From 0a0aba42b8daba55e4d2bdfc3c8ca7d7d827b723 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Thu, 17 May 2012 20:53:39 -0700 Subject: [PATCH] Bluetooth: Refactor l2cap_send_ack The function now encapsulates more of the logic to either immediately send an ack if the transmit window is over 75% full, or wait for the ack timer to expire if the transmit window is not full enough. It is also able to push out waiting iframes that can carry an acknowledgement. Signed-off-by: Mat Martineau Signed-off-by: Gustavo Padovan --- net/bluetooth/l2cap_core.c | 60 +++++++++++++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 17 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index d795d15..f4d4eaf 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1772,28 +1772,54 @@ static int l2cap_retransmit_frames(struct l2cap_chan *chan) return ret; } -static void __l2cap_send_ack(struct l2cap_chan *chan) +static void l2cap_send_ack(struct l2cap_chan *chan) { - u32 control = 0; + struct l2cap_ctrl control; + u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq, + chan->last_acked_seq); + int threshold; - control |= __set_reqseq(chan, chan->buffer_seq); + BT_DBG("chan %p last_acked_seq %d buffer_seq %d", + chan, chan->last_acked_seq, chan->buffer_seq); - if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) { - control |= __set_ctrl_super(chan, L2CAP_SUPER_RNR); - set_bit(CONN_RNR_SENT, &chan->conn_state); - return; - } + memset(&control, 0, sizeof(control)); + control.sframe = 1; - if (l2cap_ertm_send(chan) > 0) - return; + if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) && + chan->rx_state == L2CAP_RX_STATE_RECV) { + __clear_ack_timer(chan); + control.super = L2CAP_SUPER_RNR; + control.reqseq = chan->buffer_seq; + l2cap_send_sframe(chan, &control); + } else { + if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) { + l2cap_ertm_send(chan); + /* If any i-frames were sent, they included an ack */ + if (chan->buffer_seq == chan->last_acked_seq) + frames_to_ack = 0; + } - control |= __set_ctrl_super(chan, L2CAP_SUPER_RR); -} + /* Ack now if the tx window is 3/4ths full. + * Calculate without mul or div + */ + threshold = chan->tx_win; + threshold += threshold << 1; + threshold >>= 2; + + BT_DBG("frames_to_ack %d, threshold %d", (int)frames_to_ack, + threshold); + + if (frames_to_ack >= threshold) { + __clear_ack_timer(chan); + control.super = L2CAP_SUPER_RR; + control.reqseq = chan->buffer_seq; + l2cap_send_sframe(chan, &control); + frames_to_ack = 0; + } -static void l2cap_send_ack(struct l2cap_chan *chan) -{ - __clear_ack_timer(chan); - __l2cap_send_ack(chan); + if (frames_to_ack) + __set_ack_timer(chan); + } } static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan, @@ -2539,7 +2565,7 @@ static void l2cap_ack_timeout(struct work_struct *work) l2cap_chan_lock(chan); - __l2cap_send_ack(chan); + l2cap_send_ack(chan); l2cap_chan_unlock(chan); -- 2.7.4