ALSA: control: Consolidate helpers for adding and replacing ctl elements

Both snd_ctl_add() and snd_ctl_replace() process the things in a
fairly similar way, and indeed the most of the codes can be unified.

This patch is a refactoring to consolidate the both functions to call
a single helper with an extra "mode" argument.  There should be no
functional difference, except for one additional sanity check applied
now to snd_ctl_replace() (which was rather overlooking, IMO), too.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/control.c

@@ -348,22 +348,41 @@ static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 	return 0;
 }
 
-/* add a new kcontrol object; call with card->controls_rwsem locked */
+enum snd_ctl_add_mode {
-static int __snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
+	CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
+};
+
+/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
+static int __snd_ctl_add_replace(struct snd_card *card,
+				 struct snd_kcontrol *kcontrol,
+				 enum snd_ctl_add_mode mode)
 {
 	struct snd_ctl_elem_id id;
 	unsigned int idx;
 	unsigned int count;
+	struct snd_kcontrol *old;
+	int err;
 
 	id = kcontrol->id;
 	if (id.index > UINT_MAX - kcontrol->count)
 		return -EINVAL;
 
-	if (snd_ctl_find_id(card, &id)) {
+	old = snd_ctl_find_id(card, &id);
-		dev_err(card->dev,
+	if (!old) {
-			"control %i:%i:%i:%s:%i is already present\n",
+		if (mode == CTL_REPLACE)
-			id.iface, id.device, id.subdevice, id.name, id.index);
+			return -EINVAL;
-		return -EBUSY;
+	} else {
+		if (mode == CTL_ADD_EXCLUSIVE) {
+			dev_err(card->dev,
+				"control %i:%i:%i:%s:%i is already present\n",
+				id.iface, id.device, id.subdevice, id.name,
+				id.index);
+			return -EBUSY;
+		}
+
+		err = snd_ctl_remove(card, old);
+		if (err < 0)
+			return err;
 	}
 
 	if (snd_ctl_find_hole(card, kcontrol->count) < 0)
@@ -382,6 +401,29 @@ static int __snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 	return 0;
 }
 
+static int snd_ctl_add_replace(struct snd_card *card,
+			       struct snd_kcontrol *kcontrol,
+			       enum snd_ctl_add_mode mode)
+{
+	int err = -EINVAL;
+
+	if (! kcontrol)
+		return err;
+	if (snd_BUG_ON(!card || !kcontrol->info))
+		goto error;
+
+	down_write(&card->controls_rwsem);
+	err = __snd_ctl_add_replace(card, kcontrol, mode);
+	up_write(&card->controls_rwsem);
+	if (err < 0)
+		goto error;
+	return 0;
+
+ error:
+	snd_ctl_free_one(kcontrol);
+	return err;
+}
+
 /**
  * snd_ctl_add - add the control instance to the card
  * @card: the card instance
@@ -398,23 +440,7 @@ static int __snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
  */
 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 {
-	int err = -EINVAL;
+	return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
-
-	if (! kcontrol)
-		return err;
-	if (snd_BUG_ON(!card || !kcontrol->info))
-		goto error;
-
-	down_write(&card->controls_rwsem);
-	err = __snd_ctl_add(card, kcontrol);
-	up_write(&card->controls_rwsem);
-	if (err < 0)
-		goto error;
-	return 0;
-
- error:
-	snd_ctl_free_one(kcontrol);
-	return err;
 }
 EXPORT_SYMBOL(snd_ctl_add);
 
@@ -435,53 +461,8 @@ EXPORT_SYMBOL(snd_ctl_add);
 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 		    bool add_on_replace)
 {
-	struct snd_ctl_elem_id id;
+	return snd_ctl_add_replace(card, kcontrol,
-	unsigned int count;
+				   add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
-	unsigned int idx;
-	struct snd_kcontrol *old;
-	int ret;
-
-	if (!kcontrol)
-		return -EINVAL;
-	if (snd_BUG_ON(!card || !kcontrol->info)) {
-		ret = -EINVAL;
-		goto error;
-	}
-	id = kcontrol->id;
-	down_write(&card->controls_rwsem);
-	old = snd_ctl_find_id(card, &id);
-	if (!old) {
-		if (add_on_replace)
-			goto add;
-		up_write(&card->controls_rwsem);
-		ret = -EINVAL;
-		goto error;
-	}
-	ret = snd_ctl_remove(card, old);
-	if (ret < 0) {
-		up_write(&card->controls_rwsem);
-		goto error;
-	}
-add:
-	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
-		up_write(&card->controls_rwsem);
-		ret = -ENOMEM;
-		goto error;
-	}
-	list_add_tail(&kcontrol->list, &card->controls);
-	card->controls_count += kcontrol->count;
-	kcontrol->id.numid = card->last_numid + 1;
-	card->last_numid += kcontrol->count;
-	id = kcontrol->id;
-	count = kcontrol->count;
-	up_write(&card->controls_rwsem);
-	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
-		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
-	return 0;
-
-error:
-	snd_ctl_free_one(kcontrol);
-	return ret;
 }
 EXPORT_SYMBOL(snd_ctl_replace);
 
@@ -1369,7 +1350,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
 
 	/* This function manage to free the instance on failure. */
 	down_write(&card->controls_rwsem);
-	err = __snd_ctl_add(card, kctl);
+	err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
 	if (err < 0) {
 		snd_ctl_free_one(kctl);
 		goto unlock;