Re: [PATCH RFT] ata: ahci_brcmstb: Fix misuse of IS_ENABLED

[Florian Fainelli <f.fainelli@gmail.com>]

Le 08/05/15 19:16, Axel Lin a écrit :
> While IS_ENABLED() is perfectly fine for CONFIG_* symbols, it is not
> for other symbols such as __BIG_ENDIAN that is provided directly by
> the compiler.
> 
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> ---
> Hi,
> I don't have a big endian machine to test this, so I'd appreciate if
> someone can review and test this patch.
> 
> A similar misuse of IS_ENABLED is reported and fixed in:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/dma/mv_xor.c?id=0ec9ebc706fbd394bc233d87ac7aaad1c4f3ab54

Would not CONFIG_CPU_BIG_ENDIAN be more appropriate here? On MIPS at
least, this is what gets set when selecting a big-endian kernel.

Thanks!

> 
>  drivers/ata/ahci_brcmstb.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/ata/ahci_brcmstb.c b/drivers/ata/ahci_brcmstb.c
> index 42b6cf4..fc6413f 100644
> --- a/drivers/ata/ahci_brcmstb.c
> +++ b/drivers/ata/ahci_brcmstb.c
> @@ -92,19 +92,21 @@ static inline u32 brcm_sata_readreg(void __iomem *addr)
>  	 * Other architectures (e.g., ARM) either do not support big endian, or
>  	 * else leave I/O in little endian mode.
>  	 */
> -	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(__BIG_ENDIAN))
> -		return __raw_readl(addr);
> -	else
> -		return readl_relaxed(addr);
> +#if defined(__BIG_ENDIAN) && IS_ENABLED(CONFIG_MIPS)
> +	return __raw_readl(addr);
> +#else
> +	return readl_relaxed(addr);
> +#endif
>  }
>  
>  static inline void brcm_sata_writereg(u32 val, void __iomem *addr)
>  {
>  	/* See brcm_sata_readreg() comments */
> -	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(__BIG_ENDIAN))
> -		__raw_writel(val, addr);
> -	else
> -		writel_relaxed(val, addr);
> +#if defined(__BIG_ENDIAN) && IS_ENABLED(CONFIG_MIPS)
> +	__raw_writel(val, addr);
> +#else
> +	writel_relaxed(val, addr);
> +#endif
>  }
>  
>  static void brcm_sata_phy_enable(struct brcm_ahci_priv *priv, int port)
> 


-- 
Florian