[PATCH v3 0/7] drm/display: hdmi: add drm_hdmi_connector_mode_valid()

[PATCH v3 0/7] drm/display: hdmi: add drm_hdmi_connector_mode_valid()

[Dmitry Baryshkov]

Several HDMI drivers have common code pice in the .mode_valid function
that validates RGB / 8bpc rate using the TMDS char rate callbacks.

Move this code piece to the common helper and remove the need to perform
this check manually. In case of DRM_BRIDGE_OP_HDMI bridges, they can
skip the check in favour of performing it in drm_bridge_connector.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
Changes in v3:
- Moved drm_hdmi_connector_mode_valid() to drm_hdmi_state_helper.c
  (Maxime)
- Added commnt next to the preferred = list_first_entry() assignment
  (Maxime)
- Added comments to new tests, describing what is being tested (Maxime)
- Replaced sun4i_hdmi_connector_atomic_check() with
  drm_atomic_helper_connector_hdmi_check() (Maxime)
- Link to v2: https://lore.kernel.org/r/20241101-hdmi-mode-valid-v2-0-a6478fd20fa6@linaro.org

Changes in v2:
- Switched drm_hdmi_connector_mode_valid() to use common helper
  (ex-hdmi_clock_valid()) (Maxime)
- Added simple unit tests for drm_hdmi_connector_mode_valid().
- Link to v1: https://lore.kernel.org/r/20241018-hdmi-mode-valid-v1-0-6e49ae4801f7@linaro.org

---
Dmitry Baryshkov (7):
      drm/display: hdmi: add generic mode_valid helper
      drm/sun4i: use drm_hdmi_connector_mode_valid()
      drm/vc4: use drm_hdmi_connector_mode_valid()
      drm/display: bridge_connector: use drm_bridge_connector_mode_valid()
      drm/bridge: lontium-lt9611: drop TMDS char rate check in mode_valid
      drm/bridge: dw-hdmi-qp: replace mode_valid with tmds_char_rate
      drm/sun4i: use drm_atomic_helper_connector_hdmi_check()

 drivers/gpu/drm/bridge/lontium-lt9611.c            |   4 +-
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c       |  12 +-
 drivers/gpu/drm/display/drm_bridge_connector.c     |  16 +-
 drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  21 +++
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c             |  32 +---
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 181 ++++++++++++++++++++-
 drivers/gpu/drm/vc4/vc4_hdmi.c                     |   4 +-
 include/drm/display/drm_hdmi_state_helper.h        |   4 +
 8 files changed, 228 insertions(+), 46 deletions(-)
---
base-commit: 929beafbe7acce3267c06115e13e03ff6e50548a
change-id: 20241018-hdmi-mode-valid-aaec4428501c

Best regards,
-- 
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[PATCH v3 1/7] drm/display: hdmi: add generic mode_valid helper

[Dmitry Baryshkov]

Add drm_hdmi_connector_mode_valid(), generic helper for HDMI connectors.
It can be either used directly or as a part of the .mode_valid callback.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  21 +++
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 181 ++++++++++++++++++++-
 include/drm/display/drm_hdmi_state_helper.h        |   4 +
 3 files changed, 204 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index feb7a3a759811aed70c679be8704072093e2a79b..80bf2829ba89b5f84fed4fa9eb1d6302e10a4f9e 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -521,6 +521,27 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_check);
 
+/**
+ * drm_hdmi_connector_mode_valid() - Check if mode is valid for HDMI connector
+ * @connector: DRM connector to validate the mode
+ * @mode: Display mode to validate
+ *
+ * Generic .mode_valid implementation for HDMI connectors.
+ */
+enum drm_mode_status
+drm_hdmi_connector_mode_valid(struct drm_connector *connector,
+			      struct drm_display_mode *mode)
+{
+	unsigned long long clock;
+
+	clock = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
+	if (!clock)
+		return MODE_ERROR;
+
+	return hdmi_clock_valid(connector, mode, clock);
+}
+EXPORT_SYMBOL(drm_hdmi_connector_mode_valid);
+
 static int clear_device_infoframe(struct drm_connector *connector,
 				  enum hdmi_infoframe_type type)
 {
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 294773342e710dc56772f839c2db9c2e487bbc1e..67c3e882592b00d803d8cba5d183aa90339a16b4 100644
--- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
@@ -43,10 +43,14 @@ struct drm_atomic_helper_connector_hdmi_priv {
 static struct drm_display_mode *find_preferred_mode(struct drm_connector *connector)
 {
 	struct drm_device *drm = connector->dev;
-	struct drm_display_mode *mode, *preferred;
+	struct drm_display_mode *mode, *preferred = NULL;
 
 	mutex_lock(&drm->mode_config.mutex);
-	preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
+
+	/* Handle the case when all modes were rejected by mode_valid() */
+	if (!list_empty(&connector->modes))
+		preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
+
 	list_for_each_entry(mode, &connector->modes, head)
 		if (mode->type & DRM_MODE_TYPE_PREFERRED)
 			preferred = mode;
@@ -125,6 +129,18 @@ static const struct drm_connector_hdmi_funcs reject_connector_hdmi_funcs = {
 	.tmds_char_rate_valid	= reject_connector_tmds_char_rate_valid,
 };
 
