[PATCH v2 0/6] drm/display: hdmi: add drm_hdmi_connector_mode_valid()

[PATCH v2 0/6] 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 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 (6):
      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

 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_helper.c          |  45 ++++++
 drivers/gpu/drm/display/drm_hdmi_helper_internal.h |  11 ++
 drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  26 +---
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c             |  12 +-
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 168 ++++++++++++++++++++-
 drivers/gpu/drm/vc4/vc4_hdmi.c                     |   4 +-
 include/drm/display/drm_hdmi_helper.h              |   4 +
 10 files changed, 252 insertions(+), 50 deletions(-)
---
base-commit: 623b1e4d2eace0958996995f9f88cb659a6f69dd
change-id: 20241018-hdmi-mode-valid-aaec4428501c

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

[PATCH v2 1/6] 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_helper.c          |  45 ++++++
 drivers/gpu/drm/display/drm_hdmi_helper_internal.h |  11 ++
 drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  26 +---
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 168 ++++++++++++++++++++-
 include/drm/display/drm_hdmi_helper.h              |   4 +
 5 files changed, 229 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c b/drivers/gpu/drm/display/drm_hdmi_helper.c
index 74dd4d01dd9bb2c9e69ec1c60b0056bd69417e8a..560c5d4365ca54d3f669395349cedfd6f75fa033 100644
--- a/drivers/gpu/drm/display/drm_hdmi_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
@@ -9,6 +9,8 @@
 #include <drm/drm_print.h>
 #include <drm/drm_property.h>
 
+#include "drm_hdmi_helper_internal.h"
+
 static inline bool is_eotf_supported(u8 output_eotf, u8 sink_eotf)
 {
 	return sink_eotf & BIT(output_eotf);
@@ -256,3 +258,46 @@ drm_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
 	return DIV_ROUND_CLOSEST_ULL(clock * bpc, 8);
 }
 EXPORT_SYMBOL(drm_hdmi_compute_mode_clock);
+
+enum drm_mode_status
+__drm_hdmi_connector_clock_valid(const struct drm_connector *connector,
+				 const struct drm_display_mode *mode,
+				 unsigned long long clock)
+{
+	const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs;
+	const struct drm_display_info *info = &connector->display_info;
+
+	if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
+		return MODE_CLOCK_HIGH;
+
+	if (funcs && funcs->tmds_char_rate_valid) {
+		enum drm_mode_status status;
+
+		status = funcs->tmds_char_rate_valid(connector, mode, clock);
+		if (status != MODE_OK)
+			return status;
+	}
+
+	return MODE_OK;
+}
+
+/**
+ * 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 __drm_hdmi_connector_clock_valid(connector, mode, clock);
+}
+EXPORT_SYMBOL(drm_hdmi_connector_mode_valid);
diff --git a/drivers/gpu/drm/display/drm_hdmi_helper_internal.h b/drivers/gpu/drm/display/drm_hdmi_helper_internal.h
new file mode 100644
index 0000000000000000000000000000000000000000..ee74435c04f62cf71b9857bdc427c46442b85697
--- /dev/null
+++ b/drivers/gpu/drm/display/drm_hdmi_helper_internal.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef DRM_DP_HELPER_INTERNAL_H
+#define DRM_DP_HELPER_INTERNAL_H
+
+enum drm_mode_status
+__drm_hdmi_connector_clock_valid(const struct drm_connector *connector,
+				 const struct drm_display_mode *mode,
+				 unsigned long long clock);
+
+#endif
diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index feb7a3a759811aed70c679be8704072093e2a79b..29c2cb2c3171366a2a68fc6ad48f8ad8a4dc7e30 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -8,6 +8,8 @@
 #include <drm/display/drm_hdmi_helper.h>
 #include <drm/display/drm_hdmi_state_helper.h>
 
+#include "drm_hdmi_helper_internal.h"
+
 /**
  * __drm_atomic_helper_connector_hdmi_reset() - Initializes all HDMI @drm_connector_state resources
  * @connector: DRM connector
@@ -198,28 +200,6 @@ sink_supports_format_bpc(const struct drm_connector *connector,
 	return false;
 }
 
