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| author | Andreas Klinger <ak@it-klinger.de> | 2017-04-10 19:00:01 +0200 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2017-04-14 16:54:49 +0100 |
| commit | ed3730c435f1a9f9559ed7762035d22d8a95adfe (patch) | |
| tree | 677e87223f1e19d556faec1d463da4d1af834f29 /drivers/iio | |
| parent | 84ca8e364acb26aba3292bc113ca8ed4335380fd (diff) | |
| download | linux-ed3730c435f1a9f9559ed7762035d22d8a95adfe.tar.gz linux-ed3730c435f1a9f9559ed7762035d22d8a95adfe.tar.bz2 linux-ed3730c435f1a9f9559ed7762035d22d8a95adfe.zip | |
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.
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>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/pressure/bmp280-core.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c index 4d18826ac63c..d82b788374b6 100644 --- a/drivers/iio/pressure/bmp280-core.c +++ b/drivers/iio/pressure/bmp280-core.c @@ -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; }; |