Hi Lukasz, On 2018년 12월 03일 23:31, Lukasz Luba wrote: > This patch adds implementation for global suspend/resume for > devfreq framework. System suspend will next use these functions. > > The patch is based on earlier work by Tobias Jakobi. Please remove it from each patch description. > > 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 | 42 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/devfreq.h | 6 ++++++ > 2 files changed, 48 insertions(+) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 36bed24..7d60423 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -935,6 +935,48 @@ 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"); When I checked the cpufreq_suspend(), cpufreq_suspend() prints message as 'err' level. I think that dev_err is more proper than dev_warn. I'm not sure what is more correct log. But, 'devfreq->dev' device has the separate suspend/resume function. So, I think that devfreq_suspend() should print error log containing that it is error by devfreq framework. "device suspend failed" -> "failed to suspend devfreq device" > + } > + 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, "device resume failed\n"); ditto. "device resume failed" -> "failed to resume devfreq device" > + } > + 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