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Subject: Re: [PATCH] powerpc: Fix build warning
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Guenter Roeck <linux@roeck-us.net>
Date: Tue, 24 Jun 2014 14:35:01 +1000
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Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras <paulus@samba.org>,
 linux-kernel@vger.kernel.org, Vincent Guittot <vincent.guittot@linaro.org>
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On Fri, 2014-06-13 at 09:38 -0700, Guenter Roeck wrote:
> If compiled with W=1, the following warning is seen in powerpc builds.
> 
> arch/powerpc/kernel/smp.c:750:18: warning:
> 	type qualifiers ignored on function return type
> static const int powerpc_smt_flags(void)
>                  ^
> 
> This is caused by a function returning 'const int', which doesn't
> make sense to gcc. Drop 'const' to fix the problem.

This breaks the 64-bit build:

arch/powerpc/kernel/smp.c:764:2: error: initialization from incompatible pointer type [-Werror]
arch/powerpc/kernel/smp.c:764:2: error: (near initialization for 'powerpc_topology[0].sd_flags') [-Werror]

It appears that the generic definition in sched.h has this function
defined as const int, so that needs to be fixed too along with all
instances in all archs.

Cheers,
Ben.

> Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  arch/powerpc/kernel/smp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index 10ffffe..49d5d4e 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -768,7 +768,7 @@ int setup_profiling_timer(unsigned int multiplier)
>  
>  #ifdef CONFIG_SCHED_SMT
>  /* cpumask of CPUs with asymetric SMT dependancy */
> -static const int powerpc_smt_flags(void)
> +static int powerpc_smt_flags(void)
>  {
>  	int flags = SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES;
>