linux-kernel - [bugreport] "hwclock -w" reset time instead of setting the right time

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Date:   Thu, 2 Jan 2020 13:08:41 +0500
From:   Mikhail Gavrilov <mikhail.v.gavrilov@...il.com>
To:     util-linux@...r.kernel.org,
        Linux List Kernel Mailing <linux-kernel@...r.kernel.org>
Cc:     linux-ext4@...r.kernel.org
Subject: [bugreport] "hwclock -w" reset time instead of setting the right time

"hwclock -w" reset time instead of setting the right time on M/B "ROG
Strix X570-I Gaming"
Demonstration: https://youtu.be/QRB7ZLiEfrc
Some DE like GNOME has automatic time synchronization option and there
is a feeling that hardware time reset after each Linux boot.

--
Best Regards,
Mike Gavrilov.
On Thu, 2 Jan 2020 at 04:19, Mikhail Gavrilov
<mikhail.v.gavrilov@...il.com> wrote:
>
> On Wed, 1 Jan 2020 at 19:17, Theodore Y. Ts'o <tytso@....edu> wrote:
> >
> > The problem is casued by the fact that the mount time is incorrect,
> > which indicates that the system time was incorrect at the time when
> > the file system was mounted and when it fsck was run.  Since the last
> > write time was in the future, this triggered "time is insane" check.
> >
> > This is inconsistent with your report that started happening when you
> > switched to a new motherboard.  That's because the real time clock is
> > not reporting the correct time when the system is booted.  Later on,
> > in the boot cycle, after the root file system is checked and remounted
> > read-write, the system time is getting set from an internet time
> > server.  This then causes the last write time to be ahead of the last
> > mount time, and "in the future" with respect to the real time clock.
> >
> > Normally, the hardware clock's time gets set to match system time when
> > it is set from network time, or when the system is getting shut down
> > cleanly, but your init scripts aren't doing this properly --- or you
> > normally shut down your system by just flipping the power switch, and
> > not letting the shutdown sequence run correctly.  The other possibilty
> > is the real time clock on your system is just completly busted
> > (although normally when that happens, the last mount time would be in
> > the 1970's.)
> >
> > Running "/sbin/hwclock -w" as root may fix things; as is figuring out
> > why this isn't run automatically by your boot scripts.  Another
> > workaround is to add to /etc/e2fsck.conf the following:
> >
> > [options]
> >         broken_system_lock = true
> >
> > This will disable e2fsck's time checks.
> >
>
> Thank you very much for the tip, I would never have guessed that the
> cause of this issue in hwclock.
> I started to watch hwclock through the motherboard BIOS and found that
> hwclock resets every time after booting Linux.
> Demonstration: https://youtu.be/TBrLNFbBaPo
> Apparently for this reason, "hwclock -w" did not help me, workaround
> with "broken_system_clock = true" is working, but I would like to fix
> the root of the cause.
> Who can help with this?
>