[haiku-development] Re: [gsoc2012] cpuidle support
- From: Fredrik Holmqvist <fredrik.holmqvist@xxxxxxxxx>
- To: haiku-development@xxxxxxxxxxxxx
- Date: Tue, 27 Mar 2012 10:36:31 +0200
Den 27 mars 2012 09:03 skrev Enrique Medina Gremaldos <quiqueiii@xxxxxxxxx>:
>> 1. I still don't know whether haiku's acpi can get and change
> c-states(NOTE: c-states not p-states)
>
> I guess it is possible. I found p-states through acpi module and performed
> some transitions, so whenever your acpi table is not a totally crap, it
> should be the same for c-states.
>
>> 2. acpi is complex, I don't know can it be completed in one summer
>
> As I said, I guess currect acpi stack is mature enought for your project
A little info about ACPI in Haiku and its current state:
We use ACPICA, http://www.acpica.org/ to do the ACPI handling (except
in early boot stages).
ACPICA has been improving a lot in later years and tries to compensate
for buggy bioses and is fairly successful at it now. We also have a
ACPI Embedded Controller driver, based on FreeBSD's which I'm quite
certain isn't completly bug-free yet and there is also the integration
code between the OS and ACPICA.
All this works ok I guess, but it do expose lack of ACPI drivers
(brightness for instance) and irq-routing issues (probably fixed) and
the steps taken on shutdown are not completly right.
Other than that ACPICA should handle most the complexity and is quite
mature. What may be needed is debugging our integration of it in
Haiku. So add time for that.
Btw I'd love to have this as a GSoC project, ACPI really needs some
fresh eyes and ideas.
/Fredrik Holmqvist, TQH
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