ALSA: timer: Use guard() for locking

We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

For making changes easier, some functions widen the application of
register_mutex, but those shouldn't influence on any actual
performance.

Also, one code block was factored out as a function so that guard()
can be applied cleanly without much indentation.

There are still a few remaining explicit spin_lock/unlock calls, and
those are for the places where we do temporary unlock/relock, which
doesn't fit well with the guard(), so far.

Only the code refactoring, and no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-4-tiwai@suse.de

2 files changed, 177 insertions, 259 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index a595c4fb4b2a0f..15b07d09c4b720 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -224,14 +224,12 @@ static int check_matching_master_slave(struct snd_timer_instance *master,
 		return -EBUSY;
 	list_move_tail(&slave->open_list, &master->slave_list_head);
 	master->timer->num_instances++;
-	spin_lock_irq(&slave_active_lock);
-	spin_lock(&master->timer->lock);
+	guard(spinlock_irq)(&slave_active_lock);
+	guard(spinlock)(&master->timer->lock);
 	slave->master = master;
 	slave->timer = master->timer;
 	if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 		list_add_tail(&slave->active_list, &master->slave_active_head);
-	spin_unlock(&master->timer->lock);
-	spin_unlock_irq(&slave_active_lock);
 	return 1;
 }
 
@@ -382,6 +380,25 @@ list_added:
 }
 EXPORT_SYMBOL(snd_timer_open);
 
+/* remove slave links, called from snd_timer_close_locked() below */
+static void remove_slave_links(struct snd_timer_instance *timeri,
+			       struct snd_timer *timer)
+{
+	struct snd_timer_instance *slave, *tmp;
+
+	guard(spinlock_irq)(&slave_active_lock);
+	guard(spinlock)(&timer->lock);
+	timeri->timer = NULL;
+	list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head, open_list) {
+		list_move_tail(&slave->open_list, &snd_timer_slave_list);
+		timer->num_instances--;
+		slave->master = NULL;
+		slave->timer = NULL;
+		list_del_init(&slave->ack_list);
+		list_del_init(&slave->active_list);
+	}
+}
+
 /*
  * close a timer instance
  * call this with register_mutex down.
@@ -390,12 +407,10 @@ static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 				   struct device **card_devp_to_put)
 {
 	struct snd_timer *timer = timeri->timer;
-	struct snd_timer_instance *slave, *tmp;
 
 	if (timer) {
-		spin_lock_irq(&timer->lock);
+		guard(spinlock)(&timer->lock);
 		timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
-		spin_unlock_irq(&timer->lock);
 	}
 
 	if (!list_empty(&timeri->open_list)) {
@@ -418,21 +433,7 @@ static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 		}
 		spin_unlock_irq(&timer->lock);
 
-		/* remove slave links */
-		spin_lock_irq(&slave_active_lock);
-		spin_lock(&timer->lock);
-		timeri->timer = NULL;
-		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
-					 open_list) {
-			list_move_tail(&slave->open_list, &snd_timer_slave_list);
-			timer->num_instances--;
-			slave->master = NULL;
-			slave->timer = NULL;
-			list_del_init(&slave->ack_list);
-			list_del_init(&slave->active_list);
-		}
-		spin_unlock(&timer->lock);
-		spin_unlock_irq(&slave_active_lock);
+		remove_slave_links(timeri, timer);
 
 		/* slave doesn't need to release timer resources below */
 		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
@@ -459,9 +460,8 @@ void snd_timer_close(struct snd_timer_instance *timeri)
 	if (snd_BUG_ON(!timeri))
 		return;
 
