[PATCH] RDMA/bnxt_re: remove redundant initialization of rc to zero

[PATCH] RDMA/bnxt_re: remove redundant initialization of rc to zero

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

rc is initialized to zero but is then updated by calls to
bnxt_qplib_free_fast_reg_page_list and/or bnxt_qpliob_free_mrw
so the initialization is redundant and can be removed.

Detected with CoverityScan, CID#1408448 ("Unused Value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/infiniband/hw/bnxt_re/ib_verbs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index 33af2e3..17aa087 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -2818,7 +2818,7 @@ int bnxt_re_dereg_mr(struct ib_mr *ib_mr)
 {
 	struct bnxt_re_mr *mr = container_of(ib_mr, struct bnxt_re_mr, ib_mr);
 	struct bnxt_re_dev *rdev = mr->rdev;
-	int rc = 0;
+	int rc;
 
 	if (mr->npages && mr->pages) {
 		rc = bnxt_qplib_free_fast_reg_page_list(&rdev->qplib_res,
-- 
2.10.2

Re: [PATCH] RDMA/bnxt_re: remove redundant initialization of rc to zero

[Laurence Oberman]

----- Original Message -----
> From: "Colin King" <colin.king@canonical.com>
> To: "Selvin Xavier" <selvin.xavier@broadcom.com>, "Devesh Sharma" <devesh.sharma@broadcom.com>, "Somnath Kotur"
> <somnath.kotur@broadcom.com>, "Sriharsha Basavapatna" <sriharsha.basavapatna@broadcom.com>, "Doug Ledford"
> <dledford@redhat.com>, "Sean Hefty" <sean.hefty@intel.com>, "Hal Rosenstock" <hal.rosenstock@gmail.com>,
> linux-rdma@vger.kernel.org
> Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
> Sent: Friday, February 17, 2017 10:35:22 AM
> Subject: [PATCH] RDMA/bnxt_re: remove redundant initialization of rc to zero
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> rc is initialized to zero but is then updated by calls to
> bnxt_qplib_free_fast_reg_page_list and/or bnxt_qpliob_free_mrw
> so the initialization is redundant and can be removed.
> 
> Detected with CoverityScan, CID#1408448 ("Unused Value")
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/infiniband/hw/bnxt_re/ib_verbs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> index 33af2e3..17aa087 100644
> --- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> +++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
> @@ -2818,7 +2818,7 @@ int bnxt_re_dereg_mr(struct ib_mr *ib_mr)
>  {
>  	struct bnxt_re_mr *mr = container_of(ib_mr, struct bnxt_re_mr, ib_mr);
>  	struct bnxt_re_dev *rdev = mr->rdev;
> -	int rc = 0;
> +	int rc;
>  
>  	if (mr->npages && mr->pages) {
>  		rc = bnxt_qplib_free_fast_reg_page_list(&rdev->qplib_res,
> --
> 2.10.2
> 
> --
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> 
Makes sense, looks fine.
Reviewed-by: Laurence Oberman <loberman@redhat.com>

Re: [PATCH] RDMA/bnxt_re: remove redundant initialization of rc to zero

[Dan Carpenter]

drivers/infiniband/hw/bnxt_re/ib_verbs.c
  2817  int bnxt_re_dereg_mr(struct ib_mr *ib_mr)
  2818  {
  2819          struct bnxt_re_mr *mr = container_of(ib_mr, struct bnxt_re_mr, ib_mr);
  2820          struct bnxt_re_dev *rdev = mr->rdev;
  2821          int rc = 0;

It's weird that it would complain about this because initializing
variables to bogus values is a prefered style for some people.  It's
bad style obviously, yes, but it's common and it seems like it would
lead to a lot of false postives.

  2822  
  2823          if (mr->npages && mr->pages) {
  2824                  rc = bnxt_qplib_free_fast_reg_page_list(&rdev->qplib_res,
  2825                                                          &mr->qplib_frpl);

And then it doesn't complain about this one which seems like a legit
bug.

  2826                  kfree(mr->pages);
  2827                  mr->npages = 0;
  2828                  mr->pages = NULL;
  2829          }
  2830          rc = bnxt_qplib_free_mrw(&rdev->qplib_res, &mr->qplib_mr);
  2831  
  2832          if (!IS_ERR(mr->ib_umem) && mr->ib_umem)
  2833                  ib_umem_release(mr->ib_umem);
  2834  
  2835          kfree(mr);
  2836          atomic_dec(&rdev->mr_count);
  2837          return rc;
  2838  }

regards,
dan carpenter