From: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
According to SAE J1939/21 (Chapter 5.12.3 and APPENDIX C), for transmit side
the required time interval between packets of a multipacket broadcast message
is 50 to 200 ms, the responder shall use a timeout of 250ms (provides margin
allowing for the maximumm spacing of 200ms). For receive side a timeout will
occur when a time of greater than 750 ms elapsed between two message packets
when more packets were expected.
So this patch fix and add rxtimer for multipacket broadcast session.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1596599425-5534-5-git-send-email-zhangchangzhong@xxxxxxxxxx
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
net/can/j1939/transport.c | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 047118d5270b..a8dd956b5e8e 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -723,10 +723,12 @@ static int j1939_session_tx_rts(struct j1939_session *session)
return ret;
session->last_txcmd = dat[0];
- if (dat[0] == J1939_TP_CMD_BAM)
+ if (dat[0] == J1939_TP_CMD_BAM) {
j1939_tp_schedule_txtimer(session, 50);
-
- j1939_tp_set_rxtimeout(session, 1250);
+ j1939_tp_set_rxtimeout(session, 250);
+ } else {
+ j1939_tp_set_rxtimeout(session, 1250);
+ }
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
@@ -1687,11 +1689,15 @@ static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
}
session->last_cmd = cmd;
- j1939_tp_set_rxtimeout(session, 1250);
-
- if (cmd != J1939_TP_CMD_BAM && !session->transmission) {
- j1939_session_txtimer_cancel(session);
- j1939_tp_schedule_txtimer(session, 0);
+ if (cmd == J1939_TP_CMD_BAM) {
+ if (!session->transmission)
+ j1939_tp_set_rxtimeout(session, 750);
+ } else {
+ if (!session->transmission) {
+ j1939_session_txtimer_cancel(session);
+ j1939_tp_schedule_txtimer(session, 0);
+ }
+ j1939_tp_set_rxtimeout(session, 1250);
}
j1939_session_put(session);
@@ -1742,6 +1748,7 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
int offset;
int nbytes;
bool final = false;
+ bool remain = false;
bool do_cts_eoma = false;
int packet;
@@ -1817,6 +1824,8 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
j1939_cb_is_broadcast(&session->skcb)) {
if (session->pkt.rx >= session->pkt.total)
final = true;
+ else
+ remain = true;
} else {
/* never final, an EOMA must follow */
if (session->pkt.rx >= session->pkt.last)
@@ -1826,6 +1835,9 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
if (final) {
j1939_session_timers_cancel(session);
j1939_session_completed(session);
+ } else if (remain) {
+ if (!session->transmission)
+ j1939_tp_set_rxtimeout(session, 750);
} else if (do_cts_eoma) {
j1939_tp_set_rxtimeout(session, 1250);
if (!session->transmission)
--
2.28.0
