1 files changed, 40 insertions, 3 deletions

diff --git a/sound/soc/soc-jack.c b/sound/soc/soc-jack.c
index 3c07a94c2e30..29159e1781d0 100644
--- a/sound/soc/soc-jack.c
+++ b/sound/soc/soc-jack.c
@@ -37,6 +37,7 @@ int snd_soc_jack_new(struct snd_soc_card *card, const char *id, int type,
 {
         jack->card = card;
         INIT_LIST_HEAD(&jack->pins);
+        BLOCKING_INIT_NOTIFIER_HEAD(&jack->notifier);
 
         return snd_jack_new(card->codec->card, id, type, &jack->jack);
 }
@@ -63,10 +64,9 @@ void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
         int enable;
         int oldstatus;
 
-        if (!jack) {
-                WARN_ON_ONCE(!jack);
+        if (!jack)
                 return;
-        }
+
         codec = jack->card->codec;
 
         mutex_lock(&codec->mutex);
@@ -93,6 +93,9 @@ void snd_soc_jack_report(struct snd_soc_jack *jack, int status, int mask)
                         snd_soc_dapm_disable_pin(codec, pin->pin);
         }
 
+        /* Report before the DAPM sync to help users updating micbias status */
+        blocking_notifier_call_chain(&jack->notifier, status, NULL);
+
         snd_soc_dapm_sync(codec);
 
         snd_jack_report(jack->jack, status);
@@ -143,6 +146,40 @@ int snd_soc_jack_add_pins(struct snd_soc_jack *jack, int count,
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_add_pins);
 
+/**
+ * snd_soc_jack_notifier_register - Register a notifier for jack status
+ *
+ * @jack:  ASoC jack
+ * @nb:    Notifier block to register
+ *
+ * Register for notification of the current status of the jack.  Note
+ * that it is not possible to report additional jack events in the
+ * callback from the notifier, this is intended to support
+ * applications such as enabling electrical detection only when a
+ * mechanical detection event has occurred.
+ */
+void snd_soc_jack_notifier_register(struct snd_soc_jack *jack,
+                                    struct notifier_block *nb)
+{
+        blocking_notifier_chain_register(&jack->notifier, nb);
+}
+EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_register);
+
+/**
+ * snd_soc_jack_notifier_unregister - Unregister a notifier for jack status
+ *
+ * @jack:  ASoC jack
+ * @nb:    Notifier block to unregister
+ *
+ * Stop notifying for status changes.
+ */
+void snd_soc_jack_notifier_unregister(struct snd_soc_jack *jack,
+                                      struct notifier_block *nb)
+{
+        blocking_notifier_chain_unregister(&jack->notifier, nb);
+}
+EXPORT_SYMBOL_GPL(snd_soc_jack_notifier_unregister);
+
 #ifdef CONFIG_GPIOLIB
 /* gpio detect */
 static void snd_soc_jack_gpio_detect(struct snd_soc_jack_gpio *gpio)