Return-Path: Date: Fri, 18 May 2012 16:54:22 -0300 From: Gustavo Padovan To: Mat Martineau Cc: linux-bluetooth@vger.kernel.org, marcel@holtmann.org, ulisses@profusion.mobi, pkrystad@codeaurora.org Subject: Re: [PATCH 02/25] Bluetooth: Add a new L2CAP ERTM transmit state machine. Message-ID: <20120518195422.GA16942@joana> References: <1337313235-26535-1-git-send-email-mathewm@codeaurora.org> <1337313235-26535-3-git-send-email-mathewm@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1337313235-26535-3-git-send-email-mathewm@codeaurora.org> List-ID: Hi Mat, * Mat Martineau [2012-05-17 20:53:32 -0700]: > This implements a top-level transmit state machine with handlers for > the two ERTM states defined in the specification: XMIT and WAIT_F. > > The state machine accepts an event and, optionally, a list of skbs to > transmit. In addition to data transmission, the local busy state can > be modified, acks are processed, and monitor and retransmit timeouts > are handled. This mirrors the structure of the state tables in the > spec. > > Signed-off-by: Mat Martineau > --- > net/bluetooth/l2cap_core.c | 254 ++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 246 insertions(+), 8 deletions(-) > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > index 6557367..a131403 100644 > --- a/net/bluetooth/l2cap_core.c > +++ b/net/bluetooth/l2cap_core.c > @@ -73,6 +73,9 @@ static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data); > static void l2cap_send_disconn_req(struct l2cap_conn *conn, > struct l2cap_chan *chan, int err); > > +static int l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control, > + struct sk_buff_head *skbs, u8 event); > + > /* ---- L2CAP channels ---- */ > > static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid) > @@ -224,6 +227,19 @@ static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err) > release_sock(sk); > } > > +static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head, > + u16 seq) > +{ > + struct sk_buff *skb; > + > + skb_queue_walk(head, skb) { > + if (bt_cb(skb)->control.txseq == seq) > + return skb; > + } > + > + return NULL; > +} > + > /* ---- L2CAP sequence number lists ---- */ > > /* For ERTM, ordered lists of sequence numbers must be tracked for > @@ -2117,16 +2133,15 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, > if (err) > break; > > - if (chan->mode == L2CAP_MODE_ERTM && chan->tx_send_head == NULL) > - chan->tx_send_head = seg_queue.next; > - skb_queue_splice_tail_init(&seg_queue, &chan->tx_q); > - > - if (chan->mode == L2CAP_MODE_ERTM) > - err = l2cap_ertm_send(chan); > - else > + if (chan->mode == L2CAP_MODE_ERTM) { > + err = l2cap_tx(chan, 0, &seg_queue, > + L2CAP_EV_DATA_REQUEST); > + } else { > + skb_queue_splice_tail_init(&seg_queue, &chan->tx_q); > l2cap_streaming_send(chan); > + } > > - if (err >= 0) > + if (!err) > err = len; > > /* If the skbs were not queued for sending, they'll still be in > @@ -2143,6 +2158,229 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, > return err; > } > > +static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq) > +{ > + struct sk_buff *acked_skb; > + u16 ackseq; > + > + BT_DBG("chan %p, reqseq %d", chan, reqseq); > + > + if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq) > + return; > + > + BT_DBG("expected_ack_seq %d, unacked_frames %d", > + chan->expected_ack_seq, chan->unacked_frames); > + > + for (ackseq = chan->expected_ack_seq; ackseq != reqseq; > + ackseq = __next_seq(chan, ackseq)) { > + > + acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq); > + if (acked_skb) { > + skb_unlink(acked_skb, &chan->tx_q); > + kfree_skb(acked_skb); > + chan->unacked_frames--; > + } > + } > + > + chan->expected_ack_seq = reqseq; > + > + if (chan->unacked_frames == 0) > + __clear_retrans_timer(chan); > + > + BT_DBG("unacked_frames %d", (int) chan->unacked_frames); > +} > + > +static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan) > +{ > + BT_DBG("chan %p", chan); > + > + chan->expected_tx_seq = chan->buffer_seq; > + l2cap_seq_list_clear(&chan->srej_list); > + skb_queue_purge(&chan->srej_q); > + chan->rx_state = L2CAP_RX_STATE_RECV; > +} > + > +static int l2cap_tx_state_xmit(struct l2cap_chan *chan, > + struct l2cap_ctrl *control, > + struct sk_buff_head *skbs, u8 event) > +{ > + int err = 0; > + > + BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs, > + event); > + > + switch (event) { > + case L2CAP_EV_DATA_REQUEST: > + if (chan->tx_send_head == NULL) > + chan->tx_send_head = skb_peek(skbs); > + > + skb_queue_splice_tail_init(skbs, &chan->tx_q); > + l2cap_ertm_send(chan); > + break; > + case L2CAP_EV_LOCAL_BUSY_DETECTED: > + BT_DBG("Enter LOCAL_BUSY"); > + set_bit(CONN_LOCAL_BUSY, &chan->conn_state); > + > + if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) { > + /* The SREJ_SENT state must be aborted if we are to > + * enter the LOCAL_BUSY state. > + */ > + l2cap_abort_rx_srej_sent(chan); > + } > + > + l2cap_send_ack(chan); > + > + break; > + case L2CAP_EV_LOCAL_BUSY_CLEAR: > + BT_DBG("Exit LOCAL_BUSY"); > + clear_bit(CONN_LOCAL_BUSY, &chan->conn_state); > + > + if (test_bit(CONN_RNR_SENT, &chan->conn_state)) { > + struct l2cap_ctrl local_control; > + > + memset(&local_control, 0, sizeof(local_control)); > + local_control.sframe = 1; > + local_control.super = L2CAP_SUPER_RR; > + local_control.poll = 1; > + local_control.reqseq = chan->buffer_seq; You are not using local_control anywhere? Should it be removed, or other patch in this patchset uses it? Gustavo