Patent ID: 7711886

Claim:
A method of dynamically allocating communication lanes for a plurality of input/output (‘I/O’) adapter sockets in a point-to-point, serial I/O expansion subsystem of a computing system, the point-to-point, serial I/O expansion subsystem including an expansion subsystem switch that supports a maximum number of enabled communication lanes, each I/O adapter socket having a same form factor, each I/O adapter socket connected to the expansion subsystem switch using a same predefined number of communication lanes, the method comprising: identifying, by a lane configuration module during a boot process for the computing system, each of the I/O adapter sockets in which an I/O adapter is installed; determining, by the lane configuration module for each installed I/O adapter, a maximum link width for that I/O adapter; and enabling, by the lane configuration module for each of the I/O adapter sockets in which an I/O adapter is installed, a set of communication lanes for communications between the I/O adapter installed in that I/O adapter socket and the expansion subsystem switch in dependence upon the maximum link width for each I/O adapter and the maximum number of enabled communication lanes supported by the expansion subsystem switch; wherein enabling, by the lane configuration module for each of the I/O adapter sockets in which an I/O adapter is installed, a set of communication lanes further comprises; determining whether a sum of the maximum link width for all of the installed I/O adapters exceeds the maximum number of enabled communication lanes supported by the expansion subsystem switch; and enabling set of communication lanes in dependence on the maximum link width for the I/O adapter installed in that I/O adapter socket, the sum of the maximum link width for all of the installed I/O adapters, and the maximum number of enabled communication lanes supported by the expansion subsystem switch if the sum of the maximum link width for all of the installed I/O adapters exceeds the maximum number of enabled communication lanes supported by the expansion subsystem switch.