Bluetooth: Use event-driven approach for handling ERTM receive buffer

[pandora-kernel.git] / net / bluetooth / l2cap_sock.c

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 39082d4..146b614 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -711,13 +711,15 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
 static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags)
 {
        struct sock *sk = sock->sk;
+       struct l2cap_pinfo *pi = l2cap_pi(sk);
+       int err;
 
        lock_sock(sk);
 
        if (sk->sk_state == BT_CONNECT2 && bt_sk(sk)->defer_setup) {
                sk->sk_state = BT_CONFIG;
 
-               __l2cap_connect_rsp_defer(l2cap_pi(sk)->chan);
+               __l2cap_connect_rsp_defer(pi->chan);
                release_sock(sk);
                return 0;
        }
@@ -725,9 +727,37 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
        release_sock(sk);
 
        if (sock->type == SOCK_STREAM)
-               return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+               err = bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+       else
+               err = bt_sock_recvmsg(iocb, sock, msg, len, flags);
+
+       if (pi->chan->mode != L2CAP_MODE_ERTM)
+               return err;
+
+       /* Attempt to put pending rx data in the socket buffer */
+
+       lock_sock(sk);
+
+       if (!test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state))
+               goto done;
+
+       if (pi->rx_busy_skb) {
+               if (!sock_queue_rcv_skb(sk, pi->rx_busy_skb))
+                       pi->rx_busy_skb = NULL;
+               else
+                       goto done;
+       }
 
-       return bt_sock_recvmsg(iocb, sock, msg, len, flags);
+       /* Restore data flow when half of the receive buffer is
+        * available.  This avoids resending large numbers of
+        * frames.
+        */
+       if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
+               l2cap_chan_busy(pi->chan, 0);
+
+done:
+       release_sock(sk);
+       return err;
 }
 
 /* Kill socket (only if zapped and orphan)
@@ -811,9 +841,31 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(void *data)
 
 static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 {
+       int err;
        struct sock *sk = data;
+       struct l2cap_pinfo *pi = l2cap_pi(sk);
 
-       return sock_queue_rcv_skb(sk, skb);
+       if (pi->rx_busy_skb)
+               return -ENOMEM;
+
+       err = sock_queue_rcv_skb(sk, skb);
+
+       /* For ERTM, handle one skb that doesn't fit into the recv
+        * buffer.  This is important to do because the data frames
+        * have already been acked, so the skb cannot be discarded.
+        *
+        * Notify the l2cap core that the buffer is full, so the
+        * LOCAL_BUSY state is entered and no more frames are
+        * acked and reassembled until there is buffer space
+        * available.
+        */
+       if (err < 0 && pi->chan->mode == L2CAP_MODE_ERTM) {
+               pi->rx_busy_skb = skb;
+               l2cap_chan_busy(pi->chan, 1);
+               err = 0;
+       }
+
+       return err;
 }
 
 static void l2cap_sock_close_cb(void *data)
@@ -842,6 +894,11 @@ static void l2cap_sock_destruct(struct sock *sk)
 {
        BT_DBG("sk %p", sk);
 
+       if (l2cap_pi(sk)->rx_busy_skb) {
+               kfree_skb(l2cap_pi(sk)->rx_busy_skb);
+               l2cap_pi(sk)->rx_busy_skb = NULL;
+       }
+
        skb_queue_purge(&sk->sk_receive_queue);
        skb_queue_purge(&sk->sk_write_queue);
 }