[PATCH v2 8/8] board: ns3: start sp805 watchdog service

[Rayagonda Kokatanur]

On Mon, Jun 22, 2020 at 3:08 PM Stefan Roese <sr at denx.de> wrote:
>
> On 22.06.20 11:33, Rayagonda Kokatanur wrote:
>
> <snip>
>
> >>>>>> Sure it takes time to update images. But all this should be possible
> >>>>>> with an actively serviced watchdog while still running in U-Boot.
> >>>>>> This is why we have all these WATCHDOG_RESET() calls sprinkled all over
> >>>>>> the system. If some code paths are missing such WDT triggering, then we
> >>>>>> should find and fix them.
> >>>>>
> >>>>> One more issue we are facing is,
> >>>>
> >>>> So did you work on fixing some of he missing WDT trigger calls?
> >>>
> >>> No, this issue we used to face before this patch.
> >>>
> >>> So you are suggesting to use WATCHDOF_RESET instead of stopping and
> >>> starting the wdt.
> >>> WATCHDOG_RESET will take care of resetting wdt in uboot.
> >>
> >> Yes.
> > Thank you.
> >
> >>
> >>> And it won't
> >>> lead to system reboot while running any test (ex-i2c read/write test)
> >>> in uboot or debugging any issue in uboot ?
> >>
> >> Correct. The U-Boot code is "sprinkled" with these calls, easpecially
> >> ion places where looping might take some time (polling for input etc).
> >> So the WD timer is triggered / services via this WATCHDOG_RESET call
> >> to keep U-Boot running even with an active watchdog.
> >
> > What is the motivation to start watchdog service during uboot and keep
> > on resetting it.
>
> Its similar to why this is done in the OS. There might be execution
> paths, where the bootloader might crash or hang (loading an image
> from some device etc). And this WD behavior makes sure, that the
> system does not hang but reboots in such cases.

Thank you Stefan for the detailed explanation.

Best regards,
Rayagonda

>
> Thanks,
> Stefan