[PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Pierluigi Passaro]

Both the functions gpiochip_request_own_desc and
gpiochip_free_own_desc are exported from
    drivers/gpio/gpiolib.c
but this file is compiled only when CONFIG_GPIOLIB is enabled.
Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
reasonable definitions in the "#else" branch.

Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
Reported-by: kernel test robot <lkp@intel.com>
---
 include/linux/gpio/driver.h | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 44783fc16125..ed77c6fc0beb 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
 
 #endif /* CONFIG_PINCTRL */
 
+#ifdef CONFIG_GPIOLIB
+
 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 					    unsigned int hwnum,
 					    const char *label,
@@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
 					    enum gpiod_flags dflags);
 void gpiochip_free_own_desc(struct gpio_desc *desc);
 
-#ifdef CONFIG_GPIOLIB
-
 /* lock/unlock as IRQ */
 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
@@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 
 #else /* CONFIG_GPIOLIB */
 
+static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
+					    unsigned int hwnum,
+					    const char *label,
+					    enum gpio_lookup_flags lflags,
+					    enum gpiod_flags dflags)
+{
+	/* GPIO can never have been requested */
+	WARN_ON(1);
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
+{
+	WARN_ON(1);
+}
+
 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 {
 	/* GPIO can never have been requested */
-- 
2.37.2

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Alexander Stein]

Hi,

Am Montag, 16. Januar 2023, 15:08:11 CET schrieb Pierluigi Passaro:
> Both the functions gpiochip_request_own_desc and
> gpiochip_free_own_desc are exported from
>     drivers/gpio/gpiolib.c
> but this file is compiled only when CONFIG_GPIOLIB is enabled.
> Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> reasonable definitions in the "#else" branch.
> 
> Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> Reported-by: kernel test robot <lkp@intel.com>
> ---
>  include/linux/gpio/driver.h | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 44783fc16125..ed77c6fc0beb 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
> 
>  #endif /* CONFIG_PINCTRL */
> 
> +#ifdef CONFIG_GPIOLIB
> +
>  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
>  					    unsigned int hwnum,
>  					    const char *label,
> @@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct
> gpio_chip *gc, enum gpiod_flags dflags);
>  void gpiochip_free_own_desc(struct gpio_desc *desc);
> 
> -#ifdef CONFIG_GPIOLIB
> -
>  /* lock/unlock as IRQ */
>  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
>  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
> @@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc
> *desc);
> 
>  #else /* CONFIG_GPIOLIB */
> 
> +static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip
> *gc, +					    unsigned int hwnum,
> +					    const char *label,
> +					    enum gpio_lookup_flags 
lflags,
> +					    enum gpiod_flags dflags)
> +{
> +	/* GPIO can never have been requested */
> +	WARN_ON(1);

This will raise the warning on each invocation. How about using 
WARN_ON_ONCE(1), or even WARN_ONCE("Kernel compiled without CONFIG_GPIOLIB 
support")?

> +	return ERR_PTR(-ENODEV);
> +}
> +
> +static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
> +{
> +	WARN_ON(1);

Same as above.

Best regards,
Alexander

> +}
> +
>  static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> {
>  	/* GPIO can never have been requested */

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Pierluigi Passaro]

