Patch "IIO: bmp280-core.c: fix error in humidity calculation" has been added to the 4.11-stable tree

Patch "IIO: bmp280-core.c: fix error in humidity calculation" has been added to the 4.11-stable tree

[gregkh]

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 the 4.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iio-bmp280-core.c-fix-error-in-humidity-calculation.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ed3730c435f1a9f9559ed7762035d22d8a95adfe Mon Sep 17 00:00:00 2001
From: Andreas Klinger <ak@it-klinger.de>
Date: Mon, 10 Apr 2017 19:00:01 +0200
Subject: IIO: bmp280-core.c: fix error in humidity calculation

From: Andreas Klinger <ak@it-klinger.de>

commit ed3730c435f1a9f9559ed7762035d22d8a95adfe upstream.

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.

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -175,11 +175,12 @@ static u32 bmp280_compensate_humidity(st
 	}
 	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;
 };


Patches currently in stable-queue which might be from ak@it-klinger.de are

queue-4.11/iio-bmp280-core.c-fix-error-in-humidity-calculation.patch