Re: [RFC v4 1/8] PM / Domains: structure changes for multiple states

[Axel Haslam <ahaslam@baylibre.com>]

Hi Geert,

On 22/04/2015 15:57, Geert Uytterhoeven wrote:
> Hi Axel,
>
> On Wed, Apr 22, 2015 at 3:23 PM, Axel Haslam <ahaslam@baylibre.com> wrote:
>>>> if the genpd is initially off, the user should set the
>>>> .init_state field when registering the genpd,
>>>> so that genpd knows which callbacks to call to set the
>>>> domain to on.
>>>
>>> The initial state may depend on various factors (hardware default,
>>> boot loader, previously loaded kernel, ...). This is even true with the
>>> current binary states.
>>
>> This would mean that the inital state of the genpd cannot be
>> hardcoded right?
>
> Indeed. And it should be filled in by the platform code before registration.
>
>>> What about keeping the .power_o{ff,n}() callbacks in struct
>>> generic_pm_domain,
>>> but adding a state index parameter to the callbacks?
>>> That would save even more memory on systems where all callbacks are
>>> identical.
>>
>> makes sense.
>
> It will complicate compilability/bisectability, though.
>

since the genpd pointer is allready an argument to the .power_o{ff,n}() 
callbacks, it would be simpler if the platform could check 
genpd->target_state to know what state is powering on/off to, instead of 
adding a new argument.

That way i can remove the power on/off callbacks from the state array,
and there are no big issues with bisectability.

regards,
Axel

> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds
>