On Tue, Jan 17, 2023 at 7:23 AM Alexander Stein <alexander.stein@ew.tq-group.com> wrote:
> Hi,
>
> Am Montag, 16. Januar 2023, 15:08:11 CET schrieb Pierluigi Passaro:
> > Both the functions gpiochip_request_own_desc and
> > gpiochip_free_own_desc are exported from
> >     drivers/gpio/gpiolib.c
> > but this file is compiled only when CONFIG_GPIOLIB is enabled.
> > Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> > reasonable definitions in the "#else" branch.
> >
> > Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> > Reported-by: kernel test robot <lkp@intel.com>
> > ---
> >  include/linux/gpio/driver.h | 20 ++++++++++++++++++--
> >  1 file changed, 18 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> > index 44783fc16125..ed77c6fc0beb 100644
> > --- a/include/linux/gpio/driver.h
> > +++ b/include/linux/gpio/driver.h
> > @@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
> >
> >  #endif /* CONFIG_PINCTRL */
> >
> > +#ifdef CONFIG_GPIOLIB
> > +
> >  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> >                                           unsigned int hwnum,
> >                                           const char *label,
> > @@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct
> > gpio_chip *gc, enum gpiod_flags dflags);
> >  void gpiochip_free_own_desc(struct gpio_desc *desc);
> >
> > -#ifdef CONFIG_GPIOLIB
> > -
> >  /* lock/unlock as IRQ */
> >  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
> >  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
> > @@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc
> > *desc);
> >
> >  #else /* CONFIG_GPIOLIB */
> >
> > +static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip
> > *gc, +                                            unsigned int hwnum,
> > +                                         const char *label,
> > +                                         enum gpio_lookup_flags
> lflags,
> > +                                         enum gpiod_flags dflags)
> > +{
> > +     /* GPIO can never have been requested */
> > +     WARN_ON(1);
>
> This will raise the warning on each invocation. How about using
> WARN_ON_ONCE(1), or even WARN_ONCE("Kernel compiled without CONFIG_GPIOLIB
> support")?
>
No problem on my side, but this would create a misalignment with all other
GPIOLIB "dummy" calls.
Personally I would prefer WARN_ONCE("Kernel compiled without CONFIG_GPIOLIB
support").
Please confirm your preferences and I'll provide a patch v2.
Thanks
>
> > +     return ERR_PTR(-ENODEV);
> > +}
> > +
> > +static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
> > +{
> > +     WARN_ON(1);
>
> Same as above.
>
> Best regards,
> Alexander
>
> > +}
> > +
> >  static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> > {
> >       /* GPIO can never have been requested */

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Bartosz Golaszewski]

On Tue, Jan 17, 2023 at 8:44 AM Pierluigi Passaro
<pierluigi.p@variscite.com> wrote:
>
> On Tue, Jan 17, 2023 at 7:23 AM Alexander Stein <alexander.stein@ew.tq-group.com> wrote:
> > Hi,
> >
> > Am Montag, 16. Januar 2023, 15:08:11 CET schrieb Pierluigi Passaro:
> > > Both the functions gpiochip_request_own_desc and
> > > gpiochip_free_own_desc are exported from
> > >     drivers/gpio/gpiolib.c
> > > but this file is compiled only when CONFIG_GPIOLIB is enabled.
> > > Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> > > reasonable definitions in the "#else" branch.
> > >
> > > Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > ---
> > >  include/linux/gpio/driver.h | 20 ++++++++++++++++++--
> > >  1 file changed, 18 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> > > index 44783fc16125..ed77c6fc0beb 100644
> > > --- a/include/linux/gpio/driver.h
> > > +++ b/include/linux/gpio/driver.h
> > > @@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
> > >
> > >  #endif /* CONFIG_PINCTRL */
> > >
> > > +#ifdef CONFIG_GPIOLIB
> > > +
> > >  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> > >                                           unsigned int hwnum,
> > >                                           const char *label,
> > > @@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct
> > > gpio_chip *gc, enum gpiod_flags dflags);
> > >  void gpiochip_free_own_desc(struct gpio_desc *desc);
> > >
> > > -#ifdef CONFIG_GPIOLIB
> > > -
> > >  /* lock/unlock as IRQ */
> > >  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
> > >  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
> > > @@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc
> > > *desc);
> > >
> > >  #else /* CONFIG_GPIOLIB */
> > >
> > > +static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip
> > > *gc, +                                            unsigned int hwnum,
> > > +                                         const char *label,
> > > +                                         enum gpio_lookup_flags
> > lflags,
> > > +                                         enum gpiod_flags dflags)
> > > +{
> > > +     /* GPIO can never have been requested */
> > > +     WARN_ON(1);
> >
> > This will raise the warning on each invocation. How about using
> > WARN_ON_ONCE(1), or even WARN_ONCE("Kernel compiled without CONFIG_GPIOLIB
> > support")?
> >
> No problem on my side, but this would create a misalignment with all other
> GPIOLIB "dummy" calls.
> Personally I would prefer WARN_ONCE("Kernel compiled without CONFIG_GPIOLIB
> support").
> Please confirm your preferences and I'll provide a patch v2.
> Thanks
> >
> > > +     return ERR_PTR(-ENODEV);
> > > +}
> > > +
> > > +static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
> > > +{
> > > +     WARN_ON(1);
> >
> > Same as above.
> >
> > Best regards,
> > Alexander
> >
> > > +}
> > > +
> > >  static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> > > {
> > >       /* GPIO can never have been requested */