-	mutex_lock(&register_mutex);
-	snd_timer_close_locked(timeri, &card_dev_to_put);
-	mutex_unlock(&register_mutex);
+	scoped_guard(mutex, &register_mutex)
+		snd_timer_close_locked(timeri, &card_dev_to_put);
 	/* put_device() is called after unlock for avoiding deadlock */
 	if (card_dev_to_put)
 		put_device(card_dev_to_put);
@@ -480,15 +480,13 @@ unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 {
 	struct snd_timer * timer;
 	unsigned long ret = 0;
-	unsigned long flags;
 
 	if (timeri == NULL)
 		return 0;
 	timer = timeri->timer;
 	if (timer) {
-		spin_lock_irqsave(&timer->lock, flags);
+		guard(spinlock_irqsave)(&timer->lock);
 		ret = snd_timer_hw_resolution(timer);
-		spin_unlock_irqrestore(&timer->lock, flags);
 	}
 	return ret;
 }
@@ -532,26 +530,19 @@ static int snd_timer_start1(struct snd_timer_instance *timeri,
 {
 	struct snd_timer *timer;
 	int result;
-	unsigned long flags;
 
 	timer = timeri->timer;
 	if (!timer)
 		return -EINVAL;
 
-	spin_lock_irqsave(&timer->lock, flags);
-	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
-		result = -EINVAL;
-		goto unlock;
-	}
-	if (timer->card && timer->card->shutdown) {
-		result = -ENODEV;
-		goto unlock;
-	}
+	guard(spinlock_irqsave)(&timer->lock);
+	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
+		return -EINVAL;
+	if (timer->card && timer->card->shutdown)
+		return -ENODEV;
 	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
-			     SNDRV_TIMER_IFLG_START)) {
-		result = -EBUSY;
-		goto unlock;
-	}
+			     SNDRV_TIMER_IFLG_START))
+		return -EBUSY;
 
 	if (start)
 		timeri->ticks = timeri->cticks = ticks;
@@ -577,8 +568,6 @@ static int snd_timer_start1(struct snd_timer_instance *timeri,
 	}
 	snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 			  SNDRV_TIMER_EVENT_CONTINUE);
- unlock:
-	spin_unlock_irqrestore(&timer->lock, flags);
 	return result;
 }
 
@@ -586,53 +575,38 @@ static int snd_timer_start1(struct snd_timer_instance *timeri,
 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
 				 bool start)
 {
-	unsigned long flags;
-	int err;
-
-	spin_lock_irqsave(&slave_active_lock, flags);
-	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
-		err = -EINVAL;
-		goto unlock;
-	}
-	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
-		err = -EBUSY;
-		goto unlock;
-	}
+	guard(spinlock_irqsave)(&slave_active_lock);
+	if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
+		return -EINVAL;
+	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING)
+		return -EBUSY;
 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 	if (timeri->master && timeri->timer) {
-		spin_lock(&timeri->timer->lock);
+		guard(spinlock)(&timeri->timer->lock);
 		list_add_tail(&timeri->active_list,
 			      &timeri->master->slave_active_head);
 		snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 				  SNDRV_TIMER_EVENT_CONTINUE);
-		spin_unlock(&timeri->timer->lock);
 	}
-	err = 1; /* delayed start */
- unlock:
-	spin_unlock_irqrestore(&slave_active_lock, flags);
-	return err;
+	return 1; /* delayed start */
 }
 
 /* stop/pause a master timer */
 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
 {
 	struct snd_timer *timer;
-	int result = 0;
-	unsigned long flags;
 
 	timer = timeri->timer;
 	if (!timer)
 		return -EINVAL;
-	spin_lock_irqsave(&timer->lock, flags);
+	guard(spinlock_irqsave)(&timer->lock);
 	list_del_init(&timeri->ack_list);
 	list_del_init(&timeri->active_list);
 	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
-			       SNDRV_TIMER_IFLG_START))) {
-		result = -EBUSY;
-		goto unlock;
-	}
+			       SNDRV_TIMER_IFLG_START)))
+		return -EBUSY;
 	if (timer->card && timer->card->shutdown)
-		goto unlock;
+		return 0;
 	if (stop) {
 		timeri->cticks = timeri->ticks;
 		timeri->pticks = 0;
@@ -656,30 +630,25 @@ static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
 		timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
 	snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 			  SNDRV_TIMER_EVENT_PAUSE);
- unlock:
-	spin_unlock_irqrestore(&timer->lock, flags);
-	return result;
+	return 0;
 }
 
