Is there any reason I can't have the radio notification run at priority 0? By definition it will never run at the same time as the lower stack, so it seems like I should be able to make it high priority.
By the same token, is there a reason I can't use priority 2? I can use priority 1, meaning I'm allowed to interrupt the upper stack—any reason I can't just use priority 2 as well?
Alternatively, is there any way I can make one interrupt (e.g. SWI1) take priority over another (e.g. ADC) if both interrupts want to run?