ALSA: core: Remove child proc file elements recursively

This patch changes the way to manage the resource release of proc
files: namely, let snd_info_free_entry() freeing the whole children.

This makes it us possible to drop the snd_device_*() management.  Then
snd_card_proc_new() becomes merely a wrapper to
snd_info_create_card_entry().

Together with this change, now you need to call snd_info_free_entry()
for a proc entry created via snd_card_proc_new(), while it was freed
via snd_device_free() beforehand.

Acked-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/info.h

@@ -24,6 +24,7 @@
 
 #include <linux/poll.h>
 #include <linux/seq_file.h>
+#include <sound/core.h>
 
 /* buffer for information */
 struct snd_info_buffer {
@@ -146,8 +147,12 @@ void snd_info_card_id_change(struct snd_card *card);
 int snd_info_register(struct snd_info_entry *entry);
 
 /* for card drivers */
-int snd_card_proc_new(struct snd_card *card, const char *name,
+static inline int snd_card_proc_new(struct snd_card *card, const char *name,
-		      struct snd_info_entry **entryp);
+				    struct snd_info_entry **entryp)
+{
+	*entryp = snd_info_create_card_entry(card, name, card->proc_root);
+	return *entryp ? 0 : -ENOMEM;
+}
 
 static inline void snd_info_set_text_ops(struct snd_info_entry *entry, 
 	void *private_data,

sound/core/info.c

@@ -760,92 +760,39 @@ EXPORT_SYMBOL(snd_info_create_card_entry);
 
 static void snd_info_disconnect(struct snd_info_entry *entry)
 {
-	struct list_head *p, *n;
+	struct snd_info_entry *p, *n;
 
-	list_for_each_safe(p, n, &entry->children) {
+	if (!entry->p)
-		snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
-	}
-
-	if (! entry->p)
 		return;
+	list_for_each_entry_safe(p, n, &entry->children, list)
+		snd_info_disconnect(p);
 	list_del_init(&entry->list);
 	proc_remove(entry->p);
 	entry->p = NULL;
 }
 
-static int snd_info_dev_free_entry(struct snd_device *device)
-{
-	struct snd_info_entry *entry = device->device_data;
-	snd_info_free_entry(entry);
-	return 0;
-}
-
-static int snd_info_dev_register_entry(struct snd_device *device)
-{
-	struct snd_info_entry *entry = device->device_data;
-	return snd_info_register(entry);
-}
-
-/**
- * snd_card_proc_new - create an info entry for the given card
- * @card: the card instance
- * @name: the file name
- * @entryp: the pointer to store the new info entry
- *
- * Creates a new info entry and assigns it to the given card.
- * Unlike snd_info_create_card_entry(), this function registers the
- * info entry as an ALSA device component, so that it can be
- * unregistered/released without explicit call.
- * Also, you don't have to register this entry via snd_info_register(),
- * since this will be registered by snd_card_register() automatically.
- *
- * The parent is assumed as card->proc_root.
- *
- * For releasing this entry, use snd_device_free() instead of
- * snd_info_free_entry(). 
- *
- * Return: Zero if successful, or a negative error code on failure.
- */
-int snd_card_proc_new(struct snd_card *card, const char *name,
-		      struct snd_info_entry **entryp)
-{
-	static struct snd_device_ops ops = {
-		.dev_free = snd_info_dev_free_entry,
-		.dev_register =	snd_info_dev_register_entry,
-		/* disconnect is done via snd_info_card_disconnect() */
-	};
-	struct snd_info_entry *entry;
-	int err;
-
-	entry = snd_info_create_card_entry(card, name, card->proc_root);
-	if (! entry)
-		return -ENOMEM;
-	if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
-		snd_info_free_entry(entry);
-		return err;
-	}
-	if (entryp)
-		*entryp = entry;
-	return 0;
-}
-
-EXPORT_SYMBOL(snd_card_proc_new);
-
 /**
  * snd_info_free_entry - release the info entry
  * @entry: the info entry
  *
- * Releases the info entry.  Don't call this after registered.
+ * Releases the info entry.
  */
 void snd_info_free_entry(struct snd_info_entry * entry)
 {
-	if (entry == NULL)
+	struct snd_info_entry *p, *n;
+
+	if (!entry)
 		return;
 	if (entry->p) {
 		mutex_lock(&info_mutex);
 		snd_info_disconnect(entry);
 		mutex_unlock(&info_mutex);
 	}
+
+	/* free all children at first */
+	list_for_each_entry_safe(p, n, &entry->children, list)
+		snd_info_free_entry(p);
+
 	kfree(entry->name);
 	if (entry->private_free)
 		entry->private_free(entry);

sound/pci/hda/patch_hdmi.c

@@ -592,7 +592,7 @@ static int eld_proc_new(struct hdmi_spec_per_pin *per_pin, int index)
 static void eld_proc_free(struct hdmi_spec_per_pin *per_pin)
 {
 	if (!per_pin->codec->bus->shutdown && per_pin->proc_entry) {
-		snd_device_free(per_pin->codec->card, per_pin->proc_entry);
+		snd_info_free_entry(per_pin->proc_entry);
 		per_pin->proc_entry = NULL;
 	}
 }