[PATCH v5 03/11] soc: renesas: rcar-sysc: Add DT support for SYSC PM domains

[Geert Uytterhoeven]

Hi Ulf,

On Mon, Apr 18, 2016 at 4:02 PM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
> On 18 April 2016 at 15:39, Geert Uytterhoeven <geert at linux-m68k.org> wrote:
>> On Mon, Apr 18, 2016 at 2:59 PM, Geert Uytterhoeven
>> <geert at linux-m68k.org> wrote:
>>> On Mon, Apr 18, 2016 at 2:21 PM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
>>>> [...]
>>>>
>>>>> +
>>>>> +static bool rcar_sysc_active_wakeup(struct device *dev)
>>>>> +{
>>>>> +       return true;
>>>>
>>>> I am interested to know why this is always returning true. Perhaps you
>>>> can elaborate a bit on that?
>>>
>>> Too many copying from old shmobile PM Domain code?
>>> Honestly, I don't know...
>>>
>>> Perhaps Rafael still remembers the original rationale, as git history for
>>> commit e3e0109138376bb2 ("ARM / shmobile: Support for I/O power domains for
>>> SH7372 (v9)") doesn't have it.
>>>
>>> Google did find: https://lkml.org/lkml/2011/6/30/471
>>>
>>> Do we still need this at all? I.e. aren't PM Domains containing wake-up
>>> devices kept powered automatically during system suspend?
>>
>> No they aren't. So for pm-rmobile we do need it.
>
> I don't quite understand why genpd should need to treat all devices
> within the same domain exactly the same, it seems suboptimal.
>
> I guess it would be more clever to allow this to be controlled on per
> device basis instead, so let's say from each driver.

Perhaps this can be handled through device_set_wakeup_enable()?
Unfortunately this doesn't seem to be called from e.g. gpio-keys.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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