iio: stm32: fix adc/trigger link error

Message ID 20170906125722.2522781-1-arnd@arndb.de
State New
Headers show
Series
  • iio: stm32: fix adc/trigger link error
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Commit Message

Arnd Bergmann Sept. 6, 2017, 12:56 p.m.
The ADC driver can trigger on either the timer or the lptim
trigger, but it only uses a Kconfig 'select' statement
to ensure that the first of the two is present. When the lptim
trigger is enabled as a loadable module, and the adc driver
is built-in, we now get a link error:

drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':
stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

We could use a second 'select' statement and always have both
trigger drivers enabled when the adc driver is, but it seems that
the lptimer trigger was intentionally left optional, so it seems
better to keep it that way.

This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',
which avoids the link error, but instead leads to the lptimer trigger
not being used in the broken configuration. I've added a runtime
warning for this case to help users figure out what they did wrong
if this should ever be done by accident.

Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

-- 
2.9.0

Comments

Fabrice Gasnier Sept. 6, 2017, 4:16 p.m. | #1
On 09/06/2017 02:56 PM, Arnd Bergmann wrote:
> The ADC driver can trigger on either the timer or the lptim

> trigger, but it only uses a Kconfig 'select' statement

> to ensure that the first of the two is present. When the lptim

> trigger is enabled as a loadable module, and the adc driver

> is built-in, we now get a link error:

> 

> drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':

> stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

> 

> We could use a second 'select' statement and always have both

> trigger drivers enabled when the adc driver is, but it seems that

> the lptimer trigger was intentionally left optional, so it seems

> better to keep it that way.

Hi Arnd,

This is correct, not all stm32 have this hardware.
> 

> This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',

> which avoids the link error, but instead leads to the lptimer trigger

> not being used in the broken configuration. I've added a runtime

> warning for this case to help users figure out what they did wrong

> if this should ever be done by accident.

> 

> Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Tested-by: Fabrice Gasnier <fabrice.gasnier@st.com>


Many thanks for the fix,
Best Regards,
Fabrice
> ---

>  include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-

>  1 file changed, 4 insertions(+), 1 deletion(-)

> 

> diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h

> index 34d59bfdce2d..464458d20b16 100644

> --- a/include/linux/iio/timer/stm32-lptim-trigger.h

> +++ b/include/linux/iio/timer/stm32-lptim-trigger.h

> @@ -16,11 +16,14 @@

>  #define LPTIM2_OUT	"lptim2_out"

>  #define LPTIM3_OUT	"lptim3_out"

>  

> -#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> +#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

>  bool is_stm32_lptim_trigger(struct iio_trigger *trig);

>  #else

>  static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)

>  {

> +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> +	pr_warn_once("stm32 lptim_trigger not linked in\n");

> +#endif

>  	return false;

>  }

>  #endif

>
Jonathan Cameron Sept. 10, 2017, 4 p.m. | #2
On Wed, 6 Sep 2017 18:16:33 +0200
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> On 09/06/2017 02:56 PM, Arnd Bergmann wrote:

> > The ADC driver can trigger on either the timer or the lptim

> > trigger, but it only uses a Kconfig 'select' statement

> > to ensure that the first of the two is present. When the lptim

> > trigger is enabled as a loadable module, and the adc driver

> > is built-in, we now get a link error:

> > 

> > drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':

> > stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

> > 

> > We could use a second 'select' statement and always have both

> > trigger drivers enabled when the adc driver is, but it seems that

> > the lptimer trigger was intentionally left optional, so it seems

> > better to keep it that way.  

> Hi Arnd,

> 

> This is correct, not all stm32 have this hardware.

> > 

> > This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',

> > which avoids the link error, but instead leads to the lptimer trigger

> > not being used in the broken configuration. I've added a runtime

> > warning for this case to help users figure out what they did wrong

> > if this should ever be done by accident.

> > 

> > Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")

> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>  

> Tested-by: Fabrice Gasnier <fabrice.gasnier@st.com>


This may take me a few weeks to pick up.  I don't want to
pull the mfd immutable branch in just to have this fix, so this will
get sorted after rc1 is out.

As ever, poke me if it looks like I've forgotten about it.
Sorry for the delay!

