ASoC: generic: Free jack GPIOs on card remove

Chancel Liu <chancel.liu@oss.nxp.com> says:

simple_util_init_jack() acquires a jack detection GPIO with
gpiod_get_optional() and passes it to snd_soc_jack_add_gpios(), which
also installs an IRQ handler, a PM notifier, a delayed work and a sysfs
export for it. None of simple-card, audio-graph-card or
audio-graph-card2 implements a card->remove() callback, so none of this
is ever released.

That goes unnoticed while the card is only torn down together with its
platform device, because the devres cleanup registered by
snd_soc_jack_add_gpios() is tied to that platform device. It becomes a
problem once the card alone is unregistered and registered again while
the platform device stays bound - for instance when a codec component is
unbound and bound again. card->probe() then runs a second time and
gpiod_get_optional() fails with -EBUSY, because the descriptor is still
held by the previous bind. The card is not registered again and audio
stays broken until the platform device itself is unbound.

Patch 1 adds the simple_util_remove_jack() helper, patches 2-4 wire it
up in the three generic card drivers.

Verified with audio-graph-card2 and a wm8962 codec using hp-det-gpios.
Before the series, the first

  echo 3-001a > /sys/bus/i2c/drivers/wm8962/unbind
  echo 3-001a > /sys/bus/i2c/drivers/wm8962/bind

leaves the GPIO line and IRQ claimed while the card is gone, and the
re-bind fails with

  ASoC error (-16): at graph_util_card_probe()
  ASoC error (-16): at snd_soc_card_probe() on wm8962-audio

after which the sound card never comes back. With the series applied,
both codec unbind/bind and platform unbind/bind cycles release the GPIO
and IRQ on unbind and fully restore the card.

Link: https://patch.msgid.link/20260913102502.2805912-1-chancel.liu@oss.nxp.com

5 files changed, 36 insertions, 0 deletions

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index bd8c3a033577..68faec56970e 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -219,12 +219,14 @@ static inline int simple_util_parse_aux_devs(struct simple_util_priv *priv, char
 int simple_util_init_jack(struct snd_soc_card *card,
 			       struct simple_util_jack *sjack,
 			       int is_hp, char *prefix, char *pin);
+void simple_util_remove_jack(struct simple_util_jack *sjack);
 int simple_util_init_aux_jacks(struct snd_soc_card *card, char *prefix);
 int simple_util_init_priv(struct simple_util_priv *priv,
 			       struct link_info *li);
 void simple_util_remove(struct platform_device *pdev);
 
 int graph_util_card_probe(struct snd_soc_card *card);
+int graph_util_card_remove(struct snd_soc_card *card);
 int graph_util_is_ports0(struct device_node *port);
 int graph_util_parse_dai(struct simple_util_priv *priv, struct device_node *ep,
 			 struct snd_soc_dai_link_component *dlc, int *is_single_link);
diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c
index 0a8a6d891d1f..127c2e6b308e 100644
--- a/sound/soc/generic/audio-graph-card.c
+++ b/sound/soc/generic/audio-graph-card.c
@@ -629,6 +629,7 @@ static int graph_probe(struct platform_device *pdev)
 	card->dapm_widgets	= graph_dapm_widgets;
 	card->num_dapm_widgets	= ARRAY_SIZE(graph_dapm_widgets);
 	card->probe		= graph_util_card_probe;
+	card->remove		= graph_util_card_remove;
 
 	if (of_device_get_match_data(dev))
 		priv->dpcm_selectable = 1;
diff --git a/sound/soc/generic/audio-graph-card2.c b/sound/soc/generic/audio-graph-card2.c
index 9fb3d3df5cf6..e11bc8135cb0 100644
--- a/sound/soc/generic/audio-graph-card2.c
+++ b/sound/soc/generic/audio-graph-card2.c
@@ -1310,6 +1310,7 @@ int audio_graph2_parse_of(struct simple_util_priv *priv, struct device *dev,
 		goto end;
 
 	card->probe	= graph_util_card_probe;
+	card->remove	= graph_util_card_remove;
 	card->owner	= THIS_MODULE;
 	card->dev	= dev;
 
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 7df5253499cd..de27163eeb0b 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -825,6 +825,16 @@ int simple_util_init_jack(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(simple_util_init_jack);
 
+void simple_util_remove_jack(struct simple_util_jack *sjack)
+{
+	if (!sjack->gpio.desc)
+		return;
+
+	snd_soc_jack_free_gpios(&sjack->jack, 1, &sjack->gpio);
+	sjack->gpio.desc = NULL;
+}
+EXPORT_SYMBOL_GPL(simple_util_remove_jack);
+
 int simple_util_init_aux_jacks(struct snd_soc_card *card, char *prefix)
 {
 	struct simple_util_priv *priv = snd_soc_card_get_drvdata(card);
@@ -1018,6 +1028,17 @@ end:
 }
 EXPORT_SYMBOL_GPL(graph_util_card_probe);
 
+int graph_util_card_remove(struct snd_soc_card *card)
+{
+	struct simple_util_priv *priv = snd_soc_card_get_drvdata(card);
+
+	simple_util_remove_jack(&priv->hp_jack);
+	simple_util_remove_jack(&priv->mic_jack);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(graph_util_card_remove);
+
 int graph_util_is_ports0(struct device_node *np)
 {
 	struct device_node *parent __free(device_node) = of_get_parent(np);
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 0a769c177149..b2fc91b8ab81 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -666,6 +666,16 @@ end:
 	return simple_ret(priv, ret);
 }
 
+static int simple_soc_remove(struct snd_soc_card *card)
+{
+	struct simple_util_priv *priv = snd_soc_card_get_drvdata(card);
+
+	simple_util_remove_jack(&priv->hp_jack);
+	simple_util_remove_jack(&priv->mic_jack);
+
+	return 0;
+}
+
 static int simple_parse_of(struct simple_util_priv *priv)
 {
 	struct snd_soc_card *card = simple_priv_to_card(priv);
@@ -754,6 +764,7 @@ static int simple_probe(struct platform_device *pdev)
 	card->owner		= THIS_MODULE;
 	card->dev		= dev;
 	card->probe		= simple_soc_probe;
+	card->remove		= simple_soc_remove;
 	card->driver_name       = "simple-card";
 
 	return simple_parse_of(priv);