Method, apparatus, and system for plugin mechanism of computer extension bus

A method comprising:

• selecting between an in-band hot-plug detection mechanism, an out-of-band hot-plug detection mechanism, or both the in-band hot-plug detection and the out-of-band hot-plug detection;
• detecting a hot-plug event when inserting or removing a device from an extension bus slot, wherein according to the in-band hot-plug detection mechanism, detecting the hot-plug event is by a state machine having at least three states and by masking at least two states of the state machine;
• and
• generating a hot-plug event message to notify of an occurrence of the hot-plug event.

A system comprising:

• an apparatus comprising:
• a processor;
• a plurality of buses operably coupled to the processor;
• a plurality of extension bus slots operably coupled to the plurality of buses;
• and
• a circuitry to detect a hot-plug event when inserting or removing a device from an extension bus slot of the plurality of extension bus slots, and to generate a hot-plug message to notify of an occurrence of the hot-plug event, the circuitry comprising:
• a state machine to detect the hot-plug event;
• and
• a register to provide at least two bits to mask at least two states of the state machine.