Linux IOMMU Development
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Baolu Lu <baolu.lu@linux.intel.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>,
	linux-tegra@vger.kernel.org, iommu@lists.linux.dev,
	Thierry Reding <thierry.reding@gmail.com>,
	Krishna Reddy <vdumpa@nvidia.com>, Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Jonathan Hunter <jonathanh@nvidia.com>
Subject: Re: [PATCH] iommu/tegra-smmu: Fix the NULL vs IS_ERR() bug for debugfs_create_dir()
Date: Wed, 6 Sep 2023 10:36:51 -0300	[thread overview]
Message-ID: <ZPiAc4MuNAJfnTaY@ziepe.ca> (raw)
In-Reply-To: <8830ecd1-f7a3-a708-66b1-2d9698d0d477@linux.intel.com>

On Fri, Sep 01, 2023 at 11:05:48AM +0800, Baolu Lu wrote:
> On 2023/8/31 20:38, Jinjie Ruan wrote:
> > The debugfs_create_dir() function returns error pointers.
> > It never returns NULL. So use IS_ERR() to check it.
> > 
> > Fixes: d1313e7896e9 ("iommu/tegra-smmu: Add debugfs support")
> > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.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;
> 
> There is no need to check the return value of debugfs_create_dir(). This
> change cannot fix anything as far as I can see. Just remove the
> check.

Right

Jason

      reply	other threads:[~2023-09-06 13:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-31 12:38 [PATCH] iommu/tegra-smmu: Fix the NULL vs IS_ERR() bug for debugfs_create_dir() Jinjie Ruan
2023-09-01  3:05 ` Baolu Lu
2023-09-06 13:36   ` Jason Gunthorpe [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ZPiAc4MuNAJfnTaY@ziepe.ca \
    --to=jgg@ziepe.ca \
    --cc=baolu.lu@linux.intel.com \
    --cc=iommu@lists.linux.dev \
    --cc=jonathanh@nvidia.com \
    --cc=joro@8bytes.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=ruanjinjie@huawei.com \
    --cc=thierry.reding@gmail.com \
    --cc=vdumpa@nvidia.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox