This is a note to let you know that I've just added the patch titled iio: scd4x: check return of scd4x_write_and_fetch to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From f50232193e61cf89a73130b5e843fef30763c428 Mon Sep 17 00:00:00 2001 From: Tom Rix <trix@xxxxxxxxxx> Date: Mon, 28 Feb 2022 18:52:23 -0800 Subject: iio: scd4x: check return of scd4x_write_and_fetch 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> --- 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