disable_irq -- disable an irq and wait for completion
(unsigned int irq);
Disable the selected interrupt line. Disables of an interrupt
stack. That is for two disables you need two enables. This
function waits for any pending IRQ handlers for this interrupt
to complete before returning. If you use this function while
holding a resource the IRQ handler may need you will deadlock.
This function may be called - with care - from IRQ context.