Re: [PATCH 2/2] PM / Domains: Choose the deepest state to enter if no devices using it

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 6 Mar 2019 at 14:35, Aisheng Dong <aisheng.dong@nxp.com> wrote:
>
> For a domain has no working devices anymore, let's choose the deepest state
> to enter to save power. e.g. driver probe failure.
>
> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> ---
>  drivers/base/power/domain.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 847a69e..d3f57c2 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -550,6 +550,10 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
>         if (!genpd->gov)
>                 genpd->state_idx = 0;
>
> +       /* Choose the deepest state if no devices using this domain */
> +       if (!genpd->device_count)
> +               genpd->state_idx = genpd->state_count - 1;
> +

This doesn't work, sorry.

For example, there may be a sub-domain with devices in it and which
have constraints applicable also for the master (current) domain.

>         /*
>          * If sd_count > 0 at this point, one of the subdomains hasn't
>          * managed to call genpd_power_on() for the master yet after
> --
> 2.7.4
>

Kind regards
Uffe