drm/display/dp_mst: convert to struct drm_edid

Convert the topology manager to use struct drm_edid, add
drm_dp_mst_edid_read() that returns drm_edid, and rewrite the old
drm_dp_mst_get_edid() to use it.

Note that the old drm_get_edid() ended up calling
drm_connector_update_edid_property(). This responsibility is now
deferred to drivers, which all do it anyway after calling
drm_dp_mst_edid_read() or drm_dp_mst_get_edid().
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9c32e5c241934093fc4144eed4c01155e1f03af1.1685437501.git.jani.nikula@intel.com

drivers/gpu/drm/display/drm_dp_mst_topology.c

@@ -1823,7 +1823,7 @@ static void drm_dp_destroy_port(struct kref *kref)
 		return;
 	}
 
-	kfree(port->cached_edid);
+	drm_edid_free(port->cached_edid);
 
 	/*
 	 * we can't destroy the connector here, as we might be holding the
@@ -2272,8 +2272,8 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
 	if (port->pdt != DP_PEER_DEVICE_NONE &&
 	    drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
 	    port->port_num >= DP_MST_LOGICAL_PORT_0)
-		port->cached_edid = drm_get_edid(port->connector,
-						 &port->aux.ddc);
+		port->cached_edid = drm_edid_read_ddc(port->connector,
+						      &port->aux.ddc);
 
 	drm_connector_register(port->connector);
 	return;
@@ -4133,7 +4133,7 @@ drm_dp_mst_detect_port(struct drm_connector *connector,
 		ret = connector_status_connected;
 		/* for logical ports - cache the EDID */
 		if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
-			port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
+			port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
 		break;
 	case DP_PEER_DEVICE_DP_LEGACY_CONV:
 		if (port->ldps)
@@ -4147,7 +4147,7 @@ drm_dp_mst_detect_port(struct drm_connector *connector,
 EXPORT_SYMBOL(drm_dp_mst_detect_port);
 
 /**
- * drm_dp_mst_get_edid() - get EDID for an MST port
+ * drm_dp_mst_edid_read() - get EDID for an MST port
  * @connector: toplevel connector to get EDID for
  * @mgr: manager for this port
  * @port: unverified pointer to a port.
@@ -4156,9 +4156,11 @@ EXPORT_SYMBOL(drm_dp_mst_detect_port);
  * It validates the pointer still exists so the caller doesn't require a
  * reference.
  */
-struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
+					    struct drm_dp_mst_topology_mgr *mgr,
+					    struct drm_dp_mst_port *port)
 {
-	struct edid *edid = NULL;
+	const struct drm_edid *drm_edid;
 
 	/* we need to search for the port in the mgr in case it's gone */
 	port = drm_dp_mst_topology_get_port_validated(mgr, port);
@@ -4166,12 +4168,41 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_
 		return NULL;
 
 	if (port->cached_edid)
-		edid = drm_edid_duplicate(port->cached_edid);
-	else {
-		edid = drm_get_edid(connector, &port->aux.ddc);
-	}
+		drm_edid = drm_edid_dup(port->cached_edid);
+	else
+		drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
 
 	drm_dp_mst_topology_put_port(port);
+
+	return drm_edid;
+}
+EXPORT_SYMBOL(drm_dp_mst_edid_read);
+
+/**
+ * drm_dp_mst_get_edid() - get EDID for an MST port
+ * @connector: toplevel connector to get EDID for
+ * @mgr: manager for this port
+ * @port: unverified pointer to a port.
+ *
+ * This function is deprecated; please use drm_dp_mst_edid_read() instead.
+ *
+ * This returns an EDID for the port connected to a connector,
+ * It validates the pointer still exists so the caller doesn't require a
+ * reference.
+ */
+struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
+				 struct drm_dp_mst_topology_mgr *mgr,
+				 struct drm_dp_mst_port *port)
+{
+	const struct drm_edid *drm_edid;
+	struct edid *edid;
+
+	drm_edid = drm_dp_mst_edid_read(connector, mgr, port);
+
+	edid = drm_edid_duplicate(drm_edid_raw(drm_edid));
+
+	drm_edid_free(drm_edid);
+
 	return edid;
 }
 EXPORT_SYMBOL(drm_dp_mst_get_edid);

include/drm/display/drm_dp_mst_helper.h

@@ -138,7 +138,7 @@ struct drm_dp_mst_port {
 	 * @cached_edid: for DP logical ports - make tiling work by ensuring
 	 * that the EDID for all connectors is read immediately.
 	 */
-	struct edid *cached_edid;
+	const struct drm_edid *cached_edid;
 
 	/**
 	 * @fec_capable: bool indicating if FEC can be supported up to that
@@ -819,7 +819,12 @@ drm_dp_mst_detect_port(struct drm_connector *connector,
 		       struct drm_dp_mst_topology_mgr *mgr,
 		       struct drm_dp_mst_port *port);
 
-struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
+					    struct drm_dp_mst_topology_mgr *mgr,
+					    struct drm_dp_mst_port *port);
+struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
+				 struct drm_dp_mst_topology_mgr *mgr,
+				 struct drm_dp_mst_port *port);
 
 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
 			     int link_rate, int link_lane_count);