[PATCH RFC v2 05/24] drm/display: bridge-connector: use a dynamic connector

[Luca Ceresoli]

Currently the drm_bridge_connector uses drmm functions to add the
drm_connector. For bridge hotplug drmm allocations are not suitable because
a connector may have to be added and removed multiple times in the lifetime
of a card.

In preparation for bridge hotplug, use the dynamic variants of
drm_connector[_hdmi]_init() so the drm_connector can be removed without
removing the whole card.

| [TODO]
| - there is a hack about state creation, already discussed,
|   still to be sorted out
| - there are still 2 drmm calls to be converted to non-drmm:
|   drmm_connector_hdmi_cec_notifier_register() and
|   drmm_connector_hdmi_cec_register

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
---
 drivers/gpu/drm/display/drm_bridge_connector.c | 86 ++++++++++++++++++--------
 1 file changed, 59 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 2aff745f0147..1c222e27767d 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -137,6 +137,18 @@ struct drm_bridge_connector {
 #define to_drm_bridge_connector(x) \
 	container_of(x, struct drm_bridge_connector, base)
 
+static void drm_bridge_connector_put_bridges(struct drm_bridge_connector *bridge_connector)
+{
+	drm_bridge_put(bridge_connector->bridge_edid);
+	drm_bridge_put(bridge_connector->bridge_hpd);
+	drm_bridge_put(bridge_connector->bridge_detect);
+	drm_bridge_put(bridge_connector->bridge_modes);
+	drm_bridge_put(bridge_connector->bridge_hdmi);
+	drm_bridge_put(bridge_connector->bridge_hdmi_audio);
+	drm_bridge_put(bridge_connector->bridge_dp_audio);
+	drm_bridge_put(bridge_connector->bridge_hdmi_cec);
+}
+
 /* -----------------------------------------------------------------------------
  * Bridge Connector Hot-Plug Handling
  */
@@ -267,6 +279,14 @@ drm_bridge_connector_color_format(const struct drm_connector_state *conn_state)
 	return conn_state->color_format;
 }
 
+static void drm_bridge_connector_dynconn_destroy(struct drm_connector *connector)
+{
+	struct drm_bridge_connector *bridge_connector = to_drm_bridge_connector(connector);
+
+	drm_connector_cleanup(connector);
+	drm_bridge_connector_put_bridges(bridge_connector);
+}
+
 static const struct drm_connector_funcs drm_bridge_connector_funcs = {
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.atomic_create_state = drm_bridge_connector_create_state,
@@ -275,6 +295,7 @@ static const struct drm_connector_funcs drm_bridge_connector_funcs = {
 	.debugfs_init = drm_bridge_connector_debugfs_init,
 	.oob_hotplug_event = drm_bridge_connector_oob_hotplug_event,
 	.color_format = drm_bridge_connector_color_format,
+	.destroy = drm_bridge_connector_dynconn_destroy,
 };
 
 /* -----------------------------------------------------------------------------
@@ -823,20 +844,6 @@ static const struct drm_connector_hdmi_cec_funcs drm_bridge_connector_hdmi_cec_f
  * Bridge Connector Initialisation
  */
 
-static void drm_bridge_connector_put_bridges(struct drm_device *dev, void *data)
-{
-	struct drm_bridge_connector *bridge_connector = (struct drm_bridge_connector *)data;
-
-	drm_bridge_put(bridge_connector->bridge_edid);
-	drm_bridge_put(bridge_connector->bridge_hpd);
-	drm_bridge_put(bridge_connector->bridge_detect);
-	drm_bridge_put(bridge_connector->bridge_modes);
-	drm_bridge_put(bridge_connector->bridge_hdmi);
-	drm_bridge_put(bridge_connector->bridge_hdmi_audio);
-	drm_bridge_put(bridge_connector->bridge_dp_audio);
-	drm_bridge_put(bridge_connector->bridge_hdmi_cec);
-}
-
 static struct drm_connector *
 drm_bridge_connector_initialize(struct drm_bridge_connector *bridge_connector,
 				struct drm_device *drm,
@@ -849,10 +856,6 @@ drm_bridge_connector_initialize(struct drm_bridge_connector *bridge_connector,
 	int connector_type;
 	int ret;
 