 /* stop/pause a slave timer */
 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
 {
-	unsigned long flags;
 	bool running;
 
-	spin_lock_irqsave(&slave_active_lock, flags);
+	guard(spinlock_irqsave)(&slave_active_lock);
 	running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
 	timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 	if (timeri->timer) {
-		spin_lock(&timeri->timer->lock);
+		guard(spinlock)(&timeri->timer->lock);
 		list_del_init(&timeri->ack_list);
 		list_del_init(&timeri->active_list);
 		if (running)
 			snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 					  SNDRV_TIMER_EVENT_PAUSE);
-		spin_unlock(&timeri->timer->lock);
 	}
-	spin_unlock_irqrestore(&slave_active_lock, flags);
 	return running ? 0 : -EBUSY;
 }
 
@@ -804,12 +773,9 @@ static void snd_timer_process_callbacks(struct snd_timer *timer,
 static void snd_timer_clear_callbacks(struct snd_timer *timer,
 				      struct list_head *head)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&timer->lock, flags);
+	guard(spinlock_irqsave)(&timer->lock);
 	while (!list_empty(head))
 		list_del_init(head->next);
-	spin_unlock_irqrestore(&timer->lock, flags);
 }
 
 /*
@@ -819,16 +785,14 @@ static void snd_timer_clear_callbacks(struct snd_timer *timer,
 static void snd_timer_work(struct work_struct *work)
 {
 	struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
-	unsigned long flags;
 
 	if (timer->card && timer->card->shutdown) {
 		snd_timer_clear_callbacks(timer, &timer->sack_list_head);
 		return;
 	}
 
-	spin_lock_irqsave(&timer->lock, flags);
+	guard(spinlock_irqsave)(&timer->lock);
 	snd_timer_process_callbacks(timer, &timer->sack_list_head);
-	spin_unlock_irqrestore(&timer->lock, flags);
 }
 
 /*
@@ -842,8 +806,6 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 	struct snd_timer_instance *ti, *ts, *tmp;
 	unsigned long resolution;
 	struct list_head *ack_list_head;
-	unsigned long flags;
-	bool use_work = false;
 
 	if (timer == NULL)
 		return;
@@ -853,7 +815,7 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 		return;
 	}
 
-	spin_lock_irqsave(&timer->lock, flags);
+	guard(spinlock_irqsave)(&timer->lock);
 
 	/* remember the current resolution */
 	resolution = snd_timer_hw_resolution(timer);
@@ -919,10 +881,7 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 	snd_timer_process_callbacks(timer, &timer->ack_list_head);
 
 	/* do we have any slow callbacks? */
-	use_work = !list_empty(&timer->sack_list_head);
-	spin_unlock_irqrestore(&timer->lock, flags);
-
-	if (use_work)
+	if (!list_empty(&timer->sack_list_head))
 		queue_work(system_highpri_wq, &timer->task_work);
 }
 EXPORT_SYMBOL(snd_timer_interrupt);
@@ -988,7 +947,7 @@ static int snd_timer_free(struct snd_timer *timer)
 	if (!timer)
 		return 0;
 
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	if (! list_empty(&timer->open_list_head)) {
 		struct list_head *p, *n;
 		struct snd_timer_instance *ti;
@@ -1000,7 +959,6 @@ static int snd_timer_free(struct snd_timer *timer)
 		}
 	}
 	list_del(&timer->device_list);
-	mutex_unlock(&register_mutex);
 
 	if (timer->private_free)
 		timer->private_free(timer);
@@ -1025,7 +983,7 @@ static int snd_timer_dev_register(struct snd_device *dev)
 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
 	    	return -EINVAL;
 