+static enum drm_mode_status
+reject_100MHz_connector_tmds_char_rate_valid(const struct drm_connector *connector,
+					     const struct drm_display_mode *mode,
+					     unsigned long long tmds_rate)
+{
+	return (tmds_rate > 100ULL * 1000 * 1000) ? MODE_BAD : MODE_OK;
+}
+
+static const struct drm_connector_hdmi_funcs reject_100_MHz_connector_hdmi_funcs = {
+	.tmds_char_rate_valid	= reject_100MHz_connector_tmds_char_rate_valid,
+};
+
 static int dummy_connector_get_modes(struct drm_connector *connector)
 {
 	struct drm_atomic_helper_connector_hdmi_priv *priv =
@@ -147,6 +163,33 @@ static int dummy_connector_get_modes(struct drm_connector *connector)
 static const struct drm_connector_helper_funcs dummy_connector_helper_funcs = {
 	.atomic_check	= drm_atomic_helper_connector_hdmi_check,
 	.get_modes	= dummy_connector_get_modes,
+	.mode_valid	= drm_hdmi_connector_mode_valid,
+};
+
+static int dummy_connector_get_modes_100MHz_max_clock(struct drm_connector *connector)
+{
+	struct drm_atomic_helper_connector_hdmi_priv *priv =
+		connector_to_priv(connector);
+	const struct drm_edid *edid;
+	unsigned int num_modes;
+
+	edid = drm_edid_alloc(priv->current_edid, priv->current_edid_len);
+	if (!edid)
+		return -EINVAL;
+
+	drm_edid_connector_update(connector, edid);
+	connector->display_info.max_tmds_clock = 100 * 1000;
+	num_modes = drm_edid_connector_add_modes(connector);
+
+	drm_edid_free(edid);
+
+	return num_modes;
+}
+
+static const struct drm_connector_helper_funcs dummy_connector_helper_funcs_max_tmds_clock = {
+	.atomic_check	= drm_atomic_helper_connector_hdmi_check,
+	.get_modes	= dummy_connector_get_modes_100MHz_max_clock,
+	.mode_valid	= drm_hdmi_connector_mode_valid,
 };
 
 static void dummy_hdmi_connector_reset(struct drm_connector *connector)
@@ -1734,9 +1777,143 @@ static struct kunit_suite drm_atomic_helper_connector_hdmi_reset_test_suite = {
 	.test_cases	= drm_atomic_helper_connector_hdmi_reset_tests,
 };
 
