• Andreas Klinger's avatar
    iio: bmp280: fix compensation of humidity · 6dd652f6
    Andreas Klinger authored
    [ Upstream commit dee2dabc ]
    
    Limit the output of humidity compensation to the range between 0 and 100
    percent.
    
    Depending on the calibration parameters of the individual sensor it
    happens, that a humidity above 100 percent or below 0 percent is
    calculated, which don't make sense in terms of relative humidity.
    
    Add a clamp to the compensation formula as described in the datasheet of
    the sensor in chapter 4.2.3.
    
    Although this clamp is documented, it was never in the driver of the
    kernel.
    
    It depends on the circumstances (calibration parameters, temperature,
    humidity) if one can see a value above 100 percent without the clamp.
    The writer of this patch was working with this type of sensor without
    noting this error. So it seems to be a rare event when this bug occures.
    Signed-off-by: default avatarAndreas Klinger <ak@it-klinger.de>
    Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    6dd652f6
bmp280-core.c 27.5 KB