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
 		if (timer1->tmr_class > timer->tmr_class)
 			break;
@@ -1046,11 +1004,9 @@ static int snd_timer_dev_register(struct snd_device *dev)
 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
 			continue;
 		/* conflicts.. */
-		mutex_unlock(&register_mutex);
 		return -EBUSY;
 	}
 	list_add_tail(&timer->device_list, &timer1->device_list);
-	mutex_unlock(&register_mutex);
 	return 0;
 }
 
@@ -1059,20 +1015,18 @@ static int snd_timer_dev_disconnect(struct snd_device *device)
 	struct snd_timer *timer = device->device_data;
 	struct snd_timer_instance *ti;
 
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	list_del_init(&timer->device_list);
 	/* wake up pending sleepers */
 	list_for_each_entry(ti, &timer->open_list_head, open_list) {
 		if (ti->disconnect)
 			ti->disconnect(ti);
 	}
-	mutex_unlock(&register_mutex);
 	return 0;
 }
 
 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
 {
-	unsigned long flags;
 	unsigned long resolution = 0;
 	struct snd_timer_instance *ti, *ts;
 
@@ -1083,7 +1037,7 @@ void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tst
 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
 		       event > SNDRV_TIMER_EVENT_MRESUME))
 		return;
-	spin_lock_irqsave(&timer->lock, flags);
+	guard(spinlock_irqsave)(&timer->lock);
 	if (event == SNDRV_TIMER_EVENT_MSTART ||
 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
 	    event == SNDRV_TIMER_EVENT_MRESUME)
@@ -1095,7 +1049,6 @@ void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tst
 			if (ts->ccallback)
 				ts->ccallback(ts, event, tstamp, resolution);
 	}
-	spin_unlock_irqrestore(&timer->lock, flags);
 }
 EXPORT_SYMBOL(snd_timer_notify);
 
@@ -1248,7 +1201,7 @@ static void snd_timer_proc_read(struct snd_info_entry *entry,
 	struct snd_timer_instance *ti;
 	unsigned long resolution;
 
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	list_for_each_entry(timer, &snd_timer_list, device_list) {
 		if (timer->card && timer->card->shutdown)
 			continue;
@@ -1270,9 +1223,8 @@ static void snd_timer_proc_read(struct snd_info_entry *entry,
 				    timer->tmr_device, timer->tmr_subdevice);
 		}
 		snd_iprintf(buffer, "%s :", timer->name);
-		spin_lock_irq(&timer->lock);
-		resolution = snd_timer_hw_resolution(timer);
-		spin_unlock_irq(&timer->lock);
+		scoped_guard(spinlock_irq, &timer->lock)
+			resolution = snd_timer_hw_resolution(timer);
 		if (resolution)
 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
 				    resolution / 1000,
@@ -1288,7 +1240,6 @@ static void snd_timer_proc_read(struct snd_info_entry *entry,
 						  SNDRV_TIMER_IFLG_RUNNING))
 				    ? "running" : "stopped");
 	}
-	mutex_unlock(&register_mutex);
 }
 
 static struct snd_info_entry *snd_timer_proc_entry;
@@ -1329,7 +1280,7 @@ static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
 	struct snd_timer_read *r;
 	int prev;
 
