Return-Path: From: Mat Martineau To: linux-bluetooth@vger.kernel.org, gustavo@padovan.org Cc: sunnyk@codeaurora.org, marcel@holtmann.org, andrei.emeltchenko.news@gmail.com Subject: [PATCHv4 15/18] Bluetooth: Configure appropriate timeouts for AMP controllers Date: Fri, 19 Oct 2012 14:34:06 -0700 Message-Id: <1350682449-24818-16-git-send-email-mathewm@codeaurora.org> In-Reply-To: <1350682449-24818-1-git-send-email-mathewm@codeaurora.org> References: <1350682449-24818-1-git-send-email-mathewm@codeaurora.org> List-ID: The L2CAP spec recommends specific retransmit and monitor timeouts for ERTM channels that are on AMP controllers. These timeouts are calculated from the AMP controller's best effort flush timeout. BR/EDR controllers use the default retransmit and monitor timeouts. Signed-off-by: Mat Martineau Acked-by: Marcel Holtmann --- net/bluetooth/l2cap_core.c | 47 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 4995462..2d3fc42 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2980,6 +2980,44 @@ static inline bool __l2cap_efs_supported(struct l2cap_chan *chan) return enable_hs && chan->conn->feat_mask & L2CAP_FEAT_EXT_FLOW; } +static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan, + struct l2cap_conf_rfc *rfc) +{ + if (chan->local_amp_id && chan->hs_hcon) { + u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to; + + /* Class 1 devices have must have ERTM timeouts + * exceeding the Link Supervision Timeout. The + * default Link Supervision Timeout for AMP + * controllers is 10 seconds. + * + * Class 1 devices use 0xffffffff for their + * best-effort flush timeout, so the clamping logic + * will result in a timeout that meets the above + * requirement. ERTM timeouts are 16-bit values, so + * the maximum timeout is 65.535 seconds. + */ + + /* Convert timeout to milliseconds and round */ + ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000); + + /* This is the recommended formula for class 2 devices + * that start ERTM timers when packets are sent to the + * controller. + */ + ertm_to = 3 * ertm_to + 500; + + if (ertm_to > 0xffff) + ertm_to = 0xffff; + + rfc->retrans_timeout = cpu_to_le16((u16) ertm_to); + rfc->monitor_timeout = rfc->retrans_timeout; + } else { + rfc->retrans_timeout = __constant_cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO); + rfc->monitor_timeout = __constant_cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO); + } +} + static inline void l2cap_txwin_setup(struct l2cap_chan *chan) { if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW && @@ -3046,8 +3084,8 @@ done: case L2CAP_MODE_ERTM: rfc.mode = L2CAP_MODE_ERTM; rfc.max_transmit = chan->max_tx; - rfc.retrans_timeout = 0; - rfc.monitor_timeout = 0; + + __l2cap_set_ertm_timeouts(chan, &rfc); size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu - L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE - @@ -3275,10 +3313,7 @@ done: rfc.max_pdu_size = cpu_to_le16(size); chan->remote_mps = size; - rfc.retrans_timeout = - __constant_cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO); - rfc.monitor_timeout = - __constant_cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO); + __l2cap_set_ertm_timeouts(chan, &rfc); set_bit(CONF_MODE_DONE, &chan->conf_state); -- 1.7.12.3 -- Mat Martineau Employee of Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation