Re: [PATCH v2 3/3] devfreq: Add current freq callback in device profile

From: Rafael J. Wysocki
Date: Mon Sep 17 2012 - 15:57:46 EST


On Monday, September 17, 2012, MyungJoo Ham wrote:
> > From: Rajagopal Venkat <rajagopal.venkat@xxxxxxxxxx>
> >
> > Devfreq returns governor predicted frequency as current frequency
> > via sysfs interface. But device may not support all frequencies
> > that governor predicts. So add a callback in device profile to get
> > current freq from driver. Also add a new sysfs node to expose
> > governor predicted next target frequency.
> >
> > Signed-off-by: Rajagopal Venkat <rajagopal.venkat@xxxxxxxxxx>
>
> Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>

OK, I'm taking this as an acked-by (signed-off-by would be appropriate if
the patch went through your hands).

Does it apply to [3/3] only or to all of the patches in the series?

Rafael


> > ---
> > Documentation/ABI/testing/sysfs-class-devfreq | 11 ++++++++++-
> > drivers/devfreq/devfreq.c | 14 ++++++++++++++
> > include/linux/devfreq.h | 3 +++
> > 3 files changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq
> > index 89283b1..e6cf08e 100644
> > --- a/Documentation/ABI/testing/sysfs-class-devfreq
> > +++ b/Documentation/ABI/testing/sysfs-class-devfreq
> > @@ -19,7 +19,16 @@ Date: September 2011
> > Contact: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
> > Description:
> > The /sys/class/devfreq/.../cur_freq shows the current
> > - frequency of the corresponding devfreq object.
> > + frequency of the corresponding devfreq object. Same as
> > + target_freq when get_cur_freq() is not implemented by
> > + devfreq driver.
> > +
> > +What: /sys/class/devfreq/.../target_freq
> > +Date: September 2012
> > +Contact: Rajagopal Venkat <rajagopal.venkat@xxxxxxxxxx>
> > +Description:
> > + The /sys/class/devfreq/.../target_freq shows the next governor
> > + predicted target frequency of the corresponding devfreq object.
> >
> > What: /sys/class/devfreq/.../polling_interval
> > Date: September 2011
> > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> > index 309c46e..049e273 100644
> > --- a/drivers/devfreq/devfreq.c
> > +++ b/drivers/devfreq/devfreq.c
> > @@ -401,6 +401,19 @@ static ssize_t show_governor(struct device *dev,
> > static ssize_t show_freq(struct device *dev,
> > struct device_attribute *attr, char *buf)
> > {
> > + unsigned long freq;
> > + struct devfreq *devfreq = to_devfreq(dev);
> > +
> > + if (devfreq->profile->get_cur_freq &&
> > + !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
> > + return sprintf(buf, "%lu\n", freq);
> > +
> > + return sprintf(buf, "%lu\n", devfreq->previous_freq);
> > +}
> > +
> > +static ssize_t show_target_freq(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
> > }
> >
> > @@ -504,6 +517,7 @@ static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr,
> > static struct device_attribute devfreq_attrs[] = {
> > __ATTR(governor, S_IRUGO, show_governor, NULL),
> > __ATTR(cur_freq, S_IRUGO, show_freq, NULL),
> > + __ATTR(target_freq, S_IRUGO, show_target_freq, NULL),
> > __ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval,
> > store_polling_interval),
> > __ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq),
> > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> > index 7c7e179..d12ed41 100644
> > --- a/include/linux/devfreq.h
> > +++ b/include/linux/devfreq.h
> > @@ -66,6 +66,8 @@ struct devfreq_dev_status {
> > * explained above with "DEVFREQ_FLAG_*" macros.
> > * @get_dev_status The device should provide the current performance
> > * status to devfreq, which is used by governors.
> > + * @get_cur_freq The device should provide the current frequency
> > + * at which it is operating.
> > * @exit An optional callback that is called when devfreq
> > * is removing the devfreq object due to error or
> > * from devfreq_remove_device() call. If the user
> > @@ -79,6 +81,7 @@ struct devfreq_dev_profile {
> > int (*target)(struct device *dev, unsigned long *freq, u32 flags);
> > int (*get_dev_status)(struct device *dev,
> > struct devfreq_dev_status *stat);
> > + int (*get_cur_freq)(struct device *dev, unsigned long *freq);
> > void (*exit)(struct device *dev);
> > };
> >
>

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