Additions to existing runtime power management patch
- Linux ACPI has replaced earlier BIOS-based APM.
- Kernel already has support for underclocking (cpu_freq == "P states") and
hibernation (cpu_idle == "C states")
- Next step is to implement per-bus and per-device granularity.
- Traditional device-driver approach is addition of new
dev_pm_ops methods to API.
- Runtime power management framework provides the kernel interface
for the new driver methods.