> I guess this is depends whether the most usual case is to have all > these interrupts being actively in use or not. Most interrupts only > use a limited portion of their interrupt space at any given time. > Allocating all interrupts and creating mappings upfront is a waste of > memory. > > If the use case here is that all these interrupts will be wired and > used in most cases, then upfront allocation is probably not a problem. Hi Marc The interrupts are generally used. Since this is an Ethernet switch, generally the port is administratively up, even if there is no cable plugged in. Once/if a cable is plugged in and there is a link peer, the PHY will interrupt to indicate this. The only real case i can think of when the interrupts are not used is when the switch has more ports than connected to the front panel. This can happen in industrial settings, but not SOHO. Those ports which don't go anywhere are never configured up and so the interrupt is never used. Andrew