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References: <20220909041645.2612842-1-floridsleeves@gmail.com> <4ff0b209-2770-3790-ae93-3ea81c15a03e@intel.com>
In-Reply-To: <4ff0b209-2770-3790-ae93-3ea81c15a03e@intel.com>
From:   Li Zhong <floridsleeves@gmail.com>
Date:   Fri, 16 Sep 2022 17:02:14 -0700
Message-ID: <CAMEuxRqbmds-XXjbGsgCup1_aj4EMfRO2dVurcS1O4fd0mdygA@mail.gmail.com>
Subject: Re: [PATCH net-next v1] drivers/net/ethernet/intel/e100: check the
 return value of e100_exec_cmd()
To:     Tony Nguyen <anthony.l.nguyen@intel.com>
Cc:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        intel-wired-lan@lists.osuosl.org, pabeni@redhat.com,
        kuba@kernel.org, edumazet@google.com, davem@davemloft.net,
        jesse.brandeburg@intel.com
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On Mon, Sep 12, 2022 at 3:08 PM Tony Nguyen <anthony.l.nguyen@intel.com> wrote:
>
> On 9/8/2022 9:16 PM, Li Zhong wrote:
> > Check the return value of e100_exec_cmd() which could return error code
> > when execution fails.
>
> Are you coming across this as a real bug or as something reported by
> static analysis? If the latter, I suggest checking the return value and
> reporting it as debug, however, not changing existing behavior. We don't
> have validation on this driver so there is limited ability to check for
> regressions and the code has been like this for a long time without
> reported issues.

Thanks for replying and suggestions! This is detected by static analysis.
I submit a v2 patch that fixes it as debug printk.

>
> Thanks,
> Tony
>
> > Signed-off-by: Li Zhong <floridsleeves@gmail.com>
> > ---
> >   drivers/net/ethernet/intel/e100.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c
> > index 11a884aa5082..3b84745376fe 100644
> > --- a/drivers/net/ethernet/intel/e100.c
> > +++ b/drivers/net/ethernet/intel/e100.c
> > @@ -1911,7 +1911,8 @@ static inline void e100_start_receiver(struct nic *nic, struct rx *rx)
> >
> >       /* (Re)start RU if suspended or idle and RFA is non-NULL */
> >       if (rx->skb) {
> > -             e100_exec_cmd(nic, ruc_start, rx->dma_addr);
> > +             if (!e100_exec_cmd(nic, ruc_start, rx->dma_addr))
> > +                     return;
> >               nic->ru_running = RU_RUNNING;
> >       }
> >   }