[alsa-devel] [PATCH] ALSA: control: obsolete 'already present' messaging because it's caller's fault

[Takashi Iwai]

At Sun,  8 Feb 2015 19:29:08 +0900,
Takashi Sakamoto wrote:
> 
> When drivers or userspace applications add a duplicated control, snd
> module outputs error message and return -EBUSY.
> 
> This state is a bug in driver or application, therefore the messaging
> should be done by them, not by snd module.

The message should be hidden for user-space actions, indeed, but it's
been very helpful for the driver developments, so I'm against the
unconditional removal.

Also, think what you really suggested: there are almost 500 calls of
snd_ctl_add() in the tree and you suggest to put the error message to
each of them.

Rather try to show the error only for the kernel snd_ctl_add() calls.


thanks,

Takashi

> 
> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
> ---
>  sound/core/control.c | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/sound/core/control.c b/sound/core/control.c
> index d482997..8906b66 100644
> --- a/sound/core/control.c
> +++ b/sound/core/control.c
> @@ -357,18 +357,10 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
>  
>  	down_write(&card->controls_rwsem);
>  	if (snd_ctl_find_id(card, &id)) {
> -		up_write(&card->controls_rwsem);
> -		dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
> -					id.iface,
> -					id.device,
> -					id.subdevice,
> -					id.name,
> -					id.index);
>  		err = -EBUSY;
>  		goto error;
>  	}
>  	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
> -		up_write(&card->controls_rwsem);
>  		err = -ENOMEM;
>  		goto error;
>  	}
> @@ -388,6 +380,7 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
>  	return 0;
>  
>   error:
> +	up_write(&card->controls_rwsem);
>  	snd_ctl_free_one(kcontrol);
>  	return err;
>  }
> -- 
> 2.1.0
>