Subtleties of runtime power management
framework
- Devices run if they please: OS does not, in general, force a shut-down.
- System hibernate and wakeup must bring all devices up and down.
- Settings are configured through /sys/devices/<device>/power.
- Event-listener-callback paradigm for wakeup.
- A queue holds per-device requests to sleep and wake.
- Reference-counting mechanism blocks suspension of devices.