[PATCH] iio: adc: ad7476: fix clang -Wpointer-bool-conversion warning

[Arnd Bergmann]

Checking the pointer value of st->chip_info->convst_channel is pointless
since this this an array inside of a struct: even if st->chip_info is NULL,
the pointer is non-zero. Clang warns about this:

drivers/iio/adc/ad7476.c:312:40: warning: address of array 'st->chip_info->convst_channel' will always evaluate to 'true' [-Wpointer-bool-conversion]
if (st->convst_gpio && st->chip_info->convst_channel)
~~ ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

I could not come up with a sane way to check whether the entry
is valid, so just remove the check and keep the behavior as it
is today but without the warning.

Fixes: 3a6af93dd66e ("iio: adc: ad7476: Add IIO_CHAN_INFO_RAW for AD7091R")
Signed-off-by: Arnd Bergmann <ar...@arndb.de>
---
drivers/iio/adc/ad7476.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
index e9984a38fc4c..4e816d714ad2 100644
--- a/drivers/iio/adc/ad7476.c
+++ b/drivers/iio/adc/ad7476.c
@@ -309,7 +309,7 @@ static int ad7476_probe(struct spi_device *spi)
indio_dev->num_channels = 2;
indio_dev->info = &ad7476_info;

- if (st->convst_gpio && st->chip_info->convst_channel)
+ if (st->convst_gpio)
indio_dev->channels = st->chip_info->convst_channel;
/* Setup default message */

--
2.26.0

[Ardelean, Alexandru]

On Tue, 2020-05-05 at 16:23 +0200, Arnd Bergmann wrote:
> [External]

>
> Checking the pointer value of st->chip_info->convst_channel is pointless
> since this this an array inside of a struct: even if st->chip_info is NULL,
> the pointer is non-zero. Clang warns about this:
>
> drivers/iio/adc/ad7476.c:312:40: warning: address of array 'st->chip_info-
> >convst_channel' will always evaluate to 'true' [-Wpointer-bool-conversion]
> if (st->convst_gpio && st->chip_info->convst_channel)
> ~~ ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
>
> I could not come up with a sane way to check whether the entry
> is valid, so just remove the check and keep the behavior as it
> is today but without the warning.

There's already a patch for this, in one of Jonathan's branches.
https://patchwork.kernel.org/patch/11507829/

Thanks
Alex

[Nick Desaulniers]

On Tue, May 5, 2020 at 7:24 AM Arnd Bergmann <ar...@arndb.de> wrote:
>
> Checking the pointer value of st->chip_info->convst_channel is pointless
> since this this an array inside of a struct: even if st->chip_info is NULL,
> the pointer is non-zero. Clang warns about this:
>
> drivers/iio/adc/ad7476.c:312:40: warning: address of array 'st->chip_info->convst_channel' will always evaluate to 'true' [-Wpointer-bool-conversion]
> if (st->convst_gpio && st->chip_info->convst_channel)
> ~~ ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
>
> I could not come up with a sane way to check whether the entry
> is valid, so just remove the check and keep the behavior as it
> is today but without the warning.

Me too. Thanks for the patch.
Reviewed-by: Nick Desaulniers <ndesau...@google.com>

>
> Fixes: 3a6af93dd66e ("iio: adc: ad7476: Add IIO_CHAN_INFO_RAW for AD7091R")
> Signed-off-by: Arnd Bergmann <ar...@arndb.de>
> ---
> drivers/iio/adc/ad7476.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
> index e9984a38fc4c..4e816d714ad2 100644
> --- a/drivers/iio/adc/ad7476.c
> +++ b/drivers/iio/adc/ad7476.c
> @@ -309,7 +309,7 @@ static int ad7476_probe(struct spi_device *spi)
> indio_dev->num_channels = 2;
> indio_dev->info = &ad7476_info;
>
> - if (st->convst_gpio && st->chip_info->convst_channel)
> + if (st->convst_gpio)
> indio_dev->channels = st->chip_info->convst_channel;
> /* Setup default message */
>
> --
> 2.26.0
>

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--
Thanks,
~Nick Desaulniers