If someone calls these functions without GPIOLIB enabled then they
deserve lots of warnings to remind them to fix their config. :)

Let's keep it like in other places.

Bart

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Bartosz Golaszewski]

On Mon, Jan 16, 2023 at 3:08 PM Pierluigi Passaro
<pierluigi.p@variscite.com> wrote:
>
> Both the functions gpiochip_request_own_desc and
> gpiochip_free_own_desc are exported from
>     drivers/gpio/gpiolib.c
> but this file is compiled only when CONFIG_GPIOLIB is enabled.
> Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> reasonable definitions in the "#else" branch.
>
> Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> Reported-by: kernel test robot <lkp@intel.com>

Please add a Fixes tag.

Bart

> ---
>  include/linux/gpio/driver.h | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 44783fc16125..ed77c6fc0beb 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
>
>  #endif /* CONFIG_PINCTRL */
>
> +#ifdef CONFIG_GPIOLIB
> +
>  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
>                                             unsigned int hwnum,
>                                             const char *label,
> @@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
>                                             enum gpiod_flags dflags);
>  void gpiochip_free_own_desc(struct gpio_desc *desc);
>
> -#ifdef CONFIG_GPIOLIB
> -
>  /* lock/unlock as IRQ */
>  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
>  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
> @@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
>
>  #else /* CONFIG_GPIOLIB */
>
> +static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> +                                           unsigned int hwnum,
> +                                           const char *label,
> +                                           enum gpio_lookup_flags lflags,
> +                                           enum gpiod_flags dflags)
> +{
> +       /* GPIO can never have been requested */
> +       WARN_ON(1);
> +       return ERR_PTR(-ENODEV);
> +}
> +
> +static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
> +{
> +       WARN_ON(1);
> +}
> +
>  static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
>  {
>         /* GPIO can never have been requested */
> --
> 2.37.2
>

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Pierluigi Passaro]

On Tue, Jan 17, 2023 at 10:36 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> On Mon, Jan 16, 2023 at 3:08 PM Pierluigi Passaro
> <pierluigi.p@variscite.com> wrote:
> >
> > Both the functions gpiochip_request_own_desc and
> > gpiochip_free_own_desc are exported from
> >     drivers/gpio/gpiolib.c
> > but this file is compiled only when CONFIG_GPIOLIB is enabled.
> > Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> > reasonable definitions in the "#else" branch.
> >
> > Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> > Reported-by: kernel test robot <lkp@intel.com>
>
> Please add a Fixes tag.
>
I beg your pardon for the question: how can I "add a Fixes tag" ?
Can you point me to any reference documentation / instructions ?
Thanks
>
> Bart
>
> > ---
> >  include/linux/gpio/driver.h | 20 ++++++++++++++++++--
> >  1 file changed, 18 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> > index 44783fc16125..ed77c6fc0beb 100644
> > --- a/include/linux/gpio/driver.h
> > +++ b/include/linux/gpio/driver.h
> > @@ -758,6 +758,8 @@ gpiochip_remove_pin_ranges(struct gpio_chip *gc)
> >
> >  #endif /* CONFIG_PINCTRL */
> >
> > +#ifdef CONFIG_GPIOLIB
> > +
> >  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> >                                             unsigned int hwnum,
> >                                             const char *label,
> > @@ -765,8 +767,6 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> >                                             enum gpiod_flags dflags);
> >  void gpiochip_free_own_desc(struct gpio_desc *desc);
> >
> > -#ifdef CONFIG_GPIOLIB
> > -
> >  /* lock/unlock as IRQ */
> >  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset);
> >  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset);
> > @@ -776,6 +776,22 @@ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
> >
> >  #else /* CONFIG_GPIOLIB */
> >
> > +static inline struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
> > +                                           unsigned int hwnum,
> > +                                           const char *label,
> > +                                           enum gpio_lookup_flags lflags,
> > +                                           enum gpiod_flags dflags)
> > +{
> > +       /* GPIO can never have been requested */
> > +       WARN_ON(1);
> > +       return ERR_PTR(-ENODEV);
> > +}
> > +
> > +static inline void gpiochip_free_own_desc(struct gpio_desc *desc)
> > +{
> > +       WARN_ON(1);
> > +}
> > +
> >  static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> >  {
> >         /* GPIO can never have been requested */
> > --
> > 2.37.2
> >