+static void drm_test_check_mode_valid(struct kunit *test)
+{
+	struct drm_atomic_helper_connector_hdmi_priv *priv;
+	struct drm_connector *conn;
+	struct drm_display_mode *preferred;
+
+	priv = drm_atomic_helper_connector_hdmi_init(test,
+						     BIT(HDMI_COLORSPACE_RGB),
+						     8);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	conn = &priv->connector;
+	preferred = find_preferred_mode(conn);
+	KUNIT_ASSERT_NOT_NULL(test, preferred);
+
+	KUNIT_EXPECT_EQ(test, preferred->hdisplay, 1920);
+	KUNIT_EXPECT_EQ(test, preferred->vdisplay, 1080);
+	KUNIT_EXPECT_EQ(test, preferred->clock, 148500);
+}
+
+/*
+ * Verify that tmds_char_rate_valid() can reject all modes.
+ */
+static void drm_test_check_mode_valid_reject(struct kunit *test)
+{
+	struct drm_atomic_helper_connector_hdmi_priv *priv;
+	struct drm_connector *conn;
+	struct drm_display_mode *preferred;
+	struct drm_device *drm;
+	int ret;
+
+	priv = drm_atomic_helper_connector_hdmi_init(test,
+						     BIT(HDMI_COLORSPACE_RGB),
+						     8);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	conn = &priv->connector;
+
+	/* You shouldn't be doing that at home. */
+	conn->hdmi.funcs = &reject_connector_hdmi_funcs;
+
+	priv->current_edid = test_edid_hdmi_1080p_rgb_max_200mhz;
+	priv->current_edid_len = ARRAY_SIZE(test_edid_hdmi_1080p_rgb_max_200mhz);
+
+	drm = &priv->drm;
+
+	mutex_lock(&drm->mode_config.mutex);
+	ret = conn->funcs->fill_modes(conn, 4096, 4096);
+	mutex_unlock(&drm->mode_config.mutex);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	preferred = find_preferred_mode(conn);
+	KUNIT_ASSERT_NULL(test, preferred);
+}
+
+/*
+ * Verify that tmds_char_rate_valid() can correctly filter out high-rate modes,
+ * but allows small modes.
+ */
+static void drm_test_check_mode_valid_reject_rate(struct kunit *test)
+{
+	struct drm_atomic_helper_connector_hdmi_priv *priv;
+	struct drm_connector *conn;
+	struct drm_display_mode *preferred;
+	int ret;
+
+	priv = drm_atomic_helper_connector_hdmi_init(test,
+						     BIT(HDMI_COLORSPACE_RGB),
+						     8);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	conn = &priv->connector;
+
+	/* You shouldn't be doing that at home. */
+	conn->hdmi.funcs = &reject_100_MHz_connector_hdmi_funcs;
+
+	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);
+
+	preferred = find_preferred_mode(conn);
+	KUNIT_ASSERT_NOT_NULL(test, preferred);
+	KUNIT_EXPECT_EQ(test, preferred->hdisplay, 640);
+	KUNIT_EXPECT_EQ(test, preferred->vdisplay, 480);
+	KUNIT_EXPECT_EQ(test, preferred->clock, 25200);
+}
+
+/*
+ * Verify that the framework filters modes based on info.max_tmds_clock, while
+ * allowing small resolution modes.
+ */
+static void drm_test_check_mode_valid_reject_max_clock(struct kunit *test)
+{
+	struct drm_atomic_helper_connector_hdmi_priv *priv;
+	struct drm_connector *conn;
+	struct drm_display_mode *preferred;
+	int ret;
+
+	priv = drm_atomic_helper_connector_hdmi_init(test,
+						     BIT(HDMI_COLORSPACE_RGB),
+						     8);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	conn = &priv->connector;
+
+	drm_connector_helper_add(conn, &dummy_connector_helper_funcs_max_tmds_clock);
+
+	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);
+
+	preferred = find_preferred_mode(conn);
+	KUNIT_ASSERT_NOT_NULL(test, preferred);
+	KUNIT_EXPECT_EQ(test, preferred->hdisplay, 640);
+	KUNIT_EXPECT_EQ(test, preferred->vdisplay, 480);
+	KUNIT_EXPECT_EQ(test, preferred->clock, 25200);
+}
+
+static struct kunit_case drm_atomic_helper_connector_hdmi_mode_valid_tests[] = {
+	KUNIT_CASE(drm_test_check_mode_valid),
+	KUNIT_CASE(drm_test_check_mode_valid_reject),
+	KUNIT_CASE(drm_test_check_mode_valid_reject_rate),
+	KUNIT_CASE(drm_test_check_mode_valid_reject_max_clock),
+	{ }
+};
+
+static struct kunit_suite drm_atomic_helper_connector_hdmi_mode_valid_test_suite = {
+	.name		= "drm_atomic_helper_connector_hdmi_mode_valid",
+	.test_cases	= drm_atomic_helper_connector_hdmi_mode_valid_tests,
+};
+
 kunit_test_suites(
 	&drm_atomic_helper_connector_hdmi_check_test_suite,
 	&drm_atomic_helper_connector_hdmi_reset_test_suite,
+	&drm_atomic_helper_connector_hdmi_mode_valid_test_suite,
 );
 
 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
diff --git a/include/drm/display/drm_hdmi_state_helper.h b/include/drm/display/drm_hdmi_state_helper.h
index 2d45fcfa461985065a5e5ad67eddc0b1c556d526..d6d65da6d8f9ee46de33114cce2d6fbe6098a862 100644
--- a/include/drm/display/drm_hdmi_state_helper.h
+++ b/include/drm/display/drm_hdmi_state_helper.h
@@ -20,4 +20,8 @@ int drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector
 int drm_atomic_helper_connector_hdmi_update_infoframes(struct drm_connector *connector,
 						       struct drm_atomic_state *state);
 
+enum drm_mode_status
+drm_hdmi_connector_mode_valid(struct drm_connector *connector,
+			      struct drm_display_mode *mode);
+
 #endif // DRM_HDMI_STATE_HELPER_H_

-- 
2.39.5

[PATCH v3 2/7] drm/sun4i: use drm_hdmi_connector_mode_valid()

