A method and apparatus for data storage devices, or other devices that are L1 sub-state capable, to enter these sub-states while on the same network or bus as a device not enabled for transition to an L1 power sub-state. According to certain embodiments, a PCI FW register is configured to place a CLKREQ de-assert signal to a MAC of the data storage device, independent of the power state of the host. The CLKREQ de-assert signal causes the MAC to place the data storage device in an L1 power substate such as L1.2. A sensor of the controller remains active to detect a wakeup signal from the host that causes the data storage device to transition to a higher power state.