Re: [PATCH] iommu/tegra-smmu: fix error checking for debugfs_create_dir()

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2023/10/25 19:01, Dario Binacchi wrote:
> The return value of debugfs_create_dir() should be checked using the
> IS_ERR() function.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
>   drivers/iommu/tegra-smmu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index e445f80d0226..cd1d80c4c673 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -1056,7 +1056,7 @@ DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
>   static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
>   {
>   	smmu->debugfs = debugfs_create_dir("smmu", NULL);
> -	if (!smmu->debugfs)
> +	if (IS_ERR(smmu->debugfs))
>   		return;

This check can be removed, as debugfs_create_file() can handle the case
where @parent is an error pointer.

>   
>   	debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,

Best regards,
baolu