Subject: Re: ACPI suspend support.
To: Kentaro A. Kurahone <email@example.com>
From: Lennart Augustsson <firstname.lastname@example.org>
Date: 01/26/2005 00:35:28
We should redo the powerhook stuff.
I think we should extend struct cfdriver with a powerstate
function. If it is left as NULL nothing will get called,
otherwise it will get called when the power state changes.
Like the addition of the detach&activate methods this would
be upwards compatible. You don't need to do anything to
drivers that don't have a powerstate function.
Kentaro A. Kurahone wrote:
> On Tue, Jan 25, 2005 at 09:02:27AM -0800, Jason Thorpe wrote:
>>...and I think something a lot more than the current powerhook stuff is
>>really needed. We need to be able to express a richer set of power
>>states. It might make sense to adopt the S* nomenclature of ACPI,
>>since PCI also uses the same nomenclature.
> Sounds good. The ACPI S* states are a lot more flexible than the APM
> equivalents, so this should ease some of the pain when trying to deal with
> this on hpc/macppc targets.
> On the changing powerhook note, I'm wondering if passing POWER_STATE_S[0-5],
> via why is sufficient. Device drivers can use this to transition between
> power states/save or restore context as needed. The current strongpoint of
> the powerhook stuff is that devices that don't/can't do powermanagement
> don't need the code for it. The downside being that it's a bit on the
> minimalistic side, and there's no easy way to have a default behavior
> apart from "do nothing".