[PATCH 12/17] ARM: mvebu: Armada XP GP specific suspend/resume code

Andrew Lunn andrew at lunn.ch
Mon Oct 27 07:59:39 PDT 2014


> > I'm making some assumptions here, which could be wrong.
> > 
> > #1 This GPIO interface does more than suspend to RAM power off. I
> > assume it also does full power off? It might also support Wake on LAN?
> 
> This I don't know, but we can probably assume it's the case.
> 
> > #2 Any code can call a notifier chain and pass parameters to that
> > chain?
> 
> Right. But for existing notifier chains, the existence, semantic and
> meaning of the parameters are already defined, and the gazillions users
> of that notifier chain in the kernel rely on those parameters to not
> change.

That is not really true. Lets start off with:

https://lkml.org/lkml/2014/10/21/56

This is brand new code, implementing the poweroff handler call chain.
Take a look at do_kernel_power_off(). It passes a NULL pointer as the
parameter to the handler function. So there are not gazillions users
of that notifier chain in the kernel rely on those parameters to not
change.

What i'm suggesting is to extend this new code and make it more
general. Currently it only handle full power off. Make it also handle
suspend to RAM power off as well.

	Andrew



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