Re: [PATCH 31/31] PM / devfreq: convert to devm_pm_opp_register_notifier and remove unused API

[Chanwoo Choi <cwchoi00@xxxxxxxxx>]

On Sun, Jan 3, 2021 at 12:59 PM Yangtao Li <tiny.windzz@xxxxxxxxx> wrote:
>
>  Use devm_pm_opp_* API to simplify code.
>
> Signed-off-by: Yangtao Li <tiny.windzz@xxxxxxxxx>
> ---
>  drivers/devfreq/devfreq.c | 66 +--------------------------------------
>  include/linux/devfreq.h   | 23 --------------
>  2 files changed, 1 insertion(+), 88 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 6aa10de792b3..f593f30529ec 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -2004,40 +2004,6 @@ struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
>  }
>  EXPORT_SYMBOL(devfreq_recommended_opp);
>
> -/**
> - * devfreq_register_opp_notifier() - Helper function to get devfreq notified
> - *                                  for any changes in the OPP availability
> - *                                  changes
> - * @dev:       The devfreq user device. (parent of devfreq)
> - * @devfreq:   The devfreq object.
> - */
> -int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
> -{
> -       return dev_pm_opp_register_notifier(dev, &devfreq->nb);
> -}
> -EXPORT_SYMBOL(devfreq_register_opp_notifier);
> -
> -/**
> - * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
> - *                                    notified for any changes in the OPP
> - *                                    availability changes anymore.
> - * @dev:       The devfreq user device. (parent of devfreq)
> - * @devfreq:   The devfreq object.
> - *
> - * At exit() callback of devfreq_dev_profile, this must be included if
> - * devfreq_recommended_opp is used.
> - */
> -int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
> -{
> -       return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
> -}
> -EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
> -
> -static void devm_devfreq_opp_release(struct device *dev, void *res)
> -{
> -       devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
> -}
> -
>  /**
>   * devm_devfreq_register_opp_notifier() - Resource-managed
>   *                                       devfreq_register_opp_notifier()
> @@ -2047,40 +2013,10 @@ static void devm_devfreq_opp_release(struct device *dev, void *res)
>  int devm_devfreq_register_opp_notifier(struct device *dev,
>                                        struct devfreq *devfreq)
>  {
> -       struct devfreq **ptr;
> -       int ret;
> -
> -       ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
> -       if (!ptr)
> -               return -ENOMEM;
> -
> -       ret = devfreq_register_opp_notifier(dev, devfreq);
> -       if (ret) {
> -               devres_free(ptr);
> -               return ret;
> -       }
> -
> -       *ptr = devfreq;
> -       devres_add(dev, ptr);
> -
> -       return 0;
> +       return devm_pm_opp_register_notifier(dev, &devfreq->nb);
>  }
>  EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
>
> -/**
> - * devm_devfreq_unregister_opp_notifier() - Resource-managed
> - *                                         devfreq_unregister_opp_notifier()
> - * @dev:       The devfreq user device. (parent of devfreq)
> - * @devfreq:   The devfreq object.
> - */
> -void devm_devfreq_unregister_opp_notifier(struct device *dev,
> -                                        struct devfreq *devfreq)
> -{
> -       WARN_ON(devres_release(dev, devm_devfreq_opp_release,
> -                              devm_devfreq_dev_match, devfreq));
> -}
> -EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);

Need to support devm_devfreq_unregister_opp_notifier()
because sometimes, the user wants to release the resource by himself.

(snip)

Best Regards,
Chanwoo Choi