[systemd-devel] systemd-shutdown disarms hardware watchdog when finished

[Luca Boccassi]

On Wed, 29 May 2024 at 11:01, Andreas Svensson
<andreas.svensson at axis.com> wrote:
>
> Hello,
>
> I have a system that should keep the hardware watchdog active while
> rebooting the system. It has worked fine up to systemd version v254.
>
> I noticed that since systemd version v254 my system stops the hardware
> watchdog after systemd-shutdown completes. I think it's the
> watchdog_free_device function that's responsible.
>
> The watchdog_free_device function will call watchdog_set_device(NULL)
> from watchdog.h. Since commit f81048f8 the watchdog will be disarmed and
> stopped if changed in watchdog_set_device.
>
> There's a comment just above watchdog_free_device in shutdown.c that
> contradicts what's actually happening right now: "Note that the watchdog
> is explicitly not stopped here".
>
> Is this the intended behavior? Anything I can do to get my system back
> to its behavior before version v254 where my hardware watchdog is still
> active/running after systemd-shutdown has finished?

Use the Reboot/KexecWatchdog settings:
https://www.freedesktop.org/software/systemd/man/latest/systemd-system.conf.html#RuntimeWatchdogSec=