Hi,
On 2018년 11월 22일 03:01, Lukasz Luba wrote:
> This patch adds implementation for global suspend/resume for
> devfreq framework. System suspend will next use these functions.
>
> The patch draws on Tobias Jakobi's work posted ~2 years ago, who tried to
> solve issue with devfreq device's frequency during suspend/resume.
> During the discussion on LKML some corner cases and comments appeared
> related to the design. This patch address them keeping in mind suggestions
> from Chanwoo Choi.
Please remove the duplicate information about patch history.
>
> 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 | 49 +++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/devfreq.h | 7 +++++++
> 2 files changed, 56 insertions(+)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 7e09de8..2f4391c 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -44,6 +44,9 @@ static LIST_HEAD(devfreq_governor_list);
> static LIST_HEAD(devfreq_list);
> static DEFINE_MUTEX(devfreq_list_lock);
>
> +/* Flag showing state of suspend/resume */
> +static bool devfreq_suspended;
Is it necessary? This patch just saves the 'true' or 'false' to this variable.
And there are no any point to check the value of this variable.
Please remove it.
> +
> /**
> * find_device_devfreq() - find devfreq struct using device pointer
> * @dev: device pointer used to lookup device devfreq.
> @@ -938,6 +941,52 @@ 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_warn(&devfreq->dev, "device suspend failed\n");
> + }
> + mutex_unlock(&devfreq_list_lock);
> +
> + devfreq_suspended = true;
Remove it.
> +}
> +
> +/**
> + * 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;
> +
> + devfreq_suspended = false;
Remove it.
> +
> + mutex_lock(&devfreq_list_lock);
> + list_for_each_entry(devfreq, &devfreq_list, node) {
> + ret = devfreq_resume_device(devfreq);
> + if (ret)
> + dev_warn(&devfreq->dev, "device resume failed\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 7fe96f9..4f0fea8 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -202,6 +202,10 @@ 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);
>
> +
Remove the blank line.
> +extern void devfreq_suspend(void);
> +extern void devfreq_resume(void);
> +
> /**
> * update_devfreq() - Reevaluate the device and configure frequency
> * @devfreq: the devfreq device
> @@ -396,6 +400,9 @@ static inline int devfreq_update_stats(struct devfreq *df)
> {
> return -EINVAL;
> }
> +
> +static inline void devfreq_suspend(void) {}
> +static inline void devfreq_resume(void) {}
You better to move the inline definitions
under 'devfreq_resume_device' inline function.
> #endif /* CONFIG_PM_DEVFREQ */
>
> #endif /* __LINUX_DEVFREQ_H__ */
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
