[PATCH 1/3] drm/connector: Create a helper to attach the hdr_output_metadata property

[PATCH 1/3] drm/connector: Create a helper to attach the hdr_output_metadata property

[Maxime Ripard]

All the drivers that implement HDR output call pretty much the same
function to initialise the hdr_output_metadata property, and while the
creation of that property is in a helper, every driver uses the same
code to attach it.

Provide a helper for it as well

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  4 +---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     |  3 +--
 drivers/gpu/drm/drm_connector.c               | 21 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_hdmi.c     |  3 +--
 include/drm/drm_connector.h                   |  1 +
 5 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 22124f76d0b5..06908a3cee0f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7017,9 +7017,7 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 	if (connector_type == DRM_MODE_CONNECTOR_HDMIA ||
 	    connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
 	    connector_type == DRM_MODE_CONNECTOR_eDP) {
-		drm_object_attach_property(
-			&aconnector->base.base,
-			dm->ddev->mode_config.hdr_output_metadata_property, 0);
+		drm_connector_attach_hdr_output_metadata_property(&aconnector->base);
 
 		if (!aconnector->mst_port)
 			drm_connector_attach_vrr_capable_property(&aconnector->base);
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index dda4fa9a1a08..f24bbb840dbf 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2492,8 +2492,7 @@ static int dw_hdmi_connector_create(struct dw_hdmi *hdmi)
 	drm_connector_attach_max_bpc_property(connector, 8, 16);
 
 	if (hdmi->version >= 0x200a && hdmi->plat_data->use_drm_infoframe)
-		drm_object_attach_property(&connector->base,
-			connector->dev->mode_config.hdr_output_metadata_property, 0);
+		drm_connector_attach_hdr_output_metadata_property(connector);
 
 	drm_connector_attach_encoder(connector, hdmi->bridge.encoder);
 
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 98b6ec45ef96..e25248e23e18 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2149,6 +2149,27 @@ int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
 
+/**
+ * drm_connector_attach_hdr_output_metadata_property - attach "HDR_OUTPUT_METADA" property
+ * @connector: connector to attach the property on.
+ *
+ * This is used to allow the userspace to send HDR Metadata to the
+ * driver.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop = dev->mode_config.hdr_output_metadata_property;
+
+	drm_object_attach_property(&connector->base, prop, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_hdr_output_metadata_property);
+
 /**
  * drm_connector_set_vrr_capable_property - sets the variable refresh rate
  * capable property for a connector
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index c5959590562b..52c051efb7b7 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2958,8 +2958,7 @@ intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *c
 	drm_connector_attach_content_type_property(connector);
 
 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
-		drm_object_attach_property(&connector->base,
-			connector->dev->mode_config.hdr_output_metadata_property, 0);
+		drm_connector_attach_hdr_output_metadata_property(connector);
 
 	if (!HAS_GMCH(dev_priv))
 		drm_connector_attach_max_bpc_property(connector, 8, 12);
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 1922b278ffad..32172dab8427 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1671,6 +1671,7 @@ int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
 					       u32 scaling_mode_mask);
 int drm_connector_attach_vrr_capable_property(
 		struct drm_connector *connector);
+int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *connector);
 int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
 int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector);
 int drm_mode_create_dp_colorspace_property(struct drm_connector *connector);
-- 
2.30.2

[PATCH 2/3] drm/connector: Add helper to compare HDR metadata

[Maxime Ripard]

All the drivers that support the HDR metadata property have a similar
function to compare the metadata from one connector state to the next,
and force a mode change if they differ.

