Disabling all the gpioX nodes in the dts is not an option because some Linux peripherals need some of them (ethernet, USB, …)
Modify the Device Tree: You’ll need to adjust the interrupt controller settings in the Device Tree to ensure that interrupts from the peripherals you’re interested in are directed to the M7 core. This involves specifying the interrupt parent and the interrupts properties for the device nodes of the peripherals you’re using.
How should I modify this?
Which is the proper interrupt parent?
I think NVIC for M7 core, but I don’t find any nvic node in the supplied dts or overlays.
I would expect a nvic defined in verdin-imx8mp_hmp_overlay.dts.
Is this right?
My issue seems the same as IMX8MP GPIO interrupts for M7 but it’s not clear to me how it has been solved.
I did additional test and I can say I can drive a general purpose output from M7, and so I think that the issue is that the interrupt is not routed to the NVIC (but only to GIC).
Am I right?