Code outline is:
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palEnablePadEvent(GPIOA, GPIOA_PAD, PAL_EVENT_MODE_FALLING_EDGE);
palWaitPadTimeout(GPIOA, GPIOA_PAD, TIME_INFINITE);
if (!palReadPad(GPIOA, GPIOA_PAD))
After a few hundred interrupts this gets stuck in the palWaitPadTimeout with the interrupt line asserted ie low. The issue I'm sure is that when interrupts are processed in ProcessInterrupt() and are then enabled again, an interrupt occurs BEFORE the code loops around to the palWaitPadTimeout which then waits for the NEXT interrupt as it's edge triggered.
One solution, which I've always used in the past with 'real' interrupt handlers is that these should be level triggered rather than edge triggered, but I can't see that option in the PAL handler (this is on an STM32L4xx to be clear).
Surely there must be some way to ensure that if this race occurs, the palWaitPadTimeout call will still return?
If not, then palWaitPadTimeout is pretty worthless in real life use......