Hi, I didn't see any framework which exporting the class instance. It is very dangerous. Unknown device drivers is able to reset the 'devfreq_class' instance. I can't agree this approach. Regards, Chanwoo Choi On 2018년 07월 04일 08:47, Matthias Kaehlcke wrote: > Exporting the device class allows other parts of the kernel to enumerate > the devfreq devices and receive notification when a devfreq device is > added or removed. > > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> > Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> > --- > Changes in v5: > - none > > Changes in v4: > - added 'Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>' tag > > Changes in v3: > - none > > Changes in v2: > - patch added to series > --- > drivers/devfreq/devfreq.c | 3 ++- > include/linux/devfreq.h | 2 ++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 4cbaa7ad1972..38b90b64fc6e 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -31,7 +31,8 @@ > #define MAX(a,b) ((a > b) ? a : b) > #define MIN(a,b) ((a < b) ? a : b) > > -static struct class *devfreq_class; > +struct class *devfreq_class; > +EXPORT_SYMBOL_GPL(devfreq_class); > > /* > * devfreq core provides delayed work based load monitoring helper > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > index c4f84a769cb5..964e064a951f 100644 > --- a/include/linux/devfreq.h > +++ b/include/linux/devfreq.h > @@ -206,6 +206,8 @@ struct devfreq_freqs { > }; > > #if defined(CONFIG_PM_DEVFREQ) > +extern struct class *devfreq_class; > + > extern struct devfreq *devfreq_add_device(struct device *dev, > struct devfreq_dev_profile *profile, > const char *governor_name, > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html