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+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?
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
