Hi Mike, * Mike Tsai <Mike.Tsai@xxxxxxxxxxx> [2010-03-17 14:47:49 -0700]: > Just out of curiosity, where does this (pi->txWindow/6 + 1) come from? L2CAP spec says that we don't need to ack every packet received, so I have choose this number for optimization to not send an ack for each packet received. We can do a study and choose the better value for this, but it's better to have the Extended Tx Window Implemented. > > Thanks, > > Mike > > > -----Original Message----- > From: linux-bluetooth-owner@xxxxxxxxxxxxxxx [mailto:linux-bluetooth-owner@xxxxxxxxxxxxxxx] On Behalf Of Gustavo F. Padovan > Sent: Wednesday, March 17, 2010 11:54 AM > To: linux-bluetooth@xxxxxxxxxxxxxxx > Cc: marcel@xxxxxxxxxxxx; gustavo@xxxxxxxxxxx; mathewm@xxxxxxxxxxxxxx > Subject: [PATCH 2/4] Bluetooth: Change acknowledgement to use the value of txWindow > > Now that we can set the txWindow we need to change the acknowledgement > procedure to ack after each (pi->txWindow/6 + 1). The plus 1 is to avoid > the zero value. > It also renames pi->num_to_ack to a better name: pi->num_acked. > > Signed-off-by: Gustavo F. Padovan <gustavo@xxxxxxxxxxx> > --- > include/net/bluetooth/l2cap.h | 3 +-- > net/bluetooth/l2cap.c | 9 +++++---- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h > index c7bf676..9358b9e 100644 > --- a/include/net/bluetooth/l2cap.h > +++ b/include/net/bluetooth/l2cap.h > @@ -30,7 +30,6 @@ > #define L2CAP_DEFAULT_MIN_MTU 48 > #define L2CAP_DEFAULT_FLUSH_TO 0xffff > #define L2CAP_DEFAULT_TX_WINDOW 63 > -#define L2CAP_DEFAULT_NUM_TO_ACK (L2CAP_DEFAULT_TX_WINDOW/5) > #define L2CAP_DEFAULT_MAX_TX 3 > #define L2CAP_DEFAULT_RETRANS_TO 1000 /* 1 second */ > #define L2CAP_DEFAULT_MONITOR_TO 12000 /* 12 seconds */ > @@ -333,7 +332,7 @@ struct l2cap_pinfo { > __u8 frames_sent; > __u8 unacked_frames; > __u8 retry_count; > - __u8 num_to_ack; > + __u8 num_acked; > __u16 sdu_len; > __u16 partial_sdu_len; > struct sk_buff *sdu; > diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c > index 6679418..959be0f 100644 > --- a/net/bluetooth/l2cap.c > +++ b/net/bluetooth/l2cap.c > @@ -2248,7 +2248,7 @@ static inline void l2cap_ertm_init(struct sock *sk) > l2cap_pi(sk)->expected_ack_seq = 0; > l2cap_pi(sk)->unacked_frames = 0; > l2cap_pi(sk)->buffer_seq = 0; > - l2cap_pi(sk)->num_to_ack = 0; > + l2cap_pi(sk)->num_acked = 0; > l2cap_pi(sk)->frames_sent = 0; > > setup_timer(&l2cap_pi(sk)->retrans_timer, > @@ -2571,7 +2571,7 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data, > if (*result == L2CAP_CONF_SUCCESS) { > switch (rfc.mode) { > case L2CAP_MODE_ERTM: > - pi->remote_tx_win = rfc.txwin_size; > + pi->tx_win = rfc.txwin_size; > pi->retrans_timeout = rfc.retrans_timeout; > pi->monitor_timeout = rfc.monitor_timeout; > pi->max_pdu_size = le16_to_cpu(rfc.max_pdu_size); > @@ -3408,6 +3408,7 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str > u8 tx_seq = __get_txseq(rx_control); > u8 req_seq = __get_reqseq(rx_control); > u8 sar = rx_control >> L2CAP_CTRL_SAR_SHIFT; > + int num_to_ack = (pi->tx_win/6) + 1; > int err = 0; > > BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len); > @@ -3501,8 +3502,8 @@ expected: > > __mod_ack_timer(); > > - pi->num_to_ack = (pi->num_to_ack + 1) % L2CAP_DEFAULT_NUM_TO_ACK; > - if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1) > + pi->num_acked = (pi->num_acked + 1) % num_to_ack; > + if (pi->num_acked == num_to_ack - 1) > l2cap_send_ack(pi); > > return 0; > -- > 1.6.4.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gustavo F. Padovan http://padovan.org -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
