[v3,1/3] PM: runtime: add devm_pm_runtime_enable helper

A typical code pattern for pm_runtime_enable() call is to call it in the
_probe function and to call pm_runtime_disable() both from _probe error
path and from _remove function. For some drivers the whole remove
function would consist of the call to pm_remove_disable().

Add helper function to replace this bolierplate piece of code. Calling
devm_pm_runtime_enable() removes the need for calling
pm_runtime_disable() both in the probe()'s error path and in the
remove() function.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

---
 drivers/base/power/runtime.c | 17 +++++++++++++++++
 include/linux/pm_runtime.h   |  4 ++++
 2 files changed, 21 insertions(+)

-- 
2.30.2

On Sat, Jul 31, 2021 at 9:50 PM Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> A typical code pattern for pm_runtime_enable() call is to call it in the
> _probe function and to call pm_runtime_disable() both from _probe error
> path and from _remove function. For some drivers the whole remove
> function would consist of the call to pm_remove_disable().
>
> Add helper function to replace this bolierplate piece of code. Calling
> devm_pm_runtime_enable() removes the need for calling
> pm_runtime_disable() both in the probe()'s error path and in the
> remove() function.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/base/power/runtime.c | 17 +++++++++++++++++
>  include/linux/pm_runtime.h   |  4 ++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 8a66eaf731e4..ec94049442b9 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -1447,6 +1447,23 @@ void pm_runtime_enable(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(pm_runtime_enable);
>
> +static void pm_runtime_disable_action(void *data)
> +{
> +       pm_runtime_disable(data);
> +}
> +
> +/**
> + * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.
> + * @dev: Device to handle.
> + */
> +int devm_pm_runtime_enable(struct device *dev)
> +{
> +       pm_runtime_enable(dev);
> +
> +       return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);

When exactly is pm_runtime_disable_action() going to run by this rule?
 When the device goes away or when the driver is unbound from it?

> +}
> +EXPORT_SYMBOL_GPL(devm_pm_runtime_enable);
> +
>  /**
>   * pm_runtime_forbid - Block runtime PM of a device.
>   * @dev: Device to handle.
> diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
> index aab8b35e9f8a..222da43b7096 100644
> --- a/include/linux/pm_runtime.h
> +++ b/include/linux/pm_runtime.h
> @@ -59,6 +59,8 @@ extern void pm_runtime_put_suppliers(struct device *dev);
>  extern void pm_runtime_new_link(struct device *dev);
>  extern void pm_runtime_drop_link(struct device_link *link);
>
> +extern int devm_pm_runtime_enable(struct device *dev);
> +
>  /**
>   * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter.
>   * @dev: Target device.
> @@ -253,6 +255,8 @@ static inline void __pm_runtime_disable(struct device *dev, bool c) {}
>  static inline void pm_runtime_allow(struct device *dev) {}
>  static inline void pm_runtime_forbid(struct device *dev) {}
>
> +static inline int devm_pm_runtime_enable(struct device *dev) { return 0; }
> +
>  static inline void pm_suspend_ignore_children(struct device *dev, bool enable) {}
>  static inline void pm_runtime_get_noresume(struct device *dev) {}
>  static inline void pm_runtime_put_noidle(struct device *dev) {}
> --
> 2.30.2
>

On Wed, 4 Aug 2021 at 21:07, Rafael J. Wysocki <rafael@kernel.org> wrote:
>

> On Sat, Jul 31, 2021 at 9:50 PM Dmitry Baryshkov

> <dmitry.baryshkov@linaro.org> wrote:

> >

> > A typical code pattern for pm_runtime_enable() call is to call it in the

> > _probe function and to call pm_runtime_disable() both from _probe error

> > path and from _remove function. For some drivers the whole remove

> > function would consist of the call to pm_remove_disable().

> >

> > Add helper function to replace this bolierplate piece of code. Calling

> > devm_pm_runtime_enable() removes the need for calling

> > pm_runtime_disable() both in the probe()'s error path and in the

> > remove() function.

> >

> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> > ---

> >  drivers/base/power/runtime.c | 17 +++++++++++++++++

> >  include/linux/pm_runtime.h   |  4 ++++

> >  2 files changed, 21 insertions(+)

> >

> > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c

> > index 8a66eaf731e4..ec94049442b9 100644

> > --- a/drivers/base/power/runtime.c

> > +++ b/drivers/base/power/runtime.c

> > @@ -1447,6 +1447,23 @@ void pm_runtime_enable(struct device *dev)

> >  }

> >  EXPORT_SYMBOL_GPL(pm_runtime_enable);

> >

> > +static void pm_runtime_disable_action(void *data)

> > +{

> > +       pm_runtime_disable(data);

> > +}

> > +

> > +/**

> > + * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.

