On Wed, Sep 13, 2023 at 05:09:04PM +0000, Maciek Machnikowski wrote:
> Implement auto mode for frequency setting. In this mode the tool
> will measure the frequency difference between PHC and CLOCK_REALTIME
> and apply the correction to the PHC to match the system clock.

...

> +             /* Try sysoff first */
> +             method = sysoff_probe(fd, N_SAMPLES);
> +             if (method >= 0) {
> +                     if (sysoff_measure(fd, method, N_SAMPLES,
> +                                        &t1_sys_offset,
> +                                        &t1_sys_ts, &t1_delay)) {
> +                             return -1;
> +                     }
> +
> +                     sleep(1);

This measurement interval is WAY too short.  The time stamp error will
spoil the syntonization.
 
> +                     if (sysoff_measure(fd, method, N_SAMPLES,
> +                                        &t2_sys_offset,
> +                                        &t2_sys_ts, &t2_delay)) {
> +                             return -1;
> +                    }
> +
> +                     sys_diff = t2_sys_ts - t1_sys_ts;
> +                     clk_diff = t2_sys_offset - t1_sys_offset;
> +                     ppb += (1e9 - ppb) * ((double)clk_diff / 
> (double)sys_diff);

Thanks,
Richard


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