adding sync method in phosphor-time-manager

[Lei Yu]

On Fri, Apr 9, 2021 at 2:17 AM Alexander Amelkin <a.amelkin at yadro.com> wrote:
>
> Hi Patrick, everybody!
>
> As far as I can see, this discussion has had no development, to our regret.
> We would really like to read some clarification on what is the proposed
> method
> of timekeeping for x86 systems nowadays, because with TimeOwner interface
> removed, it's not clear to me anymore.
>
> Do you allow the users to set time/date on the BMC side? If so, how do you
> propagate those changes on to the host, which in x86 is the owner of RTC?
> What if the BMC is rebooted before the time settings are propagated?
>
> If you don't allow setting the time in BMC, then what are the options
> for the user?
> Do you allow a choice between NTP and Host time only?
>
> How and when is the time synced from the host? Is there a method to
> force a sync?

In our x86 system, what we do is:
1. Sync time during BMC boot from ME;
2. Use NTP in BMC side and never sync time from host (ME) anymore.
3. Ignore time settings from host if there is any.

-- 
BRs,
Lei YU