-	spin_lock(&tu->qlock);
+	guard(spinlock)(&tu->qlock);
 	if (tu->qused > 0) {
 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
 		r = &tu->queue[prev];
@@ -1348,7 +1299,6 @@ static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
 		tu->qused++;
 	}
       __wake:
-	spin_unlock(&tu->qlock);
 	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
 	wake_up(&tu->qchange_sleep);
 }
@@ -1372,7 +1322,6 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
 {
 	struct snd_timer_user *tu = timeri->callback_data;
 	struct snd_timer_tread64 r1;
-	unsigned long flags;
 
 	if (event >= SNDRV_TIMER_EVENT_START &&
 	    event <= SNDRV_TIMER_EVENT_PAUSE)
@@ -1384,9 +1333,8 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
 	r1.tstamp_sec = tstamp->tv_sec;
 	r1.tstamp_nsec = tstamp->tv_nsec;
 	r1.val = resolution;
-	spin_lock_irqsave(&tu->qlock, flags);
-	snd_timer_user_append_to_tqueue(tu, &r1);
-	spin_unlock_irqrestore(&tu->qlock, flags);
+	scoped_guard(spinlock_irqsave, &tu->qlock)
+		snd_timer_user_append_to_tqueue(tu, &r1);
 	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
 	wake_up(&tu->qchange_sleep);
 }
@@ -1410,51 +1358,48 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
 
 	memset(&r1, 0, sizeof(r1));
 	memset(&tstamp, 0, sizeof(tstamp));
-	spin_lock(&tu->qlock);
-	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
-			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
-		spin_unlock(&tu->qlock);
-		return;
-	}
-	if (tu->last_resolution != resolution || ticks > 0) {
-		if (timer_tstamp_monotonic)
-			ktime_get_ts64(&tstamp);
-		else
-			ktime_get_real_ts64(&tstamp);
-	}
-	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
-	    tu->last_resolution != resolution) {
-		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
+	scoped_guard(spinlock, &tu->qlock) {
+		if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
+				   (1 << SNDRV_TIMER_EVENT_TICK))) == 0)
+			return;
+		if (tu->last_resolution != resolution || ticks > 0) {
+			if (timer_tstamp_monotonic)
+				ktime_get_ts64(&tstamp);
+			else
+				ktime_get_real_ts64(&tstamp);
+		}
+		if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
+		    tu->last_resolution != resolution) {
+			r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
+			r1.tstamp_sec = tstamp.tv_sec;
+			r1.tstamp_nsec = tstamp.tv_nsec;
+			r1.val = resolution;
+			snd_timer_user_append_to_tqueue(tu, &r1);
+			tu->last_resolution = resolution;
+			append++;
+		}
+		if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
+			break;
+		if (ticks == 0)
+			break;
+		if (tu->qused > 0) {
+			prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
+			r = &tu->tqueue[prev];
+			if (r->event == SNDRV_TIMER_EVENT_TICK) {
+				r->tstamp_sec = tstamp.tv_sec;
+				r->tstamp_nsec = tstamp.tv_nsec;
+				r->val += ticks;
+				append++;
+				break;
+			}
+		}
+		r1.event = SNDRV_TIMER_EVENT_TICK;
 		r1.tstamp_sec = tstamp.tv_sec;
 		r1.tstamp_nsec = tstamp.tv_nsec;
-		r1.val = resolution;
+		r1.val = ticks;
 		snd_timer_user_append_to_tqueue(tu, &r1);
-		tu->last_resolution = resolution;
 		append++;
 	}
-	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
-		goto __wake;
-	if (ticks == 0)
-		goto __wake;
-	if (tu->qused > 0) {
-		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
-		r = &tu->tqueue[prev];
-		if (r->event == SNDRV_TIMER_EVENT_TICK) {
-			r->tstamp_sec = tstamp.tv_sec;
-			r->tstamp_nsec = tstamp.tv_nsec;
-			r->val += ticks;
-			append++;
-			goto __wake;
-		}
-	}
-	r1.event = SNDRV_TIMER_EVENT_TICK;
-	r1.tstamp_sec = tstamp.tv_sec;
-	r1.tstamp_nsec = tstamp.tv_nsec;
-	r1.val = ticks;
-	snd_timer_user_append_to_tqueue(tu, &r1);
-	append++;
-      __wake:
-	spin_unlock(&tu->qlock);
 	if (append == 0)
 		return;
 	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
@@ -1476,14 +1421,13 @@ static int realloc_user_queue(struct snd_timer_user *tu, int size)
 			return -ENOMEM;
 	}
 
