watchdog does not expire

[jiez]

wdt start 1999 will expire, but wdt start 2000 will not.

I tested on SC598 SOM EZKIT board.

[pamolloy]

@jiez this issue needs a lot more context. Where did you come up with those values? Is the watchdog not enabled by default?

[pamolloy]

@analogdevicesinc/linux-for-adsp do you know if the watchdog has been tested or how it is typically enabled?

[CalebEthridgeADI]

Are these commands that are being run from the U-boot command line? Is this saying that the watchdog is not resetting the board when intentionally causing a fault that would cause it to expire? Or that certain timeouts with the watchdog don't work?

I believe @qasim-ijaz was working on a watchdog related issue recently.

[qasim-ijaz]

@analogdevicesinc/linux-for-adsp do you know if the watchdog has been tested or how it is typically enabled?

AFAIK the watchdog hasn't been tested. I am working on a watchdog related issue on the Linux side (rather than u-boot) where killing the user-space watchdog pinging process does not result in a system reset once the watchdog times out (instead the system freezes and the fault LED is lit) this was reproduced on the SC589-mini. From what I have seen so far it looks like the watchdog does expire as expected (after 20 seconds or so) and it does generate a watchdog expiry event, however for the system to restart the RCU and SEC have to be configured in a specific way (which our SEC and RCU drivers seem to correctly). But for some reason those RCU and SEC configurations are overwritten by something, meaning the restart doesn't happened.

[pamolloy]

@analogdevicesinc/adsp-apps I assume you've done some work with the watchdog? Have you run into any issues?

[jiez]

More information. The watchdog is not enabled by default in u-boot SC598 SOM EZKIT defconfig. Because u-boot will feed watchdog timer once per second, both "wdt start 1999" and "wdt start 2000" should not expire. A fix has been implemented. See PR #99 .

BTW, There is a divide by 2 for SC58x watchdog in the original calculation. I cannot find the reason in SC58x hardware reference manuals. So I just remove it. We need to give it a test on a SC58x board. But I don't have one.

[CalebEthridgeADI]

I testes the PR on an sc589-mini. Watchdog is behaving as expected with the fix.