Re: [RFC] watchdog: renesas_wdt: don't keep timer value during suspend/resume

[Wolfram Sang <wsa@xxxxxxxxxxxxx>]

Hi Guenter, all,

> > After discussing this mail thread [1] again, we concluded that giving
> > userspace enough time to prepare is our favourite option. So, do not
> > keep the time value when suspended but reset it when resuming.
> > 
> > [1] https://patchwork.kernel.org/patch/10252209/
> > 
> > Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> 
> Above exchange says it all, no need to repeat.
> 
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Thanks.

I can relate to the policy argument, though. Regardless of this patch, I
wonder if we can make it configurable from userspace. A draft:

#define	WDIOF_RESUME_OPTS	0x0800

#define	WDIOS_RESUME_KEEP	0x0008
#define	WDIOS_RESUME_RESET	0x0010

and then in watchdog_ioctl() under WDIOC_SETOPTIONS:

	if (!(wdd->info->options & WDIOF_RESUME_OPTS))
		err = -EOPNOTSUPP;
		goto break;

	if (val & WDIOS_RESUME_KEEP)
		wdd->status |= WDOG_KEEP_TIMER_WHEN_RESUME;

	if (val & WDIOS_RESUME_RESET)
		wdd->status ~= ~WDOG_KEEP_TIMER_WHEN_RESUME;

So, drivers with WDIOF_RESUME_OPTS could act on the
WDOG_KEEP_TIMER_WHEN_RESUME flag.

Opinions?

Thanks,

   Wolfram