• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 100 subscribers
  • Views 162 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM4379: AM437x IDK Eval WDT

changxing cui
Prodigy 50 points
Part Number: AM4379


Tool/software:

I tested WDT for the AM437x IDK eval board. After booting up the board, I saw the watchdogd process that may indicate the watchdog is enabled. But I am not 100% sure since (1) after enabling the WDT without kicking the dog, I saw the Timeleft counts down and eventually the board resets. (2) I did not see the watchdog enabled message in the journal. How we can be 100% sure that WDT is running after booting up AM437x IDK board?

  • 0
    TI__Guru** 103540 points

    Hello,

    What version of software are you running?

    How are you enabling the WDT?

    The default filesystem image that is provided with the Linux SDK is not going to start the watchdog counter automatically on boot. You need to make sure that something will be petting the watchdog regularly to prevent a reboot.

    Regards,

    Nick

  • 0 in reply to Nick Saulnier
    Prodigy 50 points

    Here is the version of the SW -

    root@am437x-evm:~# uname -a
    Linux am437x-evm 5.10.100-g7a7a3af903 #1 PREEMPT Thu Jun 2 20:33:08 UTC 2022 armv7l armv7l armv7l GNU/Linux

    Here is how the WDT is enabled -

    root@am437x-evm:~# echo 10 > /dev/watchdog
    [374963.747439] watchdog: watchdog0: watchdog did not stop!

    --- Wait for about 15 seconds ---


    root@am437x-evm:~# wdctl
    Device: /dev/watchdog0
    Identity: OMAP Watchdog [version 0]
    Timeout: 60 seconds
    Pre-timeout: 0 seconds
    Timeleft: 42 seconds
    FLAG DESCRIPTION STATUS BOOT-STATUS
    KEEPALIVEPING Keep alive ping reply 1 0
    MAGICCLOSE Supports magic close char 0 0
    SETTIMEOUT Set timeout (in seconds) 0 0
    root@am437x-evm:~#

  • 0 in reply to changxing cui
    TI__Guru** 103540 points

    Hello,

    On another processor, I have noticed that the print statement "watchdog did not stop" appears when you start the watchdog counting down.

    Looks like the watchdog is counting down as expected, and I would expect that once it reaches 0, the board should reboot.

    Tests you can run 

    I have not run experiments with the watchdog timer on AM437x recently, but I did do some debugging on AM62x watchdog a couple months ago. Keep in mind that AM437x & AM335x have a different kind of watchdog timer on them than AM62x does, so there will be some differences.

    However, I would suspect that you should be able to use some of these techniques to control the watchdog, like enabling the watchdog in SystemD:
    https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1311045/am623-wdt_rti-control-via-systemd/5166054#5166054

    Regards,

    Nick