| Message ID | 20240809080523.32717-1-jiapeng.chong@linux.alibaba.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [-next] pwm: lp3943: Fix an incorrect type in lp3943_pwm_parse_dt() | expand |
Hello Jiapeng, On 8/9/24 10:05, Jiapeng Chong wrote: > The return value from the call to of_property_count_u32_elems() is int. > However, the return value is being assigned to an u32 variable > 'num_outputs', so making 'num_outputs' an int. > > ./drivers/pwm/pwm-lp3943.c:238:6-17: WARNING: Unsigned expression compared with zero: num_outputs <= 0. Which tool does emit this warning? My test build (with C=1 and W=1) doesn't emit it. > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9710 > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> This problem was introduced in a commit in next: Fixes: d6a56f3bb650 ("pwm: lp3943: Use of_property_count_u32_elems() to get property length") Rob: I guess this wasn't the only conversion of this type. Maybe these others suffer from the same problem?! > --- > drivers/pwm/pwm-lp3943.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/pwm/pwm-lp3943.c b/drivers/pwm/pwm-lp3943.c > index f0e94c9e5956..90b0733c00c1 100644 > --- a/drivers/pwm/pwm-lp3943.c > +++ b/drivers/pwm/pwm-lp3943.c > @@ -218,8 +218,7 @@ static int lp3943_pwm_parse_dt(struct device *dev, > struct lp3943_platform_data *pdata; > struct lp3943_pwm_map *pwm_map; > enum lp3943_pwm_output *output; > - int i, err, count = 0; > - u32 num_outputs; > + int i, err, num_outputs, count = 0; > > if (!node) > return -EINVAL; Nitpick (maybe even a subjective one): While touching num_outputs, its scope could be reduced to the for loop. Best regards Uwe
Hello, On Fri, Aug 09, 2024 at 10:50:49AM +0200, Uwe Kleine-König wrote: > On 8/9/24 10:05, Jiapeng Chong wrote: > > The return value from the call to of_property_count_u32_elems() is int. > > However, the return value is being assigned to an u32 variable > > 'num_outputs', so making 'num_outputs' an int. > > > > ./drivers/pwm/pwm-lp3943.c:238:6-17: WARNING: Unsigned expression compared with zero: num_outputs <= 0. > > Which tool does emit this warning? My test build (with C=1 and W=1) doesn't > emit it. > > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > > Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9710 > > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > > This problem was introduced in a commit in next: > > Fixes: d6a56f3bb650 ("pwm: lp3943: Use of_property_count_u32_elems() to get > property length") > > Rob: I guess this wasn't the only conversion of this type. Maybe these > others suffer from the same problem?! I hoped for some more feedback, but anyhow: Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux.git pwm/for-next with the Fixes line. Best regards Uwe
diff --git a/drivers/pwm/pwm-lp3943.c b/drivers/pwm/pwm-lp3943.c index f0e94c9e5956..90b0733c00c1 100644 --- a/drivers/pwm/pwm-lp3943.c +++ b/drivers/pwm/pwm-lp3943.c @@ -218,8 +218,7 @@ static int lp3943_pwm_parse_dt(struct device *dev, struct lp3943_platform_data *pdata; struct lp3943_pwm_map *pwm_map; enum lp3943_pwm_output *output; - int i, err, count = 0; - u32 num_outputs; + int i, err, num_outputs, count = 0; if (!node) return -EINVAL;
The return value from the call to of_property_count_u32_elems() is int. However, the return value is being assigned to an u32 variable 'num_outputs', so making 'num_outputs' an int. ./drivers/pwm/pwm-lp3943.c:238:6-17: WARNING: Unsigned expression compared with zero: num_outputs <= 0. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9710 Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> --- drivers/pwm/pwm-lp3943.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)