commit 0914f7961babbf28aaa2f19b453951fb4841c03f
author Takashi Iwai <tiwai@suse.de> Tue Oct 16 16:43:39 2012 +0200
committer Takashi Iwai <tiwai@suse.de> Tue Oct 30 11:07:15 2012 +0100
tree fe5c14256a1d7b2116341300dd1e8ed94ac5f576
parent a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85

ALSA: Avoid endless sleep after disconnect

When disconnect callback is called, each component should wake up
sleepers and check card->shutdown flag for avoiding the endless sleep
blocking the proper resource release.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/hwdep.c

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index 53a6ba5..3f7f662 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -131,6 +131,10 @@
 		mutex_unlock(&hw->open_mutex);
 		schedule();
 		mutex_lock(&hw->open_mutex);
+		if (hw->card->shutdown) {
+			err = -ENODEV;
+			break;
+		}
 		if (signal_pending(current)) {
 			err = -ERESTARTSYS;
 			break;
@@ -462,12 +466,15 @@
 		mutex_unlock(&register_mutex);
 		return -EINVAL;
 	}
+	mutex_lock(&hwdep->open_mutex);
+	wake_up(&hwdep->open_wait);
 #ifdef CONFIG_SND_OSSEMUL
 	if (hwdep->ossreg)
 		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
 #endif
 	snd_unregister_device(SNDRV_DEVICE_TYPE_HWDEP, hwdep->card, hwdep->device);
 	list_del_init(&hwdep->list);
+	mutex_unlock(&hwdep->open_mutex);
 	mutex_unlock(&register_mutex);
 	return 0;
 }