spin_lock(&server->req_lock);
if (*credits < num) {
/*
- * Return immediately if not too many requests in flight since
- * we will likely be stuck on waiting for credits.
+ * If the server is tight on resources or just gives us less
+ * credits for other reasons (e.g. requests are coming out of
+ * order and the server delays granting more credits until it
+ * processes a missing mid) and we exhausted most available
+ * credits there may be situations when we try to send
+ * a compound request but we don't have enough credits. At this
+ * point the client needs to decide if it should wait for
+ * additional credits or fail the request. If at least one
+ * request is in flight there is a high probability that the
+ * server will return enough credits to satisfy this compound
+ * request.
+ *
+ * Return immediately if no requests in flight since we will be
+ * stuck on waiting for credits.
*/
- if (server->in_flight < num - *credits) {
+ if (server->in_flight == 0) {
spin_unlock(&server->req_lock);
return -ENOTSUPP;
}