On Wed, 24 Nov 2004, David Brownell wrote: > > If a > > device is operational (albeit perhaps with lower performance and lower > > power usage), the PM core doesn't need to know anything more. Details of > > the operating state are internal to the driver. That's how the current > > design works. > > Actually no it doesn't ... there's dev->power.power_state thing, > in the current design, which is there to record power state. > But we seem agreed that it should vanish ... Yes, I should have said that's how people currently intend to make the design work. > > When you think about it, this makes sense. After all, the PM core can't > > be aware of all the myriad details of the internal workings of every kind > > of device. We've been saying all along that this sort of knowledge has to > > be pushed out to the drivers. > > ... so that the pmcore (or perhaps more specifically its sysfs glue?) > can't try to pretend that it's aware of _any_ such internal workings. It would be okay to be aware of them, just so long as it doesn't try to interpret them in any way. For example, presenting a character string to the user through sysfs is innocent enough, provided the PM core doesn't try to figure out what that string means. Alan Stern
