2020-09-24 08:04:55

by zhuguangqing83

Subject: [PATCH] cpuidle: change #ifdef for the declaration of cpuidle_enter_s2idle()

From: zhuguangqing <[email protected]>

Currently, if CONFIG_SUSPEND=n and CONFIG_CPU_IDLE=y, the function
cpuidle_enter_s2idle() is declared but not defined, it may cause error
when cpuidle_enter_s2idle() is called.

If CONFIG_SUSPEND=y and CONFIG_CPU_IDLE=n, the function
cpuidle_enter_s2idle() is defined as "return -ENODEV;" which is not
supposed to be.

Change #ifdef CONFIG_CPU_IDLE to #ifdef CONFIG_SUSPEND for
cpuidle_enter_s2idle() in cpuidle.h, which is consistent with its
defination in cpuidle.c.

Signed-off-by: zhuguangqing <[email protected]>
---
include/linux/cpuidle.h | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 6175c77bf25e..2aa8cead1727 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -216,22 +216,26 @@ static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev,
u64 latency_limit_ns);
-extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
- struct cpuidle_device *dev);
extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
#else
static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev,
u64 latency_limit_ns)
{return -ENODEV; }
-static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
- struct cpuidle_device *dev)
-{return -ENODEV; }
static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
{
}
#endif

+#ifdef CONFIG_SUSPEND
+extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev);
+#else
+static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{return -ENODEV; }
+#endif
+
/* kernel/sched/idle.c */
extern void sched_idle_set_state(struct cpuidle_state *idle_state);
extern void default_idle_call(void);
--
2.17.1

2020-09-25 14:44:06

by Rafael J. Wysocki

Subject: Re: [PATCH] cpuidle: change #ifdef for the declaration of cpuidle_enter_s2idle()

On Thu, Sep 24, 2020 at 10:01 AM <[email protected]> wrote:
>
> From: zhuguangqing <[email protected]>
>
> Currently, if CONFIG_SUSPEND=n and CONFIG_CPU_IDLE=y, the function
> cpuidle_enter_s2idle() is declared but not defined, it may cause error
> when cpuidle_enter_s2idle() is called.
>
> If CONFIG_SUSPEND=y and CONFIG_CPU_IDLE=n, the function
> cpuidle_enter_s2idle() is defined as "return -ENODEV;" which is not
> supposed to be.
>
> Change #ifdef CONFIG_CPU_IDLE to #ifdef CONFIG_SUSPEND for
> cpuidle_enter_s2idle() in cpuidle.h, which is consistent with its
> defination in cpuidle.c.

Well, what about the case when CONFIG_SUSPEND is set, but CONFIG_CPU_IDLE isn't?

>
> Signed-off-by: zhuguangqing <[email protected]>
> ---
> include/linux/cpuidle.h | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> index 6175c77bf25e..2aa8cead1727 100644
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -216,22 +216,26 @@ static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
> extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> struct cpuidle_device *dev,
> u64 latency_limit_ns);
> -extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> - struct cpuidle_device *dev);
> extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
> #else
> static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> struct cpuidle_device *dev,
> u64 latency_limit_ns)
> {return -ENODEV; }
> -static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> - struct cpuidle_device *dev)
> -{return -ENODEV; }
> static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
> {
> }
> #endif
>
> +#ifdef CONFIG_SUSPEND
> +extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> + struct cpuidle_device *dev);
> +#else
> +static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> + struct cpuidle_device *dev)
> +{return -ENODEV; }
> +#endif
> +
> /* kernel/sched/idle.c */
> extern void sched_idle_set_state(struct cpuidle_state *idle_state);
> extern void default_idle_call(void);
> --
> 2.17.1
>

2020-09-26 01:31:34

by zhuguangqing83

Subject: Re: [PATCH] cpuidle: change #ifdef for the declaration of cpuidle_enter_s2idle()

> On Thu, Sep 24, 2020 at 10:01 AM <[email protected]> wrote:
> >
> > From: zhuguangqing <[email protected]>
> >
> > Currently, if CONFIG_SUSPEND=n and CONFIG_CPU_IDLE=y, the function
> > cpuidle_enter_s2idle() is declared but not defined, it may cause error
> > when cpuidle_enter_s2idle() is called.
> >
> > If CONFIG_SUSPEND=y and CONFIG_CPU_IDLE=n, the function
> > cpuidle_enter_s2idle() is defined as "return -ENODEV;" which is not
> > supposed to be.
> >
> > Change #ifdef CONFIG_CPU_IDLE to #ifdef CONFIG_SUSPEND for
> > cpuidle_enter_s2idle() in cpuidle.h, which is consistent with its
> > defination in cpuidle.c.
>
> Well, what about the case when CONFIG_SUSPEND is set, but CONFIG_CPU_IDLE
> isn't?
>

When CONFIG_SUSPEND is set, but CONFIG_CPU_IDLE isn't, the function
cpuidle_enter_s2idle() is defined in cpuidle.c, but the defination in
cpuidle.c is not used actually because CONFIG_CPU_IDLE isn't set, we
only use its defination as "return -ENODEV;" in cpuidle.h.