All these functions run pretty much the same code, so let's turn it into
an helper that can be shared across those drivers.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 21 +-------------
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     | 17 +----------
 drivers/gpu/drm/drm_connector.c               | 28 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_atomic.c   | 13 +--------
 include/drm/drm_connector.h                   |  2 ++
 5 files changed, 33 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 06908a3cee0f..4eb5201e566a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5924,25 +5924,6 @@ static int fill_hdr_info_packet(const struct drm_connector_state *state,
 	return 0;
 }
 
-static bool
-is_hdr_metadata_different(const struct drm_connector_state *old_state,
-			  const struct drm_connector_state *new_state)
-{
-	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
-	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
-
-	if (old_blob != new_blob) {
-		if (old_blob && new_blob &&
-		    old_blob->length == new_blob->length)
-			return memcmp(old_blob->data, new_blob->data,
-				      old_blob->length);
-
-		return true;
-	}
-
-	return false;
-}
-
 static int
 amdgpu_dm_connector_atomic_check(struct drm_connector *conn,
 				 struct drm_atomic_state *state)
@@ -5960,7 +5941,7 @@ amdgpu_dm_connector_atomic_check(struct drm_connector *conn,
 	if (!crtc)
 		return 0;
 
-	if (is_hdr_metadata_different(old_con_state, new_con_state)) {
+	if (!drm_connector_atomic_hdr_metadata_equal(old_con_state, new_con_state)) {
 		struct dc_info_packet hdr_infopacket;
 
 		ret = fill_hdr_info_packet(new_con_state, &hdr_infopacket);
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index f24bbb840dbf..f871e33c2fc9 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2395,21 +2395,6 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
-static bool hdr_metadata_equal(const struct drm_connector_state *old_state,
-			       const struct drm_connector_state *new_state)
-{
-	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
-	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
-
-	if (!old_blob || !new_blob)
-		return old_blob == new_blob;
-
-	if (old_blob->length != new_blob->length)
-		return false;
-
-	return !memcmp(old_blob->data, new_blob->data, old_blob->length);
-}
-
 static int dw_hdmi_connector_atomic_check(struct drm_connector *connector,
 					  struct drm_atomic_state *state)
 {
@@ -2423,7 +2408,7 @@ static int dw_hdmi_connector_atomic_check(struct drm_connector *connector,
 	if (!crtc)
 		return 0;
 
-	if (!hdr_metadata_equal(old_state, new_state)) {
+	if (!drm_connector_atomic_hdr_metadata_equal(old_state, new_state)) {
 		crtc_state = drm_atomic_get_crtc_state(state, crtc);
 		if (IS_ERR(crtc_state))
 			return PTR_ERR(crtc_state);
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index e25248e23e18..d781a3a1e9bf 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2170,6 +2170,34 @@ int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *conn
 }
 EXPORT_SYMBOL(drm_connector_attach_hdr_output_metadata_property);
 
+/**
+ * drm_connector_atomic_hdr_metadata_equal - checks if the hdr metadata changed
+ * @old_state: old connector state to compare
+ * @new_state: new connector state to compare
+ *
+ * This is used by HDR-enabled drivers to test whether the HDR metadata
+ * have changed between two different connector state (and thus probably
+ * requires a full blown mode change).
+ *
+ * Returns:
+ * True if the metadata are equal, False otherwise
+ */
+bool drm_connector_atomic_hdr_metadata_equal(struct drm_connector_state *old_state,
+					     struct drm_connector_state *new_state)
+{
+	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
+	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
+
+	if (!old_blob || !new_blob)
+		return old_blob == new_blob;
+
+	if (old_blob->length != new_blob->length)
+		return false;
+
+	return !memcmp(old_blob->data, new_blob->data, old_blob->length);
+}
+EXPORT_SYMBOL(drm_connector_atomic_hdr_metadata_equal);
+
 /**
  * drm_connector_set_vrr_capable_property - sets the variable refresh rate
  * capable property for a connector
diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
index e00fdc47c0eb..efec9454af5a 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic.c
@@ -109,16 +109,6 @@ int intel_digital_connector_atomic_set_property(struct drm_connector *connector,
 	return -EINVAL;
 }
 
