wrs-socket: retry getting a tx_timestamp on failure

Sometimes we get error in the recv(MSGQUEUE), with EAGAIN. Likely we got a real frame (so poll for reading is ok) but no stamp yet. This unsynced the transmitted frames and the error queue. This fix, i.e. retry if getting nothing, seems to fix the (rare) problem. Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

wrs-socket: retry getting a tx_timestamp on failure
Sometimes we get error in the recv(MSGQUEUE), with EAGAIN. Likely we got a real frame (so poll for reading is ok) but no stamp yet. This unsynced the transmitted frames and the error queue. This fix, i.e. retry if getting nothing, seems to fix the (rare) problem. Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
f47f5656 · Alessandro Rubini · 6cdecd8b · f47f5656
Commit f47f5656 authored Jul 20, 2015 by Alessandro Rubini
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wrs-socket.c time-wrs/wrs-socket.c +3 -1

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--- a/time-wrs/wrs-socket.c
+++ b/time-wrs/wrs-socket.c
@@ -375,7 +375,9 @@ static void poll_tx_timestamp(struct pp_instance *ppi, void *pkt, int len,
 		if (res != 1) {
 			pp_diag(ppi, time, 1, "%s: poll() = %i (%s)\n",
 				__func__, res, strerror(errno));
-			return;
+			if (retry++ > 5)
+				return;
+			continue;
 		}

 		res = recvmsg(fd, &msg, MSG_ERRQUEUE);