Jonathan

> 

> Many thanks for the fix,

> Best Regards,

> Fabrice

> > ---

> >  include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-

> >  1 file changed, 4 insertions(+), 1 deletion(-)

> > 

> > diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h

> > index 34d59bfdce2d..464458d20b16 100644

> > --- a/include/linux/iio/timer/stm32-lptim-trigger.h

> > +++ b/include/linux/iio/timer/stm32-lptim-trigger.h

> > @@ -16,11 +16,14 @@

> >  #define LPTIM2_OUT	"lptim2_out"

> >  #define LPTIM3_OUT	"lptim3_out"

> >  

> > -#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> > +#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> >  bool is_stm32_lptim_trigger(struct iio_trigger *trig);

> >  #else

> >  static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)

> >  {

> > +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> > +	pr_warn_once("stm32 lptim_trigger not linked in\n");

> > +#endif

> >  	return false;

> >  }

> >  #endif

> >   

> --

> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

> the body of a message to majordomo@vger.kernel.org

> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Fabrice Gasnier Sept. 25, 2017, 9:54 a.m. | #3
On 09/10/2017 06:00 PM, Jonathan Cameron wrote:
> On Wed, 6 Sep 2017 18:16:33 +0200

> Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> 

>> On 09/06/2017 02:56 PM, Arnd Bergmann wrote:

>>> The ADC driver can trigger on either the timer or the lptim

>>> trigger, but it only uses a Kconfig 'select' statement

>>> to ensure that the first of the two is present. When the lptim

>>> trigger is enabled as a loadable module, and the adc driver

>>> is built-in, we now get a link error:

>>>

>>> drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':

>>> stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

>>>

>>> We could use a second 'select' statement and always have both

>>> trigger drivers enabled when the adc driver is, but it seems that

>>> the lptimer trigger was intentionally left optional, so it seems

>>> better to keep it that way.  

>> Hi Arnd,

>>

>> This is correct, not all stm32 have this hardware.

>>>

>>> This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',

>>> which avoids the link error, but instead leads to the lptimer trigger

>>> not being used in the broken configuration. I've added a runtime

>>> warning for this case to help users figure out what they did wrong

>>> if this should ever be done by accident.

>>>

>>> Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")

>>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>  

>> Tested-by: Fabrice Gasnier <fabrice.gasnier@st.com>

> 

> This may take me a few weeks to pick up.  I don't want to

> pull the mfd immutable branch in just to have this fix, so this will

> get sorted after rc1 is out.

> 

> As ever, poke me if it looks like I've forgotten about it.


Hi Jonathan,

Di you apply this one?

Thanks,
Best Regards,
Fabrice
> Sorry for the delay!

> 

> Jonathan

> 

>>

>> Many thanks for the fix,

>> Best Regards,

>> Fabrice

>>> ---

>>>  include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-

>>>  1 file changed, 4 insertions(+), 1 deletion(-)

>>>

>>> diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h

>>> index 34d59bfdce2d..464458d20b16 100644

>>> --- a/include/linux/iio/timer/stm32-lptim-trigger.h

>>> +++ b/include/linux/iio/timer/stm32-lptim-trigger.h

>>> @@ -16,11 +16,14 @@

>>>  #define LPTIM2_OUT	"lptim2_out"

>>>  #define LPTIM3_OUT	"lptim3_out"

>>>  

>>> -#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

>>> +#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

>>>  bool is_stm32_lptim_trigger(struct iio_trigger *trig);

>>>  #else

>>>  static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)

>>>  {

>>> +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

>>> +	pr_warn_once("stm32 lptim_trigger not linked in\n");

>>> +#endif

>>>  	return false;

>>>  }

>>>  #endif

>>>   

>> --

>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

>> the body of a message to majordomo@vger.kernel.org

>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

>
Jonathan Cameron Sept. 25, 2017, 10:16 a.m. | #4
On Mon, 25 Sep 2017 11:54:06 +0200
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> On 09/10/2017 06:00 PM, Jonathan Cameron wrote:

> > On Wed, 6 Sep 2017 18:16:33 +0200

> > Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> >   

> >> On 09/06/2017 02:56 PM, Arnd Bergmann wrote:  

> >>> The ADC driver can trigger on either the timer or the lptim

> >>> trigger, but it only uses a Kconfig 'select' statement

> >>> to ensure that the first of the two is present. When the lptim

> >>> trigger is enabled as a loadable module, and the adc driver

> >>> is built-in, we now get a link error:

> >>>

> >>> drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':

> >>> stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

> >>>

> >>> We could use a second 'select' statement and always have both

> >>> trigger drivers enabled when the adc driver is, but it seems that

> >>> the lptimer trigger was intentionally left optional, so it seems

> >>> better to keep it that way.    

