| Message ID | 20220227154331.80338-1-trix@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: scd4x: check return of scd4x_write_and_fetch | expand |
On Sun, 27 Feb 2022 07:43:31 -0800 trix@redhat.com wrote: > From: Tom Rix <trix@redhat.com> > > 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@redhat.com> 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; } Thanks, Jonathan
On 2/27/22 9:48 AM, Jonathan Cameron wrote: > On Sun, 27 Feb 2022 07:43:31 -0800 > trix@redhat.com wrote: > >> From: Tom Rix <trix@redhat.com> >> >> 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@redhat.com> > 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 >
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; }