[Dmitry Baryshkov]

Use new drm_hdmi_connector_mode_valid() helper instead of a
module-specific copy.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index b3649449de3026784ae2f3466906403a0b6e3b47..54b72fe220afacc208b3fd48d5160031127ea14a 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -205,16 +205,6 @@ static int sun4i_hdmi_connector_atomic_check(struct drm_connector *connector,
 	return 0;
 }
 
-static enum drm_mode_status
-sun4i_hdmi_connector_mode_valid(struct drm_connector *connector,
-				struct drm_display_mode *mode)
-{
-	unsigned long long rate = drm_hdmi_compute_mode_clock(mode, 8,
-							      HDMI_COLORSPACE_RGB);
-
-	return sun4i_hdmi_connector_clock_valid(connector, mode, rate);
-}
-
 static int sun4i_hdmi_get_modes(struct drm_connector *connector)
 {
 	struct sun4i_hdmi *hdmi = drm_connector_to_sun4i_hdmi(connector);
@@ -269,7 +259,7 @@ static const struct drm_connector_hdmi_funcs sun4i_hdmi_hdmi_connector_funcs = {
 
 static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
 	.atomic_check	= sun4i_hdmi_connector_atomic_check,
-	.mode_valid	= sun4i_hdmi_connector_mode_valid,
+	.mode_valid	= drm_hdmi_connector_mode_valid,
 	.get_modes	= sun4i_hdmi_get_modes,
 };
 

-- 
2.39.5

[PATCH v3 3/7] drm/vc4: use drm_hdmi_connector_mode_valid()

[Dmitry Baryshkov]

Use new drm_hdmi_connector_mode_valid() helper instead of a
module-specific copy.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 62b82b1eeb3694d1685969c49b2760cbbddc840e..486e513b898d7f761e8615f2afc193ca44b23200 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1752,7 +1752,6 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
 			    const struct drm_display_mode *mode)
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
-	unsigned long long rate;
 
 	if (vc4_hdmi->variant->unsupported_odd_h_timings &&
 	    !(mode->flags & DRM_MODE_FLAG_DBLCLK) &&
@@ -1760,8 +1759,7 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
 	     (mode->hsync_end % 2) || (mode->htotal % 2)))
 		return MODE_H_ILLEGAL;
 
-	rate = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
-	return vc4_hdmi_connector_clock_valid(&vc4_hdmi->connector, mode, rate);
+	return drm_hdmi_connector_mode_valid(&vc4_hdmi->connector, mode);
 }
 
 static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = {

-- 
2.39.5

[PATCH v3 4/7] drm/display: bridge_connector: use drm_bridge_connector_mode_valid()

[Dmitry Baryshkov]

Use new drm_bridge_connector_mode_valid() helper if there is a HDMI
bridge in the bridge chain. This removes the need to perform TMDS char
rate check manually in the bridge driver.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/drm_bridge_connector.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 320c297008aaa8b6ef5b1f4c71928849b202e8ac..512ced87ea18c74e182a558a686ddd83de891814 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -18,6 +18,7 @@
 #include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/display/drm_hdmi_helper.h>
 #include <drm/display/drm_hdmi_state_helper.h>
 
 /**
@@ -299,9 +300,22 @@ static int drm_bridge_connector_get_modes(struct drm_connector *connector)
 	return 0;
 }
 
+static enum drm_mode_status
+drm_bridge_connector_mode_valid(struct drm_connector *connector,
+				struct drm_display_mode *mode)
+{
+	struct drm_bridge_connector *bridge_connector =
+		to_drm_bridge_connector(connector);
+
+	if (bridge_connector->bridge_hdmi)
+		return drm_hdmi_connector_mode_valid(connector, mode);
+
+	return MODE_OK;
+}
+
 static const struct drm_connector_helper_funcs drm_bridge_connector_helper_funcs = {
 	.get_modes = drm_bridge_connector_get_modes,
-	/* No need for .mode_valid(), the bridges are checked by the core. */
+	.mode_valid = drm_bridge_connector_mode_valid,
 	.enable_hpd = drm_bridge_connector_enable_hpd,
 	.disable_hpd = drm_bridge_connector_disable_hpd,
 };

-- 
2.39.5

[PATCH v3 5/7] drm/bridge: lontium-lt9611: drop TMDS char rate check in mode_valid

[Dmitry Baryshkov]

