From 61493eba2918294ee62855d2943aa563aa301c0d Mon Sep 17 00:00:00 2001
From: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Date: Mon, 21 Mar 2011 17:59:35 +0100
Subject: [PATCH] hwmon: (sht15) Fix integer overflow in humidity calculation

commit ccd32e735de7a941906e093f8dca924bb05c5794 upstream.

An integer overflow occurs in the calculation of RHlinear when the
relative humidity is greater than around 30%. The consequence is a subtle
(but noticeable) error in the resulting humidity measurement.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/hwmon/sht15.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index a610e7880fb3e..38a41d27f3da1 100644
--- a/drivers/hwmon/sht15.c
+++ b/drivers/hwmon/sht15.c
@@ -333,11 +333,11 @@ static inline int sht15_calc_humid(struct sht15_data *data)
 
 	const int c1 = -4;
 	const int c2 = 40500; /* x 10 ^ -6 */
-	const int c3 = -2800; /* x10 ^ -9 */
+	const int c3 = -28; /* x 10 ^ -7 */
 
 	RHlinear = c1*1000
 		+ c2 * data->val_humid/1000
-		+ (data->val_humid * data->val_humid * c3)/1000000;
+		+ (data->val_humid * data->val_humid * c3) / 10000;
 	return (temp - 25000) * (10000 + 80 * data->val_humid)
 		/ 1000000 + RHlinear;
 }