[alsa-devel] Applied "ASoC: tlv320aic3x: fix reset gpio reference counting" to the asoc tree

[Mark Brown]

The patch

   ASoC: tlv320aic3x: fix reset gpio reference counting

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 82ad759143ed77673db0d93d53c1cde7b99917ee Mon Sep 17 00:00:00 2001
From: Philipp Puschmann <philipp.puschmann at emlix.com>
Date: Wed, 27 Feb 2019 16:17:33 +0100
Subject: [PATCH] ASoC: tlv320aic3x: fix reset gpio reference counting

This patch fixes a bug that prevents freeing the reset gpio on unloading
the module.

aic3x_i2c_probe is called when loading the module and it calls list_add
with a probably uninitialized list entry aic3x->list (next = prev = NULL)).
So even if list_del is called it does nothing and in the end the gpio_reset
is not freed. Then a repeated module probing fails silently because
gpio_request fails.

When moving INIT_LIST_HEAD to aic3x_i2c_probe we also have to move
list_del to aic3x_i2c_remove because aic3x_remove may be called
multiple times without aic3x_i2c_remove being called which leads to
a NULL pointer dereference.

Signed-off-by: Philipp Puschmann <philipp.puschmann at emlix.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/codecs/tlv320aic3x.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/tlv320aic3x.c b/sound/soc/codecs/tlv320aic3x.c
index 6aa0edf8c5ef..cea3ebecdb12 100644
--- a/sound/soc/codecs/tlv320aic3x.c
+++ b/sound/soc/codecs/tlv320aic3x.c
@@ -1609,7 +1609,6 @@ static int aic3x_probe(struct snd_soc_component *component)
 	struct aic3x_priv *aic3x = snd_soc_component_get_drvdata(component);
 	int ret, i;
 
-	INIT_LIST_HEAD(&aic3x->list);
 	aic3x->component = component;
 
 	for (i = 0; i < ARRAY_SIZE(aic3x->supplies); i++) {
@@ -1692,7 +1691,6 @@ static void aic3x_remove(struct snd_soc_component *component)
 	struct aic3x_priv *aic3x = snd_soc_component_get_drvdata(component);
 	int i;
 
-	list_del(&aic3x->list);
 	for (i = 0; i < ARRAY_SIZE(aic3x->supplies); i++)
 		regulator_unregister_notifier(aic3x->supplies[i].consumer,
 					      &aic3x->disable_nb[i].nb);
@@ -1890,6 +1888,7 @@ static int aic3x_i2c_probe(struct i2c_client *i2c,
 	if (ret != 0)
 		goto err_gpio;
 
+	INIT_LIST_HEAD(&aic3x->list);
 	list_add(&aic3x->list, &reset_list);
 
 	return 0;
@@ -1906,6 +1905,8 @@ static int aic3x_i2c_remove(struct i2c_client *client)
 {
 	struct aic3x_priv *aic3x = i2c_get_clientdata(client);
 
+	list_del(&aic3x->list);
+
 	if (gpio_is_valid(aic3x->gpio_reset) &&
 	    !aic3x_is_shared_reset(aic3x)) {
 		gpio_set_value(aic3x->gpio_reset, 0);
-- 
2.20.1