[PATCH 1/3] power: domain: add pm_genpd_uninit

[Ulf Hansson]

On 19 November 2015 at 19:08, Alexander Aring <alex.aring at gmail.com> wrote:
> This patch adds function pm_genpd_uninit for undo a pm_genpd_init. This
> is useful for multiple power domains while probing. If the probing fails
> after one pm_genpd_init was called we need to undo all previous
> registrations of generic pm domains inside the gpd_list list.
>
> There is a check on IS_ERR_OR_NULL(genpd) which is useful to check again
> registered power domains and not registered domains, the driver can use
> this mechanism to have an array with registered and non-registered power
> domains, where non-registered power domains are NULL.
>
> Cc: Rafael J. Wysocki <rjw at rjwysocki.net>
> Cc: Kevin Hilman <khilman at kernel.org>
> Cc: Ulf Hansson <ulf.hansson at linaro.org>
> Cc: Pavel Machek <pavel at ucw.cz>
> Cc: Len Brown <len.brown at intel.com>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Signed-off-by: Alexander Aring <alex.aring at gmail.com>
> ---
>  drivers/base/power/domain.c | 22 ++++++++++++++++++++++
>  include/linux/pm_domain.h   |  4 ++++
>  2 files changed, 26 insertions(+)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index e03b1ad..24f54b8 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1509,6 +1509,28 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
>  }
>  EXPORT_SYMBOL_GPL(pm_genpd_init);
>
> +/**
> + * pm_genpd_uninit - Uninitialize a generic I/O PM domain object.
> + * @genpd: PM domain object to initialize.
> + */
> +void pm_genpd_uninit(struct generic_pm_domain *genpd)
> +{
> +       if (IS_ERR_OR_NULL(genpd))
> +               return;
> +
> +       /* check if domain is still in registered inside the pm subsystem */
> +       WARN_ON_ONCE(!list_empty(&genpd->master_links) ||
> +                    !list_empty(&genpd->slave_links) ||
> +                    !list_empty(&genpd->dev_list));
> +

We did discuss about verifying that the genpd mustn't have a
corresponding DT provider. I do realize that it becomes a bit complex
to verify that, unless we decide to add some handle to it within the
genpd struct.

Anyway, perhaps this minimal effort is good enough as is. Especially
since we won't be able to handle the error cases, besides giving a
WARN.

> +       mutex_lock(&gpd_list_lock);
> +       list_del(&genpd->gpd_list_node);
> +       mutex_unlock(&gpd_list_lock);
> +
> +       mutex_destroy(&genpd->lock);
> +}
> +EXPORT_SYMBOL_GPL(pm_genpd_uninit);
> +
>  #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
>  /*
>   * Device Tree based PM domain providers.
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index ba4ced3..df84a45 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -123,6 +123,7 @@ extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
>                                      struct generic_pm_domain *target);
>  extern void pm_genpd_init(struct generic_pm_domain *genpd,
>                           struct dev_power_governor *gov, bool is_off);
> +extern void pm_genpd_uninit(struct generic_pm_domain *genpd);
>
>  extern struct dev_power_governor simple_qos_governor;
>  extern struct dev_power_governor pm_domain_always_on_gov;
> @@ -161,6 +162,9 @@ static inline void pm_genpd_init(struct generic_pm_domain *genpd,
>                                  struct dev_power_governor *gov, bool is_off)
>  {
>  }
> +static inline void pm_genpd_uninit(struct generic_pm_domain *genpd)
> +{
> +}
>  #endif
>
>  static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
> --
> 2.6.1
>

So, I am fine with this, but let's see if other people have objections.

Acked-by: Ulf Hansson <ulf.hansson at linaro.org>

Kind regards
Uffe