[PATCH] ALSA: control: preserve snd_card_file_add() error code in snd_ctl_open()

[PATCH] ALSA: control: preserve snd_card_file_add() error code in snd_ctl_open()

[phucduc.bui]

From: bui duc phuc <phucduc.bui@gmail.com>

snd_ctl_open() unconditionally overwrites the return value of
snd_card_file_add() with -ENODEV on failure, discarding the actual
error code.
This also preserves the original error code returned by
snd_card_file_add() (e.g. -ENOMEM or -ENODEV), instead of
unconditionally overwriting it with -ENODEV.
No functional change other than the returned error code in this
failure path.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
 sound/core/control.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/sound/core/control.c b/sound/core/control.c
index 0ca9fff56e51..f64b2dec746a 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -64,7 +64,6 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
 	}
 	err = snd_card_file_add(card, file);
 	if (err < 0) {
-		err = -ENODEV;
 		goto __error1;
 	}
 	if (!try_module_get(card->module)) {
-- 
2.43.0

Re: [PATCH] ALSA: control: preserve snd_card_file_add() error code in snd_ctl_open()

[Takashi Iwai]

On Tue, 07 Jul 2026 11:09:58 +0200,
phucduc.bui@gmail.com wrote:
> 
> From: bui duc phuc <phucduc.bui@gmail.com>
> 
> snd_ctl_open() unconditionally overwrites the return value of
> snd_card_file_add() with -ENODEV on failure, discarding the actual
> error code.
> This also preserves the original error code returned by
> snd_card_file_add() (e.g. -ENOMEM or -ENODEV), instead of
> unconditionally overwriting it with -ENODEV.
> No functional change other than the returned error code in this
> failure path.
> 
> Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
> ---
>  sound/core/control.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/sound/core/control.c b/sound/core/control.c
> index 0ca9fff56e51..f64b2dec746a 100644
> --- a/sound/core/control.c
> +++ b/sound/core/control.c
> @@ -64,7 +64,6 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
>  	}
>  	err = snd_card_file_add(card, file);
>  	if (err < 0) {
> -		err = -ENODEV;
>  		goto __error1;
>  	}

Please drop superfluous braces, too, as it becomes a single-line now.


thanks,

Takashi

Re: [PATCH] ALSA: control: preserve snd_card_file_add() error code in snd_ctl_open()

[Bui Duc Phuc]

Hi Takashi-san,

Thank you for your review!

> >       if (err < 0) {
> > -             err = -ENODEV;
> >               goto __error1;
> >       }
>
> Please drop superfluous braces, too, as it becomes a single-line now.
>
I'll update the patch according to your comments.
I'll also expand the commit message to mention that returning the
error directly from snd_card_file_add()
is consistent with the error handling used in functions such as
snd_mixer_oss_open(), snd_hwdep_open(),
snd_pcm_oss_open(), and others.

I'd also like to add one more observation. It seems that checkpatch.pl
did not detect the style issue that
you pointed out:
------------------------
phuc@phuc-desktop:~/work/linux$ ./scripts/checkpatch.pl --strict
0001-ALSA-control-preserve-snd_card_file_add-error-code-i.patch
total: 0 errors, 0 warnings, 0 checks, 7 lines checked

0001-ALSA-control-preserve-snd_card_file_add-error-code-i.patch has no
obvious style problems and is ready for submission.
phuc@phuc-desktop:~/work/linux$
-------------------------

Best regards,
Phuc