1. An apparatus comprising: a non-transparent bridge coupled with a device via a Root Port; and logic coupled with the non-transparent bridge to maintain an order of a plurality of interrupt signals to be sent to the device via the Root Port, wherein the logic is to: determine whether a doorbell transaction is next to be popped from a transmission queue; determine whether a doorbell register associated with the doorbell transaction has been updated; and generate one of the plurality of interrupt signals in response to a determination that the doorbell transaction is next to be popped from the transmission queue and a determination that the doorbell register associated with the doorbell transaction has been updated.