Re: [PATCH 33/69] ALSA: gus: properly handle snd_ctl_add() error

[Takashi Iwai]

On Mon, 03 May 2021 13:57:00 +0200,
Greg Kroah-Hartman wrote:
> 
> From: Kurt Manucredo <fuzzybritches0@xxxxxxxxx>
> 
> snd_gus_init_control() does not properly return any possible error that
> might have happened in a call to snd_ctl_add() so resolve this by
> propagating the error back up the call change correctly.
> 
> Cc: Takashi Iwai <tiwai@xxxxxxx>
> Signed-off-by: Kurt Manucredo <fuzzybritches0@xxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This change doesn't look good, either.
It results in the bogus error message "version check failed".

If we really want to fix this, it's better to call
snd_gus_init_control() from snd_gus_initialize() itself while changing
snd_gus_init_control() to return an error code.

However, this error is really not what we should be bothered too
much.  Even if a creation of control element failed, it's no fatal
error and nothing really wrong would happen by itself.  And, under
such a situation, the system memory is already too tight and the OS
would hang up sooner or later (or OOM killer starts genocide).


thanks,

Takashi

> ---
>  sound/isa/gus/gus_main.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/sound/isa/gus/gus_main.c b/sound/isa/gus/gus_main.c
> index b7518122a10d..4c2703ea55fb 100644
> --- a/sound/isa/gus/gus_main.c
> +++ b/sound/isa/gus/gus_main.c
> @@ -75,10 +75,11 @@ static const struct snd_kcontrol_new snd_gus_joystick_control = {
>  	.put = snd_gus_joystick_put
>  };
>  
> -static void snd_gus_init_control(struct snd_gus_card *gus)
> +static int snd_gus_init_control(struct snd_gus_card *gus)
>  {
>  	if (!gus->ace_flag)
> -		snd_ctl_add(gus->card, snd_ctl_new1(&snd_gus_joystick_control, gus));
> +		return snd_ctl_add(gus->card, snd_ctl_new1(&snd_gus_joystick_control, gus));
> +	return 0;
>  }
>  
>  /*
> @@ -386,8 +387,7 @@ static int snd_gus_check_version(struct snd_gus_card * gus)
>  	}
>  	strcpy(card->shortname, card->longname);
>  	gus->uart_enable = 1;	/* standard GUSes doesn't have midi uart trouble */
> -	snd_gus_init_control(gus);
> -	return 0;
> +	return snd_gus_init_control(gus);
>  }
>  
>  int snd_gus_initialize(struct snd_gus_card *gus)
> -- 
> 2.31.1
>