Drop manual check of the TMDS char rate in the mode_valid callback. This
check is now being performed by the core.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/bridge/lontium-lt9611.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index 1b31fdebe164063e6f3972fdf8a5801ef4c35c4e..b8ccffdf515ade6e3bf863edbedc41e6f2030f29 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
@@ -757,7 +757,6 @@ static enum drm_mode_status lt9611_bridge_mode_valid(struct drm_bridge *bridge,
 						     const struct drm_display_mode *mode)
 {
 	struct lt9611 *lt9611 = bridge_to_lt9611(bridge);
-	unsigned long long rate;
 
 	if (mode->hdisplay > 3840)
 		return MODE_BAD_HVALUE;
@@ -765,8 +764,7 @@ static enum drm_mode_status lt9611_bridge_mode_valid(struct drm_bridge *bridge,
 	if (mode->hdisplay > 2000 && !lt9611->dsi1_node)
 		return MODE_PANEL;
 
-	rate = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
-	return bridge->funcs->hdmi_tmds_char_rate_valid(bridge, mode, rate);
+	return MODE_OK;
 }
 
 static int lt9611_bridge_atomic_check(struct drm_bridge *bridge,

-- 
2.39.5

[PATCH v3 6/7] drm/bridge: dw-hdmi-qp: replace mode_valid with tmds_char_rate

[Dmitry Baryshkov]

Replace .mode_valid() callback with .hdmi_tmds_char_rate_valid(). It is
more generic and is used in other mode validation paths. The rate
validation for .mode_valid() will be performed by the
drm_bridge_connector code.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index 181c5164b23192f0b557624d73c6223032b90ec6..c686671e4850a1af75b82995185ffc3cbb22a447 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -442,16 +442,14 @@ dw_hdmi_qp_bridge_edid_read(struct drm_bridge *bridge,
 }
 
 static enum drm_mode_status
-dw_hdmi_qp_bridge_mode_valid(struct drm_bridge *bridge,
-			     const struct drm_display_info *info,
-			     const struct drm_display_mode *mode)
+dw_hdmi_qp_bridge_tmds_char_rate_valid(const struct drm_bridge *bridge,
+				       const struct drm_display_mode *mode,
+				       unsigned long long rate)
 {
 	struct dw_hdmi_qp *hdmi = bridge->driver_private;
-	unsigned long long rate;
 
-	rate = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
 	if (rate > HDMI14_MAX_TMDSCLK) {
-		dev_dbg(hdmi->dev, "Unsupported mode clock: %d\n", mode->clock);
+		dev_dbg(hdmi->dev, "Unsupported TMDS char rate: %lld\n", rate);
 		return MODE_CLOCK_HIGH;
 	}
 
@@ -510,7 +508,7 @@ static const struct drm_bridge_funcs dw_hdmi_qp_bridge_funcs = {
 	.atomic_disable = dw_hdmi_qp_bridge_atomic_disable,
 	.detect = dw_hdmi_qp_bridge_detect,
 	.edid_read = dw_hdmi_qp_bridge_edid_read,
-	.mode_valid = dw_hdmi_qp_bridge_mode_valid,
+	.hdmi_tmds_char_rate_valid = dw_hdmi_qp_bridge_tmds_char_rate_valid,
 	.hdmi_clear_infoframe = dw_hdmi_qp_bridge_clear_infoframe,
 	.hdmi_write_infoframe = dw_hdmi_qp_bridge_write_infoframe,
 };

-- 
2.39.5

[PATCH v3 7/7] drm/sun4i: use drm_atomic_helper_connector_hdmi_check()

[Dmitry Baryshkov]

Replace sun4i_hdmi_connector_atomic_check(), which performs just TMDS
char rate check, with drm_atomic_helper_connector_hdmi_check(), which
performs additional checks basing on the HDMI Connector's state.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index 54b72fe220afacc208b3fd48d5160031127ea14a..b05fd77870b00aac97d003f3fb9c2b98cb73abc0 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -187,24 +187,6 @@ sun4i_hdmi_connector_clock_valid(const struct drm_connector *connector,
 	return MODE_NOCLOCK;
 }
 
-static int sun4i_hdmi_connector_atomic_check(struct drm_connector *connector,
-					     struct drm_atomic_state *state)
-{
-	struct drm_connector_state *conn_state =
-		drm_atomic_get_new_connector_state(state, connector);
-	struct drm_crtc *crtc = conn_state->crtc;
-	struct drm_crtc_state *crtc_state = crtc->state;
-	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
-	enum drm_mode_status status;
-
-	status = sun4i_hdmi_connector_clock_valid(connector, mode,
-						  conn_state->hdmi.tmds_char_rate);
-	if (status != MODE_OK)
-		return -EINVAL;
-
-	return 0;
-}
-
 static int sun4i_hdmi_get_modes(struct drm_connector *connector)
 {
 	struct sun4i_hdmi *hdmi = drm_connector_to_sun4i_hdmi(connector);
@@ -258,7 +240,7 @@ static const struct drm_connector_hdmi_funcs sun4i_hdmi_hdmi_connector_funcs = {
 };
 
 static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
-	.atomic_check	= sun4i_hdmi_connector_atomic_check,
+	.atomic_check	= drm_atomic_helper_connector_hdmi_check,
 	.mode_valid	= drm_hdmi_connector_mode_valid,
 	.get_modes	= sun4i_hdmi_get_modes,
 };

-- 
2.39.5

Re: [PATCH v3 3/7] drm/vc4: use drm_hdmi_connector_mode_valid()

[kernel test robot]

Hi Dmitry,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 929beafbe7acce3267c06115e13e03ff6e50548a]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Baryshkov/drm-display-hdmi-add-generic-mode_valid-helper/20241109-203557
base:   929beafbe7acce3267c06115e13e03ff6e50548a
patch link:    https://lore.kernel.org/r/20241109-hdmi-mode-valid-v3-3-5348c2368076%40linaro.org
patch subject: [PATCH v3 3/7] drm/vc4: use drm_hdmi_connector_mode_valid()
config: i386-allmodconfig (https://download.01.org/0day-ci/archive/20241110/202411100456.0JcsAx2b-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241110/202411100456.0JcsAx2b-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411100456.0JcsAx2b-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/vc4/vc4_hdmi.c: In function 'vc4_hdmi_encoder_mode_valid':
>> drivers/gpu/drm/vc4/vc4_hdmi.c:1762:68: warning: passing argument 2 of 'drm_hdmi_connector_mode_valid' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
    1762 |         return drm_hdmi_connector_mode_valid(&vc4_hdmi->connector, mode);
         |                                                                    ^~~~
   In file included from drivers/gpu/drm/vc4/vc4_hdmi.c:35:
   include/drm/display/drm_hdmi_state_helper.h:25:56: note: expected 'struct drm_display_mode *' but argument is of type 'const struct drm_display_mode *'
      25 |                               struct drm_display_mode *mode);
         |                               ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~


vim +1762 drivers/gpu/drm/vc4/vc4_hdmi.c

  1749	
  1750	static enum drm_mode_status
  1751	vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
  1752				    const struct drm_display_mode *mode)
  1753	{
  1754		struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
  1755	
  1756		if (vc4_hdmi->variant->unsupported_odd_h_timings &&
  1757		    !(mode->flags & DRM_MODE_FLAG_DBLCLK) &&
  1758		    ((mode->hdisplay % 2) || (mode->hsync_start % 2) ||
  1759		     (mode->hsync_end % 2) || (mode->htotal % 2)))
  1760			return MODE_H_ILLEGAL;
  1761	
> 1762		return drm_hdmi_connector_mode_valid(&vc4_hdmi->connector, mode);
  1763	}
  1764	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 3/7] drm/vc4: use drm_hdmi_connector_mode_valid()

[kernel test robot]

Hi Dmitry,

kernel test robot noticed the following build errors:

[auto build test ERROR on 929beafbe7acce3267c06115e13e03ff6e50548a]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Baryshkov/drm-display-hdmi-add-generic-mode_valid-helper/20241109-203557
base:   929beafbe7acce3267c06115e13e03ff6e50548a
patch link:    https://lore.kernel.org/r/20241109-hdmi-mode-valid-v3-3-5348c2368076%40linaro.org
patch subject: [PATCH v3 3/7] drm/vc4: use drm_hdmi_connector_mode_valid()
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20241110/202411100659.T6WKBFbI-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241110/202411100659.T6WKBFbI-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411100659.T6WKBFbI-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/gpu/drm/vc4/vc4_hdmi.c:37:
   In file included from include/drm/drm_atomic_helper.h:31:
   In file included from include/drm/drm_crtc.h:32:
   In file included from include/drm/drm_modes.h:33:
   In file included from include/drm/drm_connector.h:32:
   In file included from include/drm/drm_util.h:36:
   In file included from include/linux/kgdb.h:19:
   In file included from include/linux/kprobes.h:28:
   In file included from include/linux/ftrace.h:13:
   In file included from include/linux/kallsyms.h:13:
   In file included from include/linux/mm.h:2223:
   include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     504 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     505 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     511 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     512 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     524 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     525 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
>> drivers/gpu/drm/vc4/vc4_hdmi.c:1762:61: error: passing 'const struct drm_display_mode *' to parameter of type 'struct drm_display_mode *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
    1762 |         return drm_hdmi_connector_mode_valid(&vc4_hdmi->connector, mode);
         |                                                                    ^~~~
   include/drm/display/drm_hdmi_state_helper.h:25:35: note: passing argument to parameter 'mode' here
      25 |                               struct drm_display_mode *mode);
         |                                                        ^
   4 warnings and 1 error generated.


