[PATCH -next] backlight: qcom-wled: fix unsigned comparison to zero

[PATCH -next] backlight: qcom-wled: fix unsigned comparison to zero

[Chen Zhou]

Fixes coccicheck warning:
./drivers/video/backlight/qcom-wled.c:1104:5-15:
	WARNING: Unsigned expression compared with zero: string_len > 0

The unsigned variable string_len is assigned a return value from the call
to wled_configure, which may return negative error code.

Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3")
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
---
 drivers/video/backlight/qcom-wled.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index d46052d..3d276b3 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -956,8 +956,8 @@ static int wled_configure(struct wled *wled, int version)
 	struct wled_config *cfg = &wled->cfg;
 	struct device *dev = wled->dev;
 	const __be32 *prop_addr;
-	u32 size, val, c, string_len;
-	int rc, i, j;
+	u32 size, val, c;
+	int rc, i, j, string_len;
 
 	const struct wled_u32_opts *u32_opts = NULL;
 	const struct wled_u32_opts wled3_opts[] = {
-- 
2.7.4

Re: [PATCH -next] backlight: qcom-wled: fix unsigned comparison to zero

[Bjorn Andersson]

On Mon 20 Jan 05:01 PST 2020, Chen Zhou wrote:

> Fixes coccicheck warning:
> ./drivers/video/backlight/qcom-wled.c:1104:5-15:
> 	WARNING: Unsigned expression compared with zero: string_len > 0
> 
> The unsigned variable string_len is assigned a return value from the call
> to wled_configure, which may return negative error code.
> 

Afaict string_len is the return value of
of_property_count_elems_of_size(), rather than wled_configure(). (And
please append () to function names to make it even more obvious)

Except for that your patch looks good, so please update the commit
message and add my Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3")
> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
> ---
>  drivers/video/backlight/qcom-wled.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index d46052d..3d276b3 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -956,8 +956,8 @@ static int wled_configure(struct wled *wled, int version)
>  	struct wled_config *cfg = &wled->cfg;
>  	struct device *dev = wled->dev;
>  	const __be32 *prop_addr;
> -	u32 size, val, c, string_len;
> -	int rc, i, j;
> +	u32 size, val, c;
> +	int rc, i, j, string_len;
>  
>  	const struct wled_u32_opts *u32_opts = NULL;
>  	const struct wled_u32_opts wled3_opts[] = {
> -- 
> 2.7.4
> 

Re: [PATCH -next] backlight: qcom-wled: fix unsigned comparison to zero

[Chen Zhou]

Hi Bjorn,

On 2020/1/22 8:39, Bjorn Andersson wrote:
> On Mon 20 Jan 05:01 PST 2020, Chen Zhou wrote:
> 
>> Fixes coccicheck warning:
>> ./drivers/video/backlight/qcom-wled.c:1104:5-15:
>> 	WARNING: Unsigned expression compared with zero: string_len > 0
>>
>> The unsigned variable string_len is assigned a return value from the call
>> to wled_configure, which may return negative error code.
>>
> 
> Afaict string_len is the return value of
> of_property_count_elems_of_size(), rather than wled_configure(). (And
> please append () to function names to make it even more obvious)
> 
> Except for that your patch looks good, so please update the commit
> message and add my Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> 
> Regards,
> Bjorn

Thanks for your review, i will fix this in next version.

Thanks,
Chen Zhou

> 
>> Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3")
>> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
>> ---
>>  drivers/video/backlight/qcom-wled.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
>> index d46052d..3d276b3 100644
>> --- a/drivers/video/backlight/qcom-wled.c
>> +++ b/drivers/video/backlight/qcom-wled.c
>> @@ -956,8 +956,8 @@ static int wled_configure(struct wled *wled, int version)
>>  	struct wled_config *cfg = &wled->cfg;
>>  	struct device *dev = wled->dev;
>>  	const __be32 *prop_addr;
>> -	u32 size, val, c, string_len;
>> -	int rc, i, j;
>> +	u32 size, val, c;
>> +	int rc, i, j, string_len;
>>  
>>  	const struct wled_u32_opts *u32_opts = NULL;
>>  	const struct wled_u32_opts wled3_opts[] = {
>> -- 
>> 2.7.4
>>
> 
> .
>