On 26 April 2016 at 09:09, Geert Uytterhoeven <[email protected]> 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.

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?

>
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
>  drivers/clk/renesas/clk-mstp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/renesas/clk-mstp.c b/drivers/clk/renesas/clk-mstp.c
> index 969fbb61ab07b9b8..5093a250650dad6d 100644
> --- a/drivers/clk/renesas/clk-mstp.c
> +++ b/drivers/clk/renesas/clk-mstp.c
> @@ -319,7 +319,7 @@ void __init cpg_mstp_add_clk_domain(struct device_node 
> *np)
>         pd->flags = GENPD_FLAG_PM_CLK;
>         pd->attach_dev = cpg_mstp_attach_dev;
>         pd->detach_dev = cpg_mstp_detach_dev;
> -       pm_genpd_init(pd, &simple_qos_governor, false);
> +       pm_genpd_init(pd, &pm_domain_always_on_gov, false);
>
>         of_genpd_add_provider_simple(np, pd);
>  }
> --
> 1.9.1
>

Kind regards
Uffe

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