Re: [PATCH 1/3] CLK: uninline clk_prepare() and clk_unprepare()

From: Mike Turquette
Date: Wed Nov 21 2012 - 15:43:31 EST


Quoting Viresh Kumar (2012-11-20 02:13:55)
> On 20 November 2012 14:52, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote:
> > We'll need to invoke clk_unprepare() via a pointer in our devm_*
> > conversion so let's uninline the pair.
>
> Sorry, but you aren't doing this :(
> This routine is already uninlined as it is in clk.c
>
> Instead you are just moving clk_prepare(), etc calls within
> #ifdef CONFIG_HAVE_CLK
> #else
> #endif
>
> I doubt why they have been added under #ifdef CONFIG_HAVE_CLK_PREPARE
> earlier. Can they exist without CONFIG_HAVE_CLK
>
> @Mike: ?
>

HAVE_CLK logically wraps HAVE_CLK_PREPARE. There is no point in
selecting HAVE_CLK_PREPARE without HAVE_CLK.

Looking through the code I see that this used to be the case. Commit
93abe8e "clk: add non CONFIG_HAVE_CLK routines" moved the
clk_(un)prepare declarations outside of #ifdef CONFIG_HAVE_CLK. That
commit was authored by you. Can you elaborate on why that aspect of the
patch was needed?

Thanks,
Mike

> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > ---
> > drivers/clk/clk.c | 4 ++++
> > include/linux/clk.h | 68 +++++++++++++++++++++++++----------------------------
> > 2 files changed, 36 insertions(+), 36 deletions(-)
> >
> > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> > index 56e4495e..1b642f2 100644
> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -374,6 +374,7 @@ struct clk *__clk_lookup(const char *name)
> >
> > void __clk_unprepare(struct clk *clk)
> > {
> > +#ifdef CONFIG_HAVE_CLK_PREPARE
>
> clk.c is compiled if COMMON_CLK is selected. And COMMON_CLK has following:
> select HAVE_CLK_PREPARE
>
> So, these checks you added don't have a meaning.
>
> > if (!clk)
> > return;
> >
> > @@ -389,6 +390,7 @@ void __clk_unprepare(struct clk *clk)
> > clk->ops->unprepare(clk->hw);
> >
> > __clk_unprepare(clk->parent);
> > +#endif
> > }
> >
> > /**
> > @@ -412,6 +414,7 @@ EXPORT_SYMBOL_GPL(clk_unprepare);
> >
> > int __clk_prepare(struct clk *clk)
> > {
> > +#ifdef CONFIG_HAVE_CLK_PREPARE
>
> ditto.
>
> > int ret = 0;
> >
> > if (!clk)
> > @@ -432,6 +435,7 @@ int __clk_prepare(struct clk *clk)
> > }
> >
> > clk->prepare_count++;
> > +#endif
> >
> > return 0;
> > }
> > diff --git a/include/linux/clk.h b/include/linux/clk.h
> > index b3ac22d..f8204c3 100644
> > --- a/include/linux/clk.h
> > +++ b/include/linux/clk.h
> > @@ -84,42 +84,6 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
> >
> > #endif
> >
> > -/**
> > - * clk_prepare - prepare a clock source
> > - * @clk: clock source
> > - *
> > - * This prepares the clock source for use.
> > - *
> > - * Must not be called from within atomic context.
> > - */
> > -#ifdef CONFIG_HAVE_CLK_PREPARE
> > -int clk_prepare(struct clk *clk);
> > -#else
> > -static inline int clk_prepare(struct clk *clk)
> > -{
> > - might_sleep();
> > - return 0;
> > -}
> > -#endif
> > -
> > -/**
> > - * clk_unprepare - undo preparation of a clock source
> > - * @clk: clock source
> > - *
> > - * This undoes a previously prepared clock. The caller must balance
> > - * the number of prepare and unprepare calls.
> > - *
> > - * Must not be called from within atomic context.
> > - */
> > -#ifdef CONFIG_HAVE_CLK_PREPARE
> > -void clk_unprepare(struct clk *clk);
> > -#else
> > -static inline void clk_unprepare(struct clk *clk)
> > -{
> > - might_sleep();
> > -}
> > -#endif
> > -
> > #ifdef CONFIG_HAVE_CLK
> > /**
> > * clk_get - lookup and obtain a reference to a clock producer.
> > @@ -159,6 +123,27 @@ struct clk *clk_get(struct device *dev, const char *id);
> > struct clk *devm_clk_get(struct device *dev, const char *id);
> >
> > /**
> > + * clk_prepare - prepare a clock source
> > + * @clk: clock source
> > + *
> > + * This prepares the clock source for use.
> > + *
> > + * Must not be called from within atomic context.
> > + */
> > +int clk_prepare(struct clk *clk);
> > +
> > +/**
> > + * clk_unprepare - undo preparation of a clock source
> > + * @clk: clock source
> > + *
> > + * This undoes a previously prepared clock. The caller must balance
> > + * the number of prepare and unprepare calls.
> > + *
> > + * Must not be called from within atomic context.
> > + */
> > +void clk_unprepare(struct clk *clk);
> > +
> > +/**
> > * clk_enable - inform the system when the clock source should be running.
> > * @clk: clock source
> > *
> > @@ -292,6 +277,17 @@ static inline void clk_put(struct clk *clk) {}
> >
> > static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
> >
> > +static inline int clk_prepare(struct clk *clk)
> > +{
> > + might_sleep();
> > + return 0;
> > +}
> > +
> > +static inline void clk_unprepare(struct clk *clk)
> > +{
> > + might_sleep();
> > +}
> > +
> > static inline int clk_enable(struct clk *clk)
> > {
> > return 0;
> > --
> > 1.7.11.7
> >
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