Patent ID: 7426597

Claim:
A method of bus power management in a graphics system, comprising: for a first operational state having a first link bandwidth requirement for a bus, negotiating a first link width between a first bus interface and a second bus interface disposed at opposite ends of said bus based on said first link bandwidth requirement, said first link width having a first integer number, M, of active data lanes that is less than or equal to a maximum integer number, K, of operable data lanes; and in response to detecting a second operational state having a second link bandwidth requirement, negotiating a second link width between said first bus interface and said second bus interface based on said second link bandwidth requirement, said second link width having a second integer number, N, of active data lanes, where N is not equal to M, and N is also less than or equal to K; wherein each negotiation includes preparing any operable lanes of said bus which were disabled in a previous configuration for a negotiation of link width to facilitate dynamic negotiation up and down of the number of active data lanes during a user session; the number of active data lanes that is negotiated in at least one of the negotiations being based on a bandwidth constraint to reduce the power consumption associated with active data lanes and the operational state is an operational state of a graphics system.