Re: [PATCH v3 2/3] docs: watchdog: npcm: Add reset status description

Hi,

On Sun, 5 Jul 2026 at 17:06, <[email protected]> wrote:
>
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] The watchdog driver abuses standard Watchdog UAPI constants to report non-watchdog platform reset causes, violating the userspace ABI contract.
> --
>
> commit 72fd6c8b87d96376853f3dcd5ef1597495cf9817
> Author: Tomer Maimon <[email protected]>
>
> docs: watchdog: npcm: Add reset status description
>
> Add documentation describing how the NPCM watchdog driver reports reset
> causes through bootstatus on NPCM750 and NPCM845 systems.
>
> > diff --git a/Documentation/watchdog/npcm_wdt.rst b/Documentation/watchdog/npcm_wdt.rst
> > new file mode 100644
> > index 0000000000000..cdc45ade9e0d9
> > --- /dev/null
> > +++ b/Documentation/watchdog/npcm_wdt.rst
>
> [ ... ]
>
> > +.. list-table:: Reset-cause mapping
> > +   :header-rows: 1
> > +
> > +   * - Platform
> > +     - Reset indication
> > +     - Bootstatus flag
> > +     - Reported meaning
> > +   * - NPCM750 and NPCM845
> > +     - ``PORST``
> > +     - ``WDIOF_OVERHEAT``
> > +     - power-on reset
> > +   * - NPCM750 and NPCM845
> > +     - ``CORST``
> > +     - ``WDIOF_FANFAULT``
> > +     - core reset
>
> [Severity: High]
> Is it correct to map generic Watchdog UAPI thermal and fan failure flags to
> standard platform reset indications?
>
Yes, it is something that was already discussed with the WD
maintainer; This is why it is mentioned in the rst document
> The generic Watchdog API defines strict semantics for its status flags.
> For instance, WDIOF_OVERHEAT means a reset due to CPU overheat, and
> WDIOF_FANFAULT means a fan failed. By mapping standard SoC reset causes like
> Power-On Reset (PORST) to WDIOF_OVERHEAT and Core Reset (CORST) to
> WDIOF_FANFAULT, might this break the userspace ABI contract?
>
> During a normal cold boot, reading the SoC latch would unconditionally expose
> this to userspace via the WDIOC_GETBOOTSTATUS ioctl or sysfs. Standard
> userspace monitoring daemons (like systemd or wdctl) reading bootstatus
> might erroneously conclude the system suffered a thermal event or fan failure,
> potentially triggering unintended emergency actions or false alarms.
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2

Thanks,

Tomer