Re: [PATCH] HID: hiddev: use IS_ENABLED() for USB_HIDDEV

[Arnd Bergmann <arnd@arndb.de>]

On Friday, June 24, 2016 10:28:50 AM CEST Jiri Kosina wrote:
> From: Jiri Kosina <jkosina@suse.cz>
> 
> Use IS_ENABLED() for checking USB_HIDDEV to make sure compilation works 
> for all possible config combinations.
> 
> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
> ---
>  include/linux/hiddev.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/hiddev.h b/include/linux/hiddev.h
> index a5dd814..b6f48d6 100644
> --- a/include/linux/hiddev.h
> +++ b/include/linux/hiddev.h
> @@ -37,7 +37,7 @@ struct hid_usage;
>  struct hid_field;
>  struct hid_report;
>  
> -#ifdef CONFIG_USB_HIDDEV
> +#if IS_ENABLED(CONFIG_USB_HIDDEV)
>  int hiddev_connect(struct hid_device *hid, unsigned int force);
>  void hiddev_disconnect(struct hid_device *);
>  void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
> 
> 

CONFIG_USB_HIDDEV is a 'bool' option, so the two look completely
equivalent.

If we wanted to make USB_HIDDEV a loadable module by itself,
we'd also need to export those functions and change both the Kconfig
and Makefile files to ensure that you can't have USB_HIDDEV=m
in combination with USB_HID=y.

What problem are you trying to fix specifically?

	Arnd