-	ret = drmm_add_action(drm, drm_bridge_connector_put_bridges, bridge_connector);
-	if (ret)
-		return ERR_PTR(ret);
-
 	bridge_connector->encoder = encoder;
 
 	/*
@@ -1053,17 +1056,21 @@ drm_bridge_connector_initialize(struct drm_bridge_connector *bridge_connector,
 				drm_bridge_connector_scrambler_disable;
 		}
 
-		ret = drmm_connector_hdmi_init(drm, connector,
-					       &drm_bridge_connector_funcs,
-					       &bridge_connector->hdmi_funcs,
-					       connector_type, ddc);
+		ret = drm_connector_hdmi_dynamic_init(drm, connector,
+						      &drm_bridge_connector_funcs,
+						      &bridge_connector->hdmi_funcs,
+						      connector_type, ddc);
 	} else {
-		ret = drmm_connector_init(drm, connector,
-					  &drm_bridge_connector_funcs,
-					  connector_type, ddc);
+		ret = drm_connector_dynamic_init(drm, connector,
+						 &drm_bridge_connector_funcs,
+						 connector_type, ddc);
 	}
-	if (ret)
-		return ret;
+	if (ret) {
+		drm_bridge_connector_put_bridges(bridge_connector);
+		return ERR_PTR(ret);
+	}
+
+	/* From now on the connector is referenced and has to be put */
 
 	if (bridge_connector->bridge_hdmi_audio ||
 	    bridge_connector->bridge_dp_audio) {
@@ -1113,6 +1120,9 @@ drm_bridge_connector_initialize(struct drm_bridge_connector *bridge_connector,
 
 	drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
 
+	if (!connector->state)
+		connector->state = drm_bridge_connector_create_state(connector);
+
 	if (bridge_connector->bridge_hpd)
 		connector->polled = DRM_CONNECTOR_POLL_HPD;
 	else if (bridge_connector->bridge_detect)
@@ -1130,9 +1140,26 @@ drm_bridge_connector_initialize(struct drm_bridge_connector *bridge_connector,
 	if (ret)
 		return ERR_PTR(ret);
 
+	ret = drm_connector_dynamic_register(connector);
+	if (ret)
+		return ERR_PTR(ret);
+
 	return connector;
 }
 
+static void drm_bridge_connector_fini(struct drm_bridge_connector *bridge_connector)
+{
+	drm_connector_unregister(&bridge_connector->base);
+	drm_connector_put(&bridge_connector->base);
+}
+
+static void drmm_bridge_connector_fini(struct drm_device *dev, void *res)
+{
+	struct drm_bridge_connector *bridge_connector = (struct drm_bridge_connector *)res;
+
+	drm_bridge_connector_fini(bridge_connector);
+}
+
 /**
  * drm_bridge_connector_init - Initialise a connector for a chain of bridges
  * @drm: the DRM device
@@ -1155,6 +1182,7 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 {
 	struct drm_bridge_connector *bridge_connector;
 	struct drm_connector *connector;
+	int ret;
 
 	bridge_connector = drmm_kzalloc(drm, sizeof(*bridge_connector), GFP_KERNEL);
 	if (!bridge_connector)
@@ -1164,6 +1192,10 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 	if (IS_ERR(connector))
 		return connector;
 
+	ret = drmm_add_action_or_reset(drm, drmm_bridge_connector_fini, bridge_connector);
+	if (ret)
+		return ERR_PTR(ret);
+
 	return connector;
 }
 EXPORT_SYMBOL_GPL(drm_bridge_connector_init);

-- 
2.55.0