On 12/7/18 1:45 PM, Wolfram Sang wrote:
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+rene...@sang-engineering.com>

Above exchange says it all, no need to repeat.

Reviewed-by: Guenter Roeck <li...@roeck-us.net>

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?


Not entirely sure I understand the use case.

Having said that, if we were to add this option, I think only a single
flag would be needed - WDIOF_RESUME_KEEP. All we need to do is declare
that a ping on resume shall be the default. Anything else would result
in undefined per-driver default behavior.

Guenter

Reply via email to