Re: [PATCH] power: supply: move power_supply_attr_group into #ifdef block

[Nathan Chancellor]

On Wed, Feb 28, 2024 at 10:46:28AM -0300, Ricardo B. Marliere wrote:
> When building with CONFIG_SYSFS=n, the build error below is triggered:
> 
> ld: drivers/power/supply/power_supply_core.o:(.data+0x0): undefined
> reference to `power_supply_attr_group'
> 
> The problem is that power_supply_attr_group is needed in
> power_supply_core.c but defined in power_supply_sysfs.c, which is only
> targeted with CONFIG_SYSFS=y. Therefore, move the extern declaration into
> the #ifdef block that checks for CONFIG_SYSFS, and define an empty static
> const struct otherwise. This is safe because the macro __ATRIBUTE_GROUPS in
> power_supply_core.c will expand into an empty attribute_group array.
> 
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Link: https://lore.kernel.org/all/20240227214916.GA3699076@dev-arch.thelio-3990X/
> Fixes: 7b46b60944d7 ("power: supply: core: constify the struct device_type usage")
> Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>

Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx> # build

Thanks for the quick fix!

> ---
> This patch depends on [1].
> [1]: 20240227-fix-power_supply_init_attrs-stub-v1-1-43365e68d4b3@xxxxxxxxxx
> ---
>  drivers/power/supply/power_supply.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/power/supply/power_supply.h b/drivers/power/supply/power_supply.h
> index 7d05756398b9..06749a534db4 100644
> --- a/drivers/power/supply/power_supply.h
> +++ b/drivers/power/supply/power_supply.h
> @@ -13,16 +13,16 @@ struct device;
>  struct device_type;
>  struct power_supply;
>  
> -extern const struct attribute_group power_supply_attr_group;
> -
>  #ifdef CONFIG_SYSFS
>  
>  extern void power_supply_init_attrs(void);
>  extern int power_supply_uevent(const struct device *dev, struct kobj_uevent_env *env);
> +extern const struct attribute_group power_supply_attr_group;
>  
>  #else
>  
>  static inline void power_supply_init_attrs(void) {}
> +static const struct attribute_group power_supply_attr_group;
>  #define power_supply_uevent NULL
>  
>  #endif /* CONFIG_SYSFS */
> 
> ---
> base-commit: 837af6b0cdb2b8df56d2df35db0444cfa1ea47c2
> change-id: 20240228-device_cleanup-power-2dcfaa7b7f2b
> 
> Best regards,
> -- 
> Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
>