-static enum drm_mode_status
-hdmi_clock_valid(const struct drm_connector *connector,
-		 const struct drm_display_mode *mode,
-		 unsigned long long clock)
-{
-	const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs;
-	const struct drm_display_info *info = &connector->display_info;
-
-	if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
-		return MODE_CLOCK_HIGH;
-
-	if (funcs && funcs->tmds_char_rate_valid) {
-		enum drm_mode_status status;
-
-		status = funcs->tmds_char_rate_valid(connector, mode, clock);
-		if (status != MODE_OK)
-			return status;
-	}
-
-	return MODE_OK;
-}
-
 static int
 hdmi_compute_clock(const struct drm_connector *connector,
 		   struct drm_connector_state *conn_state,
@@ -233,7 +213,7 @@ hdmi_compute_clock(const struct drm_connector *connector,
 	if (!clock)
 		return -EINVAL;
 
-	status = hdmi_clock_valid(connector, mode, clock);
+	status = __drm_hdmi_connector_clock_valid(connector, mode, clock);
 	if (status != MODE_OK)
 		return -EINVAL;
 
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 34ee95d41f2966ab23a60deb37d689430f6b0985..8640e7280053bd95852f53b92159f493b141f2bf 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 +43,12 @@ 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);
+	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 +127,18 @@ 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 +161,33 @@ 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 +1775,132 @@ 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);
+}
+
+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);
+}
+
+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);
+}
+
+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_helper.h b/include/drm/display/drm_hdmi_helper.h
index 57e3b18c15ec79636d89267aba0e88f434c5d4db..93f0e566257338fb6e9a1f0b2cc14ce9c97ec0a5 100644
--- a/include/drm/display/drm_hdmi_helper.h
+++ b/include/drm/display/drm_hdmi_helper.h
@@ -28,4 +28,8 @@ unsigned long long
 drm_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
 			    unsigned int bpc, enum hdmi_colorspace fmt);
 
+enum drm_mode_status
+drm_hdmi_connector_mode_valid(struct drm_connector *connector,
+			      struct drm_display_mode *mode);
+
 #endif

-- 
2.39.5

[PATCH v2 2/6] 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 v2 3/6] 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>
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 v2 4/6] 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>
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 v2 5/6] 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>
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 v2 6/6] 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>
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

Re: [PATCH v2 3/6] drm/vc4: use drm_hdmi_connector_mode_valid()

[Dave Stevenson]

On Fri, 1 Nov 2024 at 00:25, Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> 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>

Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

> ---
>  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
>

Re: [PATCH v2 1/6] drm/display: hdmi: add generic mode_valid helper

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 10730 bytes --]

Hi,

On Fri, Nov 01, 2024 at 02:25:04AM +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_helper.c          |  45 ++++++
>  drivers/gpu/drm/display/drm_hdmi_helper_internal.h |  11 ++
>  drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  26 +---
>  drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 168 ++++++++++++++++++++-
>  include/drm/display/drm_hdmi_helper.h              |   4 +
>  5 files changed, 229 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c b/drivers/gpu/drm/display/drm_hdmi_helper.c
> index 74dd4d01dd9bb2c9e69ec1c60b0056bd69417e8a..560c5d4365ca54d3f669395349cedfd6f75fa033 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> @@ -9,6 +9,8 @@
>  #include <drm/drm_print.h>
>  #include <drm/drm_property.h>
>  
> +#include "drm_hdmi_helper_internal.h"
> +
>  static inline bool is_eotf_supported(u8 output_eotf, u8 sink_eotf)
>  {
>  	return sink_eotf & BIT(output_eotf);
> @@ -256,3 +258,46 @@ drm_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
>  	return DIV_ROUND_CLOSEST_ULL(clock * bpc, 8);
>  }
>  EXPORT_SYMBOL(drm_hdmi_compute_mode_clock);
> +
> +enum drm_mode_status
> +__drm_hdmi_connector_clock_valid(const struct drm_connector *connector,
> +				 const struct drm_display_mode *mode,
> +				 unsigned long long clock)
> +{
> +	const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs;
> +	const struct drm_display_info *info = &connector->display_info;
> +
> +	if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
> +		return MODE_CLOCK_HIGH;
> +
> +	if (funcs && funcs->tmds_char_rate_valid) {
> +		enum drm_mode_status status;
> +
> +		status = funcs->tmds_char_rate_valid(connector, mode, clock);
> +		if (status != MODE_OK)
> +			return status;
> +	}
> +
> +	return MODE_OK;
> +}
> +
> +/**
> + * 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 __drm_hdmi_connector_clock_valid(connector, mode, clock);
> +}
> +EXPORT_SYMBOL(drm_hdmi_connector_mode_valid);

