[U-Boot] OMAP watchdog timer reset on BBB

[Suniel Mahesh]

Hi Sam,

On 12/09/19 22:03, 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).

No, I didn't see any target reset issues because of DM WDT.
It was well tested when it was converted to DM(both on hardware and travis). 
Yes the config uses both CONFIG_WDT + CONFIG_WDT_OMAP3.

Any clues what can be wrong?

compiled and ran latest u-boot (am335x_evm_defconfig) as it is on the target(BBB). 
Checked three boot modes MMC, SD and serial, didn't see any issues.
https://paste.ubuntu.com/p/tjcPhv4FMQ/ (sd card boot)
https://pastebin.ubuntu.com/p/X4tkp4ngMK/ (serial boot)

I am suspecting something else might be causing the issue.
Hope this helps

Thanks
Suniel
> 
>> Does this help?
>>
>> Thanks,
>> Stefan