[PATCH v2] pinctrl: single: fix a never true comparison

[Pratyush Yadav]

On 22/04/21 10:28PM, Dario Binacchi wrote:
> As reported by Coverity Scan for Das U-Boot, the 'less-than-zero'
> comparison of an unsigned value is never true.
> 
> Signed-off-by: Dario Binacchi <dariobin at libero.it>
> Reviewed-by: Pratyush Yadav <p.yadav at ti.com>
> 
> ---
> 
> Changes in v2:
> - Balance quote in commit message
> - Add review tag
> 
>  drivers/pinctrl/pinctrl-single.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
> index 48bdd0f6f5..7e1c5bb0a5 100644
> --- a/drivers/pinctrl/pinctrl-single.c
> +++ b/drivers/pinctrl/pinctrl-single.c
> @@ -295,7 +295,7 @@ static int single_configure_pins(struct udevice *dev,
>  	func->npins = 0;
>  	for (n = 0; n < count; n++, pins++) {
>  		offset = fdt32_to_cpu(pins->reg);
> -		if (offset < 0 || offset > pdata->offset) {
> +		if (offset > pdata->offset) {

I went back and took a look at it again. The "offset < 0" comes from 
"reg < 0" in 9b884e79a6 (pinctrl: single: fix offset management, 
2021-04-11), where reg is of type phys_addr_t. But phys_addr_t is also 
an unsigned value so I suppose the check was wrong to begin with. And 
fdt32_to_cpu() just does byte order conversions so it shouldn't return a 
negative value because there is no scope for failure.

So again, the patch looks good to me, but some added context for anyone 
interested.

>  			dev_err(dev, "  invalid register offset 0x%x\n",
>  				offset);
>  			continue;
> @@ -344,7 +344,7 @@ static int single_configure_bits(struct udevice *dev,
>  	func->npins = 0;
>  	for (n = 0; n < count; n++, pins++) {
>  		offset = fdt32_to_cpu(pins->reg);
> -		if (offset < 0 || offset > pdata->offset) {
> +		if (offset > pdata->offset) {
>  			dev_dbg(dev, "  invalid register offset 0x%x\n",
>  				offset);
>  			continue;
> -- 
> 2.17.1
> 

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.