Re: [PATCH 4/5] ALSA: control: improve returned value because of the rest

[Takashi Iwai <tiwai@suse.de>]

At Wed, 11 Feb 2015 19:40:12 +0900,
Takashi Sakamoto wrote:
 
> When a character device doesn't have enough spaces for requested number
> of controls or values, currently return -ENOMEM. This should be -ENOSPC
> (No space left on device).
> 
> This commit improves this behaviour.

Well, if the error code is passed to user-space, we must not change
the value now unless this change is mandatory.  Otherwise this would
break the user-space behavior.


Takashi

> 
> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
> ---
>  sound/core/control.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/core/control.c b/sound/core/control.c
> index bce4730..9944d75 100644
> --- a/sound/core/control.c
> +++ b/sound/core/control.c
> @@ -313,7 +313,7 @@ static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
>  
>  		/* this situation is very unlikely */
>  		dev_err(card->dev, "unable to allocate new control numid\n");
> -		return -ENOMEM;
> +		return -ENOSPC;
>  	}
>  	return 0;
>  }
> @@ -355,9 +355,9 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
>  		err = -EBUSY;
>  		goto error;
>  	}
> -	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
> +	err = snd_ctl_find_hole(card, kcontrol->count);
> +	if (err < 0) {
>  		up_write(&card->controls_rwsem);
> -		err = -ENOMEM;
>  		goto error;
>  	}
>  	list_add_tail(&kcontrol->list, &card->controls);
> @@ -422,9 +422,9 @@ int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
>  		goto error;
>  	}
>  add:
> -	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
> +	err = snd_ctl_find_hole(card, kcontrol->count);
> +	if (err < 0) {
>  		up_write(&card->controls_rwsem);
> -		ret = -ENOMEM;
>  		goto error;
>  	}
>  	list_add_tail(&kcontrol->list, &card->controls);
> -- 
> 2.1.0
>