Hi Ulf,
On Wed, Apr 27, 2016 at 3:59 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 26 April 2016 at 09:09, Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>> As a pure Clock Domain does not have the concept of powering the domain
>> itself, the CPG/MSTP driver does not provide power_off() and power_on()
>> callbacks.
>> However, the genpd core may still perform a dummy power down, causing
>> /sys/kernel/debug/pm_genpd/pm_genpd_summary to report the domain's
>> status being "off-0".
>>
>> Use the always-on governor to make sure the domain is never powered
>> down, and always shows up as "on" in pm_genpd_summary.
>
> Hmm.
>
> Hypothetically, what if the clock domain would be a subdomain, where
> its master is able to power down? Using the always on governor would
> prevent the master from power off as well.
That's correct. However, on R-Mobile/R-Car SoCs, this is not the case, so it
doesn't matter here.
> I am wondering whether we should introduce some similar as
> pm_runtime_no_callbacks() but for the generic PM domain instead.
>
> What do you think?
In my case, the domain is not managed by its parent, to there's no such
analogy.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
