Re: [PATCH] bcm47xx: Fix GPIO API return codes

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 14 Feb 2009 21:27:19 +0100
Michael Buesch <mb@bu3sch.de> wrote:

> The GPIO API is supposed to return 0 or a negative error code,
> but the SSB GPIO functions return the bitmask of the GPIO register.
> Fix this by ignoring the bitmask and always returning 0. The SSB GPIO functions can't fail.
> 
> Signed-off-by: Michael Buesch <mb@bu3sch.de>
> 
> ---
> 
> Index: linux-2.6/arch/mips/include/asm/mach-bcm47xx/gpio.h
> ===================================================================
> --- linux-2.6.orig/arch/mips/include/asm/mach-bcm47xx/gpio.h	2009-01-01 19:27:06.000000000 +0100
> +++ linux-2.6/arch/mips/include/asm/mach-bcm47xx/gpio.h	2009-02-14 21:26:14.000000000 +0100
> @@ -31,24 +31,28 @@ static inline void gpio_set_value(unsign
>  
>  static inline int gpio_direction_input(unsigned gpio)
>  {
> -	return ssb_gpio_outen(&ssb_bcm47xx, 1 << gpio, 0);
> +	ssb_gpio_outen(&ssb_bcm47xx, 1 << gpio, 0);
> +	return 0;
>  }
>  
>  static inline int gpio_direction_output(unsigned gpio, int value)
>  {
> -	return ssb_gpio_outen(&ssb_bcm47xx, 1 << gpio, 1 << gpio);
> +	ssb_gpio_outen(&ssb_bcm47xx, 1 << gpio, 1 << gpio);
> +	return 0;
>  }
>  
> -static int gpio_intmask(unsigned gpio, int value)
> +static inline int gpio_intmask(unsigned gpio, int value)
>  {
> -	return ssb_gpio_intmask(&ssb_bcm47xx, 1 << gpio,
> -				value ? 1 << gpio : 0);
> +	ssb_gpio_intmask(&ssb_bcm47xx, 1 << gpio,
> +			 value ? 1 << gpio : 0);
> +	return 0;
>  }
>  
> -static int gpio_polarity(unsigned gpio, int value)
> +static inline int gpio_polarity(unsigned gpio, int value)
>  {
> -	return ssb_gpio_polarity(&ssb_bcm47xx, 1 << gpio,
> -				 value ? 1 << gpio : 0);
> +	ssb_gpio_polarity(&ssb_bcm47xx, 1 << gpio,
> +			  value ? 1 << gpio : 0);
> +	return 0;
>  }

What are the consequences of the bug which you fixed?  User-visible
runtime failures?  Something else?

Please always include this information in the changelogs - without it I
cannot make which-kernel-needs-this decisions.