic_state_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_atomic_state_helper_test.c
@@ -70,9 +70,6 @@ static int light_up_connector(struct kunit *test,
conn_state = drm_atomic_get_connector_state(state, connector);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);

- conn_state->hdmi.output_bpc = connector->max_bpc;
- conn_state->hdmi.output_format = HDMI_COLORSPACE_RGB;
-
ret = drm_atomic_set_crtc_for_connector(conn_state, crtc);
KUNIT_EXPECT_EQ(test, ret, 0);

@@ -720,10 +717,15 @@ static void drm_test_check_output_bpc_crtc_mode_changed(struct kunit *test)
10);
KUNIT_ASSERT_NOT_NULL(test, priv);

+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- conn = &priv->connector;
preferred = find_preferred_mode(conn);
KUNIT_ASSERT_NOT_NULL(test, preferred);

@@ -741,11 +743,11 @@ static void drm_test_check_output_bpc_crtc_mode_changed(struct kunit *test)
old_conn_state = drm_atomic_get_old_connector_state(state, conn);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, old_conn_state);

- new_conn_state->hdmi.output_bpc = 8;
+ new_conn_state->max_requested_bpc = 8;

KUNIT_ASSERT_NE(test,
- old_conn_state->hdmi.output_bpc,
- new_conn_state->hdmi.output_bpc);
+ old_conn_state->max_requested_bpc,
+ new_conn_state->max_requested_bpc);

ret = drm_atomic_check_only(state);
KUNIT_ASSERT_EQ(test, ret, 0);
@@ -789,10 +791,15 @@ static void drm_test_check_output_bpc_crtc_mode_not_changed(struct kunit *test)
10);
KUNIT_ASSERT_NOT_NULL(test, priv);

+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
ctx = drm_kunit_helper_acquire_ctx_alloc(test);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

- conn = &priv->connector;
preferred = find_preferred_mode(conn);
KUNIT_ASSERT_NOT_NULL(test, preferred);

@@ -832,6 +839,56 @@ static void drm_test_check_output_bpc_crtc_mode_not_changed(struct kunit *test)
KUNIT_EXPECT_FALSE(test, crtc_state->mode_changed);
}

+/*
+ * Test that if we have an HDMI connector but a !HDMI display, we always
+ * output RGB with 8 bpc.
+ */
+static void drm_test_check_output_bpc_dvi(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB) |
+ BIT(HDMI_COLORSPACE_YUV422) |
+ BIT(HDMI_COLORSPACE_YUV444),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_dvi_1080p,
+ ARRAY_SIZE(test_edid_dvi_1080p));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_FALSE(test, info->is_hdmi);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 8);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
/*
* Test that when doing a commit which would use RGB 8bpc, the TMDS
* clock rate stored in the connector state is equal to the mode clock
@@ -1024,6 +1081,452 @@ static void drm_test_check_hdmi_funcs_reject_rate(struct kunit *test)
KUNIT_EXPECT_LT(test, ret, 0);
}

