Subject: Re: linux-next: build warning after merge of the crypto tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 25 Aug 2016 21:14:11 +1000

Hi Herbert,

On Thu, 25 Aug 2016 15:47:01 +0800 Herbert Xu <[email-masked]> wrote:
>
> I'm going to do something like this:
> 
> ---8<---
> This patch fixes an unused label warning triggered when the macro
> XOR_SELECT_TEMPLATE is not set.
> 
> Fixes: 39457acda913 ("crypto: xor - skip speed test if the xor...")
> Reported-by: Stephen Rothwell <[email-masked]>
> Signed-off-by: Herbert Xu <[email-masked]>
> 
> diff --git a/crypto/xor.c b/crypto/xor.c
> index b8975d9..69866e9 100644
> --- a/crypto/xor.c
> +++ b/crypto/xor.c
> @@ -113,13 +113,14 @@ calibrate_xor_blocks(void)
>  
>  #ifdef XOR_SELECT_TEMPLATE
>  	fastest = XOR_SELECT_TEMPLATE(fastest);
> +#endif
> +
>  	if (fastest) {
>  		printk(KERN_INFO "xor: automatically using best "
>  				 "checksumming function   %-10s\n",
>  		       fastest->name);
>  		goto out;
>  	}
> -#endif

That looks fine to me.  An alternative might be to have:

#ifndef XOR_SELECT_TEMPLATE
#define XOR_SELECT_TEMPLATE(x)	(x)
#endif

near the top of the file.  That gets the #ifdef out of the code flow
and serves as some hint that such a thing can be defined by arch header
files.

Either way.
-- 
Cheers,
Stephen Rothwell