Re: [PATCH 01/21] powerpc: Remove warning on array size when empty

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Sun, Feb 25, 2018 at 7:22 PM, Mathieu Malaterre <malat@debian.org> wrote:
> When neither CONFIG_ALTIVEC, nor CONFIG_VSX or CONFIG_PPC64 is defined, the
> array feature_properties is defined as an empty array, which in turn
> triggers the following warning (treated as error on W=1):
>
>   CC      arch/powerpc/kernel/prom.o
> arch/powerpc/kernel/prom.c: In function ‘check_cpu_feature_properties’:
> arch/powerpc/kernel/prom.c:298:16: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]
>   for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
>                 ^
> cc1: all warnings being treated as errors
>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> ---
>  arch/powerpc/kernel/prom.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 4dffef947b8a..6e8e4122820e 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -291,11 +291,10 @@ static inline void identical_pvr_fixup(unsigned long node)
>
>  static void __init check_cpu_feature_properties(unsigned long node)
>  {
> -       unsigned long i;
>         struct feature_property *fp = feature_properties;
>         const __be32 *prop;
>

Much simpler is just add

if (ARRAY_SIZE() == 0)
 return;

> -       for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
> +       for (; fp != feature_properties + ARRAY_SIZE(feature_properties); ++fp) {
>                 prop = of_get_flat_dt_prop(node, fp->name, NULL);
>                 if (prop && be32_to_cpup(prop) >= fp->min_value) {
>                         cur_cpu_spec->cpu_features |= fp->cpu_feature;
> --
> 2.11.0
>



-- 
With Best Regards,
Andy Shevchenko