Adaptive direct-attached hotplug detection

A method comprising, in an information handling system having a backplane comprising a plurality of connectors, each connector configured to receive an input/output device, and a motherboard communicatively coupled to the backplane via a cable having a presence detection wire configured to transmit presence detection information associated with the plurality of connectors and further having a plurality of data transmission wires:

• during a discrete mode, monitoring for an indicator from the backplane via the presence detection wire to determine if the backplane is configured for communication of serial presence detection information regarding the plurality of connectors and enter a serial mode in response to receiving the indicator;
• during the serial mode, receiving via the presence detection wire serialized frames including serialized presence detection information regarding input/output devices received in the plurality of connectors;
• and
• deserializing the serialized presence detection information and communicating deserialized presence detection information to a host controller configured to communicate with input/output devices received in the plurality of connectors via the plurality of data transmission wires.

An article of manufacture comprising:

• a non-transitory computer-readable medium;
• and
• computer-executable instructions carried on the computer-readable medium, the instructions readable by a processing device, the instructions, when read and executed, for causing the processing device to, in an information handling system having a backplane comprising a plurality of connectors, each connector configured to receive an input/output device, and a motherboard communicatively coupled to the backplane via a cable having a presence detection wire configured to transmit presence detection information associated with the plurality of connectors and further having a plurality of data transmission wires:
• during a discrete mode, monitor for an indicator from the backplane via the presence detection wire to determine if the backplane is configured for communication of serial presence detection information regarding the plurality of connectors and enter a serial mode in response to receiving the indicator;
• during the serial mode, receive via the presence detection wire serialized frames including serialized presence detection information regarding input/output devices received in the plurality of connectors;
• and
• deserialize the serialized presence detection information and communicate deserialized presence detection information to a host controller configured to communicate with input/output devices received in the plurality of connectors via the plurality of data transmission wires.