linux-kernel - Re: [PATCH] RDMA/cxgb4: Cleanup unused assignments

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Message-ID: <CAOaDN_TJ7vD=jLYUh+ZZFDYchfim_4FgjeRgYDEbV-qjiRS6HA@mail.gmail.com>
Date:   Fri, 22 Jul 2022 12:47:06 +0800
From:   Katrin Jo <zys.zljxml@...il.com>
To:     Leon Romanovsky <leon@...nel.org>
Cc:     bharat@...lsio.com, jgg@...pe.ca, linux-rdma@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>,
        Yushan Zhou <katrinzhou@...cent.com>
Subject: Re: [PATCH] RDMA/cxgb4: Cleanup unused assignments

On Thu, Jul 21, 2022 at 3:18 PM Leon Romanovsky <leon@...nel.org> wrote:
>
> On Tue, Jul 19, 2022 at 05:09:48PM +0800, zys.zljxml@...il.com wrote:
> > From: Yushan Zhou <katrinzhou@...cent.com>
> >
> > The variable err is reassigned before the assigned value works.
> > Cleanup unused assignments reported by Coverity.
> >
> > Addresses-Coverity: ("UNUSED_VALUE")
> > Signed-off-by: Yushan Zhou <katrinzhou@...cent.com>
> > ---
> >  drivers/infiniband/hw/cxgb4/cm.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> > index c16017f6e8db..3462fe991f93 100644
> > --- a/drivers/infiniband/hw/cxgb4/cm.c
> > +++ b/drivers/infiniband/hw/cxgb4/cm.c
> > @@ -1590,7 +1590,6 @@ static int process_mpa_reply(struct c4iw_ep *ep, struct sk_buff *skb)
> >                                       insuff_ird = 1;
> >                       }
> >                       if (insuff_ird) {
> > -                             err = -ENOMEM;
> >                               ep->ird = resp_ord;
> >                               ep->ord = resp_ird;
> >                       }
> > @@ -1655,7 +1654,7 @@ static int process_mpa_reply(struct c4iw_ep *ep, struct sk_buff *skb)
> >               attrs.ecode = MPA_NOMATCH_RTR;
> >               attrs.next_state = C4IW_QP_STATE_TERMINATE;
> >               attrs.send_term = 1;
> > -             err = c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
> > +             c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
> >                               C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
> >               err = -ENOMEM;
>
> I would prefer do not overwrite errors returned from the functions
> unless it is really necessary.
>
> Can anyone from chelsio help here?
>
> Thanks
>
> >               disconnect = 1;
> > @@ -1674,7 +1673,7 @@ static int process_mpa_reply(struct c4iw_ep *ep, struct sk_buff *skb)
> >               attrs.ecode = MPA_INSUFF_IRD;
> >               attrs.next_state = C4IW_QP_STATE_TERMINATE;
> >               attrs.send_term = 1;
> > -             err = c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
> > +             c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
> >                               C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
> >               err = -ENOMEM;
> >               disconnect = 1;
> > --
> > 2.27.0
> >

The issue is that, in the original code, there were 2 subsequent
assignments to the `err` variable. I assume this is not expected. (I
tried to keep the exact same behavior as original code in this patch)

Should we keep the first assignment (c4iw_modify_qp), or the second
assignment (-ENOMEM)? I'd really appreciate some help here.

Best Regards,
Katrin