[PATCH] watchdog: sunplus: fix sp_wdt_restart spin loop and timeout

[Guenter Roeck]

On Thu, Aug 20, 2026 at 05:12:11PM +0200, Andrew Gaylard wrote:
> Guenter Roeck <linux at roeck-us.net> writes:
> 
> > On Thu, Aug 20, 2026 at 02:53:04PM +0200, Andrew Gaylard wrote:
> >> sp_wdt_restart() returns immediately after writing WDT_RESUME. The
> >> kernel continues executing and the watchdog kthread could pet the
> >> watchdog before the short timeout expired, preventing reset.
> >
> > Is this observed behavior or just an assumption ?
> 
> It's an assumption.
> 
So you habve no idea if this is a real problem. I am not going to apply
this patch.

Guenter

> >> Add a spin loop so no other CPU can pet the watchdog while waiting for
> >> the reset. Set the restart timeout to ~1.5s.
> >
> > I understand the first part, but why delay the reset by 1.5s ?
> > That is a functional change which needs an explanation.
> 
> I had a printf there to confirm that it actually reached that point,
> so I needed the delay.
> 
> -- 
> Andrew
>