Re: [PATCH v3 3/5] devfreq: add devfreq_suspend/resume() functions

From: Chanwoo Choi
Date: Wed Dec 05 2018 - 20:30:56 EST


Hi Lukasz,

On 2018ë 12ì 05ì 20:05, Lukasz Luba wrote:
> This patch adds implementation for global suspend/resume for
> devfreq framework. System suspend will next use these functions.
>
> Suggested-by: Tobias Jakobi <tjakobi@xxxxxxxxxxxxxxxxxxxxx>
> Suggested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/devfreq/devfreq.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> include/linux/devfreq.h | 6 ++++++
> 2 files changed, 50 insertions(+)

Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>

>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 46517b6..0ae3de7 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -935,6 +935,50 @@ int devfreq_resume_device(struct devfreq *devfreq)
> EXPORT_SYMBOL(devfreq_resume_device);
>
> /**
> + * devfreq_suspend() - Suspend devfreq governors and devices
> + *
> + * Called during system wide Suspend/Hibernate cycles for suspending governors
> + * and devices preserving the state for resume. On some platforms the devfreq
> + * device must have precise state (frequency) after resume in order to provide
> + * fully operating setup.
> + */
> +void devfreq_suspend(void)
> +{
> + struct devfreq *devfreq;
> + int ret;
> +
> + mutex_lock(&devfreq_list_lock);
> + list_for_each_entry(devfreq, &devfreq_list, node) {
> + ret = devfreq_suspend_device(devfreq);
> + if (ret)
> + dev_err(&devfreq->dev,
> + "failed to suspend devfreq device\n");
> + }
> + mutex_unlock(&devfreq_list_lock);
> +}
> +
> +/**
> + * devfreq_resume() - Resume devfreq governors and devices
> + *
> + * Called during system wide Suspend/Hibernate cycle for resuming governors and
> + * devices that are suspended with devfreq_suspend().
> + */
> +void devfreq_resume(void)
> +{
> + struct devfreq *devfreq;
> + int ret;
> +
> + mutex_lock(&devfreq_list_lock);
> + list_for_each_entry(devfreq, &devfreq_list, node) {
> + ret = devfreq_resume_device(devfreq);
> + if (ret)
> + dev_warn(&devfreq->dev,
> + "failed to resume devfreq device\n");
> + }
> + mutex_unlock(&devfreq_list_lock);
> +}
> +
> +/**
> * devfreq_add_governor() - Add devfreq governor
> * @governor: the devfreq governor to be added
> */
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index d985199..fbffa74 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -205,6 +205,9 @@ extern void devm_devfreq_remove_device(struct device *dev,
> extern int devfreq_suspend_device(struct devfreq *devfreq);
> extern int devfreq_resume_device(struct devfreq *devfreq);
>
> +extern void devfreq_suspend(void);
> +extern void devfreq_resume(void);
> +
> /**
> * update_devfreq() - Reevaluate the device and configure frequency
> * @devfreq: the devfreq device
> @@ -331,6 +334,9 @@ static inline int devfreq_resume_device(struct devfreq *devfreq)
> return 0;
> }
>
> +static inline void devfreq_suspend(void) {}
> +static inline void devfreq_resume(void) {}
> +
> static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
> unsigned long *freq, u32 flags)
> {
>


--
Best Regards,
Chanwoo Choi
Samsung Electronics