+/*
+ * Test that if:
+ * - We have an HDMI connector supporting RGB only
+ * - The chosen mode has a TMDS character rate higher than the display
+ * supports in RGB/12bpc
+ * - The chosen mode has a TMDS character rate lower than the display
+ * supports in RGB/10bpc.
+ *
+ * Then we will pick the latter, and the computed TMDS character rate
+ * will be equal to 1.25 times the mode pixel clock.
+ */
+static void drm_test_check_max_tmds_rate_bpc_fallback(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+ KUNIT_ASSERT_FALSE(test, preferred->flags & DRM_MODE_FLAG_DBLCLK);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_GT(test, rate, info->max_tmds_clock * 1000);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 10, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 10);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.tmds_char_rate, preferred->clock * 1250);
+}
+
+/*
+ * Test that if:
+ * - We have an HDMI connector supporting both RGB and YUV422 and up to
+ * 12 bpc
+ * - The chosen mode has a TMDS character rate higher than the display
+ * supports in RGB/12bpc
+ * - The chosen mode has a TMDS character rate lower than the display
+ * supports in YUV422/12bpc.
+ *
+ * Then we will pick the latter, and the computed TMDS character rate
+ * will be equal to the mode pixel clock.
+ */
+static void drm_test_check_max_tmds_rate_format_fallback(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB) |
+ BIT(HDMI_COLORSPACE_YUV422) |
+ BIT(HDMI_COLORSPACE_YUV444),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+ KUNIT_ASSERT_FALSE(test, preferred->flags & DRM_MODE_FLAG_DBLCLK);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_GT(test, rate, info->max_tmds_clock * 1000);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_YUV422);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 12);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_YUV422);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.tmds_char_rate, preferred->clock * 1000);
+}
+
+/*
+ * Test that if a driver and screen supports RGB and YUV formats, and we
+ * try to set the VIC 1 mode, we end up with 8bpc RGB even if we could
+ * have had a higher bpc.
+ */
+static void drm_test_check_output_bpc_format_vic_1(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *mode;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB) |
+ BIT(HDMI_COLORSPACE_YUV422) |
+ BIT(HDMI_COLORSPACE_YUV444),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ mode = drm_display_mode_from_cea_vic(drm, 1);
+ KUNIT_ASSERT_NOT_NULL(test, mode);
+
+ /*
+ * NOTE: We can't use drm_connector_hdmi_compute_mode_clock()
+ * here because we're trying to get the rate of an invalid
+ * configuration.
+ *
+ * Thus, we have to calculate the rate by hand.
+ */
+ rate = mode->clock * 1500;
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, mode, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 8);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
+/*
+ * Test that if a driver supports only RGB but the screen also supports
+ * YUV formats, we only end up with an RGB format.
+ */
+static void drm_test_check_output_bpc_format_driver_rgb_only(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+ /*
+ * We're making sure that YUV422 would be the preferred option
+ * here: we're always favouring higher bpc, we can't have RGB
+ * because the TMDS character rate exceeds the maximum supported
+ * by the display, and YUV422 works for that display.
+ *
+ * But since the driver only supports RGB, we should fallback to
+ * a lower bpc with RGB.
+ */
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_GT(test, rate, info->max_tmds_clock * 1000);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_YUV422);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_LT(test, conn_state->hdmi.output_bpc, 12);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
+/*
+ * Test that if a screen supports only RGB but the driver also supports
+ * YUV formats, we only end up with an RGB format.
+ */
+static void drm_test_check_output_bpc_format_display_rgb_only(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB) |
+ BIT(HDMI_COLORSPACE_YUV422) |
+ BIT(HDMI_COLORSPACE_YUV444),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_max_200mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_max_200mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+ /*
+ * We're making sure that YUV422 would be the preferred option
+ * here: we're always favouring higher bpc, we can't have RGB
+ * because the TMDS character rate exceeds the maximum supported
+ * by the display, and YUV422 works for that display.
+ *
+ * But since the display only supports RGB, we should fallback to
+ * a lower bpc with RGB.
+ */
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_GT(test, rate, info->max_tmds_clock * 1000);
+
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_YUV422);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_LT(test, conn_state->hdmi.output_bpc, 12);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
+/*
+ * Test that if a display supports higher bpc but the driver only
+ * supports 8 bpc, we only end up with 8 bpc even if we could have had a
+ * higher bpc.
+ */
+static void drm_test_check_output_bpc_format_driver_8bpc_only(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB),
+ 8);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_yuv_dc_max_340mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_yuv_dc_max_340mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+ /*
+ * We're making sure that we have headroom on the TMDS character
+ * clock to actually use 12bpc.
+ */
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 8);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
+/*
+ * Test that if a driver supports higher bpc but the display only
+ * supports 8 bpc, we only end up with 8 bpc even if we could have had a
+ * higher bpc.
+ */
+static void drm_test_check_output_bpc_format_display_8bpc_only(struct kunit *test)
+{
+ struct drm_atomic_helper_connector_hdmi_priv *priv;
+ struct drm_modeset_acquire_ctx *ctx;
+ struct drm_connector_state *conn_state;
+ struct drm_display_info *info;
+ struct drm_display_mode *preferred;
+ unsigned long long rate;
+ struct drm_connector *conn;
+ struct drm_device *drm;
+ struct drm_crtc *crtc;
+ int ret;
+
+ priv = drm_atomic_helper_connector_hdmi_init(test,
+ BIT(HDMI_COLORSPACE_RGB) |
+ BIT(HDMI_COLORSPACE_YUV422) |
+ BIT(HDMI_COLORSPACE_YUV444),
+ 12);
+ KUNIT_ASSERT_NOT_NULL(test, priv);
+
+ conn = &priv->connector;
+ ret = set_connector_edid(test, conn,
+ test_edid_hdmi_1080p_rgb_max_340mhz,
+ ARRAY_SIZE(test_edid_hdmi_1080p_rgb_max_340mhz));
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ info = &conn->display_info;
+ KUNIT_ASSERT_TRUE(test, info->is_hdmi);
+ KUNIT_ASSERT_GT(test, info->max_tmds_clock, 0);
+
+ ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+ preferred = find_preferred_mode(conn);
+ KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+ /*
+ * We're making sure that we have headroom on the TMDS character
+ * clock to actually use 12bpc.
+ */
+ rate = drm_connector_hdmi_compute_mode_clock(preferred, 12, HDMI_COLORSPACE_RGB);
+ KUNIT_ASSERT_LT(test, rate, info->max_tmds_clock * 1000);
+
+ drm = &priv->drm;
+ crtc = priv->crtc;
+ ret = light_up_connector(test, drm, crtc, conn, preferred, ctx);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+
+ conn_state = conn->state;
+ KUNIT_ASSERT_NOT_NULL(test, conn_state);
+
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_bpc, 8);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+}
+
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),
@@ -1034,8 +1537,16 @@ static struct kunit_case drm_atomic_helper_connector_hdmi_check_tests[] = {
KUNIT_CASE(drm_test_check_broadcast_rgb_crtc_mode_changed),
KUNIT_CASE(drm_test_check_broadcast_rgb_crtc_mode_not_changed),
KUNIT_CASE(drm_test_check_hdmi_funcs_reject_rate),
+ KUNIT_CASE(drm_test_check_max_tmds_rate_bpc_fallback),
+ KUNIT_CASE(drm_test_check_max_tmds_rate_format_fallback),
KUNIT_CASE(drm_test_check_output_bpc_crtc_mode_changed),
KUNIT_CASE(drm_test_check_output_bpc_crtc_mode_not_changed),
+ KUNIT_CASE(drm_test_check_output_bpc_dvi),
+ KUNIT_CASE(drm_test_check_output_bpc_format_vic_1),
+ KUNIT_CASE(drm_test_check_output_bpc_format_display_8bpc_only),
+ KUNIT_CASE(drm_test_check_output_bpc_format_display_rgb_only),
+ KUNIT_CASE(drm_test_check_output_bpc_format_driver_8bpc_only),
+ KUNIT_CASE(drm_test_check_output_bpc_format_driver_rgb_only),
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),
@@ -1167,7 +1678,7 @@ static void drm_test_check_format_value(struct kunit *test)

