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Date:   Tue, 12 Sep 2023 12:42:31 +0200
Message-ID: <87cyyn7jvs.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     "Arnd Bergmann" <arnd@arndb.de>
Cc:     "Peter Ujfalusi" <peter.ujfalusi@linux.intel.com>, tiwai@suse.com,
        "Jaroslav Kysela" <perex@perex.cz>,
        "Masahiro Yamada" <masahiroy@kernel.org>,
        linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org
Subject: Re: [PATCH] ALSA: core: Increase the name array size for debugfs directory name
In-Reply-To: <96c5309d-bb06-486e-a1f8-e3d71b275f13@app.fastmail.com>
References: <20230912083910.15994-1-peter.ujfalusi@linux.intel.com>
        <96c5309d-bb06-486e-a1f8-e3d71b275f13@app.fastmail.com>
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On Tue, 12 Sep 2023 12:18:04 +0200,
Arnd Bergmann wrote:
> 
> On Tue, Sep 12, 2023, at 10:39, Peter Ujfalusi wrote:
> 
> > While the code is correct, we need to silence the compiler somehow.
> > It could be done by limiting the range in sprintf like
> > sprintf(name, "card%d", idx % SNDRV_CARDS);
> > sprintf(name, "card%hhd", idx);
> > etc
> >
> > These are too workaroundish. Increase the name array to 15 instead which
> > looks better and only adds 7 bytes on stack.
> 
> It looks like we use the same string for kobject_set_name(), so
> maybe this would work as well:
> 
> --- a/sound/core/init.c
> +++ b/sound/core/init.c
> @@ -278,9 +278,6 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
>                          size_t extra_size)
>  {
>         int err;
> -#ifdef CONFIG_SND_DEBUG
> -       char name[8];
> -#endif
>  
>         if (extra_size > 0)
>                 card->private_data = (char *)card + sizeof(struct snd_card);
> @@ -364,8 +361,8 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
>         }
>  
>  #ifdef CONFIG_SND_DEBUG
> -       sprintf(name, "card%d", idx);
> -       card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
> +       card->debugfs_root = debugfs_create_dir(kobject_name(&card->card_dev.kobj),
> +                                               sound_debugfs_root);

The idea looks neat, but I suppose it's better with
dev_name(&card->card_dev) instead?


thanks,

Takashi