Re: [PATCH -next] powerpc/eeh: fix compile warning with CONFIG_PROC_FS=n

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 05/09/2020 à 13:17, Yang Yingliang a écrit :
> Fix the compile warning:
> 
> arch/powerpc/kernel/eeh.c:1639:12: error: 'proc_eeh_show' defined but not used [-Werror=unused-function]
>   static int proc_eeh_show(struct seq_file *m, void *v)
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>   arch/powerpc/kernel/eeh.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
> index 94682382fc8c..420c3c25c6e7 100644
> --- a/arch/powerpc/kernel/eeh.c
> +++ b/arch/powerpc/kernel/eeh.c
> @@ -1636,6 +1636,7 @@ int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
>   }
>   EXPORT_SYMBOL_GPL(eeh_pe_inject_err);
>   
> +#ifdef CONFIG_PROC_FS

I don't like this way of fixing the issue, because you'll get an 
unbalanced source code: proc_eeh_show() is apparently referenced all the 
time in eeh_init_proc(), but because proc_create_single() is a NULL 
macro when CONFIG_PROC_FS is not selected, you get the 'unused function' 
error.

I think the right fix should be to rewrite proc_create_single() as a 
static inline function that calls proc_create_single_data() when 
CONFIG_PROC_FS is selected and just returns NULL otherwise.

>   static int proc_eeh_show(struct seq_file *m, void *v)
>   {
>   	if (!eeh_enabled()) {
> @@ -1662,6 +1663,7 @@ static int proc_eeh_show(struct seq_file *m, void *v)
>   
>   	return 0;
>   }
> +#endif
>   
>   #ifdef CONFIG_DEBUG_FS
>   static int eeh_enable_dbgfs_set(void *data, u64 val)
> 

Christophe