Apple Inc.
Systems and methods for performing link disconnect

Abstract:

A system and method for efficiently disconnecting links in a communication fabric. A computing system includes a fabric for routing traffic among one or more agents and a memory controller for system memory. The fabric includes multiple hierarchical clusters with a split topology where the data links are physically separated from the control links. When the controller in an intermediate cluster or agent determines local resources are idle, the controller sends separate requests for link disconnect on each of the upstream control and data links. When a single acknowledgment of link disconnect is received, the controller does not proceed with any link disconnect. Rather, the controller waits until an acknowledgment of link disconnect is received for each of the upstream control and data links. If local resources remain idle, the controller sends confirmation upstream and performs a link disconnect for each of the upstream control and data links.