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Bartosz Golaszewski]

On Tue, Jan 17, 2023 at 11:17 AM Pierluigi Passaro
<pierluigi.p@variscite.com> wrote:
>
> On Tue, Jan 17, 2023 at 10:36 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > On Mon, Jan 16, 2023 at 3:08 PM Pierluigi Passaro
> > <pierluigi.p@variscite.com> wrote:
> > >
> > > Both the functions gpiochip_request_own_desc and
> > > gpiochip_free_own_desc are exported from
> > >     drivers/gpio/gpiolib.c
> > > but this file is compiled only when CONFIG_GPIOLIB is enabled.
> > > Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> > > reasonable definitions in the "#else" branch.
> > >
> > > Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> > > Reported-by: kernel test robot <lkp@intel.com>
> >
> > Please add a Fixes tag.
> >
> I beg your pardon for the question: how can I "add a Fixes tag" ?
> Can you point me to any reference documentation / instructions ?
> Thanks
> >

Look at the output of `git blame` on the file in question and see who
added the changes that introduced the problem. Then, before your
Sign-off in the git message add: Fixes: <12 chars of the commit hash>
("<commit subject>"). See Existing commits with fixes for reference.

Bart

Re: [PATCH] gpiolib: fix linker errors when GPIOLIB is disabled

[Pierluigi Passaro]

On Wed, Jan 18, 2023 at 3:22 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> On Tue, Jan 17, 2023 at 11:17 AM Pierluigi Passaro
> <pierluigi.p@variscite.com> wrote:
> >
> > On Tue, Jan 17, 2023 at 10:36 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > > On Mon, Jan 16, 2023 at 3:08 PM Pierluigi Passaro
> > > <pierluigi.p@variscite.com> wrote:
> > > >
> > > > Both the functions gpiochip_request_own_desc and
> > > > gpiochip_free_own_desc are exported from
> > > >     drivers/gpio/gpiolib.c
> > > > but this file is compiled only when CONFIG_GPIOLIB is enabled.
> > > > Move the protototypes under "#ifdef CONFIG_GPIOLIB" and provide
> > > > reasonable definitions in the "#else" branch.
> > > >
> > > > Signed-off-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> > > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > > Please add a Fixes tag.
> > >
> > I beg your pardon for the question: how can I "add a Fixes tag" ?
> > Can you point me to any reference documentation / instructions ?
> > Thanks
> > >
>
> Look at the output of `git blame` on the file in question and see who
> added the changes that introduced the problem. Then, before your
> Sign-off in the git message add: Fixes: <12 chars of the commit hash>
> ("<commit subject>"). See Existing commits with fixes for reference.
>
> Bart
>
Thanks for the guidelines: I've just sent patch v2 with Fixes tag.