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From: jic23@kernel.org
To: linux-iio@vger.kernel.org
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Tomasz Duszynski <tduszyns@gmail.com>
Subject: [PATCH] iio: chemical: sps30: Explicity truncate constant by masking
Date: Sun, 13 Oct 2019 10:55:15 +0100	[thread overview]
Message-ID: <20191013095515.1438147-1-jic23@kernel.org> (raw)

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


             reply	other threads:[~2019-10-13  9:57 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-13  9:55 jic23 [this message]
2019-10-17 16:41 ` [PATCH] iio: chemical: sps30: Explicity truncate constant by masking Tomasz Duszynski
2019-10-18 18:52   ` Jonathan Cameron

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