patch "IIO: bmp280-core.c: fix error in humidity calculation" added to staging-testing

This is a note to let you know that I've just added the patch titled

IIO: bmp280-core.c: fix error in humidity calculation

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the staging-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From: Andreas Klinger <[email protected]>
Date: Mon, 10 Apr 2017 19:00:01 +0200
Subject: IIO: bmp280-core.c: fix error in humidity calculation

While calculating the compensation of the humidity there are negative values interpreted as unsigned because of unsigned variables used. These values as well as the constants need to be casted to signed as indicated by the documentation of the sensor.

---
 drivers/iio/pressure/bmp280-core.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

index 4d18826ac63c..d82b788374b6 100644
@@ -175,11 +175,12 @@ static u32 bmp280_compensate_humidity(struct bmp280_data *data,
 	}
 	H6 = sign_extend32(tmp, 7);
 
-	var = ((s32)data->t_fine) - 76800;
-	var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + 16384) >> 15)
-		* (((((((var * H6) >> 10) * (((var * H3) >> 11) + 32768)) >> 10)
-		+ 2097152) * H2 + 8192) >> 14);
-	var -= ((((var >> 15) * (var >> 15)) >> 7) * H1) >> 4;
+	var = ((s32)data->t_fine) - (s32)76800;
+	var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var))
+		+ (s32)16384) >> 15) * (((((((var * H6) >> 10)
+		* (((var * (s32)H3) >> 11) + (s32)32768)) >> 10)
+		+ (s32)2097152) * H2 + 8192) >> 14);
+	var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)H1) >> 4;
 
 	return var >> 12;
 };

2.12.2