> >
> > Signed-off-by: zhuguangqing <[email protected]>
> > ---
> > include/linux/cpuidle.h | 14 +++++++++-----
> > 1 file changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> > index 6175c77bf25e..2aa8cead1727 100644
> > --- a/include/linux/cpuidle.h
> > +++ b/include/linux/cpuidle.h
> > @@ -216,22 +216,26 @@ static inline struct cpuidle_device
> *cpuidle_get_device(void) {return NULL; }
> > extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> > struct cpuidle_device *dev,
> > u64 latency_limit_ns);
> > -extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > - struct cpuidle_device *dev);
> > extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
> > #else
> > static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> > struct cpuidle_device *dev,
> > u64 latency_limit_ns)
> > {return -ENODEV; }
> > -static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > - struct cpuidle_device *dev)
> > -{return -ENODEV; }
> > static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
> > {
> > }
> > #endif
> >
> > +#ifdef CONFIG_SUSPEND
> > +extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > + struct cpuidle_device *dev);
> > +#else
> > +static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > + struct cpuidle_device *dev)
> > +{return -ENODEV; }
> > +#endif
> > +
> > /* kernel/sched/idle.c */
> > extern void sched_idle_set_state(struct cpuidle_state *idle_state);
> > extern void default_idle_call(void);
> > --
> > 2.17.1
> >

2020-09-28 14:12:27

by Rafael J. Wysocki

Subject: Re: [PATCH] cpuidle: change #ifdef for the declaration of cpuidle_enter_s2idle()

On Sat, Sep 26, 2020 at 3:30 AM zhuguangqing83 <[email protected]> wrote:
>
>
> > On Thu, Sep 24, 2020 at 10:01 AM <[email protected]> wrote:
> > >
> > > From: zhuguangqing <[email protected]>
> > >
> > > Currently, if CONFIG_SUSPEND=n and CONFIG_CPU_IDLE=y, the function
> > > cpuidle_enter_s2idle() is declared but not defined, it may cause error
> > > when cpuidle_enter_s2idle() is called.
> > >
> > > If CONFIG_SUSPEND=y and CONFIG_CPU_IDLE=n, the function
> > > cpuidle_enter_s2idle() is defined as "return -ENODEV;" which is not
> > > supposed to be.
> > >
> > > Change #ifdef CONFIG_CPU_IDLE to #ifdef CONFIG_SUSPEND for
> > > cpuidle_enter_s2idle() in cpuidle.h, which is consistent with its
> > > defination in cpuidle.c.
> >
> > Well, what about the case when CONFIG_SUSPEND is set, but CONFIG_CPU_IDLE
> > isn't?
> >
>
> When CONFIG_SUSPEND is set, but CONFIG_CPU_IDLE isn't, the function
> cpuidle_enter_s2idle() is defined in cpuidle.c, but the defination in
> cpuidle.c is not used actually because CONFIG_CPU_IDLE isn't set, we
> only use its defination as "return -ENODEV;" in cpuidle.h.

Actually, if CONFIG_CPU_IDLE is not set, cpuidle.c is not compiled at
all AFAICS, but after the $subject patch the compiler will be looking
for cpuidle_enter_s2idle() in that case, won't it? [The static inline
stub is only present for CONFIG_SUSPEND unset.]

> > > Signed-off-by: zhuguangqing <[email protected]>
> > > ---
> > > include/linux/cpuidle.h | 14 +++++++++-----
> > > 1 file changed, 9 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> > > index 6175c77bf25e..2aa8cead1727 100644
> > > --- a/include/linux/cpuidle.h
> > > +++ b/include/linux/cpuidle.h
> > > @@ -216,22 +216,26 @@ static inline struct cpuidle_device
> > *cpuidle_get_device(void) {return NULL; }
> > > extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> > > struct cpuidle_device *dev,
> > > u64 latency_limit_ns);
> > > -extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > > - struct cpuidle_device *dev);
> > > extern void cpuidle_use_deepest_state(u64 latency_limit_ns);
> > > #else
> > > static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> > > struct cpuidle_device *dev,
> > > u64 latency_limit_ns)
> > > {return -ENODEV; }
> > > -static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > > - struct cpuidle_device *dev)
> > > -{return -ENODEV; }
> > > static inline void cpuidle_use_deepest_state(u64 latency_limit_ns)
> > > {
> > > }
> > > #endif
> > >
> > > +#ifdef CONFIG_SUSPEND
> > > +extern int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > > + struct cpuidle_device *dev);
> > > +#else
> > > +static inline int cpuidle_enter_s2idle(struct cpuidle_driver *drv,
> > > + struct cpuidle_device *dev)
> > > +{return -ENODEV; }
> > > +#endif
> > > +
> > > /* kernel/sched/idle.c */
> > > extern void sched_idle_set_state(struct cpuidle_state *idle_state);
> > > extern void default_idle_call(void);
> > > --
> > > 2.17.1
> > >
>