-static bool blob_equal(const struct drm_property_blob *a,
-		       const struct drm_property_blob *b)
-{
-	if (a && b)
-		return a->length == b->length &&
-			!memcmp(a->data, b->data, a->length);
-
-	return !a == !b;
-}
-
 int intel_digital_connector_atomic_check(struct drm_connector *conn,
 					 struct drm_atomic_state *state)
 {
@@ -149,8 +139,7 @@ int intel_digital_connector_atomic_check(struct drm_connector *conn,
 	    new_conn_state->base.picture_aspect_ratio != old_conn_state->base.picture_aspect_ratio ||
 	    new_conn_state->base.content_type != old_conn_state->base.content_type ||
 	    new_conn_state->base.scaling_mode != old_conn_state->base.scaling_mode ||
-	    !blob_equal(new_conn_state->base.hdr_output_metadata,
-			old_conn_state->base.hdr_output_metadata))
+	    !drm_connector_atomic_hdr_metadata_equal(old_state, new_state))
 		crtc_state->mode_changed = true;
 
 	return 0;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 32172dab8427..1f51d73ca715 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1672,6 +1672,8 @@ int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
 int drm_connector_attach_vrr_capable_property(
 		struct drm_connector *connector);
 int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *connector);
+bool drm_connector_atomic_hdr_metadata_equal(struct drm_connector_state *old_state,
+					     struct drm_connector_state *new_state);
 int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
 int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector);
 int drm_mode_create_dp_colorspace_property(struct drm_connector *connector);
-- 
2.30.2

[PATCH 3/3] drm/vc4: Add HDR metadata property to the VC5 HDMI connectors

[Maxime Ripard]

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

Now that we can export deeper colour depths, add in the signalling
for HDR metadata.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 53 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_hdmi.h |  3 ++
 2 files changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index eee9751009c2..c8846cf9dd24 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -214,6 +214,31 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
+static int vc4_hdmi_connector_atomic_check(struct drm_connector *connector,
+					  struct drm_atomic_state *state)
+{
+	struct drm_connector_state *old_state =
+		drm_atomic_get_old_connector_state(state, connector);
+	struct drm_connector_state *new_state =
+		drm_atomic_get_new_connector_state(state, connector);
+	struct drm_crtc *crtc = new_state->crtc;
+
+	if (!crtc)
+		return 0;
+
+	if (!drm_connector_atomic_hdr_metadata_equal(old_state, new_state)) {
+		struct drm_crtc_state *crtc_state;
+
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+
+		crtc_state->mode_changed = true;
+	}
+
+	return 0;
+}
+
 static void vc4_hdmi_connector_reset(struct drm_connector *connector)
 {
 	struct vc4_hdmi_connector_state *old_state =
@@ -263,6 +288,7 @@ static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {
 
 static const struct drm_connector_helper_funcs vc4_hdmi_connector_helper_funcs = {
 	.get_modes = vc4_hdmi_connector_get_modes,
+	.atomic_check = vc4_hdmi_connector_atomic_check,
 };
 
 static int vc4_hdmi_connector_init(struct drm_device *dev,
@@ -299,6 +325,9 @@ static int vc4_hdmi_connector_init(struct drm_device *dev,
 	connector->interlace_allowed = 1;
 	connector->doublescan_allowed = 0;
 
+	if (vc4_hdmi->variant->supports_hdr)
+		drm_connector_attach_hdr_output_metadata_property(connector);
+
 	drm_connector_attach_encoder(connector, encoder);
 
 	return 0;
@@ -432,6 +461,25 @@ static void vc4_hdmi_set_audio_infoframe(struct drm_encoder *encoder)
 	vc4_hdmi_write_infoframe(encoder, &frame);
 }
 
+static void vc4_hdmi_set_hdr_infoframe(struct drm_encoder *encoder)
+{
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+	struct drm_connector *connector = &vc4_hdmi->connector;
+	struct drm_connector_state *conn_state = connector->state;
+	union hdmi_infoframe frame;
+
+	if (!vc4_hdmi->variant->supports_hdr)
+		return;
+
+	if (!conn_state->hdr_output_metadata)
+		return;
+
+	if (drm_hdmi_infoframe_set_hdr_metadata(&frame.drm, conn_state))
+		return;
+
+	vc4_hdmi_write_infoframe(encoder, &frame);
+}
+
 static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
@@ -444,6 +492,8 @@ static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
 	 */
 	if (vc4_hdmi->audio.streaming)
 		vc4_hdmi_set_audio_infoframe(encoder);
+
+	vc4_hdmi_set_hdr_infoframe(encoder);
 }
 
