SK-AM62: Watchdog daemon for linux

Hello Xabier,

Are you on the same team as Toby, or are you a different customer? If the same team, I will merge your thread together with their followup thread: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1244104/sk-am62-sk-am62-could-you-please-tell-me-how-to-set-the-timeout-time-and-feeding-time-with-watchdog

Regards,

Nick

Hello Nick,

Thank you for your help. I am a different customer, but I have no problem moving to the other thread if that makes management easier for you.

Apologies for having opened a new thread. I did do a preliminary search before posting, but for some reason I didn't find Toby's new thread.

Let me know if we will keep this thread alive or not. If we are closing this one I can link it on a reply to Toby's thread so that I become part of that conversation.

Hello Xabier,

No, let's keep the discussion separate for now. Let me know if the information at thread https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1230811/am625-watchdog-timeout is helpful, or if you need additional guidance.

Regards,

Nick

Hello Nick,

If I understand that thread correctly, the conclussion is that Magnus was not dealing with a SW problem, but a HW problem. In my case I am using an official SK-AM62 E3A board, so it seems unlikely we are dealing with HW problems, unless this is a faulty unit.

Is there anything I can check, or any additional feedback I can give you to make progress here?

Thanks!

Hello Xabier,

Thanks for confirming. Magnus was dealing with a HW problem, but I thought he might have posted some of his code to interact with the watchdog timer during that process.

At this point I have not done anything with the watchdog timer yet myself. I will shoot to spend some time on your request on Thursday. Things are a little wild on this end, so please feel free to ping me if I have not replied by Friday to make sure your thread stays at the top of my TODO list.

Regards,

Nick

Hello Nick,

Any chance you can have a look at this in the next few days?

Thanks!

Hello Xabier,

Thank you for the ping! Stuff keeps piling on, so I appreciate you bringing this thread back up in my inbox.

No time to experiment today unfortunately. I am going to see if I can set aside some time to play around with it on Friday.

Regards,

Nick

Hello again Nick,

I know you are really busy, so don't worry too much about this. It's just a ping to keep the thread visible. 

Thanks,

Xabier.

Hello Xabier,

Sounds good. I will keep the thread open, but if it is not critical for you to make progress here in the near term I will not worry about digging into it over the next couple of days.

Regards,

Nick

Just another ping to keep this thread open. We'll get back to it when it's the right time.

Hello again Nick,

I'm starting to reach a point where having the watchdog working would be important for me. Do you think you can help me out with this now?

Thank you in advance.

Regards,

Xabier.

I'm sorry for insisting. I fear my last message might have not have been propperly notified. I have failed to receive notifications a few times myself.

Can anyone help me with this?

Nick Saulnier , do you know if there has been any activity around the use of the watchdog lately?

Hi Xabier,

Nick is out of the office until the end of the month, so responses will be delayed until he returns and gets caught up with work. Appreciate your patience.

Regards, Andreas

Hello Xabier,

Apologies for the long delay here. I'm finally caught up enough to pivot back to your thread later this week. Have there been any other updates over the past 2 months that I should be aware of before diving back in?

Regards,

Nick

Hello Nick,

Thank you very much for getting back in touch. I hope everything is ok over there.

No news on this side. I have a pretty high workload on other projects, and I haven't been able to experiment on the watchdog. Any help would be appreciated. I will struggle to find time to test out things, but I will try to find a way to make it work.

Since the high precission PPS input thread is closed now, let me do a slight off-topic here to let you know that my mainline kernel contributions are moving forward and will probably be part of kernel 6.7 somewhere around the end of the year / beginning of 2024. I can provide assistance in which specific patches to cherry pick if you want to do back-porting of the feature.

Cheers,

Xabier.

Hello Xabier,

Sounds good, thanks for the update. I have rebuilt the default Linux SDK kernel with the watchdog driver enabled, and will run tests on Monday.

Regards,

Nick

Hello Xabier,

I've started playing around on this side. Nothing groundbreaking yet, other than a way to check which watchdog timer you are messing around with:

root@am62xx-evm:/sys# cat /sys/bus/platform/drivers/rti-wdt/

bind              e000000.watchdog/ e010000.watchdog/ e020000.watchdog/ e030000.watchdog/ e0f0000.watchdog/ uevent            unbind

root@am62xx-evm:/sys# cat /sys/bus/platform/drivers/rti-wdt/e000000.watchdog/watchdog/watchdog0

Which lines up with the watchdog timers we see defined in AM62x SDK 9.0 k3-am62-main.dtsi.

At this point in time, I am not sure 1) if it matters which of the A53 watchdog timers you are using, or 2) if the association of "watchdogX" with a specific watchdog timer instance is guaranteed, or just assigned at boot time where the order could potentially change between reboots.

On a related note, if you ever need to adjust the number of A53 cores that are enabled for your device, remember that the RTI associated with that A53 core must ALSO be disabled. We document that process here: https://dev.ti.com/tirex/explore/node?node=A__AZ853VXSIrRV0D6eoeZeeg__AM62-ACADEMY__uiYMDcq__LATEST

Regards,

Nick

I have this in mind, but my current schedule doesn't allow me to get back into this. I will come back to you as soon as I can refresh my test setup. Thanks!