> > + * @dev: Device to handle.

> > + */

> > +int devm_pm_runtime_enable(struct device *dev)

> > +{

> > +       pm_runtime_enable(dev);

> > +

> > +       return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);

>

> When exactly is pm_runtime_disable_action() going to run by this rule?

>  When the device goes away or when the driver is unbound from it?


When the driver is unbound (either because probe() returns an error or
because __device_release_driver() is being called).
This corresponds to a typical call to pm_runtime_disable() from the
probe()'s error path or in the remove() callback.

> > +}

> > +EXPORT_SYMBOL_GPL(devm_pm_runtime_enable);

> > +

> >  /**

> >   * pm_runtime_forbid - Block runtime PM of a device.

> >   * @dev: Device to handle.

> > diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h

> > index aab8b35e9f8a..222da43b7096 100644

> > --- a/include/linux/pm_runtime.h

> > +++ b/include/linux/pm_runtime.h

> > @@ -59,6 +59,8 @@ extern void pm_runtime_put_suppliers(struct device *dev);

> >  extern void pm_runtime_new_link(struct device *dev);

> >  extern void pm_runtime_drop_link(struct device_link *link);

> >

> > +extern int devm_pm_runtime_enable(struct device *dev);

> > +

> >  /**

> >   * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter.

> >   * @dev: Target device.

> > @@ -253,6 +255,8 @@ static inline void __pm_runtime_disable(struct device *dev, bool c) {}

> >  static inline void pm_runtime_allow(struct device *dev) {}

> >  static inline void pm_runtime_forbid(struct device *dev) {}

> >

> > +static inline int devm_pm_runtime_enable(struct device *dev) { return 0; }

> > +

> >  static inline void pm_suspend_ignore_children(struct device *dev, bool enable) {}

> >  static inline void pm_runtime_get_noresume(struct device *dev) {}

> >  static inline void pm_runtime_put_noidle(struct device *dev) {}

> > --

> > 2.30.2

> >




-- 
With best wishes
Dmitry

On Wed, Aug 4, 2021 at 11:03 PM Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> On Wed, 4 Aug 2021 at 21:07, Rafael J. Wysocki <rafael@kernel.org> wrote:
> >
> > On Sat, Jul 31, 2021 at 9:50 PM Dmitry Baryshkov
> > <dmitry.baryshkov@linaro.org> wrote:
> > >
> > > A typical code pattern for pm_runtime_enable() call is to call it in the
> > > _probe function and to call pm_runtime_disable() both from _probe error
> > > path and from _remove function. For some drivers the whole remove
> > > function would consist of the call to pm_remove_disable().
> > >
> > > Add helper function to replace this bolierplate piece of code. Calling
> > > devm_pm_runtime_enable() removes the need for calling
> > > pm_runtime_disable() both in the probe()'s error path and in the
> > > remove() function.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > > ---
> > >  drivers/base/power/runtime.c | 17 +++++++++++++++++
> > >  include/linux/pm_runtime.h   |  4 ++++
> > >  2 files changed, 21 insertions(+)
> > >
> > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> > > index 8a66eaf731e4..ec94049442b9 100644
> > > --- a/drivers/base/power/runtime.c
> > > +++ b/drivers/base/power/runtime.c
> > > @@ -1447,6 +1447,23 @@ void pm_runtime_enable(struct device *dev)
> > >  }
> > >  EXPORT_SYMBOL_GPL(pm_runtime_enable);
> > >
> > > +static void pm_runtime_disable_action(void *data)
> > > +{
> > > +       pm_runtime_disable(data);
> > > +}
> > > +
> > > +/**
> > > + * devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.
> > > + * @dev: Device to handle.
> > > + */
> > > +int devm_pm_runtime_enable(struct device *dev)
> > > +{
> > > +       pm_runtime_enable(dev);
> > > +
> > > +       return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev);
> >
> > When exactly is pm_runtime_disable_action() going to run by this rule?
> >  When the device goes away or when the driver is unbound from it?
>
> When the driver is unbound (either because probe() returns an error or
> because __device_release_driver() is being called).
> This corresponds to a typical call to pm_runtime_disable() from the
> probe()'s error path or in the remove() callback.

OK, so

Acked-by: Rafael J. Wysocki <rafael@kernel.org>

for the PM-runtime framework changes in this series (patches [1-2/3])
and please feel free to route them in through whatever tree is most
suitable (or let me know if you want me to pick them up).