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 <mathewm@xxxxxxxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 68 ++++++++++++++++++++++++++++++--------------
1 file changed, 47 insertions(+), 21 deletions(-)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index ce8bffd..9c3f51c 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1769,28 +1769,54 @@ static int l2cap_retransmit_frames(struct l2cap_chan *chan)
return ret;
}
-static void __l2cap_send_ack(struct l2cap_chan *chan)
-{
- u32 control = 0;
-
- control |= __set_reqseq(chan, 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;
- }
-
- if (l2cap_ertm_send(chan) > 0)
- return;
-
- control |= __set_ctrl_super(chan, L2CAP_SUPER_RR);
-}
-
static void l2cap_send_ack(struct l2cap_chan *chan)
{
- __clear_ack_timer(chan);
- __l2cap_send_ack(chan);
+ struct l2cap_ctrl control;
+ u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
+ chan->last_acked_seq);
+ int threshold;
+
+ BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
+ chan, chan->last_acked_seq, chan->buffer_seq);
+
+ memset(&control, 0, sizeof(control));
+ control.sframe = 1;
+
+ 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;
+ }
+
+ /* 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;
+ }
+
+ if (frames_to_ack)
+ __set_ack_timer(chan);
+ }
}
static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
@@ -2536,7 +2562,7 @@ 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);
--
1.7.10
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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