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earlephilhower / arduino-pico

Raspberry Pi Pico Arduino core, for all RP2040 and RP2350 boards
GNU Lesser General Public License v2.1
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IRQ stack overflow #2397

Closed Yveaux closed 1 month ago

Yveaux commented 1 month ago

Hi there! I'm working on a project which combines USB host functionality, FreeRTOS and a number of interrupt sources. Every now and then the system panics with "IRQ stack overflow" which traces back to wiring_private.cpp.

The standard maxIRQs appears to be too low for my application: https://github.com/earlephilhower/arduino-pico/blob/226a3188975b21d29d32fe4423a6c929766192a5/cores/rp2040/wiring_private.cpp#L28

Raising it to 30 makes the panics disappear.

Would it be possible to define the size of the stack as a global variable?

earlephilhower commented 1 month ago

That's a pretty massive amount of nested noInterrupt()s! Are you sure you're not over-disabling things?

The stack needs to be setup during global object instantiation, even before main runs. It can't be a variable, since you can't make a global array with a variable size, but I suppose we can let it be overridden it with a build.local file, so it'd be

#ifndef maxIRQs
#define maxIRQs 15
#endif

Changing defaults it in the core would be a non-starter because that would be a non-trivial amount of RAM being eaten (and unused) for all other apps.

Want to make a PR implementing that ifndef block?

Yveaux commented 1 month ago

That's a pretty massive amount of nested noInterrupt()s! Are you sure you're not over-disabling things?

It's been a while since I looked into this issue, but according to my notes the cause seemed to lie in the fact that FreeRTOS task preemptions are not blocked when calling noInterrupts().

Want to make a PR implementing that ifndef block?

Sure, I created #2401

earlephilhower commented 1 month ago

Closed by #2401