Re: Totally broken PCI PM calls

[Pavel Machek]

Hi!

> > Maybe the real problem is that we are trying to use the device suspend
> > functions for suspend-to-disk, when we don't really want to change the
> > device's power state at all.
> 
> An acceptable solution is certainly to instead of passing down "go to D3",
> just not do anything at all. HOWEVER, I doubt that is actually all that 
> good a solution either: devices quite possibly do want to save state 
> and/or set wake-on-events. 

And DMA needs to be stopped, or it is "bye bye data" situation.

> Which is why I suggested making it a separate type that is _not_ a normal 
> number. Exactly so that you cannot think it's a PCI state by mistake, when 
> clearly drivers _do_ think that. And force people to verify it.
> 
> You could do it with "sparse" and "bitwise" types too. Sparse will
> complain if you use the type in an inappropriate manner. But the basic
> issue remains: there are PCI power states, and there are "suspend" power
> states, and they are different. And right now people _are_ confused about
> them.

Does sparse now have typechecking on enums? Solution that was in -mm
was basically "put enums there so drivers can't be confused" + "signal
global state out-of-band in global variable". It was not too nice, but
it certainly was working.
								Pavel
-- 
Boycott Kodak -- for their patent abuse against Java.
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