Re: [PATCH v2 4/4] fbdev: sh_mobile_lcdc: Make FB_DEVICE dependency optional

From: Andy Shevchenko
Date: Sat Dec 27 2025 - 09:24:49 EST


On Fri, Dec 19, 2025 at 7:43 AM Chintan Patel <chintanlike@xxxxxxxxx> wrote:
>
> The sh_mobile_lcdc driver exposes overlay configuration via sysfs, but the
> core driver does not require CONFIG_FB_DEVICE.
>
> Make sysfs support optional by defining overlay_sysfs_groups as NULL when
> FB_DEVICE is disabled. The driver always sets .dev_groups, and the kernel
> naturally skips NULL attribute groups while the code remains buildable
> and type-checked.

> v2:
> - Replace CONFIG_FB_DEVICE ifdefs with NULL overlay_sysfs_groups
> - Always populate .dev_groups

Same comment about the changelog in the commit messages.

...

> +#ifdef CONFIG_FB_DEVICE
> ATTRIBUTE_GROUPS(overlay_sysfs);
> +#else
> +/*
> + * When CONFIG_FB_DEVICE is disabled, define overlay_sysfs_groups as NULL.
> + * The compiler will optimize out the sysfs code paths when dev_groups is NULL.
> + */
> +static const struct attribute_group *overlay_sysfs_groups[] = { NULL };
> +#endif

Hmm... I'm wondering if PTR_IF() can anyhow help here.

--
With Best Regards,
Andy Shevchenko