Re: [PATCH 4/9] mfd: max8925: fix trivial build warning for non-dt

[Haojian Zhuang]

On Fri, Feb 15, 2013 at 6:26 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> Patch fe527ea5a "mfd: max8925: Support dt for backlight"
> added a new function for DT probing but introduced a
> build warning for the case where CONFIG_OF is disabled:
>
> drivers/video/backlight/max8925_bl.c: In function 'max8925_backlight_probe':
> drivers/video/backlight/max8925_bl.c:177:3: warning: statement with no effect [-Wunused-value]
>
> A much nicer fix is to use the IS_ENABLED keyword to
> have the same effect of dropping the device tree specific
> function when it's not needed.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Qing Xu <qingx@xxxxxxxxxxx>
> Cc: Haojian Zhuang <haojian.zhuang@xxxxxxxxx>
> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> ---
>  drivers/video/backlight/max8925_bl.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/video/backlight/max8925_bl.c b/drivers/video/backlight/max8925_bl.c
> index 5ca11b0..9958fb1 100644
> --- a/drivers/video/backlight/max8925_bl.c
> +++ b/drivers/video/backlight/max8925_bl.c
> @@ -101,14 +101,13 @@ static const struct backlight_ops max8925_backlight_ops = {
>         .get_brightness = max8925_backlight_get_brightness,
>  };
>
> -#ifdef CONFIG_OF
>  static int max8925_backlight_dt_init(struct platform_device *pdev,
>                               struct max8925_backlight_pdata *pdata)
>  {
>         struct device_node *nproot = pdev->dev.parent->of_node, *np;
>         int dual_string;
>
> -       if (!nproot)
> +       if (!nproot || !IS_ENABLED(CONFIG_OF))
>                 return -ENODEV;
>         np = of_find_node_by_name(nproot, "backlight");
>         if (!np) {
> @@ -120,9 +119,6 @@ static int max8925_backlight_dt_init(struct platform_device *pdev,
>         pdata->dual_string = dual_string;
>         return 0;
>  }
> -#else
> -#define max8925_backlight_dt_init(x, y)        (-1)
> -#endif
>
>  static int max8925_backlight_probe(struct platform_device *pdev)
>  {
> --
> 1.8.1.2
>

Acked-by: Haojian Zhuang <haojian.zhuang@xxxxxxxxx>
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