* [PATCH] iio: chemical: sps30: Explicity truncate constant by masking
@ 2019-10-13 9:55 jic23
2019-10-17 16:41 ` Tomasz Duszynski
0 siblings, 1 reply; 3+ messages in thread
From: jic23 @ 2019-10-13 9:55 UTC (permalink / raw)
To: linux-iio; +Cc: Jonathan Cameron, Tomasz Duszynski
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
When breaking up a constant to write to two 8 bit registers
it isn't obvious to sparse that it was intentional.
CHECK drivers/iio/chemical/sps30.c
drivers/iio/chemical/sps30.c:120:30: warning: cast truncates bits from constant value (8004 becomes 4)
So in the interests of minimising noisy warnings, let us add
a mask.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomasz Duszynski <tduszyns@gmail.com>
---
drivers/iio/chemical/sps30.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
index edbb956e81e8..acb9f8ecbb3d 100644
--- a/drivers/iio/chemical/sps30.c
+++ b/drivers/iio/chemical/sps30.c
@@ -117,7 +117,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
break;
case SPS30_READ_AUTO_CLEANING_PERIOD:
buf[0] = SPS30_AUTO_CLEANING_PERIOD >> 8;
- buf[1] = (u8)SPS30_AUTO_CLEANING_PERIOD;
+ buf[1] = (u8)(SPS30_AUTO_CLEANING_PERIOD & 0xff);
/* fall through */
case SPS30_READ_DATA_READY_FLAG:
case SPS30_READ_DATA:
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] iio: chemical: sps30: Explicity truncate constant by masking
2019-10-13 9:55 [PATCH] iio: chemical: sps30: Explicity truncate constant by masking jic23
@ 2019-10-17 16:41 ` Tomasz Duszynski
2019-10-18 18:52 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Tomasz Duszynski @ 2019-10-17 16:41 UTC (permalink / raw)
To: jic23; +Cc: linux-iio, Jonathan Cameron, Tomasz Duszynski
On Sun, Oct 13, 2019 at 10:55:15AM +0100, jic23@kernel.org wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> When breaking up a constant to write to two 8 bit registers
> it isn't obvious to sparse that it was intentional.
>
> CHECK drivers/iio/chemical/sps30.c
> drivers/iio/chemical/sps30.c:120:30: warning: cast truncates bits from constant value (8004 becomes 4)
>
> So in the interests of minimising noisy warnings, let us add
> a mask.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Tomasz Duszynski <tduszyns@gmail.com>
> ---
> drivers/iio/chemical/sps30.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
> index edbb956e81e8..acb9f8ecbb3d 100644
> --- a/drivers/iio/chemical/sps30.c
> +++ b/drivers/iio/chemical/sps30.c
> @@ -117,7 +117,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
> break;
> case SPS30_READ_AUTO_CLEANING_PERIOD:
> buf[0] = SPS30_AUTO_CLEANING_PERIOD >> 8;
> - buf[1] = (u8)SPS30_AUTO_CLEANING_PERIOD;
> + buf[1] = (u8)(SPS30_AUTO_CLEANING_PERIOD & 0xff);
> /* fall through */
> case SPS30_READ_DATA_READY_FLAG:
> case SPS30_READ_DATA:
> --
> 2.23.0
>
Thanks for catching this.
Acked-by: Tomasz Duszynski <tduszyns@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] iio: chemical: sps30: Explicity truncate constant by masking
2019-10-17 16:41 ` Tomasz Duszynski
@ 2019-10-18 18:52 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2019-10-18 18:52 UTC (permalink / raw)
To: Tomasz Duszynski; +Cc: linux-iio, Jonathan Cameron
On Thu, 17 Oct 2019 18:41:12 +0200
Tomasz Duszynski <tduszyns@gmail.com> wrote:
> On Sun, Oct 13, 2019 at 10:55:15AM +0100, jic23@kernel.org wrote:
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> >
> > When breaking up a constant to write to two 8 bit registers
> > it isn't obvious to sparse that it was intentional.
> >
> > CHECK drivers/iio/chemical/sps30.c
> > drivers/iio/chemical/sps30.c:120:30: warning: cast truncates bits from constant value (8004 becomes 4)
> >
> > So in the interests of minimising noisy warnings, let us add
> > a mask.
> >
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Cc: Tomasz Duszynski <tduszyns@gmail.com>
> > ---
> > drivers/iio/chemical/sps30.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
> > index edbb956e81e8..acb9f8ecbb3d 100644
> > --- a/drivers/iio/chemical/sps30.c
> > +++ b/drivers/iio/chemical/sps30.c
> > @@ -117,7 +117,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
> > break;
> > case SPS30_READ_AUTO_CLEANING_PERIOD:
> > buf[0] = SPS30_AUTO_CLEANING_PERIOD >> 8;
> > - buf[1] = (u8)SPS30_AUTO_CLEANING_PERIOD;
> > + buf[1] = (u8)(SPS30_AUTO_CLEANING_PERIOD & 0xff);
> > /* fall through */
> > case SPS30_READ_DATA_READY_FLAG:
> > case SPS30_READ_DATA:
> > --
> > 2.23.0
> >
>
> Thanks for catching this.
> Acked-by: Tomasz Duszynski <tduszyns@gmail.com>
Applied. Thanks,
Jonathan
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-10-13 9:55 [PATCH] iio: chemical: sps30: Explicity truncate constant by masking jic23
2019-10-17 16:41 ` Tomasz Duszynski
2019-10-18 18:52 ` Jonathan Cameron
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