Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Message-ID: <1acd75d0-67a7-4a17-99c7-707cca305f37@linux.intel.com>
Date:   Wed, 25 Oct 2023 19:25:50 +0800
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Cc:     baolu.lu@linux.intel.com, Joerg Roedel <joro@8bytes.org>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Krishna Reddy <vdumpa@nvidia.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Will Deacon <will@kernel.org>, iommu@lists.linux.dev,
        linux-tegra@vger.kernel.org
Subject: Re: [PATCH] iommu/tegra-smmu: fix error checking for
 debugfs_create_dir()
To:     Dario Binacchi <dario.binacchi@amarulasolutions.com>,
        linux-kernel@vger.kernel.org
References: <20231025110140.2034650-1-dario.binacchi@amarulasolutions.com>
Content-Language: en-US
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20231025110140.2034650-1-dario.binacchi@amarulasolutions.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

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