conn = &priv->connector;
conn_state = conn->state;
- KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, HDMI_COLORSPACE_RGB);
+ KUNIT_EXPECT_EQ(test, conn_state->hdmi.output_format, 0);
}

/*
diff --git a/drivers/gpu/drm/tests/drm_kunit_edid.h b/drivers/gpu/drm/tests/drm_kunit_edid.h
index 24f3377ef0f0..3e3527c58c31 100644
--- a/drivers/gpu/drm/tests/drm_kunit_edid.h
+++ b/drivers/gpu/drm/tests/drm_kunit_edid.h
@@ -1,6 +1,64 @@
#ifndef DRM_KUNIT_EDID_H_
#define DRM_KUNIT_EDID_H_

+/*
+ * edid-decode (hex):
+ *
+ * 00 ff ff ff ff ff ff 00 31 d8 2a 00 00 00 00 00
+ * 00 21 01 03 81 a0 5a 78 0a 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 01 01 01 01 01 01 01 01 01 01
+ * 01 01 01 01 01 01 02 3a 80 18 71 38 2d 40 58 2c
+ * 45 00 40 84 63 00 00 1e 00 00 00 fc 00 54 65 73
+ * 74 20 45 44 49 44 0a 20 20 20 00 00 00 fd 00 32
+ * 46 1e 46 0f 00 0a 20 20 20 20 20 20 00 00 00 10
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ab
+ *
+ * ----------------
+ *
+ * Block 0, Base EDID:
+ * EDID Structure Version & Revision: 1.3
+ * Vendor & Product Identification:
+ * Manufacturer: LNX
+ * Model: 42
+ * Made in: 2023
+ * Basic Display Parameters & Features:
+ * Digital display
+ * DFP 1.x compatible TMDS
+ * Maximum image size: 160 cm x 90 cm
+ * Gamma: 2.20
+ * RGB color display
+ * First detailed timing is the preferred timing
+ * Color Characteristics:
+ * Red : 0.0000, 0.0000
+ * Green: 0.0000, 0.0000
+ * Blue : 0.0000, 0.0000
+ * White: 0.0000, 0.0000
+ * Established Timings I & II: none
+ * Standard Timings: none
+ * Detailed Timing Descriptors:
+ * DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (1600 mm x 900 mm)
+ * Hfront 88 Hsync 44 Hback 148 Hpol P
+ * Vfront 4 Vsync 5 Vback 36 Vpol P
+ * Display Product Name: 'Test EDID'
+ * Display Range Limits:
+ * Monitor ranges (GTF): 50-70 Hz V, 30-70 kHz H, max dotclock 150 MHz
+ * Dummy Descriptor:
+ * Checksum: 0xab
+ */
+const unsigned char test_edid_dvi_1080p[] = {
+ 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x31, 0xd8, 0x2a, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x01, 0x03, 0x81, 0xa0, 0x5a, 0x78,
+ 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x3a, 0x80, 0x18, 0x71, 0x38,
+ 0x2d, 0x40, 0x58, 0x2c, 0x45, 0x00, 0x40, 0x84, 0x63, 0x00, 0x00, 0x1e,
+ 0x00, 0x00, 0x00, 0xfc, 0x00, 0x54, 0x65, 0x73, 0x74, 0x20, 0x45, 0x44,
+ 0x49, 0x44, 0x0a, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x32,
+ 0x46, 0x1e, 0x46, 0x0f, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+ 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xab
+};
+
/*
* edid-decode (hex):
*
@@ -103,6 +161,108 @@ const unsigned char test_edid_hdmi_1080p_rgb_max_200mhz[] = {
0x00, 0x00, 0x00, 0xd0
};

