drm/vc4: hvs: Force modeset on gamma lut change

The HVS Gamma block can only be updated when idle, so we need to disable
the HVS channel when the gamma property is set in an atomic commit.

Since the pixelvalve cannot have its assigned channel without stalling
unless it's disabled as well, in our case that means forcing a full
disable / enable cycle on the pipeline.

Signed-off-by: Maxime Ripard <[email protected]>

Author: mripard

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -292,6 +292,23 @@ struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
 	return NULL;
 }
 
+#define drm_for_each_connector_mask(connector, dev, connector_mask) \
+	list_for_each_entry((connector), &(dev)->mode_config.connector_list, head) \
+		for_each_if ((connector_mask) & drm_connector_mask(connector))
+
+struct drm_connector *vc4_get_crtc_connector(struct drm_crtc *crtc,
+					     struct drm_crtc_state *state)
+{
+	struct drm_connector *connector;
+
+	WARN_ON(hweight32(state->connector_mask) > 1);
+
+	drm_for_each_connector_mask(connector, crtc->dev, state->connector_mask)
+		return connector;
+
+	return NULL;
+}
+
 static void vc4_crtc_pixelvalve_reset(struct drm_crtc *crtc)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);

drivers/gpu/drm/vc4/vc4_drv.h

@@ -540,6 +540,9 @@ vc4_crtc_to_vc4_pv_data(const struct vc4_crtc *crtc)
 	return container_of(data, struct vc4_pv_data, base);
 }
 
+struct drm_connector *vc4_get_crtc_connector(struct drm_crtc *crtc,
+					     struct drm_crtc_state *state);
+
 struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
 					 struct drm_crtc_state *state);
 

drivers/gpu/drm/vc4/vc4_hvs.c

@@ -519,6 +519,36 @@ void vc4_hvs_stop_channel(struct drm_device *dev, unsigned int chan)
 		     SCALER_DISPSTATX_EMPTY);
 }
 
+static int vc4_hvs_gamma_check(struct drm_crtc *crtc,
+			       struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+	struct drm_connector_state *conn_state;
+	struct drm_connector *connector;
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+
+	if (!vc4->hvs->hvs5)
+		return 0;
+
+	if (!crtc_state->color_mgmt_changed)
+		return 0;
+
+	connector = vc4_get_crtc_connector(crtc, crtc_state);
+	if (!connector)
+		return -EINVAL;
+
+	if (!(connector->connector_type == DRM_MODE_CONNECTOR_HDMIA))
+		return 0;
+
+	conn_state = drm_atomic_get_connector_state(state, connector);
+	if (!conn_state)
+		return -EINVAL;
+
+	crtc_state->mode_changed = true;
+	return 0;
+}
+
 int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
 {
 	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
@@ -549,7 +579,7 @@ int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
 	if (ret)
 		return ret;
 
-	return 0;
+	return vc4_hvs_gamma_check(crtc, state);
 }
 
 static void vc4_hvs_update_dlist(struct drm_crtc *crtc)