Configure multiple GPIO interrupts with different priorities

RE: Configure multiple GPIO interrupts with different priorities

jaberk — Fri, 22 Mar 2024 17:27:49 GMT

I have not run into issues as of yet, but development is ongoing, and I wanted to run this down before implementation. The info you've already provided will suffice for now, thank you again!

RE: Configure multiple GPIO interrupts with different priorities

Vidar Berg — Fri, 22 Mar 2024 10:52:51 GMT

Happy to help! Yes, you can increase the priority of the GPIOTE IRQ by setting the interrupt priority to a lower numerical value in the gpiote0 DT node. This will allow the GPIOTE interrupt to preempt other lower-priority interrupts. However, I'm not sure if this would be advisable, as it may introduce race conditions. Are you experiencing problem with meeting timing requirements with your current implementation?

EGU is supported through the nrfx drivers/hal: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfx/drivers/egu/index.html. But I believe I need a better understanding of your application and requirements to say whether it would make sense to use it.

RE: Configure multiple GPIO interrupts with different priorities

jaberk — Thu, 21 Mar 2024 13:15:33 GMT

Thank you for the help!

This sounds like, as it currently stands, there would be no way for the ISR of a sensor to preempt the ISR of another, lower priority sensor, and the best bet is to minimize processing within the ISR. Couple of follow-up questions:

To increase the GPIO ISR priority so it is serviced quicker than other peripherals, would you override the interrupt property in the devicetree for the GPIO or the GPIOTE node? This would need to be lower than NRF_DEFAULT_IRQ_PRIORITY and would alter the priority for all GPIOTE events? Something like the following:

&gpiote0 {
    interrupts = <13 MODIFIED_IRQ_PRIORITY>
}

Also, is there support for the EGU functionality in Zephyr, or would this be of no benefit for this specific question?

RE: Configure multiple GPIO interrupts with different priorities

Vidar Berg — Thu, 21 Mar 2024 07:07:17 GMT

Hello,

You are right that the driver uses GPIOTE for pin interrupts. However, the peripheral only has one IRQ signal. This meanst that interrupt enabled GPIOTE events will all trigger the same interrupt. But you can defer the processing of sensor tasks from the GPIO callback to an application thread. This allows you to schedule the tasks with different priorities. This will also reduce the time spent in the ISR.

Best regards,

Vidar