-	spin_lock_irq(&tu->qlock);
+	guard(spinlock_irq)(&tu->qlock);
 	kfree(tu->queue);
 	kfree(tu->tqueue);
 	tu->queue_size = size;
 	tu->queue = queue;
 	tu->tqueue = tqueue;
 	tu->qhead = tu->qtail = tu->qused = 0;
-	spin_unlock_irq(&tu->qlock);
 
 	return 0;
 }
@@ -1519,12 +1463,12 @@ static int snd_timer_user_release(struct inode *inode, struct file *file)
 	if (file->private_data) {
 		tu = file->private_data;
 		file->private_data = NULL;
-		mutex_lock(&tu->ioctl_lock);
-		if (tu->timeri) {
-			snd_timer_close(tu->timeri);
-			snd_timer_instance_free(tu->timeri);
+		scoped_guard(mutex, &tu->ioctl_lock) {
+			if (tu->timeri) {
+				snd_timer_close(tu->timeri);
+				snd_timer_instance_free(tu->timeri);
+			}
 		}
-		mutex_unlock(&tu->ioctl_lock);
 		snd_fasync_free(tu->fasync);
 		kfree(tu->queue);
 		kfree(tu->tqueue);
@@ -1559,7 +1503,7 @@ static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
 
 	if (copy_from_user(&id, _tid, sizeof(id)))
 		return -EFAULT;
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	if (id.dev_class < 0) {		/* first item */
 		if (list_empty(&snd_timer_list))
 			snd_timer_user_zero_id(&id);
@@ -1636,7 +1580,6 @@ static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
 			snd_timer_user_zero_id(&id);
 		}
 	}
-	mutex_unlock(&register_mutex);
 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
 		return -EFAULT;
 	return 0;
@@ -1649,7 +1592,6 @@ static int snd_timer_user_ginfo(struct file *file,
 	struct snd_timer_id tid;
 	struct snd_timer *t;
 	struct list_head *p;
-	int err = 0;
 
 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
 	if (IS_ERR(ginfo))
@@ -1658,56 +1600,42 @@ static int snd_timer_user_ginfo(struct file *file,
 	tid = ginfo->tid;
 	memset(ginfo, 0, sizeof(*ginfo));
 	ginfo->tid = tid;
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	t = snd_timer_find(&tid);
-	if (t != NULL) {
-		ginfo->card = t->card ? t->card->number : -1;
-		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
-			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
-		strscpy(ginfo->id, t->id, sizeof(ginfo->id));
-		strscpy(ginfo->name, t->name, sizeof(ginfo->name));
-		spin_lock_irq(&t->lock);
+	if (!t)
+		return -ENODEV;
+	ginfo->card = t->card ? t->card->number : -1;
+	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
+	strscpy(ginfo->id, t->id, sizeof(ginfo->id));
+	strscpy(ginfo->name, t->name, sizeof(ginfo->name));
+	scoped_guard(spinlock_irq, &t->lock)
 		ginfo->resolution = snd_timer_hw_resolution(t);
-		spin_unlock_irq(&t->lock);
-		if (t->hw.resolution_min > 0) {
-			ginfo->resolution_min = t->hw.resolution_min;
-			ginfo->resolution_max = t->hw.resolution_max;
-		}
-		list_for_each(p, &t->open_list_head) {
-			ginfo->clients++;
-		}
-	} else {
-		err = -ENODEV;
+	if (t->hw.resolution_min > 0) {
+		ginfo->resolution_min = t->hw.resolution_min;
+		ginfo->resolution_max = t->hw.resolution_max;
 	}
-	mutex_unlock(&register_mutex);
-	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
-		err = -EFAULT;
-	return err;
+	list_for_each(p, &t->open_list_head) {
+		ginfo->clients++;
+	}
+	if (copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
+		return -EFAULT;
+	return 0;
 }
 
 static int timer_set_gparams(struct snd_timer_gparams *gparams)
 {
 	struct snd_timer *t;
-	int err;
 
