Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190323225313.12325-1-pakki001@umn.edu> <CAHp75VdeB=jPaqY_VNDA7YeCiEdyVFJAmOmC4sDvZLBv-7KQ0w@mail.gmail.com>
In-Reply-To: <CAHp75VdeB=jPaqY_VNDA7YeCiEdyVFJAmOmC4sDvZLBv-7KQ0w@mail.gmail.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Sun, 24 Mar 2019 14:26:25 +0200
Message-ID: <CAHp75VfbPue803w06GdJwU_JYcFKEcShLpyGRMhOg9xi4ZwpAA@mail.gmail.com>
Subject: Re: [PATCH v2] tty: 8250: fix a missing check for pci_ioremap_bar
To:     Aditya Pakki <pakki001@umn.edu>
Cc:     Kangjie Lu <kjlu@umn.edu>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, Vinod Koul <vkoul@kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        "open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sun, Mar 24, 2019 at 2:05 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Sun, Mar 24, 2019 at 12:55 AM Aditya Pakki <pakki001@umn.edu> wrote:
> >
> > pci_ioremap_bar could fail. The fix captures the failure and
> > pass an error code upstream. This can avoid potential NULL
> > pointer dereferences in the future.
> >
>
> NAK.
> This will break non-DMA case.

> > @@ -172,12 +172,14 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)

Just to clarify, what you need is simple

void __iomem *regs;

chip->pdata = ... //move it here for better looking code
chip->irq = ...
chip->regs = pci_ioremap_bar(...);
if (!chip->regs)
  return;

and thank you for pointing to this.

-- 
With Best Regards,
Andy Shevchenko