> >> Hi Arnd,

> >>

> >> This is correct, not all stm32 have this hardware.  

> >>>

> >>> This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',

> >>> which avoids the link error, but instead leads to the lptimer trigger

> >>> not being used in the broken configuration. I've added a runtime

> >>> warning for this case to help users figure out what they did wrong

> >>> if this should ever be done by accident.

> >>>

> >>> Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")

> >>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>    

> >> Tested-by: Fabrice Gasnier <fabrice.gasnier@st.com>  

> > 

> > This may take me a few weeks to pick up.  I don't want to

> > pull the mfd immutable branch in just to have this fix, so this will

> > get sorted after rc1 is out.

> > 

> > As ever, poke me if it looks like I've forgotten about it.  

> 

> Hi Jonathan,

> 

> Di you apply this one?


I think I still need to rebase my branch. Greg took my fixes pull this morning
so I can fast forward that branch next time I'm on the right PC and then pick
this up.

Thanks for the reminder.

Jonathan

> 

> Thanks,

> Best Regards,

> Fabrice

> > Sorry for the delay!

> > 

> > Jonathan

> >   

> >>

> >> Many thanks for the fix,

> >> Best Regards,

> >> Fabrice  

> >>> ---

> >>>  include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-

> >>>  1 file changed, 4 insertions(+), 1 deletion(-)

> >>>

> >>> diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h

> >>> index 34d59bfdce2d..464458d20b16 100644

> >>> --- a/include/linux/iio/timer/stm32-lptim-trigger.h

> >>> +++ b/include/linux/iio/timer/stm32-lptim-trigger.h

> >>> @@ -16,11 +16,14 @@

> >>>  #define LPTIM2_OUT	"lptim2_out"

> >>>  #define LPTIM3_OUT	"lptim3_out"

> >>>  

> >>> -#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> >>> +#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> >>>  bool is_stm32_lptim_trigger(struct iio_trigger *trig);

> >>>  #else

> >>>  static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)

> >>>  {

> >>> +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> >>> +	pr_warn_once("stm32 lptim_trigger not linked in\n");

> >>> +#endif

> >>>  	return false;

> >>>  }

> >>>  #endif

> >>>     

> >> --

> >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

> >> the body of a message to majordomo@vger.kernel.org

> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html  

> >   

> 

> _______________________________________________

> linux-arm-kernel mailing list

> linux-arm-kernel@lists.infradead.org

> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Jonathan Cameron Sept. 25, 2017, 5:26 p.m. | #5
On Mon, 25 Sep 2017 11:16:04 +0100
Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:

> On Mon, 25 Sep 2017 11:54:06 +0200

> Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> 

> > On 09/10/2017 06:00 PM, Jonathan Cameron wrote:  

> > > On Wed, 6 Sep 2017 18:16:33 +0200

> > > Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> > >     

> > >> On 09/06/2017 02:56 PM, Arnd Bergmann wrote:    

> > >>> The ADC driver can trigger on either the timer or the lptim

> > >>> trigger, but it only uses a Kconfig 'select' statement

> > >>> to ensure that the first of the two is present. When the lptim

> > >>> trigger is enabled as a loadable module, and the adc driver

> > >>> is built-in, we now get a link error:

> > >>>

> > >>> drivers/iio/adc/stm32-adc.o: In function `stm32_adc_get_trig_extsel':

> > >>> stm32-adc.c:(.text+0x4e0): undefined reference to `is_stm32_lptim_trigger'

> > >>>

> > >>> We could use a second 'select' statement and always have both

> > >>> trigger drivers enabled when the adc driver is, but it seems that

> > >>> the lptimer trigger was intentionally left optional, so it seems

> > >>> better to keep it that way.      

