Re: [PM-WIP-OPP] [PATCH 2/2]: Change return value from ERR_PTR(..) to NULL in opp layer

[Kevin Hilman <khilman@deeprootsystems.com>]

Romit Dasgupta <romit@ti.com> writes:

> Returning NULL pointer from the OPP APIs instead of ERR_PTR where
> return struct omap_opp *. This is because there is no inherent value in
> returning ERR_PTR from the opp layer. Returning NULL serves the purpose.

NAK.

Using ERR_PTR allows returning different types of error conditions,
and is common practice across the kernel.

Kevin

> Signed-off-by: Romit Dasgupta <romit@ti.com>
> ---
>
> diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c
> index 5ec072e..9572062 100644
> --- a/arch/arm/mach-omap2/resource34xx.c
> +++ b/arch/arm/mach-omap2/resource34xx.c
> @@ -202,7 +202,7 @@ static int __deprecated freq_to_opp(u8 *opp_id, enum opp_t opp_t,
>  
>  	BUG_ON(opp_t >= OPP_TYPES_MAX);
>  	opp = opp_find_freq_ceil(opp_t, &freq);
> -	if (IS_ERR(opp))
> +	if (!opp)
>  		return -EINVAL;
>  	*opp_id = opp_get_opp_id(opp);
>  	return 0;
> diff --git a/arch/arm/plat-omap/opp.c b/arch/arm/plat-omap/opp.c
> index 8fd9366..7835b5d 100644
> --- a/arch/arm/plat-omap/opp.c
> +++ b/arch/arm/plat-omap/opp.c
> @@ -129,7 +129,7 @@ struct omap_opp *opp_find_freq_exact(enum opp_t opp_t,
>  
>  	if (unlikely(opp_t >= OPP_TYPES_MAX)) {
>  		pr_err("%s: Invalid parameters being passed\n", __func__);
> -		return ERR_PTR(-EINVAL);
> +		return NULL;
>  	}
>  
>  	oppl = _opp_list[opp_t];
> @@ -143,7 +143,7 @@ struct omap_opp *opp_find_freq_exact(enum opp_t opp_t,
>  		oppl++;
>  	}
>  
> -	return OPP_TERM(oppl) ? ERR_PTR(-ENOENT) : oppl;
> +	return OPP_TERM(oppl) ? NULL : oppl;
>  }
>  
>  struct omap_opp *opp_find_freq_ceil(enum opp_t opp_t, unsigned long *freq)
> @@ -153,7 +153,7 @@ struct omap_opp *opp_find_freq_ceil(enum opp_t opp_t, unsigned long *freq)
>  	if (unlikely(opp_t >= OPP_TYPES_MAX || !freq ||
>  		 IS_ERR(freq))) {
>  		pr_err("%s: Invalid parameters being passed\n", __func__);
> -		return ERR_PTR(-EINVAL);
> +		return NULL;
>  	}
>  
>  	oppl = _opp_list[opp_t];
> @@ -169,7 +169,7 @@ struct omap_opp *opp_find_freq_ceil(enum opp_t opp_t, unsigned long *freq)
>  	}
>  
>  	if (OPP_TERM(oppl))
> -		return ERR_PTR(-ENOENT);
> +		return NULL;
>  
>  	*freq = oppl->rate;
>  
> @@ -183,7 +183,7 @@ struct omap_opp *opp_find_freq_floor(enum opp_t opp_t, unsigned long *freq)
>  	if (unlikely(opp_t >= OPP_TYPES_MAX || !freq ||
>  		 IS_ERR(freq))) {
>  		pr_err("%s: Invalid parameters being passed\n", __func__);
> -		return ERR_PTR(-EINVAL);
> +		return NULL;
>  	}
>  	oppl = prev_opp = _opp_list[opp_t];
>  
> @@ -202,7 +202,7 @@ struct omap_opp *opp_find_freq_floor(enum opp_t opp_t, unsigned long *freq)
>  	}
>  
>  	if (prev_opp->rate > *freq)
> -		return ERR_PTR(-ENOENT);
> +		return NULL;
>  
>  	*freq = prev_opp->rate;
>