Re: [PATCH v2 1/2] PM: domains: add device managed version of dev_pm_domain_attach|detach_list()

[Dhruva Gole <d-gole@ti.com>]

On Aug 07, 2024 at 12:45:46 +0530, Dikshita Agarwal wrote:
> Add the devres-enabled version of dev_pm_domain_attach|detach_list.
> If client drivers use devm_pm_domain_attach_list() to attach the
> PM domains, devm_pm_domain_detach_list() will be invoked implicitly
> during remove phase.
> 
> Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
> ---
>  drivers/base/power/common.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/pm_domain.h   | 13 +++++++++++++
>  2 files changed, 57 insertions(+)
> 
> diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
> index 327d168..729d6c2 100644
> --- a/drivers/base/power/common.c
> +++ b/drivers/base/power/common.c
> @@ -277,6 +277,50 @@ int dev_pm_domain_attach_list(struct device *dev,
>  EXPORT_SYMBOL_GPL(dev_pm_domain_attach_list);
>  
>  /**
> + * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
> + * @_list: The list of PM domains to detach.
> + *
> + * This function reverse the actions from devm_pm_domain_attach_list().
> + * it will be invoked during the remove phase from drivers implicitly if driver
> + * uses devm_pm_domain_attach_list() to attach the PM domains.
> + */
> +void devm_pm_domain_detach_list(void *_list)
> +{
> +	struct dev_pm_domain_list *list = _list;
> +
> +	dev_pm_domain_detach_list(list);
> +}
> +EXPORT_SYMBOL_GPL(devm_pm_domain_detach_list);
> +
> +/**
> + * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
> + * @dev: The device used to lookup the PM domains for.
> + * @data: The data used for attaching to the PM domains.
> + * @list: An out-parameter with an allocated list of attached PM domains.
> + *
> + * NOTE: this will also handle calling devm_pm_domain_detach_list() for
> + * you during remove phase.
> + *
> + * Returns the number of attached PM domains or a negative error code in case of
> + * a failure.
> + */
> +int devm_pm_domain_attach_list(struct device *dev,
> +			       const struct dev_pm_domain_attach_data *data,
> +			       struct dev_pm_domain_list **list)
> +{
> +	int ret, num_pds = 0;

Do we require this =0? In the very next line you're initing this anyway.

> +
> +	num_pds = dev_pm_domain_attach_list(dev, data, list);
> +
> +	ret = devm_add_action_or_reset(dev, devm_pm_domain_detach_list, *list);
> +	if (ret)
> +		return ret;
> +
> +	return num_pds;
> +}
> +EXPORT_SYMBOL_GPL(devm_pm_domain_attach_list);
> +
> +/**
>   * dev_pm_domain_detach - Detach a device from its PM domain.
>   * @dev: Device to detach.
>   * @power_off: Used to indicate whether we should power off the device.
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 772d328..efd517017 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -450,8 +450,12 @@ struct device *dev_pm_domain_attach_by_name(struct device *dev,
>  int dev_pm_domain_attach_list(struct device *dev,
>  			      const struct dev_pm_domain_attach_data *data,
>  			      struct dev_pm_domain_list **list);
> +int devm_pm_domain_attach_list(struct device *dev,
> +			       const struct dev_pm_domain_attach_data *data,
> +			       struct dev_pm_domain_list **list);
>  void dev_pm_domain_detach(struct device *dev, bool power_off);
>  void dev_pm_domain_detach_list(struct dev_pm_domain_list *list);
> +void devm_pm_domain_detach_list(void *list);

Why not just call it dev_pm_domain_list *list? Why make it void? I am a
bit confused.


-- 
Best regards,
Dhruva Gole <d-gole@ti.com>