 static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder,
@@ -2101,6 +2151,7 @@ static const struct vc4_hdmi_variant bcm2835_variant = {
 	.phy_rng_enable		= vc4_hdmi_phy_rng_enable,
 	.phy_rng_disable	= vc4_hdmi_phy_rng_disable,
 	.channel_map		= vc4_hdmi_channel_map,
+	.supports_hdr		= false,
 };
 
 static const struct vc4_hdmi_variant bcm2711_hdmi0_variant = {
@@ -2128,6 +2179,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi0_variant = {
 	.phy_rng_enable		= vc5_hdmi_phy_rng_enable,
 	.phy_rng_disable	= vc5_hdmi_phy_rng_disable,
 	.channel_map		= vc5_hdmi_channel_map,
+	.supports_hdr		= true,
 };
 
 static const struct vc4_hdmi_variant bcm2711_hdmi1_variant = {
@@ -2155,6 +2207,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi1_variant = {
 	.phy_rng_enable		= vc5_hdmi_phy_rng_enable,
 	.phy_rng_disable	= vc5_hdmi_phy_rng_disable,
 	.channel_map		= vc5_hdmi_channel_map,
+	.supports_hdr		= true,
 };
 
 static const struct of_device_id vc4_hdmi_dt_match[] = {
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index 3cebd1fd00fc..060bcaefbeb5 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -99,6 +99,9 @@ struct vc4_hdmi_variant {
 
 	/* Callback to get channel map */
 	u32 (*channel_map)(struct vc4_hdmi *vc4_hdmi, u32 channel_mask);
+
+	/* Enables HDR metadata */
+	bool supports_hdr;
 };
 
 /* HDMI audio information */
-- 
2.30.2

Re: [PATCH 2/3] drm/connector: Add helper to compare HDR metadata

[Harry Wentland]

