[PATCH v2 1/3] ASoC: dapm: Fix widget lookup with prefixed names across DAPM contexts

[Chancel Liu]

> subject suggest change to
> 
> ASoC: dapm: Use snd_soc_dapm_widget_name_cmp() to fix widget lookup
> failures
> 
> Frank

OK, this looks more simplified and clearer.

Regards, 
Chancel Liu

> > Currently dapm_find_widget() manually constructs a prefixed widget name
> > based on the provided DAPM context and compares it using strcmp(). This
> > happens to work in most cases because callers usually know which DAPM
> > context the target widget belongs to and pass in the matching DAPM
> > context.
> >
> > However, this assumption breaks when search_other_contexts is enabled.
> > In such cases, callers may intentionally pass a different DAPM context,
> > while searching for a widget that actually belongs to another DAPM
> > context.
> >
> > For example, when searching for a "DAC" widget, the widget belongs to
> > the codec DAPM and be registered with a codec prefix, while the caller
> > passes card->dapm and intends to search across all DAPM contexts. The
> > current implementation incorrectly applies the caller card DAPM causing
> > the lookup to fail even though the widget exists on the card.
> >
> > Use snd_soc_dapm_widget_name_cmp() instead, which compares widget
> names
> > using the widget's own DAPM context and prefix. It fixes widget lookup
> > failures when searching across different DAPM contexts on the card.
> >
> > Fixes: ae4fc532244b ("ASoC: dapm: use component prefix when checking
> widget names")
> > Signed-off-by: Chancel Liu <chancel.liu at nxp.com>
> > Assisted-by: Cody:Claude-3.5-Sonnet
> > ---
> >  sound/soc/soc-dapm.c | 13 +------------
> >  1 file changed, 1 insertion(+), 12 deletions(-)
> >
> > diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
> > index d6192204e613..c5b80d9ed64b 100644
> > --- a/sound/soc/soc-dapm.c
> > +++ b/sound/soc/soc-dapm.c
> > @@ -2906,20 +2906,9 @@ static struct snd_soc_dapm_widget
> *dapm_find_widget(
> >  {
> >  	struct snd_soc_dapm_widget *w;
> >  	struct snd_soc_dapm_widget *fallback = NULL;
> > -	char prefixed_pin[80];
> > -	const char *pin_name;
> > -	const char *prefix = dapm_prefix(dapm);
> > -
> > -	if (prefix) {
> > -		snprintf(prefixed_pin, sizeof(prefixed_pin), "%s %s",
> > -			 prefix, pin);
> > -		pin_name = prefixed_pin;
> > -	} else {
> > -		pin_name = pin;
> > -	}
> >
> >  	for_each_card_widgets(dapm->card, w) {
> > -		if (!strcmp(w->name, pin_name)) {
> > +		if (!snd_soc_dapm_widget_name_cmp(w, pin)) {
> >  			if (w->dapm == dapm)
> >  				return w;
> >  			else
> > --
> > 2.50.1
> >