On 2/27/22 9:48 AM, Jonathan Cameron wrote:
On Sun, 27 Feb 2022 07:43:31 -0800
trix@xxxxxxxxxx wrote:
From: Tom Rix <trix@xxxxxxxxxx>
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>
Good find, but I'd prefer a separate check on ret inline with what the
other error checking paths in that function are doing.
---
drivers/iio/chemical/scd4x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/chemical/scd4x.c b/drivers/iio/chemical/scd4x.c
index 20d4e7584e923..b978330fb761c 100644
--- a/drivers/iio/chemical/scd4x.c
+++ b/drivers/iio/chemical/scd4x.c
@@ -471,7 +471,7 @@ 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 (val == 0xff) {
+ if (!ret && val == 0xff) {
dev_err(dev, "forced calibration has failed");
return -EINVAL;
}
Prefer
if (ret)
return ret;
if (val == 0xff) {
dev_err(dev, "...
return -EINVAL;
}
ok and the next line can be simplified to
return len;
Tom
Thanks,
Jonathan
