| Message ID | 20200928125424.35921-1-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] iio: adc: at91_adc: use of_device_get_match_data() helper | expand |
On Mon, 28 Sep 2020 15:54:23 +0300 Alexandru Ardelean <alexandru.ardelean@analog.com> 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. Hi, That's not the forward declaration that it is complaining about... It's a reasonable patch anyway, but doesn't fix that warning which is about of_match_ptr and the lack of #ifdef CONFIG_OF around the actual definition. For the bug warning, I'd add add a Kconfig dependency on OF. It doesn't make any sense to allow building this driver without that. So resend this as a simple tidy up patch and another one adding that build dependency. Thanks, Jonathan > > 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. > > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > --- > drivers/iio/adc/at91_adc.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > index 9b2c548fae95..c9ec0a4a357e 100644 > --- a/drivers/iio/adc/at91_adc.c > +++ b/drivers/iio/adc/at91_adc.c > @@ -829,8 +829,6 @@ static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz) > return ticks; > } > > -static const struct of_device_id at91_adc_dt_ids[]; > - > static int at91_adc_probe_dt_ts(struct device_node *node, > struct at91_adc_state *st, struct device *dev) > { > @@ -878,8 +876,7 @@ static int at91_adc_probe_dt(struct iio_dev *idev, > if (!node) > return -EINVAL; > > - st->caps = (struct at91_adc_caps *) > - of_match_device(at91_adc_dt_ids, &pdev->dev)->data; > + st->caps = (struct at91_adc_caps *)of_device_get_match_data(&pdev->dev); > > st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers"); >
On Tue, Sep 29, 2020 at 6:55 PM Jonathan Cameron <jic23@kernel.org> wrote: > > On Mon, 28 Sep 2020 15:54:23 +0300 > Alexandru Ardelean <alexandru.ardelean@analog.com> 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. > Hi, > > That's not the forward declaration that it is complaining about... > > It's a reasonable patch anyway, but doesn't fix that warning which is > about of_match_ptr and the lack of #ifdef CONFIG_OF around the > actual definition. > > For the bug warning, I'd add add a Kconfig dependency on OF. > It doesn't make any sense to allow building this driver without that. > > So resend this as a simple tidy up patch and another one adding > that build dependency. > At this point it might make sense to also remove the of_match_ptr() helper. If adding the OF build dependency, the of_match_ptr() would always return non-NULL. > Thanks, > > Jonathan > > > > > 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. > > > > Reported-by: kernel test robot <lkp@intel.com> > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > > --- > > drivers/iio/adc/at91_adc.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > > index 9b2c548fae95..c9ec0a4a357e 100644 > > --- a/drivers/iio/adc/at91_adc.c > > +++ b/drivers/iio/adc/at91_adc.c > > @@ -829,8 +829,6 @@ static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz) > > return ticks; > > } > > > > -static const struct of_device_id at91_adc_dt_ids[]; > > - > > static int at91_adc_probe_dt_ts(struct device_node *node, > > struct at91_adc_state *st, struct device *dev) > > { > > @@ -878,8 +876,7 @@ static int at91_adc_probe_dt(struct iio_dev *idev, > > if (!node) > > return -EINVAL; > > > > - st->caps = (struct at91_adc_caps *) > > - of_match_device(at91_adc_dt_ids, &pdev->dev)->data; > > + st->caps = (struct at91_adc_caps *)of_device_get_match_data(&pdev->dev); > > > > st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers"); > > >
On Tue, Sep 29, 2020 at 6:55 PM Jonathan Cameron <jic23@kernel.org> wrote: > > On Mon, 28 Sep 2020 15:54:23 +0300 > Alexandru Ardelean <alexandru.ardelean@analog.com> 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. > Hi, > > That's not the forward declaration that it is complaining about... Also, silly me here. I was just annoyed with the email from the bot, so I didn't dig too deep to understand. > > It's a reasonable patch anyway, but doesn't fix that warning which is > about of_match_ptr and the lack of #ifdef CONFIG_OF around the > actual definition. > > For the bug warning, I'd add add a Kconfig dependency on OF. > It doesn't make any sense to allow building this driver without that. > > So resend this as a simple tidy up patch and another one adding > that build dependency. > > Thanks, > > Jonathan > > > > > 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. > > > > Reported-by: kernel test robot <lkp@intel.com> > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > > --- > > drivers/iio/adc/at91_adc.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > > index 9b2c548fae95..c9ec0a4a357e 100644 > > --- a/drivers/iio/adc/at91_adc.c > > +++ b/drivers/iio/adc/at91_adc.c > > @@ -829,8 +829,6 @@ static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz) > > return ticks; > > } > > > > -static const struct of_device_id at91_adc_dt_ids[]; > > - > > static int at91_adc_probe_dt_ts(struct device_node *node, > > struct at91_adc_state *st, struct device *dev) > > { > > @@ -878,8 +876,7 @@ static int at91_adc_probe_dt(struct iio_dev *idev, > > if (!node) > > return -EINVAL; > > > > - st->caps = (struct at91_adc_caps *) > > - of_match_device(at91_adc_dt_ids, &pdev->dev)->data; > > + st->caps = (struct at91_adc_caps *)of_device_get_match_data(&pdev->dev); > > > > st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers"); > > >
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 9b2c548fae95..c9ec0a4a357e 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -829,8 +829,6 @@ static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz) return ticks; } -static const struct of_device_id at91_adc_dt_ids[]; - static int at91_adc_probe_dt_ts(struct device_node *node, struct at91_adc_state *st, struct device *dev) { @@ -878,8 +876,7 @@ static int at91_adc_probe_dt(struct iio_dev *idev, if (!node) return -EINVAL; - st->caps = (struct at91_adc_caps *) - of_match_device(at91_adc_dt_ids, &pdev->dev)->data; + st->caps = (struct at91_adc_caps *)of_device_get_match_data(&pdev->dev); st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");