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References: <20220312132856.65163-1-krzysztof.kozlowski@canonical.com> <20220312132856.65163-6-krzysztof.kozlowski@canonical.com>
In-Reply-To: <20220312132856.65163-6-krzysztof.kozlowski@canonical.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Tue, 15 Mar 2022 20:01:18 +0200
Message-ID: <CAHp75VfLtjfrB4Zj9ncOg3VYQrX58chEL+6g31_5fwuMUuURPg@mail.gmail.com>
Subject: Re: [PATCH v4 05/11] PCI: Use driver_set_override() instead of open-coding
To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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On Sat, Mar 12, 2022 at 4:09 PM Krzysztof Kozlowski
<krzysztof.kozlowski@canonical.com> wrote:
>
> Use a helper to set driver_override to reduce amount of duplicated code.

the amount

> Make the driver_override field const char, because it is not modified by
> the core and it matches other subsystems.


Seems like mine #4 here
https://gist.github.com/andy-shev/a2cb1ee4767d6d2f5d20db53ecb9aabc :-)
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Thanks!

> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
>  drivers/pci/pci-sysfs.c | 28 ++++------------------------
>  include/linux/pci.h     |  6 +++++-
>  2 files changed, 9 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 602f0fb0b007..5c42965c32c2 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -567,31 +567,11 @@ static ssize_t driver_override_store(struct device *dev,
>                                      const char *buf, size_t count)
>  {
>         struct pci_dev *pdev = to_pci_dev(dev);
> -       char *driver_override, *old, *cp;
> -
> -       /* We need to keep extra room for a newline */
> -       if (count >= (PAGE_SIZE - 1))
> -               return -EINVAL;
> -
> -       driver_override = kstrndup(buf, count, GFP_KERNEL);
> -       if (!driver_override)
> -               return -ENOMEM;
> -
> -       cp = strchr(driver_override, '\n');
> -       if (cp)
> -               *cp = '\0';
> -
> -       device_lock(dev);
> -       old = pdev->driver_override;
> -       if (strlen(driver_override)) {
> -               pdev->driver_override = driver_override;
> -       } else {
> -               kfree(driver_override);
> -               pdev->driver_override = NULL;
> -       }
> -       device_unlock(dev);
> +       int ret;
>
> -       kfree(old);
> +       ret = driver_set_override(dev, &pdev->driver_override, buf, count);
> +       if (ret)
> +               return ret;
>
>         return count;
>  }
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 60d423d8f0c4..415491fb85f4 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -516,7 +516,11 @@ struct pci_dev {
>         u16             acs_cap;        /* ACS Capability offset */
>         phys_addr_t     rom;            /* Physical address if not from BAR */
>         size_t          romlen;         /* Length if not from BAR */
> -       char            *driver_override; /* Driver name to force a match */
> +       /*
> +        * Driver name to force a match.  Do not set directly, because core
> +        * frees it.  Use driver_set_override() to set or clear it.
> +        */
> +       const char      *driver_override;
>
>         unsigned long   priv_flags;     /* Private flags for the PCI driver */
>
> --
> 2.32.0
>


-- 
With Best Regards,
Andy Shevchenko