Since the sendto syscall doesn't have msg_control buffer, the sock_tx_timestamp() in packet_snd() cannot work correctly because the socks.fsflags is set to 0. So, this patch sets the fsflags from sk.sk_tsflags if the msg_control buffer doesn't exist. Fixes: c14ac9451c34 ("sock: enable timestamping using control messages") Cc: <stable@xxxxxxxxxxxxxxx> Reported-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx> Reported-by: Keita Kobayashi <keita.kobayashi.ym@xxxxxxxxxxx> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> --- I'm not sure the network stack world. So, I submit this patch as RFC. This patch looks like a quick hack, but it could resolve an our issue. This issue happens on our platform (r8a7795-salvator-x). The test command is: # ptp4l -i eth0 -p /dev/ptp0 -m -q -f /etc/linuxptp/gPTP.cfg The failure result: ptp4l[26.815]: selected /dev/ptp0 as PTP clock ptp4l[26.872]: port 1: INITIALIZING to LISTENING on INITIALIZE ptp4l[26.872]: port 0: INITIALIZING to LISTENING on INITIALIZE ptp4l[27.873]: timed out while polling for tx timestamp ptp4l[27.873]: increasing tx_timestamp_timeout may correct this issue, but it is likely caused by a driver bug ptp4l[27.873]: port 1: send peer delay request failed ptp4l[27.873]: port 1: LISTENING to FAULTY on FAULT_DETECTED (FT_UNSPECIFIED) The result after the patch is applied (or the c14ac9451c34 is reverted): ptp4l[64.639]: selected /dev/ptp0 as PTP clock ptp4l[64.688]: port 1: INITIALIZING to LISTENING on INITIALIZE ptp4l[64.688]: port 0: INITIALIZING to LISTENING on INITIALIZE ptp4l[71.841]: port 1: LISTENING to MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES ptp4l[71.841]: selected best master clock 2e090a.fffe.00a2df ptp4l[71.841]: assuming the grand master role net/packet/af_packet.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 9f0983f..d76fd41 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2887,6 +2887,11 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) err = sock_cmsg_send(sk, msg, &sockc); if (unlikely(err)) goto out_unlock; + } else { + /* Set tsflags from sk because a syscall (e.g. sendto) doesn't + * have msg_control buffer. + */ + sockc.tsflags = sk->sk_tsflags; } if (sock->type == SOCK_RAW) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html