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Message-ID: <b7154e2c-0438-87d1-9edc-7eb1aad40cd1@hust.edu.cn>
Date:   Mon, 8 May 2023 21:40:41 +0800
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Subject: Re: [PATCH] drivers: mpt3sas: mpt3sas_debugfs: return value check of
 `mpt3sas_debugfs_root`
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To:     Dan Carpenter <dan.carpenter@linaro.org>,
        Tomas Henzl <thenzl@redhat.com>
Cc:     Jing Xu <U202112064@hust.edu.cn>,
        Sathya Prakash <sathya.prakash@broadcom.com>,
        Sreekanth Reddy <sreekanth.reddy@broadcom.com>,
        Suganath Prabu Subramani 
        <suganath-prabu.subramani@broadcom.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        hust-os-kernel-patches@googlegroups.com,
        MPT-FusionLinux.pdl@broadcom.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230423122535.31019-1-U202112064@hust.edu.cn>
 <6e69b57c-80ae-8b6e-cb5f-9e05da46ecd6@redhat.com>
 <1484408f-f68e-4354-ab59-56af9cd1ef14@kili.mountain>
From:   Dongliang Mu <dzm91@hust.edu.cn>
In-Reply-To: <1484408f-f68e-4354-ab59-56af9cd1ef14@kili.mountain>
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On 5/3/23 01:06, Dan Carpenter wrote:
> On Tue, May 02, 2023 at 05:53:10PM +0200, Tomas Henzl wrote:
>> On 4/23/23 14:25, Jing Xu wrote:
>>> Smatch complains that:
>>> mpt3sas_init_debugfs() warn: 'mpt3sas_debugfs_root' is an error
>>> pointer or valid
>>>
>>> There is no need to check the return value of the debugfs_create_dir()
>>> function, just delete the dead code.
>>>
>>> Fixes: 2b01b293f359 ("scsi: mpt3sas: Capture IOC data for debugging purposes")
>>> Signed-off-by: Jing Xu <U202112064@hust.edu.cn>
>>> Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
>>> ---
>>>   drivers/scsi/mpt3sas/mpt3sas_debugfs.c | 2 --
>>>   1 file changed, 2 deletions(-)
>>>
>>> diff --git a/drivers/scsi/mpt3sas/mpt3sas_debugfs.c b/drivers/scsi/mpt3sas/mpt3sas_debugfs.c
>>> index a6ab1db81167..c92e08c130b9 100644
>>> --- a/drivers/scsi/mpt3sas/mpt3sas_debugfs.c
>>> +++ b/drivers/scsi/mpt3sas/mpt3sas_debugfs.c
>>> @@ -99,8 +99,6 @@ static const struct file_operations mpt3sas_debugfs_iocdump_fops = {
>>>   void mpt3sas_init_debugfs(void)
>>>   {
>>>   	mpt3sas_debugfs_root = debugfs_create_dir("mpt3sas", NULL);
>>> -	if (!mpt3sas_debugfs_root)
>>> -		pr_info("mpt3sas: Cannot create debugfs root\n");
>> Hi Jing,
>> most drivers just ignore the return value but here the author wanted to
>> have the information logged.
>> Can you instead of removing the message modify the 'if' condition so it
>> suits the author's intention?
> 
> This code was always just wrong.
> 
> The history of this is slightly complicated and boring.  These days it's
> harmless dead code so I guess it's less bad than before.

Hi Dan and Tomas,

Any conclusion about this patch? The student Jing Xu is not sure about 
how to revise this patch.

> 
> 
> regards,
> dan carpenter