vim +1762 drivers/gpu/drm/vc4/vc4_hdmi.c

  1749	
  1750	static enum drm_mode_status
  1751	vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
  1752				    const struct drm_display_mode *mode)
  1753	{
  1754		struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
  1755	
  1756		if (vc4_hdmi->variant->unsupported_odd_h_timings &&
  1757		    !(mode->flags & DRM_MODE_FLAG_DBLCLK) &&
  1758		    ((mode->hdisplay % 2) || (mode->hsync_start % 2) ||
  1759		     (mode->hsync_end % 2) || (mode->htotal % 2)))
  1760			return MODE_H_ILLEGAL;
  1761	
> 1762		return drm_hdmi_connector_mode_valid(&vc4_hdmi->connector, mode);
  1763	}
  1764	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 1/7] drm/display: hdmi: add generic mode_valid helper

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 7544 bytes --]

Hi,

On Sat, Nov 09, 2024 at 02:35:05PM +0200, Dmitry Baryshkov wrote:
> Add drm_hdmi_connector_mode_valid(), generic helper for HDMI connectors.
> It can be either used directly or as a part of the .mode_valid callback.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  21 +++
>  drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 181 ++++++++++++++++++++-
>  include/drm/display/drm_hdmi_state_helper.h        |   4 +
>  3 files changed, 204 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> index feb7a3a759811aed70c679be8704072093e2a79b..80bf2829ba89b5f84fed4fa9eb1d6302e10a4f9e 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> @@ -521,6 +521,27 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector,
>  }
>  EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_check);
>  
> +/**
> + * drm_hdmi_connector_mode_valid() - Check if mode is valid for HDMI connector
> + * @connector: DRM connector to validate the mode
> + * @mode: Display mode to validate
> + *
> + * Generic .mode_valid implementation for HDMI connectors.
> + */
> +enum drm_mode_status
> +drm_hdmi_connector_mode_valid(struct drm_connector *connector,
> +			      struct drm_display_mode *mode)
> +{
> +	unsigned long long clock;
> +
> +	clock = drm_hdmi_compute_mode_clock(mode, 8, HDMI_COLORSPACE_RGB);
> +	if (!clock)
> +		return MODE_ERROR;
> +
> +	return hdmi_clock_valid(connector, mode, clock);
> +}
> +EXPORT_SYMBOL(drm_hdmi_connector_mode_valid);
> +
>  static int clear_device_infoframe(struct drm_connector *connector,
>  				  enum hdmi_infoframe_type type)
>  {
> 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 294773342e710dc56772f839c2db9c2e487bbc1e..67c3e882592b00d803d8cba5d183aa90339a16b4 100644
> --- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
> @@ -43,10 +43,14 @@ struct drm_atomic_helper_connector_hdmi_priv {
>  static struct drm_display_mode *find_preferred_mode(struct drm_connector *connector)
>  {
>  	struct drm_device *drm = connector->dev;
> -	struct drm_display_mode *mode, *preferred;
> +	struct drm_display_mode *mode, *preferred = NULL;
>  
>  	mutex_lock(&drm->mode_config.mutex);
> -	preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
> +
> +	/* Handle the case when all modes were rejected by mode_valid() */
> +	if (!list_empty(&connector->modes))
> +		preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
> +

Sorry if it wasn't clear in my previous review, but I would have
expected a separate patch for that change.

