pub fn dispatch(irq_num: u32)Expand description
Called by the arch controller driver with the IRQ number that just
fired. Looks up and calls the registered handler; a no-op if nothing
is registered for irq_num (a controller can only report interrupts
it was told to enable, so this path is only hit by a genuine
registration bug or race, not routine operation — silently ignoring it
is safer than panicking on the ISR stack).