Re: [PATCH v7 1/5] PM / Domains: prepare for multiple states

[Axel Haslam <ahaslam@baylibre.com>]

Hi Lina,

On 30/04/2015 17:29, Lina Iyer wrote:
> On Thu, Apr 30 2015 at 04:57 -0600, ahaslam@baylibre.com wrote:
>> From: Axel Haslam <ahaslam+renesas@baylibre.com>
>>
>> prepare generic power domain init function parameters
>> to accept a pointer to the states structure that describes
>> the possible states that a power domain can enter.
>>
>> There is no functional change, as support for multiple
>> domains will be added in subsequent patches.
>>
>> Signed-off-by: Axel Haslam <ahaslam+renesas@baylibre.com>
>
> <...>
>
>> extern void pm_genpd_init(struct generic_pm_domain *genpd,
>> -              struct dev_power_governor *gov, bool is_off);
>> +              struct dev_power_governor *gov,
>> +              const struct genpd_power_state *states,
>> +              unsigned int state_count, bool is_off);
>>
>
> Wouldnt it be better to setup another function pm_genpd_init_simple()
> that calls into pm_genpd_init() with no arguments?
>
> static inline void pm_genpd_init_simple(struct generic_pm_domain *genpd,
>                                struct dev_power_governor *gov, bool is_off)
> {
>      return pm_genpd_init(genpd, gov, NULL, 0, is_off);
> }

Im not against adding the wrapper if it simplifies things. But, in 
general, i think all latencies should be set, otherwise genpd may 
violate device constraints by turning a power domain off when it should 
not. So maybe, by leaving the arguments, it kind of sends the message to 
the developer that something important is needed.

Regards,
Axel

>
> It would be explicit that way to indicate the new genpd feature that
> would let
> domains support multiple states.
>
> Thanks,
> Lina