CortexR4: Spurious Data Abort Interrupt

[KroMignon]

@richard-damon

Have you made sure that vPortMalloc/vPortFree are safe to use in an ISR? That would generally require that the functions do their work inside a big critical section, which would add a lot of possible latency to ISR responce.

After double-checking the code, it looks like vPortFree() and vPortMalloc() are not used in FreeRTOS interrupt routines (xxxxFromISR()), so it was a not necessary change!