On 2021-03-19 8:49 a.m., Maxime Ripard wrote:
> All the drivers that support the HDR metadata property have a similar
> function to compare the metadata from one connector state to the next,
> and force a mode change if they differ.
> 
> All these functions run pretty much the same code, so let's turn it into
> an helper that can be shared across those drivers.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Patches 1 & 2 are
Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 21 +-------------
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     | 17 +----------
>   drivers/gpu/drm/drm_connector.c               | 28 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_atomic.c   | 13 +--------
>   include/drm/drm_connector.h                   |  2 ++
>   5 files changed, 33 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 06908a3cee0f..4eb5201e566a 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -5924,25 +5924,6 @@ static int fill_hdr_info_packet(const struct drm_connector_state *state,
>   	return 0;
>   }
>   
> -static bool
> -is_hdr_metadata_different(const struct drm_connector_state *old_state,
> -			  const struct drm_connector_state *new_state)
> -{
> -	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
> -	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
> -
> -	if (old_blob != new_blob) {
> -		if (old_blob && new_blob &&
> -		    old_blob->length == new_blob->length)
> -			return memcmp(old_blob->data, new_blob->data,
> -				      old_blob->length);
> -
> -		return true;
> -	}
> -
> -	return false;
> -}
> -
>   static int
>   amdgpu_dm_connector_atomic_check(struct drm_connector *conn,
>   				 struct drm_atomic_state *state)
> @@ -5960,7 +5941,7 @@ amdgpu_dm_connector_atomic_check(struct drm_connector *conn,
>   	if (!crtc)
>   		return 0;
>   
> -	if (is_hdr_metadata_different(old_con_state, new_con_state)) {
> +	if (!drm_connector_atomic_hdr_metadata_equal(old_con_state, new_con_state)) {
>   		struct dc_info_packet hdr_infopacket;
>   
>   		ret = fill_hdr_info_packet(new_con_state, &hdr_infopacket);
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index f24bbb840dbf..f871e33c2fc9 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2395,21 +2395,6 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
>   	return ret;
>   }
>   
> -static bool hdr_metadata_equal(const struct drm_connector_state *old_state,
> -			       const struct drm_connector_state *new_state)
> -{
> -	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
> -	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
> -
> -	if (!old_blob || !new_blob)
> -		return old_blob == new_blob;
> -
> -	if (old_blob->length != new_blob->length)
> -		return false;
> -
> -	return !memcmp(old_blob->data, new_blob->data, old_blob->length);
> -}
> -
>   static int dw_hdmi_connector_atomic_check(struct drm_connector *connector,
>   					  struct drm_atomic_state *state)
>   {
> @@ -2423,7 +2408,7 @@ static int dw_hdmi_connector_atomic_check(struct drm_connector *connector,
>   	if (!crtc)
>   		return 0;
>   
> -	if (!hdr_metadata_equal(old_state, new_state)) {
> +	if (!drm_connector_atomic_hdr_metadata_equal(old_state, new_state)) {
>   		crtc_state = drm_atomic_get_crtc_state(state, crtc);
>   		if (IS_ERR(crtc_state))
>   			return PTR_ERR(crtc_state);
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index e25248e23e18..d781a3a1e9bf 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2170,6 +2170,34 @@ int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *conn
>   }
>   EXPORT_SYMBOL(drm_connector_attach_hdr_output_metadata_property);
>   
> +/**
> + * drm_connector_atomic_hdr_metadata_equal - checks if the hdr metadata changed
> + * @old_state: old connector state to compare
> + * @new_state: new connector state to compare
> + *
> + * This is used by HDR-enabled drivers to test whether the HDR metadata
> + * have changed between two different connector state (and thus probably
> + * requires a full blown mode change).
> + *
> + * Returns:
> + * True if the metadata are equal, False otherwise
> + */
> +bool drm_connector_atomic_hdr_metadata_equal(struct drm_connector_state *old_state,
> +					     struct drm_connector_state *new_state)
> +{
> +	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
> +	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
> +
> +	if (!old_blob || !new_blob)
> +		return old_blob == new_blob;
> +
> +	if (old_blob->length != new_blob->length)
> +		return false;
> +
> +	return !memcmp(old_blob->data, new_blob->data, old_blob->length);
> +}
> +EXPORT_SYMBOL(drm_connector_atomic_hdr_metadata_equal);
> +
>   /**
>    * drm_connector_set_vrr_capable_property - sets the variable refresh rate
>    * capable property for a connector
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> index e00fdc47c0eb..efec9454af5a 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> @@ -109,16 +109,6 @@ int intel_digital_connector_atomic_set_property(struct drm_connector *connector,
>   	return -EINVAL;
>   }
>   
> -static bool blob_equal(const struct drm_property_blob *a,
> -		       const struct drm_property_blob *b)
> -{
> -	if (a && b)
> -		return a->length == b->length &&
> -			!memcmp(a->data, b->data, a->length);
> -
> -	return !a == !b;
> -}
> -
>   int intel_digital_connector_atomic_check(struct drm_connector *conn,
>   					 struct drm_atomic_state *state)
>   {
> @@ -149,8 +139,7 @@ int intel_digital_connector_atomic_check(struct drm_connector *conn,
>   	    new_conn_state->base.picture_aspect_ratio != old_conn_state->base.picture_aspect_ratio ||
>   	    new_conn_state->base.content_type != old_conn_state->base.content_type ||
>   	    new_conn_state->base.scaling_mode != old_conn_state->base.scaling_mode ||
> -	    !blob_equal(new_conn_state->base.hdr_output_metadata,
> -			old_conn_state->base.hdr_output_metadata))
> +	    !drm_connector_atomic_hdr_metadata_equal(old_state, new_state))
>   		crtc_state->mode_changed = true;
>   
>   	return 0;
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 32172dab8427..1f51d73ca715 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1672,6 +1672,8 @@ int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
>   int drm_connector_attach_vrr_capable_property(
>   		struct drm_connector *connector);
>   int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *connector);
> +bool drm_connector_atomic_hdr_metadata_equal(struct drm_connector_state *old_state,
> +					     struct drm_connector_state *new_state);
>   int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
>   int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector);
>   int drm_mode_create_dp_colorspace_property(struct drm_connector *connector);
>