Merge tag 'sound-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "This contains unexpectedly many changes in a wide range due to the
  fixes for races at disconnection of USB audio devices.  In the end, we
  end up covering fairly core parts of sound subsystem.

  Other than that, just a few usual small fixes."

* tag 'sound-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: ice1724: Fix rate setup after resume
  ALSA: Avoid endless sleep after disconnect
  ALSA: Add a reference counter to card instance
  ALSA: usb-audio: Fix races at disconnection in mixer_quirks.c
  ALSA: usb-audio: Use rwsem for disconnect protection
  ALSA: usb-audio: Fix races at disconnection
  ALSA: PCM: Fix some races at disconnection
  ASoC: omap-dmic: Correct functional clock name
  ASoC: zoom2: Fix compile error by including correct header files
  ALSA: hda - Fix mute-LED setup for HP dv5 laptop

1 files changed, 9 insertions, 2 deletions

diff --git a/sound/core/sound.c b/sound/core/sound.c
index 643976000ce..89780c323f1 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -98,6 +98,10 @@ static void snd_request_other(int minor)
  *
  * Checks that a minor device with the specified type is registered, and returns
  * its user data pointer.
+ *
+ * This function increments the reference counter of the card instance
+ * if an associated instance with the given minor number and type is found.
+ * The caller must call snd_card_unref() appropriately later.
  */
 void *snd_lookup_minor_data(unsigned int minor, int type)
 {
@@ -108,9 +112,11 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
 		return NULL;
 	mutex_lock(&sound_mutex);
 	mreg = snd_minors[minor];
-	if (mreg && mreg->type == type)
+	if (mreg && mreg->type == type) {
 		private_data = mreg->private_data;
-	else
+		if (mreg->card_ptr)
+			atomic_inc(&mreg->card_ptr->refcount);
+	} else
 		private_data = NULL;
 	mutex_unlock(&sound_mutex);
 	return private_data;
@@ -275,6 +281,7 @@ int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
 	preg->device = dev;
 	preg->f_ops = f_ops;
 	preg->private_data = private_data;
+	preg->card_ptr = card;
 	mutex_lock(&sound_mutex);
 #ifdef CONFIG_SND_DYNAMIC_MINORS
 	minor = snd_find_free_minor(type);