Re: [PATCH v1 1/1] ALSA: control: Use list_for_each_entry_safe()

[Takashi Iwai <tiwai@suse.de>]

On Tue, 29 Aug 2023 15:52:52 +0200,
Andy Shevchenko wrote:
> 
> Instead of reiterating the list, use list_for_each_entry_safe()
> that allows to continue without starting over.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Through a quick glance, it should be OK, but I need to read and
understand whether this change is perfectly safe or not -- unless
Jaroslav gives his review and ack.

> ---
> 
> Takashi, if you have anybody or want yourself to spend some time,
> I believe you can simplify a lot the parser in this file with
> the help of lib/cmdline.c APIs.

Thanks for the hint.  Yeah, it looks feasible, but too late for 6.6,
it's a nice TODO ;)


Takashi

> 
>  sound/core/control_led.c | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/core/control_led.c b/sound/core/control_led.c
> index a78eb48927c7..afc9ffc388e3 100644
> --- a/sound/core/control_led.c
> +++ b/sound/core/control_led.c
> @@ -297,16 +297,13 @@ static void snd_ctl_led_clean(struct snd_card *card)
>  {
>  	unsigned int group;
>  	struct snd_ctl_led *led;
> -	struct snd_ctl_led_ctl *lctl;
> +	struct snd_ctl_led_ctl *lctl, _lctl;
>  
>  	for (group = 0; group < MAX_LED; group++) {
>  		led = &snd_ctl_leds[group];
> -repeat:
> -		list_for_each_entry(lctl, &led->controls, list)
> -			if (!card || lctl->card == card) {
> +		list_for_each_entry_safe(lctl, _lctl, &led->controls, list)
> +			if (!card || lctl->card == card)
>  				snd_ctl_led_ctl_destroy(lctl);
> -				goto repeat;
> -			}
>  	}
>  }
>  
> @@ -314,7 +311,7 @@ static int snd_ctl_led_reset(int card_number, unsigned int group)
>  {
>  	struct snd_card *card;
>  	struct snd_ctl_led *led;
> -	struct snd_ctl_led_ctl *lctl;
> +	struct snd_ctl_led_ctl *lctl, _lctl;
>  	struct snd_kcontrol_volatile *vd;
>  	bool change = false;
>  
> @@ -329,14 +326,12 @@ static int snd_ctl_led_reset(int card_number, unsigned int group)
>  		return -ENXIO;
>  	}
>  	led = &snd_ctl_leds[group];
> -repeat:
> -	list_for_each_entry(lctl, &led->controls, list)
> +	list_for_each_entry(lctl, _lctl, &led->controls, list)
>  		if (lctl->card == card) {
>  			vd = &lctl->kctl->vd[lctl->index_offset];
>  			vd->access &= ~group_to_access(group);
>  			snd_ctl_led_ctl_destroy(lctl);
>  			change = true;
> -			goto repeat;
>  		}
>  	mutex_unlock(&snd_ctl_led_mutex);
>  	if (change)
> -- 
> 2.40.0.1.gaa8946217a0b
>