ALSA: ac97bus: Use guard() for mutex locks

[ Upstream commit c07824a ]

Replace the manual mutex lock/unlock pairs with guard() for code
simplification.

Only code refactoring, and no behavior change.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250829151335.7342-18-tiwai@suse.de
Stable-dep-of: 830988b6cf19 ("ALSA: ac97: fix a double free in snd_ac97_controller_register()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: tiwai

sound/ac97/bus.c

@@ -242,10 +242,9 @@ static ssize_t cold_reset_store(struct device *dev,
 {
 	struct ac97_controller *ac97_ctrl;
 
-	mutex_lock(&ac97_controllers_mutex);
+	guard(mutex)(&ac97_controllers_mutex);
 	ac97_ctrl = to_ac97_controller(dev);
 	ac97_ctrl->ops->reset(ac97_ctrl);
-	mutex_unlock(&ac97_controllers_mutex);
 	return len;
 }
 static DEVICE_ATTR_WO(cold_reset);
@@ -259,10 +258,9 @@ static ssize_t warm_reset_store(struct device *dev,
 	if (!dev)
 		return -ENODEV;
 
-	mutex_lock(&ac97_controllers_mutex);
+	guard(mutex)(&ac97_controllers_mutex);
 	ac97_ctrl = to_ac97_controller(dev);
 	ac97_ctrl->ops->warm_reset(ac97_ctrl);
-	mutex_unlock(&ac97_controllers_mutex);
 	return len;
 }
 static DEVICE_ATTR_WO(warm_reset);
@@ -285,10 +283,10 @@ static const struct attribute_group *ac97_adapter_groups[] = {
 
 static void ac97_del_adapter(struct ac97_controller *ac97_ctrl)
 {
-	mutex_lock(&ac97_controllers_mutex);
-	ac97_ctrl_codecs_unregister(ac97_ctrl);
-	list_del(&ac97_ctrl->controllers);
-	mutex_unlock(&ac97_controllers_mutex);
+	scoped_guard(mutex, &ac97_controllers_mutex) {
+		ac97_ctrl_codecs_unregister(ac97_ctrl);
+		list_del(&ac97_ctrl->controllers);
+	}
 
 	device_unregister(&ac97_ctrl->adap);
 }
@@ -312,7 +310,7 @@ static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
 {
 	int ret;
 
-	mutex_lock(&ac97_controllers_mutex);
+	guard(mutex)(&ac97_controllers_mutex);
 	ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL);
 	ac97_ctrl->nr = ret;
 	if (ret >= 0) {
@@ -323,13 +321,11 @@ static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
 		if (ret)
 			put_device(&ac97_ctrl->adap);
 	}
-	if (!ret)
+	if (!ret) {
 		list_add(&ac97_ctrl->controllers, &ac97_controllers);
-	mutex_unlock(&ac97_controllers_mutex);
-
-	if (!ret)
 		dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n",
 			dev_name(ac97_ctrl->parent));
+	}
 	return ret;
 }