Phonet: restore flow control credits when sending fails

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/phonet/pep.c

@@ -834,6 +834,7 @@ static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 {
 	struct pep_sock *pn = pep_sk(sk);
 	struct pnpipehdr *ph;
+	int err;
 
 	if (pn_flow_safe(pn->tx_fc) &&
 	    !atomic_add_unless(&pn->tx_credits, -1, 0)) {
@@ -852,7 +853,10 @@ static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
 		ph->message_id = PNS_PIPE_DATA;
 	ph->pipe_handle = pn->pipe_handle;
 
-	return pn_skb_send(sk, skb, &pipe_srv);
+	err = pn_skb_send(sk, skb, &pipe_srv);
+	if (err && pn_flow_safe(pn->tx_fc))
+		atomic_inc(&pn->tx_credits);
+	return err;
 }
 
 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,