It's not clear to me why you want to place it in drm_hdmi_helper? It's
relying quite heavily on the HDMI infrastructure, so it would make more
sense to me that it would be part of drm_hdmi_state_helper.c.

> 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 34ee95d41f2966ab23a60deb37d689430f6b0985..8640e7280053bd95852f53b92159f493b141f2bf 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 +43,12 @@ 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);
> +	if (!list_empty(&connector->modes))
> +		preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
> +

What is this fixing?

>  	list_for_each_entry(mode, &connector->modes, head)
>  		if (mode->type & DRM_MODE_TYPE_PREFERRED)
>  			preferred = mode;
> @@ -125,6 +127,18 @@ 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 +161,33 @@ 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 +1775,132 @@ 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);
> +}
> +
> +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);
> +}
> +
> +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);
> +}
> +
> +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,
> +};
> +

We need some documentation for these tests too, and what you're trying
to test exactly with that 100MHz cutout.

Maxime

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Re: [PATCH v2 2/6] drm/sun4i: use drm_hdmi_connector_mode_valid()

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 1905 bytes --]

On Fri, Nov 01, 2024 at 02:25:05AM +0200, Dmitry Baryshkov wrote:
> 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,
>  };

It's only slightly related, but the atomic_check implementation that
will be the last (direct) user of sun4i_hdmi_clock_valid is wrong and
doesn't call drm_atomic_helper_connector_hdmi_check

Maxime

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Re: [PATCH v2 4/6] drm/display: bridge_connector: use drm_bridge_connector_mode_valid()

[Maxime Ripard]

On Fri, 1 Nov 2024 02:25:07 +0200, Dmitry Baryshkov wrote:
> 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>

Thanks!
Maxime

Re: [PATCH v2 5/6] drm/bridge: lontium-lt9611: drop TMDS char rate check in mode_valid

[Maxime Ripard]

On Fri, 1 Nov 2024 02:25:08 +0200, Dmitry Baryshkov wrote:
> 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>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v2 6/6] drm/bridge: dw-hdmi-qp: replace mode_valid with tmds_char_rate

[Maxime Ripard]

On Fri, 1 Nov 2024 02:25:09 +0200, Dmitry Baryshkov wrote:
> 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: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v2 1/6] drm/display: hdmi: add generic mode_valid helper

[Dmitry Baryshkov]

