[LinuxPPS] PPS/ntpd fails on fresh startup

[Cirilo Bernardo]

On Wed, Oct 15, 2008 at 9:14 PM, Luca Bertagnolio <time at berta.com> wrote:
> On Wed, Oct 15, 2008 at 12:08 PM, Rodolfo Giometti
> <giometti at enneenne.com> wrote:
>> Luca, what exactly the refclock_open() does with such parameter? And
>> how it is defined inside the code?
>
> there you go:
>
[snip]
>        fd = open(dev, omode, 0777);
>        if (fd < 0) {
>                msyslog(LOG_ERR, "refclock_open %s: %m", dev);
>                return (0);
>        }
>        if (!refclock_setup(fd, speed, lflags)) {
>                close(fd);
>                return (0);
>        }
>        if (!refclock_ioctl(fd, lflags)) {
>                close(fd);
>                return (0);
>        }
[snip]
>
> refclock_ioctl is defined as such:
>
[snip]
> #if !defined SYS_VXWORKS && !defined SYS_WINNT
> #if defined(HAVE_TERMIOS) || defined(HAVE_SYSV_TTYS) || defined(HAVE_BSD_TTYS)
>
> #ifdef DEBUG
>        if (debug)
>                printf("refclock_ioctl: fd %d flags 0x%x\n", fd,
>                    lflags);
> #endif
> #ifdef TTYCLK
>
>        /*
>         * The TTYCLK option provides timestamping at the driver level.
>         * It requires the tty_clk streams module and System V STREAMS
>         * support. If not available, don't complain.
>         */
>        if (lflags & (LDISC_CLK | LDISC_CLKPPS | LDISC_ACTS)) {
>                int rval = 0;
>
>                if (ioctl(fd, I_PUSH, "clk") < 0) {
>                        msyslog(LOG_NOTICE,
>                            "refclock_ioctl fd %d I_PUSH: %m", fd);
>                        return (0);
> #ifdef CLK_SETSTR
>                } else {
>                        char *str;
>
>                        if (lflags & LDISC_CLKPPS)
>                                str = "\377";
>                        else if (lflags & LDISC_ACTS)
>                                str = "*";
>                        else
>                                str = "\n";
>                        if (ioctl(fd, CLK_SETSTR, str) < 0) {
>                                msyslog(LOG_ERR,
>                                    "refclock_ioctl fd %d CLK_SETSTR: %m", fd);
>                                return (0);
>                        }
> #endif /*CLK_SETSTR */
>                }
>        }
> #endif /* TTYCLK */
> #endif /* HAVE_TERMIOS || HAVE_SYSV_TTYS || HAVE_BSD_TTYS */
> #endif /* SYS_VXWORKS SYS_WINNT */
>        return (1);
> }
>
> and this is there is some reference to LDISC flags and their use in
> the true ioctl.
>
> HTH  --L
>

Well, you can see that if debugging is enabled, you should be able to
see in the ntpd log if the ldisc is changed.

- Cirilo