[U-Boot] OMAP watchdog timer reset on BBB

[Sam Protsenko]

Hi Grygorii,

On Fri, Sep 13, 2019 at 8:58 PM Grygorii Strashko
<grygorii.strashko at ti.com> wrote:
>
>
>
> On 12/09/2019 19:33, Sam Protsenko wrote:
> > Hi Stefan,
> >
> > On Thu, Sep 12, 2019 at 5:38 PM Stefan Roese <sr at denx.de> wrote:
> >>
> >> Hi Sam,
> >>
> >> On 12.09.19 15:45, Sam Protsenko wrote:
> >>> Hi Suniel,
> >>>
> >>> After transition to DM WDT, watchdog timer on BeagleBone Black resets
> >>> the board after 1 minute or so. I'm using this defconfig: [1]. After
> >>> disabling CONFIG_WDT and CONFIG_WATCHDOG options the board doesn't
> >>> reset. I guess it might be happening on other boards using
> >>> CONFIG_WDT_OMAP3 as well. The issue can be reproduced by stopping in
> >>> U-Boot shell (=>) and waiting for 1 minute.
> >>>
> >>> Do you know by chance why it might be happening, or maybe some fix
> >>> already exists?
> >>>
> >>> Thanks!
> >>>
> >>> [1] https://pastebin.ubuntu.com/p/Zz5bY6cYXS/
> >>
> >> So you have enabled the watchdog and should see something like this
> >> upon bootup:
> >>
> >> WDT:   Started without servicing (60s timeout)
> >>
> >> Is this correct? Then you need to enable the U-Boot internal WDT
> >> servicing by enabling CONFIG_WATCHDOG as well, as this will
> >> result in the internal U-Boot servicing of the watchdog. Then
> >> you should see this upon bootup and no reset will appear in
> >> U-Boot:
> >>
> >> WDT:   Started with servicing (60s timeout)
> >>
> >
> > I'm seeing this ("with servicing") line, and CONFIG_WATCHDOG is
> > already enabled in am335x_evm_defconfig. So I think it's an issue,
> > which *probably* appeared when watchdog drivers were converted to
> > Driver Model (this defconfig is using CONFIG_WDT + CONFIG_WDT_OMAP3
> > options). Any clues what can be wrong?
> >
> >> Does this help?
> It seems logic of hw_watchdog_reset() and omap3_wdt_reset() is different.
> Pay attention at wdt_trgr_pattern.
>
> It seems that
>         priv->wdt_trgr_pattern = 0x1234;
> need to be moved in omap3_wdt_probe()
>

Thanks a lot for the investigation. I'll check that once I have some spare time.

>
> --
> Best regards,
> grygorii