watchdog with multiple channels fails on nrf52 using zephyr (ncs v1.2.0)

RE: watchdog with multiple channels fails on nrf52 using zephyr (ncs v1.2.0)

Johan — Tue, 22 Sep 2020 08:36:28 GMT

Yes sure.
I got it working with more channels now, due to not trying to change the timer for next channel. Thanks for the help.

RE: watchdog with multiple channels fails on nrf52 using zephyr (ncs v1.2.0)

Simon — Tue, 22 Sep 2020 07:56:43 GMT

This is unfortunately not possible, if you look in the infocenter you can see that the nRF52840 only has one watchdog, with only one CRV register and counter. This is taken into account in Zephyr and if you try to configure different timeouts for different channels, it will fail in zephyr\drivers\watchdog\wdt_nrfx.c-->wdt_nrf_install_timeout():

	if (get_dev_data(dev)->m_allocated_channels == 0U) {
        .
        .
    // If choosing different timeouts
	} else if (cfg->window.max != get_dev_data(dev)->m_timeout) {
		return -EINVAL;
	}

Best regards,

Simon

RE: watchdog with multiple channels fails on nrf52 using zephyr (ncs v1.2.0)

Johan — Thu, 17 Sep 2020 16:28:04 GMT

Ok, I see you do set the same timeout for the different timers.
I want different timeouts for each channel.
We have different threads, with different challenges, thus different timeouts.

Sure worst case would be to use the longest needed timeout for every thread, if there can only be one setting for all timers. That would be strange though.

I might be misunderstanding the usage of channels for the watchdog. Can you explain what is the purpose of channels?

In my brain, I'm thinking, setting the wdt timeout, and it needs to be feed before it timeouts. One timer only exists, so any thread could reload the wdt. What is a channel I do not understand in this case, since there are not multiple wdt-timers.

Johan

RE: watchdog with multiple channels fails on nrf52 using zephyr (ncs v1.2.0)

Simon — Fri, 11 Sep 2020 11:14:51 GMT

I tested this with an nRF52840 DK (I don't have an nRF52832 DK available at the moment) and was able to make it work with NCS v1.2.0. I added two channels and configured the timeout to 1 second. In the sample I uploaded, the chip will reset after a second, since only one of the reload registers are fed.

devzone.nordicsemi.com/.../watchdog.7z

Best regards,

Simon