On Fri, Nov 08, 2024 at 03:17:22PM +0100, Maxime Ripard wrote:
> Hi,
> 
> On Fri, Nov 01, 2024 at 02:25:04AM +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_helper.c          |  45 ++++++
> >  drivers/gpu/drm/display/drm_hdmi_helper_internal.h |  11 ++
> >  drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  26 +---
> >  drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 168 ++++++++++++++++++++-
> >  include/drm/display/drm_hdmi_helper.h              |   4 +
> >  5 files changed, 229 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c b/drivers/gpu/drm/display/drm_hdmi_helper.c
> > index 74dd4d01dd9bb2c9e69ec1c60b0056bd69417e8a..560c5d4365ca54d3f669395349cedfd6f75fa033 100644
> > --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> > +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> > @@ -9,6 +9,8 @@
> >  #include <drm/drm_print.h>
> >  #include <drm/drm_property.h>
> >  
> > +#include "drm_hdmi_helper_internal.h"
> > +
> >  static inline bool is_eotf_supported(u8 output_eotf, u8 sink_eotf)
> >  {
> >  	return sink_eotf & BIT(output_eotf);
> > @@ -256,3 +258,46 @@ drm_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
> >  	return DIV_ROUND_CLOSEST_ULL(clock * bpc, 8);
> >  }
> >  EXPORT_SYMBOL(drm_hdmi_compute_mode_clock);
> > +
> > +enum drm_mode_status
> > +__drm_hdmi_connector_clock_valid(const struct drm_connector *connector,
> > +				 const struct drm_display_mode *mode,
> > +				 unsigned long long clock)
> > +{
> > +	const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs;
> > +	const struct drm_display_info *info = &connector->display_info;
> > +
> > +	if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
> > +		return MODE_CLOCK_HIGH;
> > +
> > +	if (funcs && funcs->tmds_char_rate_valid) {
> > +		enum drm_mode_status status;
> > +
> > +		status = funcs->tmds_char_rate_valid(connector, mode, clock);
> > +		if (status != MODE_OK)
> > +			return status;
> > +	}
> > +
> > +	return MODE_OK;
> > +}
> > +
> > +/**
> > + * 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 __drm_hdmi_connector_clock_valid(connector, mode, clock);
> > +}
> > +EXPORT_SYMBOL(drm_hdmi_connector_mode_valid);
> 
> It's not clear to me why you want to place it in drm_hdmi_helper? It's
> relying quite heavily on the HDMI infrastructure, so it would make more
> sense to me that it would be part of drm_hdmi_state_helper.c.

Yeah, I hesitated a bit. I selected drm_hdmi_helper.c because it doesn't
use state-related functions. As such it is usable even by the drivers
which imlement just the basic HDMI Connector functions and don't use the
reset of the framework.

ANyway, I'll move it to drm_hdmi_state_helper.c.

> 
> > 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 34ee95d41f2966ab23a60deb37d689430f6b0985..8640e7280053bd95852f53b92159f493b141f2bf 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 +43,12 @@ 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);
> > +	if (!list_empty(&connector->modes))
> > +		preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
> > +
> 
> What is this fixing?

If connector->modes is empty (e.g. because of the tmds_char_rate_valid()
rejecting all of them) then just list_first_entry() will result in an
invalid mode being assigned to preferred.

> 
> >  	list_for_each_entry(mode, &connector->modes, head)
> >  		if (mode->type & DRM_MODE_TYPE_PREFERRED)
> >  			preferred = mode;
> > @@ -125,6 +127,18 @@ 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 +161,33 @@ 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 +1775,132 @@ 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);
> > +}
> > +
> > +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);
> > +}
> > +
> > +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);
> > +}
> > +
> > +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,
> > +};
> > +
> 
> We need some documentation for these tests too, and what you're trying
> to test exactly with that 100MHz cutout.

I'll add a comment. Basically, I'm checking that
drm_hdmi_connector_mode_valid() actually rejects modes based on the
tmds_char_rate_valid() or on the info->max_tmds_clock.

> 
> Maxime



-- 
With best wishes
Dmitry

Re: [PATCH v2 2/6] drm/sun4i: use drm_hdmi_connector_mode_valid()

[Dmitry Baryshkov]

On Fri, Nov 08, 2024 at 03:20:48PM +0100, Maxime Ripard wrote:
> On Fri, Nov 01, 2024 at 02:25:05AM +0200, Dmitry Baryshkov wrote:
> > 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,
> >  };
> 
> It's only slightly related, but the atomic_check implementation that
> will be the last (direct) user of sun4i_hdmi_clock_valid is wrong and
> doesn't call drm_atomic_helper_connector_hdmi_check

I can send a patch fixing this, but I can't test it.

-- 
With best wishes
Dmitry