Re: [PATCH v2] scsi: sli4: Remove the buggy code

From: Randy Dunlap <rdunlap@infradead.org>
To: Dmitry Bogdanov <d.bogdanov@yadro.com>, coolrrsh@gmail.com
Cc: linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
	jejb@linux.ibm.com, james.smart@broadcom.com,
	linux-kernel@vger.kernel.org, target-devel@vger.kernel.org,
	ram.vegesna@broadcom.com,
	linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [PATCH v2] scsi: sli4: Remove the buggy code
Date: Thu, 17 Aug 2023 07:51:56 -0700	[thread overview]
Message-ID: <79ac6ee9-247a-c3da-c0f7-8c26bd0b1ad0@infradead.org> (raw)
In-Reply-To: <20230817105252.GA14370@yadro.com>

On 8/17/23 03:52, Dmitry Bogdanov wrote:
> On Thu, Aug 17, 2023 at 04:07:51PM +0530, coolrrsh@gmail.com wrote:
>>
>> From: Rajeshwar R Shinde <coolrrsh@gmail.com>
>>
>> In the function sli_xmit_bls_rsp64_wqe, the 'if' and 'else' conditions
>> evaluates the same expression and gives same output. Also the variable
>> bls->local_n_port_id_dword is not used anywhere. Therefore removing the
>> redundant code.
>>
>> This fixes coccinelle warning such as:
>> drivers/scsi/elx/libefc_sli/sli4.c:2320:2-4: WARNING: possible
>> condition with no effect (if == else)
>>
>> Signed-off-by: Rajeshwar R Shinde <coolrrsh@gmail.com>
>> ---
>> v1->v2
>> Modified patch and verified with checkpatch.pl.
>>
>> ---
>>  drivers/scsi/elx/libefc_sli/sli4.c | 7 -------
>>  1 file changed, 7 deletions(-)
>>
>> diff --git a/drivers/scsi/elx/libefc_sli/sli4.c b/drivers/scsi/elx/libefc_sli/sli4.c
>> index 8f96049f62dd..af661b769464 100644
>> --- a/drivers/scsi/elx/libefc_sli/sli4.c
>> +++ b/drivers/scsi/elx/libefc_sli/sli4.c
>> @@ -2317,13 +2317,6 @@ sli_xmit_bls_rsp64_wqe(struct sli4 *sli, void *buf,
>>                 SLI4_GENERIC_CONTEXT_VPI << SLI4_BLS_RSP_WQE_CT_SHFT;
>>                 bls->context_tag = cpu_to_le16(params->vpi);
>>
>> -               if (params->s_id != U32_MAX)
>> -                       bls->local_n_port_id_dword |=
>> -                               cpu_to_le32(params->s_id & 0x00ffffff);
>> -               else
>> -                       bls->local_n_port_id_dword |=
>> -                               cpu_to_le32(params->s_id & 0x00ffffff);
>> -
> 
> omg, it is not an unused variable. Whole bls is a HW descriptor, all of
> its variables are used by HW. You should keep v1 version of the patch.
> According to the comment at the beginning of the funciton s_id here shall
> be != U32_MAX. That is an explanation for your v1 patch.
> 

Thanks for your comments.

>>                 dw_ridflags = (dw_ridflags & ~SLI4_BLS_RSP_RID) |
>>                                (params->d_id & SLI4_BLS_RSP_RID);
>>
>> --
>> 2.25.1
>>

-- 
~Randy
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