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

This change moves most L2CAP ERTM receive buffer handling out of the
L2CAP core and in to the socket code.  It's up to the higher layer
(the socket code, in this case) to tell the core when its buffer is
full or has space available.  The recv op should always accept
incoming ERTM data or else the connection will go down.

Within the socket layer, an skb that does not fit in the socket
receive buffer will be temporarily stored.  When the socket is read
from, that skb will be placed in the receive buffer if possible.  Once
adequate buffer space becomes available, the L2CAP core is informed
and the ERTM local busy state is cleared.

Receive buffer management for non-ERTM modes is unchanged.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 9c18e555b6ed..66b8d9688d9e 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -422,6 +422,7 @@ struct l2cap_conn {
 struct l2cap_pinfo {
         struct bt_sock  bt;
         struct l2cap_chan       *chan;
+        struct sk_buff  *rx_busy_skb;
 };
 
 enum {
@@ -498,5 +499,6 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason);
 void l2cap_chan_destroy(struct l2cap_chan *chan);
 int l2cap_chan_connect(struct l2cap_chan *chan);
 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len);
+void l2cap_chan_busy(struct l2cap_chan *chan, int busy);
 
 #endif /* __L2CAP_H */