Set the timer only when an event causes the port to transition to the
FAULTY state, rather than potentially re-arming the timeout when an
event occurs while the port was already FAULTY.
Concretely this occurs when a port is in fault, perhaps due to a
single time out while polling for tx-timestamp. If any other port in the
system (including unrelated ones ptp4l does not even know about) cause
netlink messages to be sent. As it stands, clock_poll() will note that
the port is in fault (from before, not due to the current event) and
reset the timeout to its original value.
If such unrelated netlink messages arrive at a regular enough cadence
the timeout may be repeatedly reset, not trigger on time (if at all) and
the port may not get a chance to clear its fault, perhaps indefinitely.
Signed-off-by: David Mirabito <davi...@arista.com>
---
Change since V1:
* no change to patch contents
* hopefully the commit message is clearer.
clock.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/clock.c b/clock.c
index d37bb87..2d57a33 100644
--- a/clock.c
+++ b/clock.c
@@ -1595,6 +1595,7 @@ void clock_set_sde(struct clock *c, int sde)
int clock_poll(struct clock *c)
{
int cnt, i;
+ enum port_state prior_state;
enum fsm_event event;
struct pollfd *cur;
struct port *p;
@@ -1618,6 +1619,7 @@ int clock_poll(struct clock *c)
/* Let the ports handle their events. */
for (i = 0; i < N_POLLFD; i++) {
if (cur[i].revents & (POLLIN|POLLPRI|POLLERR)) {
+ prior_state = port_state(p);
if (cur[i].revents & POLLERR) {
pr_err("%s: unexpected socket error",
port_log_name(p));
@@ -1633,7 +1635,7 @@ int clock_poll(struct clock *c)
}
port_dispatch(p, event, 0);
/* Clear any fault after a little while. */
- if (PS_FAULTY == port_state(p)) {
+ if ((PS_FAULTY == port_state(p)) &&
(prior_state != PS_FAULTY)) {
clock_fault_timeout(p, 1);
break;
}
--
2.38.0
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