>  	list_for_each_entry(mode, &connector->modes, head)
>  		if (mode->type & DRM_MODE_TYPE_PREFERRED)
>  			preferred = mode;
> @@ -125,6 +129,18 @@ static const struct drm_connector_hdmi_funcs reject_connector_hdmi_funcs = {
>  	.tmds_char_rate_valid	= reject_connector_tmds_char_rate_valid,
>  };
>  
> +static enum drm_mode_status
> +reject_100MHz_connector_tmds_char_rate_valid(const struct drm_connector *connector,
> +					     const struct drm_display_mode *mode,
> +					     unsigned long long tmds_rate)
> +{
> +	return (tmds_rate > 100ULL * 1000 * 1000) ? MODE_BAD : MODE_OK;
> +}
> +
> +static const struct drm_connector_hdmi_funcs reject_100_MHz_connector_hdmi_funcs = {
> +	.tmds_char_rate_valid	= reject_100MHz_connector_tmds_char_rate_valid,
> +};
> +
>  static int dummy_connector_get_modes(struct drm_connector *connector)
>  {
>  	struct drm_atomic_helper_connector_hdmi_priv *priv =
> @@ -147,6 +163,33 @@ static int dummy_connector_get_modes(struct drm_connector *connector)
>  static const struct drm_connector_helper_funcs dummy_connector_helper_funcs = {
>  	.atomic_check	= drm_atomic_helper_connector_hdmi_check,
>  	.get_modes	= dummy_connector_get_modes,
> +	.mode_valid	= drm_hdmi_connector_mode_valid,
> +};
> +
> +static int dummy_connector_get_modes_100MHz_max_clock(struct drm_connector *connector)
> +{
> +	struct drm_atomic_helper_connector_hdmi_priv *priv =
> +		connector_to_priv(connector);
> +	const struct drm_edid *edid;
> +	unsigned int num_modes;
> +
> +	edid = drm_edid_alloc(priv->current_edid, priv->current_edid_len);
> +	if (!edid)
> +		return -EINVAL;
> +
> +	drm_edid_connector_update(connector, edid);
> +	connector->display_info.max_tmds_clock = 100 * 1000;
> +	num_modes = drm_edid_connector_add_modes(connector);
> +
> +	drm_edid_free(edid);
> +
> +	return num_modes;
> +}

I'd rather create a new fake edid than mess with those fields directly.

> +static const struct drm_connector_helper_funcs dummy_connector_helper_funcs_max_tmds_clock = {
> +	.atomic_check	= drm_atomic_helper_connector_hdmi_check,
> +	.get_modes	= dummy_connector_get_modes_100MHz_max_clock,
> +	.mode_valid	= drm_hdmi_connector_mode_valid,
>  };
>  
>  static void dummy_hdmi_connector_reset(struct drm_connector *connector)
> @@ -1734,9 +1777,143 @@ static struct kunit_suite drm_atomic_helper_connector_hdmi_reset_test_suite = {
>  	.test_cases	= drm_atomic_helper_connector_hdmi_reset_tests,
>  };
>  
> +static void drm_test_check_mode_valid(struct kunit *test)
> +{
> +	struct drm_atomic_helper_connector_hdmi_priv *priv;
> +	struct drm_connector *conn;
> +	struct drm_display_mode *preferred;
> +
> +	priv = drm_atomic_helper_connector_hdmi_init(test,
> +						     BIT(HDMI_COLORSPACE_RGB),
> +						     8);
> +	KUNIT_ASSERT_NOT_NULL(test, priv);
> +
> +	conn = &priv->connector;
> +	preferred = find_preferred_mode(conn);
> +	KUNIT_ASSERT_NOT_NULL(test, preferred);
> +
> +	KUNIT_EXPECT_EQ(test, preferred->hdisplay, 1920);
> +	KUNIT_EXPECT_EQ(test, preferred->vdisplay, 1080);
> +	KUNIT_EXPECT_EQ(test, preferred->clock, 148500);
> +}

We need a comment on what that test tests, and expects.

> +/*
> + * Verify that tmds_char_rate_valid() can reject all modes.
> + */
> +static void drm_test_check_mode_valid_reject(struct kunit *test)
> +{
> +	struct drm_atomic_helper_connector_hdmi_priv *priv;
> +	struct drm_connector *conn;
> +	struct drm_display_mode *preferred;
> +	struct drm_device *drm;
> +	int ret;
> +
> +	priv = drm_atomic_helper_connector_hdmi_init(test,
> +						     BIT(HDMI_COLORSPACE_RGB),
> +						     8);
> +	KUNIT_ASSERT_NOT_NULL(test, priv);
> +
> +	conn = &priv->connector;
> +
> +	/* You shouldn't be doing that at home. */
> +	conn->hdmi.funcs = &reject_connector_hdmi_funcs;

Just make drm_atomic_helper_connector_hdmi_init take an extra pointer.
(Also, that's a super bad name, drm_kunit_helper_connector_hdmi_init or
something would probably be better)

> +	priv->current_edid = test_edid_hdmi_1080p_rgb_max_200mhz;
> +	priv->current_edid_len = ARRAY_SIZE(test_edid_hdmi_1080p_rgb_max_200mhz);
> +
> +	drm = &priv->drm;
> +
> +	mutex_lock(&drm->mode_config.mutex);
> +	ret = conn->funcs->fill_modes(conn, 4096, 4096);
> +	mutex_unlock(&drm->mode_config.mutex);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	preferred = find_preferred_mode(conn);
> +	KUNIT_ASSERT_NULL(test, preferred);
> +}

Ditto, I can't really say what this test is doing. That's true for all the tests.

Maxime

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