Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220409062449.3752252-1-zheyuma97@gmail.com> <CA++WF2Np7Bk_qT68Uc3mrC38mN5p3fm9eVT7VA8NoX6=es2r2w@mail.gmail.com>
In-Reply-To: <CA++WF2Np7Bk_qT68Uc3mrC38mN5p3fm9eVT7VA8NoX6=es2r2w@mail.gmail.com>
From:   Zheyu Ma <zheyuma97@gmail.com>
Date:   Mon, 18 Apr 2022 11:04:41 +0800
Message-ID: <CAMhUBjkWcg4+YYynsd90jX1A+zp95tUUcLgYrTPAqSmbxM7TJA@mail.gmail.com>
Subject: Re: [PATCH] wireless: ipw2x00: Refine the error handling of ipw2100_pci_init_one()
To:     Stanislav Yakovlev <stas.yakovlev@gmail.com>
Cc:     kvalo@kernel.org, "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, pabeni@redhat.com,
        wireless <linux-wireless@vger.kernel.org>,
        netdev@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Apr 14, 2022 at 2:40 AM Stanislav Yakovlev
<stas.yakovlev@gmail.com> wrote:
>
> On Sat, 9 Apr 2022 at 02:25, Zheyu Ma <zheyuma97@gmail.com> wrote:
> >
> > The driver should release resources in reverse order, i.e., the
> > resources requested first should be released last, and the driver
> > should adjust the order of error handling code by this rule.
> >
> > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
> > ---
> >  drivers/net/wireless/intel/ipw2x00/ipw2100.c | 34 +++++++++-----------
> >  1 file changed, 16 insertions(+), 18 deletions(-)
> >
> [Skipped]
>
> > @@ -6306,9 +6303,13 @@ static int ipw2100_pci_init_one(struct pci_dev *pci_dev,
> >  out:
> >         return err;
> >
> > -      fail_unlock:
> > +fail_unlock:
> >         mutex_unlock(&priv->action_mutex);
> > -      fail:
> > +fail:
> > +       pci_release_regions(pci_dev);
> > +fail_disable:
> > +       pci_disable_device(pci_dev);
> We can't move these functions before the following block.
>
> > +fail_dev:
> >         if (dev) {
> >                 if (registered >= 2)
> >                         unregister_netdev(dev);
> This block continues with a function call to ipw2100_hw_stop_adapter
> which assumes that device is still accessible via pci bus.

Thanks for your reminder, but the existing error handling does need to
be revised, I got the following warning when the probing fails at
pci_resource_flags():

[   20.712160] WARNING: CPU: 1 PID: 462 at lib/iomap.c:44 pci_iounmap+0x40/0x50
[   20.716583] RIP: 0010:pci_iounmap+0x40/0x50
[   20.726342]  <TASK>
[   20.726550]  ipw2100_pci_init_one+0x101/0x1ee0 [ipw2100]

Since I am not familiar with the ipw2100, could someone give me some
advice to fix this.

Thanks,
Zheyu Ma