Deadlock detection and recovery in SAS

摘要

Systems and methods herein provide for managing devices through a Serial Attached Small Computer System Interface (SAS) expander. The SAS expander includes a processor adapted to detect deadlock conditions in a SAS environment. In one embodiment, the SAS expander is operable to detect an Open Address Frame associated with a connection request from a source device to a destination device. The Open Address Frame includes a source address and a destination address associated with the source device and the destination device, respectively. The expander receives an arbitration in progress status on a partial pathway that is associated with the connection request. The expander is further operable to modify the Open Address Frame to include a deadlock indicator and forward the modified Open Address Frame on the partial pathway. When the modified Open Address Frame is received, the expander initiates pathway recovery upon determination that the deadlock indicator is valid.

主权项

1. A Serial Attached Small Computer System Interface expander operable to interconnect a destination device to a source device through a plurality of physical transceivers, the expander comprising a processor operable to:
detect an Open Address Frame associated with a connection request from the source device to the destination device, the Open Address Frame including a source address and a destination address associated with the source device and the destination device, respectively; receive an arbitration in progress status on a partial pathway associated with the connection request; modify the Open Address Frame to include a deadlock indicator; forward the modified Open Address Frame on the partial pathway; receive the modified Open Address Frame on the partial pathway; and initiate pathway recovery upon determination that the deadlock indicator is valid.