+/*
+ * edid-decode (hex):
+ *
+ * 00 ff ff ff ff ff ff 00 31 d8 2a 00 00 00 00 00
+ * 00 21 01 03 81 a0 5a 78 02 00 00 00 00 00 00 00
+ * 00 00 00 20 00 00 01 01 01 01 01 01 01 01 01 01
+ * 01 01 01 01 01 01 02 3a 80 18 71 38 2d 40 58 2c
+ * 45 00 40 84 63 00 00 1e 00 00 00 fc 00 54 65 73
+ * 74 20 45 44 49 44 0a 20 20 20 00 00 00 fd 00 32
+ * 46 1e 46 0f 00 0a 20 20 20 20 20 20 00 00 00 10
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 92
+ *
+ * 02 03 1b 81 e3 05 00 20 41 10 e2 00 4a 6d 03 0c
+ * 00 12 34 00 28 20 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ * 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 d0
+ *
+ * ----------------
+ *
+ * Block 0, Base EDID:
+ * EDID Structure Version & Revision: 1.3
+ * Vendor & Product Identification:
+ * Manufacturer: LNX
+ * Model: 42
+ * Made in: 2023
+ * Basic Display Parameters & Features:
+ * Digital display
+ * DFP 1.x compatible TMDS
+ * Maximum image size: 160 cm x 90 cm
+ * Gamma: 2.20
+ * Monochrome or grayscale display
+ * First detailed timing is the preferred timing
+ * Color Characteristics:
+ * Red : 0.0000, 0.0000
+ * Green: 0.0000, 0.0000
+ * Blue : 0.0000, 0.0000
+ * White: 0.0000, 0.0000
+ * Established Timings I & II:
+ * DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
+ * Standard Timings: none
+ * Detailed Timing Descriptors:
+ * DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (1600 mm x 900 mm)
+ * Hfront 88 Hsync 44 Hback 148 Hpol P
+ * Vfront 4 Vsync 5 Vback 36 Vpol P
+ * Display Product Name: 'Test EDID'
+ * Display Range Limits:
+ * Monitor ranges (GTF): 50-70 Hz V, 30-70 kHz H, max dotclock 150 MHz
+ * Dummy Descriptor:
+ * Extension blocks: 1
+ * Checksum: 0x92
+ *
+ * ----------------
+ *
+ * Block 1, CTA-861 Extension Block:
+ * Revision: 3
+ * Underscans IT Video Formats by default
+ * Native detailed modes: 1
+ * Colorimetry Data Block:
+ * sRGB
+ * Video Data Block:
+ * VIC 16: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
+ * Video Capability Data Block:
+ * YCbCr quantization: No Data
+ * RGB quantization: Selectable (via AVI Q)
+ * PT scan behavior: No Data
+ * IT scan behavior: Always Underscanned
+ * CE scan behavior: Always Underscanned
+ * Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
+ * Source physical address: 1.2.3.4
+ * Maximum TMDS clock: 340 MHz
+ * Extended HDMI video details:
+ * Checksum: 0xd0 Unused space in Extension Block: 100 bytes
+ */
+const unsigned char test_edid_hdmi_1080p_rgb_max_340mhz[] = {
+ 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x31, 0xd8, 0x2a, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x21, 0x01, 0x03, 0x81, 0xa0, 0x5a, 0x78,
+ 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20,
+ 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x3a, 0x80, 0x18, 0x71, 0x38,
+ 0x2d, 0x40, 0x58, 0x2c, 0x45, 0x00, 0x40, 0x84, 0x63, 0x00, 0x00, 0x1e,
+ 0x00, 0x00, 0x00, 0xfc, 0x00, 0x54, 0x65, 0x73, 0x74, 0x20, 0x45, 0x44,
+ 0x49, 0x44, 0x0a, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x32,
+ 0x46, 0x00, 0x00, 0xc4, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+ 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x41, 0x02, 0x03, 0x1b, 0x81,
+ 0xe3, 0x05, 0x00, 0x20, 0x41, 0x10, 0xe2, 0x00, 0x4a, 0x6d, 0x03, 0x0c,
+ 0x00, 0x12, 0x34, 0x00, 0x44, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0xd0
+};
+
/*
* edid-decode (hex):
*

--
2.41.0