> I could not find anything standard that let me power gate single > device from userland. Perhaps it's considered as a too risky operation > to expose to the user. I don't want to touch drivers too much as well > not to make them dependant on extra system feature. Better to have a > separate module that handles this system mode and forces some drivers > to unload/power gate their HW. > > Are there already some proven solutions/ideas around the kernel that > can be used straight away?
For a lot of devices if you close it then it will try and put the device into a low power state. If a driver isn't doing that then (unless there are hardware constraints preventing it) it would make sense to fix it. There are some things entirely in your control - big ones. In particular the brightness of laptop panels, pulling everything off one CPU socket, disabling the nmi watchdog, hard disk power settings, stopping processes that wake up a lot. Many of those you can set anyway for best power behaviour (see powertop). Alan