> > >> Hi Arnd,

> > >>

> > >> This is correct, not all stm32 have this hardware.    

> > >>>

> > >>> This adds a hack to use 'IS_REACHABLE()' rather than 'IS_ENABLED()',

> > >>> which avoids the link error, but instead leads to the lptimer trigger

> > >>> not being used in the broken configuration. I've added a runtime

> > >>> warning for this case to help users figure out what they did wrong

> > >>> if this should ever be done by accident.

> > >>>

> > >>> Fixes: f0b638a7f6db ("iio: adc: stm32: add support for lptimer triggers")

> > >>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>      

> > >> Tested-by: Fabrice Gasnier <fabrice.gasnier@st.com>    

> > > 

> > > This may take me a few weeks to pick up.  I don't want to

> > > pull the mfd immutable branch in just to have this fix, so this will

> > > get sorted after rc1 is out.

> > > 

> > > As ever, poke me if it looks like I've forgotten about it.    

> > 

> > Hi Jonathan,

> > 

> > Di you apply this one?  

> 

> I think I still need to rebase my branch. Greg took my fixes pull this morning

> so I can fast forward that branch next time I'm on the right PC and then pick

> this up.

> 

> Thanks for the reminder.


Applied to the fixes-togreg branch of iio.git.

Thanks,

Jonathan
> 

> Jonathan

> 

> > 

> > Thanks,

> > Best Regards,

> > Fabrice  

> > > Sorry for the delay!

> > > 

> > > Jonathan

> > >     

> > >>

> > >> Many thanks for the fix,

> > >> Best Regards,

> > >> Fabrice    

> > >>> ---

> > >>>  include/linux/iio/timer/stm32-lptim-trigger.h | 5 ++++-

> > >>>  1 file changed, 4 insertions(+), 1 deletion(-)

> > >>>

> > >>> diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h

> > >>> index 34d59bfdce2d..464458d20b16 100644

> > >>> --- a/include/linux/iio/timer/stm32-lptim-trigger.h

> > >>> +++ b/include/linux/iio/timer/stm32-lptim-trigger.h

> > >>> @@ -16,11 +16,14 @@

> > >>>  #define LPTIM2_OUT	"lptim2_out"

> > >>>  #define LPTIM3_OUT	"lptim3_out"

> > >>>  

> > >>> -#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> > >>> +#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> > >>>  bool is_stm32_lptim_trigger(struct iio_trigger *trig);

> > >>>  #else

> > >>>  static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)

> > >>>  {

> > >>> +#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)

> > >>> +	pr_warn_once("stm32 lptim_trigger not linked in\n");

> > >>> +#endif

> > >>>  	return false;

> > >>>  }

> > >>>  #endif

> > >>>       

> > >> --

> > >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

> > >> the body of a message to majordomo@vger.kernel.org

> > >> More majordomo info at  http://vger.kernel.org/majordomo-info.html    

> > >     

> > 

> > _______________________________________________

> > linux-arm-kernel mailing list

> > linux-arm-kernel@lists.infradead.org

> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel  

> 

> --

> To unsubscribe from this list: send the line "unsubscribe linux-iio" in

> the body of a message to majordomo@vger.kernel.org

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Patch

diff --git a/include/linux/iio/timer/stm32-lptim-trigger.h b/include/linux/iio/timer/stm32-lptim-trigger.h
index 34d59bfdce2d..464458d20b16 100644
--- a/include/linux/iio/timer/stm32-lptim-trigger.h
+++ b/include/linux/iio/timer/stm32-lptim-trigger.h
@@ -16,11 +16,14 @@ 
 #define LPTIM2_OUT	"lptim2_out"
 #define LPTIM3_OUT	"lptim3_out"
 
-#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)
+#if IS_REACHABLE(CONFIG_IIO_STM32_LPTIMER_TRIGGER)
 bool is_stm32_lptim_trigger(struct iio_trigger *trig);
 #else
 static inline bool is_stm32_lptim_trigger(struct iio_trigger *trig)
 {
+#if IS_ENABLED(CONFIG_IIO_STM32_LPTIMER_TRIGGER)
+	pr_warn_once("stm32 lptim_trigger not linked in\n");
+#endif
 	return false;
 }
 #endif