1 files changed, 30 insertions, 20 deletions

diff --git a/sound/core/init.c b/sound/core/init.c
index d8ec849af128..7b012d15c2cf 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -213,6 +213,7 @@ int snd_card_create(int idx, const char *xid,
         spin_lock_init(&card->files_lock);
         INIT_LIST_HEAD(&card->files_list);
         init_waitqueue_head(&card->shutdown_sleep);
+        atomic_set(&card->refcount, 0);
 #ifdef CONFIG_PM
         mutex_init(&card->power_lock);
         init_waitqueue_head(&card->power_sleep);
@@ -446,21 +447,36 @@ static int snd_card_do_free(struct snd_card *card)
         return 0;
 }
 
+/**
+ * snd_card_unref - release the reference counter
+ * @card: the card instance
+ *
+ * Decrements the reference counter.  When it reaches to zero, wake up
+ * the sleeper and call the destructor if needed.
+ */
+void snd_card_unref(struct snd_card *card)
+{
+        if (atomic_dec_and_test(&card->refcount)) {
+                wake_up(&card->shutdown_sleep);
+                if (card->free_on_last_close)
+                        snd_card_do_free(card);
+        }
+}
+EXPORT_SYMBOL(snd_card_unref);
+
 int snd_card_free_when_closed(struct snd_card *card)
 {
-        int free_now = 0;
-        int ret = snd_card_disconnect(card);
-        if (ret)
-                return ret;
+        int ret;
 
-        spin_lock(&card->files_lock);
-        if (list_empty(&card->files_list))
-                free_now = 1;
-        else
-                card->free_on_last_close = 1;
-        spin_unlock(&card->files_lock);
+        atomic_inc(&card->refcount);
+        ret = snd_card_disconnect(card);
+        if (ret) {
+                atomic_dec(&card->refcount);
+                return ret;
+        }
 
-        if (free_now)
+        card->free_on_last_close = 1;
+        if (atomic_dec_and_test(&card->refcount))
                 snd_card_do_free(card);
         return 0;
 }
@@ -474,7 +490,7 @@ int snd_card_free(struct snd_card *card)
                 return ret;
 
         /* wait, until all devices are ready for the free operation */
-        wait_event(card->shutdown_sleep, list_empty(&card->files_list));
+        wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
         snd_card_do_free(card);
         return 0;
 }
@@ -886,6 +902,7 @@ int snd_card_file_add(struct snd_card *card, struct file *file)
                 return -ENODEV;
         }
         list_add(&mfile->list, &card->files_list);
+        atomic_inc(&card->refcount);
         spin_unlock(&card->files_lock);
         return 0;
 }
@@ -908,7 +925,6 @@ EXPORT_SYMBOL(snd_card_file_add);
 int snd_card_file_remove(struct snd_card *card, struct file *file)
 {
         struct snd_monitor_file *mfile, *found = NULL;
-        int last_close = 0;
 
         spin_lock(&card->files_lock);
         list_for_each_entry(mfile, &card->files_list, list) {
@@ -923,19 +939,13 @@ int snd_card_file_remove(struct snd_card *card, struct file *file)
                         break;
                 }
         }
-        if (list_empty(&card->files_list))
-                last_close = 1;
         spin_unlock(&card->files_lock);
-        if (last_close) {
-                wake_up(&card->shutdown_sleep);
-                if (card->free_on_last_close)
-                        snd_card_do_free(card);
-        }
         if (!found) {
                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
                 return -ENOENT;
         }
         kfree(found);
+        snd_card_unref(card);
         return 0;
 }