[PATCH] ALSA: hda/realtek: Serialize setting GPIO LED

[Kai-Heng Feng]

If a system has two GPIO controlled LED, one for mute and another one
for micmute, and both of them are on before system suspend, sometimes
one of them won't be turned off by system suspend.

The codec doesn't seem to be able to control multiple GPIO LEDs at the
same time, so introduce a new mutex to serialize setting the LED, to
prevent the issue from happening.

Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 include/sound/hda_codec.h     | 1 +
 sound/pci/hda/hda_codec.c     | 1 +
 sound/pci/hda/patch_realtek.c | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/include/sound/hda_codec.h b/include/sound/hda_codec.h
index d16a4229209b..3a1792bbb7ac 100644
--- a/include/sound/hda_codec.h
+++ b/include/sound/hda_codec.h
@@ -206,6 +206,7 @@ struct hda_codec {
 
 	struct mutex spdif_mutex;
 	struct mutex control_mutex;
+	struct mutex led_mutex;
 	struct snd_array spdif_out;
 	unsigned int spdif_in_enable;	/* SPDIF input enable? */
 	const hda_nid_t *slave_dig_outs; /* optional digital out slave widgets */
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 7e3ae4534df9..ec477cd8afed 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -946,6 +946,7 @@ int snd_hda_codec_device_new(struct hda_bus *bus, struct snd_card *card,
 	codec->addr = codec_addr;
 	mutex_init(&codec->spdif_mutex);
 	mutex_init(&codec->control_mutex);
+	mutex_init(&codec->led_mutex);
 	snd_array_init(&codec->mixers, sizeof(struct hda_nid_item), 32);
 	snd_array_init(&codec->nids, sizeof(struct hda_nid_item), 32);
 	snd_array_init(&codec->init_pins, sizeof(struct hda_pincfg), 16);
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 53e0eef8b042..96dac365fbb8 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -4101,7 +4101,10 @@ static void alc_update_gpio_led(struct hda_codec *codec, unsigned int mask,
 {
 	if (polarity)
 		enabled = !enabled;
+
+	mutex_lock(&codec->led_mutex);
 	alc_update_gpio_data(codec, mask, !enabled); /* muted -> LED on */
+	mutex_unlock(&codec->led_mutex);
 }
 
 /* turn on/off mute LED via GPIO per vmaster hook */
-- 
2.17.1