A mechanism to obtain a quiescence state for a component coupled to a
bidirectional communications interface is obtained. A transition to
quiescence may be may by activating a first defeature in the component to
cause messages received over a communication bus coupled between the
component and another component to be ignored, and activating a second
defeature in the component to prevent messages from being sent over the
communication bus by the component. Operations may then be performed on
the component while the defeatures are activated.