On Tue, May 03, 2005 at 11:40:09PM +0200, Pavel Machek wrote: > Hi! > > > Device Drivers > > ============== > > > > Linux device drivers must often save and restore state during power > > transitions. The following API is proposed: > > > > ->prepare_state(struct device * dev, pm_state_t state, > > unsigned int reason); > > ->complete_state(struct device * dev, pm_state_t state, > > unsigned int reason); > > > > The following would be an example of a typical transition: > > > > 1.) the policy manager decides to put a PCI ethernet card into D3 from > > D0. > > 2.) ->prepare_state is called, the ethernet driver saves its state > > information and disables the hardware > > 3.) the power driver's ->set_state function is called, and power is > > actually removed. > > 4.) ->complete_state is called to cleanup and make any final > > adjustments. > > > > * In the case of D3->D0 ->complete_state would restore state. > > > > Possible "reasons" might include DYNAMIC_PM, HALT, REBOOT, SUSPEND, > > RESUME, etc. > > > > This API is different from the current ->suspend and ->resume because it > > applies to situations outside of system suspend (e.g. runtime power > > management) and has an emphasis on specific device power states. > > No. It took 2+ years to add at at least system power states. You want > to build on that, not scratch it and start over. > > Pavel Hi Pavel, After giving it some serious thought, I've decided that I agree. I'm reworking my plans to reflect this. I was wondering, however, what do you have in mind for adding to pm_message_t? Also, are you going to use "PMSG_HALT" and/or "PMSG_REBOOT"? Thanks, Adam
