Multi-level port expansion for port multipliers

摘要

A port multiplier dynamically determines and reports its identity based on a number of supported downstream port connections. The number of supported downstream port connections can dynamically change. The port multiplier identifies devices connected to its downstream ports, whether storage devices or other port multipliers. Based on a total number of downstream ports, the port multiplier reports its identity upstream. The upstream reporting can be to another port multiplier, or the host device if directly connected to the host device. The port multiplier receives storage address space allocation from upstream based on its reported identity, and allocates the storage address space to its downstream ports.

主权项

1. A method comprising:
identifying one or more devices connected to downstream ports of a Serial Advanced Technology Attachment (SATA) port multiplier device, the one or more devices including other SATA port multiplier devices; detecting change in downstream port connections at the SATA port multiplier device; updating an identity of the SATA port multiplier device based on the change in downstream port connections of the SATA port multiplier, the identity indicative of a number of available downstream port connections of the SATA port multiplier device for connecting the one or more devices; sending the updated identity of the SATA port multiplier device to a device connected to an upstream port of the SATA port multiplier device; and receiving allocation of storage address space to the SATA port multiplier device based on the updated identity, the storage address space allocation for existing downstream port connections remaining unchanged, and newly added downstream port connection allocated with new address space.