- list_for_each_entry_reverse(cd, path, path_link) {
- if (cd == list_first_entry(path, struct coresight_device,
- path_link)) {
- coresight_disable_sink(cd);
- } else if (list_is_last(&cd->path_link, path)) {
- /*
- * The source has already been stopped, no need
- * to do it again here.
- */
- ;
- } else {
- coresight_disable_link(cd);
+ if (!path)
+ return NULL;
+
+ csdev = list_last_entry(path, struct coresight_node, link)->csdev;
+ if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
+ csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
+ return NULL;
+
+ return csdev;
+}
+
+/**
+ * _coresight_build_path - recursively build a path from a @csdev to a sink.
+ * @csdev: The device to start from.
+ * @path: The list to add devices to.
+ *
+ * The tree of Coresight device is traversed until an activated sink is
+ * found. From there the sink is added to the list along with all the
+ * devices that led to that point - the end result is a list from source
+ * to sink. In that list the source is the first device and the sink the
+ * last one.
+ */
+static int _coresight_build_path(struct coresight_device *csdev,
+ struct list_head *path)
+{
+ int i;
+ bool found = false;
+ struct coresight_node *node;
+ struct coresight_connection *conn;
+
+ /* An activated sink has been found. Enqueue the element */
+ if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+ csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && csdev->activated)
+ goto out;
+
+ /* Not a sink - recursively explore each port found on this element */
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conn = &csdev->conns[i];
+ if (_coresight_build_path(conn->child_dev, path) == 0) {
+ found = true;
+ break;