Re: [PATCH] dmaengine: ioatdma: use !kstrtoint(), not sscanf()!=-1

[Dave Jiang]

On 5/25/26 11:13 PM, Alexander A. Klimov wrote:
> Depending on the user input, sscanf() may return 0 for 0 success.
> But intr_coalesce_store() wants sscanf() to parse one number,
> so expect 1 from sscanf(), not any int except -1.
> 
> While on it, fix typo in %du by using just %d,
> as this interface expects %d or %d\n.
> Latter made scripts/checkpatch.pl complain,
> so use kstrtoint() instead of sscanf().
> 
> Fixes: 268e2519f5b7 ("dmaengine: ioatdma: Add intr_coalesce sysfs entry")
> Signed-off-by: Alexander A. Klimov <grandmaster@xxxxxxxxxxxx>
> ---
>  drivers/dma/ioat/sysfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/ioat/sysfs.c b/drivers/dma/ioat/sysfs.c
> index e796ddb5383f..f59df569956a 100644
> --- a/drivers/dma/ioat/sysfs.c
> +++ b/drivers/dma/ioat/sysfs.c
> @@ -144,7 +144,7 @@ size_t count)
>  	int intr_coalesce = 0;
>  	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
>  
> -	if (sscanf(page, "%du", &intr_coalesce) != -1) {
> +	if (!kstrtoint(page, 10, &intr_coalesce)) {

looks good. We can probably use kstrtouint() since we are expecting a positive number always.

DJ

>  		if ((intr_coalesce < 0) ||
>  		    (intr_coalesce > IOAT_INTRDELAY_MASK))
>  			return -EINVAL;