autosuspend itself does not handle waking up the system in case it is needed again. Several solutions exist for this case, which will be enumerated here.
Wake on LAN¶
A simple way to wake up the system is to enable Wake on LAN. Here, a special network packet can be used to wake up the system again. Multiple front-ends exist to send these magick packets. The typical usage scenario with this approach is to manually send the magic packet when the system is needed, wait a few seconds, and then to perform the intended tasks with the system.
Wake on LAN needs to be specifically enabled on the system. Typically, the documentation of common Linux distributions explains how to enable Wake on LAN:
A set of front-ends for various platforms allows to send the magic packets. For instance:
RTC wake up timers¶
Another option is to schedule a time at which the system shall wake up automatically using RTC timers. This can be handy in case the system shall perform a task in the future, but can sleep until this task starts. A common front-end to control these timers is rtcwake, which can be used as follow:
# wake up again at a specified date rtcwake -m no --date '2017-12-24 17:02:23' # wake up again in a number of seconds rtcwake -m no -s 600
Please refer to rtcwake(8) for further possibilities.
Scheduled wake ups are a planned feature for autosuspend.