diff options
| author | Vivien Didelot <vivien.didelot@savoirfairelinux.com> | 2011-03-21 17:59:35 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2011-03-21 17:59:35 +0100 |
| commit | ccd32e735de7a941906e093f8dca924bb05c5794 (patch) | |
| tree | 0917acbefbf51c669d4cae75daae2f5abccfbdaa /drivers/hwmon/sht15.c | |
| parent | 396bd766a604b823369962ee0203c603b9c0bdec (diff) | |
| download | lwn-ccd32e735de7a941906e093f8dca924bb05c5794.tar.gz lwn-ccd32e735de7a941906e093f8dca924bb05c5794.zip | |
hwmon: (sht15) Fix integer overflow in humidity calculation
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: stable@kernel.org
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Diffstat (limited to 'drivers/hwmon/sht15.c')
| -rw-r--r-- | drivers/hwmon/sht15.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c index 3ba7dd82589a..1a9c32d6893a 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; } |