Disclosed herein are systems and techniques for adaptive use of multiple power supplies in a communication system. For example, in some embodiments, a slave device may include: an upstream transceiver to couple to an upstream link of a bus of a communication system; and circuitry to couple to the upstream link of the bus and to a local power supply, wherein the circuitry is to switch from providing the local power supply to power the slave device to providing bus power supplied by the upstream link of the bus to power the slave device.