On 11/22/18 4:07 AM, Chanwoo Choi wrote:
> 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.
OK, I will move it there.
>
>> #endif /* CONFIG_PM_DEVFREQ */
>>
>> #endif /* __LINUX_DEVFREQ_H__ */
>>
>
>
Regards,
Lukasz Luba