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	t = snd_timer_find(&gparams->tid);
-	if (!t) {
-		err = -ENODEV;
-		goto _error;
-	}
-	if (!list_empty(&t->open_list_head)) {
-		err = -EBUSY;
-		goto _error;
-	}
-	if (!t->hw.set_period) {
-		err = -ENOSYS;
-		goto _error;
-	}
-	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
-_error:
-	mutex_unlock(&register_mutex);
-	return err;
+	if (!t)
+		return -ENODEV;
+	if (!list_empty(&t->open_list_head))
+		return -EBUSY;
+	if (!t->hw.set_period)
+		return -ENOSYS;
+	return t->hw.set_period(t, gparams->period_num, gparams->period_den);
 }
 
 static int snd_timer_user_gparams(struct file *file,
@@ -1733,10 +1661,10 @@ static int snd_timer_user_gstatus(struct file *file,
 	tid = gstatus.tid;
 	memset(&gstatus, 0, sizeof(gstatus));
 	gstatus.tid = tid;
-	mutex_lock(&register_mutex);
+	guard(mutex)(&register_mutex);
 	t = snd_timer_find(&tid);
 	if (t != NULL) {
-		spin_lock_irq(&t->lock);
+		guard(spinlock_irq)(&t->lock);
 		gstatus.resolution = snd_timer_hw_resolution(t);
 		if (t->hw.precise_resolution) {
 			t->hw.precise_resolution(t, &gstatus.resolution_num,
@@ -1745,11 +1673,9 @@ static int snd_timer_user_gstatus(struct file *file,
 			gstatus.resolution_num = gstatus.resolution;
 			gstatus.resolution_den = 1000000000uL;
 		}
-		spin_unlock_irq(&t->lock);
 	} else {
 		err = -ENODEV;
 	}
-	mutex_unlock(&register_mutex);
 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
 		err = -EFAULT;
 	return err;
@@ -1821,9 +1747,8 @@ static int snd_timer_user_info(struct file *file,
 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
 	strscpy(info->id, t->id, sizeof(info->id));
 	strscpy(info->name, t->name, sizeof(info->name));
-	spin_lock_irq(&t->lock);
-	info->resolution = snd_timer_hw_resolution(t);
-	spin_unlock_irq(&t->lock);
+	scoped_guard(spinlock_irq, &t->lock)
+		info->resolution = snd_timer_hw_resolution(t);
 	if (copy_to_user(_info, info, sizeof(*_info)))
 		return -EFAULT;
 	return 0;
@@ -1884,45 +1809,47 @@ static int snd_timer_user_params(struct file *file,
 		goto _end;
 	}
 	snd_timer_stop(tu->timeri);
-	spin_lock_irq(&t->lock);
-	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
-			       SNDRV_TIMER_IFLG_EXCLUSIVE|
-			       SNDRV_TIMER_IFLG_EARLY_EVENT);
-	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
-		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
-	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
-		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
-	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
-		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
-	spin_unlock_irq(&t->lock);
+	scoped_guard(spinlock_irq, &t->lock) {
+		tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
+				       SNDRV_TIMER_IFLG_EXCLUSIVE|
+				       SNDRV_TIMER_IFLG_EARLY_EVENT);
+		if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
+			tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
+		if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
+			tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
+		if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
+			tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
