Optional, Can't Block
Called in Init Mode only.
The kernel initially provides default handling/detection for spurious interrupts. This is done for the last IRQ line of every PIC. It does this by checking the PIC's ISR register, and if the IRQ is not in service, it does not pass the interrupt request to the interrupt manager (i.e. a spurious interrupt).
If a PSD switches into advanced interrupt mode; the kernel will no longer provide default handling/detection of spurious interrupts. It becomes the PSD's responsibility.
One way a PSD could provide handling/detection of a spurious interrupt is to register a PSD handler for an IRQ level which may be spurious. As soon as the interrupt is detected the handler should insure that it is valid. If it is not (i.e. a spurious interrupt), it should dismiss the interrupt, and return NO_ERROR to the interrupt manager. The NO_ERROR return code informs the interrupt manager that the interrupt has been handled by the PSD. If the interrupt is valid the PSD should return a -1, as this informs the interrupt manager that the interrupt should be passed on to any device drivers registered to receive that interrupt.