From: Tom Rix <trix@xxxxxxxxxx> commit f50232193e61cf89a73130b5e843fef30763c428 upstream. Clang static analysis reports this problem scd4x.c:474:10: warning: The left operand of '==' is a garbage value if (val == 0xff) { ~~~ ^ val is only set from a successful call to scd4x_write_and_fetch() So check it's return. Fixes: 49d22b695cbb ("drivers: iio: chemical: Add support for Sensirion SCD4x CO2 sensor") Signed-off-by: Tom Rix <trix@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220301025223.223223-1-trix@xxxxxxxxxx Cc: <Stable@xxxxxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/chemical/scd4x.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/iio/chemical/scd4x.c b/drivers/iio/chemical/scd4x.c index 20d4e7584e92..37143b5526ee 100644 --- a/drivers/iio/chemical/scd4x.c +++ b/drivers/iio/chemical/scd4x.c @@ -471,12 +471,15 @@ static ssize_t calibration_forced_value_store(struct device *dev, ret = scd4x_write_and_fetch(state, CMD_FRC, arg, &val, sizeof(val)); mutex_unlock(&state->lock); + if (ret) + return ret; + if (val == 0xff) { dev_err(dev, "forced calibration has failed"); return -EINVAL; } - return ret ?: len; + return len; } static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0); -- 2.36.0