diff mbox series

[v2,3/4] iio: adc: at91_adc: add Kconfig dependency on the OF symbol

Message ID 20200930060008.42134-4-alexandru.ardelean@analog.com (mailing list archive)
State New, archived
Headers show
Series iio: adc: at91: misc driver cleanups | expand

Commit Message

Alexandru Ardelean Sept. 30, 2020, 6 a.m. UTC 
This tries to solve a warning reported by the lkp bot:

>> drivers/iio/adc/at91_adc.c:1439:34: warning: unused variable
>> 'at91_adc_dt_ids' [-Wunused-const-variable]
   static const struct of_device_id at91_adc_dt_ids[] = {
                                    ^
   1 warning generated.

This shows up with 'compiler: clang version 12.0.0' and W=1 (as the bot
mentions).

Forward declarations for global variables can be a bit weird; forward
function declarations are more common.

Maybe another fix for this would have been to prefix with 'extern' the
'at91_adc_dt_ids' variable, thus making it more friendly as a forward
declaration. It would look weird, but it would work.

But, we can avoid that forward declaration altogether simply by obtaining
the private data with of_device_get_match_data().

This appeared after commit 4027860dcc4c ("iio: Kconfig: at91_adc: add
COMPILE_TEST dependency to driver"), which put this driver on the lkp's bot
radar.

Fixes: 4027860dcc4c ("iio: Kconfig: at91_adc: add COMPILE_TEST dependency to driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/iio/adc/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alexandre Belloni Sept. 30, 2020, 7:37 a.m. UTC | #1 
Hi,

On 30/09/2020 09:00:07+0300, Alexandru Ardelean wrote:
> This tries to solve a warning reported by the lkp bot:
> 
> >> drivers/iio/adc/at91_adc.c:1439:34: warning: unused variable
> >> 'at91_adc_dt_ids' [-Wunused-const-variable]
>    static const struct of_device_id at91_adc_dt_ids[] = {
>                                     ^
>    1 warning generated.
> 
> This shows up with 'compiler: clang version 12.0.0' and W=1 (as the bot
> mentions).
> 
> Forward declarations for global variables can be a bit weird; forward
> function declarations are more common.
> 
> Maybe another fix for this would have been to prefix with 'extern' the
> 'at91_adc_dt_ids' variable, thus making it more friendly as a forward
> declaration. It would look weird, but it would work.
> 
> But, we can avoid that forward declaration altogether simply by obtaining
> the private data with of_device_get_match_data().
> 
> This appeared after commit 4027860dcc4c ("iio: Kconfig: at91_adc: add
> COMPILE_TEST dependency to driver"), which put this driver on the lkp's bot
> radar.
> 

Shouldn't all of that be part of the commit message for 1/4? This
doesn't explicitly explain why you add a dependency on OF.

> Fixes: 4027860dcc4c ("iio: Kconfig: at91_adc: add COMPILE_TEST dependency to driver")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
>  drivers/iio/adc/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 91ae90514aff..17e9ceb9c6c4 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -295,7 +295,7 @@ config ASPEED_ADC
>  config AT91_ADC
>  	tristate "Atmel AT91 ADC"
>  	depends on ARCH_AT91 || COMPILE_TEST
> -	depends on INPUT && SYSFS
> +	depends on INPUT && SYSFS && OF
>  	select IIO_BUFFER
>  	select IIO_TRIGGERED_BUFFER
>  	help
> -- 
> 2.17.1
>
Alexandru Ardelean Sept. 30, 2020, 8:47 a.m. UTC | #2 
On Wed, Sep 30, 2020 at 10:39 AM Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
>
> Hi,
>
> On 30/09/2020 09:00:07+0300, Alexandru Ardelean wrote:
> > This tries to solve a warning reported by the lkp bot:
> >
> > >> drivers/iio/adc/at91_adc.c:1439:34: warning: unused variable
> > >> 'at91_adc_dt_ids' [-Wunused-const-variable]
> >    static const struct of_device_id at91_adc_dt_ids[] = {
> >                                     ^
> >    1 warning generated.
> >
> > This shows up with 'compiler: clang version 12.0.0' and W=1 (as the bot
> > mentions).
> >
> > Forward declarations for global variables can be a bit weird; forward
> > function declarations are more common.
> >
> > Maybe another fix for this would have been to prefix with 'extern' the
> > 'at91_adc_dt_ids' variable, thus making it more friendly as a forward
> > declaration. It would look weird, but it would work.
> >
> > But, we can avoid that forward declaration altogether simply by obtaining
> > the private data with of_device_get_match_data().
> >
> > This appeared after commit 4027860dcc4c ("iio: Kconfig: at91_adc: add
> > COMPILE_TEST dependency to driver"), which put this driver on the lkp's bot
> > radar.
> >
>
> Shouldn't all of that be part of the commit message for 1/4? This
> doesn't explicitly explain why you add a dependency on OF.

Hmm, I think I did this patch before drinking my morning coffee.
Looks like it's also a bad commit description.

>
> > Fixes: 4027860dcc4c ("iio: Kconfig: at91_adc: add COMPILE_TEST dependency to driver")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > ---
> >  drivers/iio/adc/Kconfig | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index 91ae90514aff..17e9ceb9c6c4 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -295,7 +295,7 @@ config ASPEED_ADC
> >  config AT91_ADC
> >       tristate "Atmel AT91 ADC"
> >       depends on ARCH_AT91 || COMPILE_TEST
> > -     depends on INPUT && SYSFS
> > +     depends on INPUT && SYSFS && OF
> >       select IIO_BUFFER
> >       select IIO_TRIGGERED_BUFFER
> >       help
> > --
> > 2.17.1
> >
>
> --
> Alexandre Belloni, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
diff mbox series

Patch

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 91ae90514aff..17e9ceb9c6c4 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -295,7 +295,7 @@  config ASPEED_ADC
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91 || COMPILE_TEST
-	depends on INPUT && SYSFS
+	depends on INPUT && SYSFS && OF
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
 	help