Ptp4l is too silent when receiving, for whatever reason, out of order
messages. If the reordering is persistent (which is either a broken
network, or a broken kernel), the behavior looks like a complete
synchronization stall, since the application is designed to never
attempt to recover from such a condition.
At least save some people some debugging hours and be loud when the
application reaches this code path.
Signed-off-by: Vladimir Oltean
---
port.c | 21 +
1 file changed, 21 insertions(+)
diff --git a/port.c b/port.c
index 58fbe669af14..58559531f7e7 100644
--- a/port.c
+++ b/port.c
@@ -1191,6 +1191,23 @@ static void port_synchronize(struct port *p,
}
}
+static void port_syfufsm_print_mismatch(struct port *p, enum syfu_event event,
+ struct ptp_message *m)
+{
+ int expected_msgtype;
+
+ if (event == SYNC_MISMATCH)
+ expected_msgtype = FOLLOW_UP;
+ else
+ expected_msgtype = SYNC;
+
+ pr_err("port %hu: have %s %d, expecting %s but got %s %d, dropping",
+ portnum(p), msg_type_string(msg_type(p->last_syncfup)),
+ p->last_syncfup->header.sequenceId,
+ msg_type_string(expected_msgtype),
+ msg_type_string(msg_type(m)), m->header.sequenceId);
+}
+
/*
* Handle out of order packets. The network stack might
* provide the follow up _before_ the sync message. After all,
@@ -1225,6 +1242,7 @@ static void port_syfufsm(struct port *p, enum syfu_event
event,
case SF_HAVE_SYNC:
switch (event) {
case SYNC_MISMATCH:
+ port_syfufsm_print_mismatch(p, event, m);
msg_put(p->last_syncfup);
msg_get(m);
p->last_syncfup = m;
@@ -1232,6 +1250,7 @@ static void port_syfufsm(struct port *p, enum syfu_event
event,
case SYNC_MATCH:
break;
case FUP_MISMATCH:
+ port_syfufsm_print_mismatch(p, event, m);
msg_put(p->last_syncfup);
msg_get(m);
p->last_syncfup = m;
@@ -1252,6 +1271,7 @@ static void port_syfufsm(struct port *p, enum syfu_event
event,
case SF_HAVE_FUP:
switch (event) {
case SYNC_MISMATCH:
+ port_syfufsm_print_mismatch(p, event, m);
msg_put(p->last_syncfup);
msg_get(m);
p->last_syncfup = m;
@@ -1267,6 +1287,7 @@ static void port_syfufsm(struct port *p, enum syfu_event
event,
p->syfu = SF_EMPTY;
break;
case FUP_MISMATCH:
+ port_syfufsm_print_mismatch(p, event, m);
msg_put(p->last_syncfup);
msg_get(m);
p->last_syncfup = m;
--
2.17.1
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