drm/vc4: Add connector check to trigger mode_change when hdr metadata changes

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------
Signed-off-by: NDom Cobley <popcornmix@gmail.com>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -527,6 +527,45 @@ static int vc4_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 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;
+	struct drm_crtc_state *crtc_state;
+
+	if (!crtc)
+		return 0;
+
+	if (!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);
+
+		crtc_state->mode_changed = true;
+	}
+
+	return 0;
+}
+
 static void vc4_hdmi_connector_reset(struct drm_connector *connector)
 {
 	struct vc4_hdmi_connector_state *old_state =
@@ -576,6 +615,7 @@ 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,