+	}
 	if (params.queue_size > 0 &&
 	    (unsigned int)tu->queue_size != params.queue_size) {
 		err = realloc_user_queue(tu, params.queue_size);
 		if (err < 0)
 			goto _end;
 	}
-	spin_lock_irq(&tu->qlock);
-	tu->qhead = tu->qtail = tu->qused = 0;
-	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
-		if (tu->tread) {
-			struct snd_timer_tread64 tread;
-			memset(&tread, 0, sizeof(tread));
-			tread.event = SNDRV_TIMER_EVENT_EARLY;
-			tread.tstamp_sec = 0;
-			tread.tstamp_nsec = 0;
-			tread.val = 0;
-			snd_timer_user_append_to_tqueue(tu, &tread);
-		} else {
-			struct snd_timer_read *r = &tu->queue[0];
-			r->resolution = 0;
-			r->ticks = 0;
-			tu->qused++;
-			tu->qtail++;
+	scoped_guard(spinlock_irq, &tu->qlock) {
+		tu->qhead = tu->qtail = tu->qused = 0;
+		if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
+			if (tu->tread) {
+				struct snd_timer_tread64 tread;
+
+				memset(&tread, 0, sizeof(tread));
+				tread.event = SNDRV_TIMER_EVENT_EARLY;
+				tread.tstamp_sec = 0;
+				tread.tstamp_nsec = 0;
+				tread.val = 0;
+				snd_timer_user_append_to_tqueue(tu, &tread);
+			} else {
+				struct snd_timer_read *r = &tu->queue[0];
+
+				r->resolution = 0;
+				r->ticks = 0;
+				tu->qused++;
+				tu->qtail++;
+			}
 		}
+		tu->filter = params.filter;
+		tu->ticks = params.ticks;
 	}
-	tu->filter = params.filter;
-	tu->ticks = params.ticks;
-	spin_unlock_irq(&tu->qlock);
 	err = 0;
  _end:
 	if (copy_to_user(_params, &params, sizeof(params)))
@@ -1945,9 +1872,8 @@ static int snd_timer_user_status32(struct file *file,
 	status.resolution = snd_timer_resolution(tu->timeri);
 	status.lost = tu->timeri->lost;
 	status.overrun = tu->overrun;
-	spin_lock_irq(&tu->qlock);
-	status.queue = tu->qused;
-	spin_unlock_irq(&tu->qlock);
+	scoped_guard(spinlock_irq, &tu->qlock)
+		status.queue = tu->qused;
 	if (copy_to_user(_status, &status, sizeof(status)))
 		return -EFAULT;
 	return 0;
@@ -1968,9 +1894,8 @@ static int snd_timer_user_status64(struct file *file,
 	status.resolution = snd_timer_resolution(tu->timeri);
 	status.lost = tu->timeri->lost;
 	status.overrun = tu->overrun;
-	spin_lock_irq(&tu->qlock);
-	status.queue = tu->qused;
-	spin_unlock_irq(&tu->qlock);
+	scoped_guard(spinlock_irq, &tu->qlock)
+		status.queue = tu->qused;
 	if (copy_to_user(_status, &status, sizeof(status)))
 		return -EFAULT;
 	return 0;
@@ -2128,12 +2053,9 @@ static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
 				 unsigned long arg)
 {
 	struct snd_timer_user *tu = file->private_data;
-	long ret;
 
-	mutex_lock(&tu->ioctl_lock);
-	ret = __snd_timer_user_ioctl(file, cmd, arg, false);
-	mutex_unlock(&tu->ioctl_lock);
-	return ret;
+	guard(mutex)(&tu->ioctl_lock);
+	return __snd_timer_user_ioctl(file, cmd, arg, false);
 }
 
 static int snd_timer_user_fasync(int fd, struct file * file, int on)
@@ -2260,12 +2182,11 @@ static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
         poll_wait(file, &tu->qchange_sleep, wait);
 
 	mask = 0;
-	spin_lock_irq(&tu->qlock);
+	guard(spinlock_irq)(&tu->qlock);
 	if (tu->qused)
 		mask |= EPOLLIN | EPOLLRDNORM;
 	if (tu->disconnected)
 		mask |= EPOLLERR;
-	spin_unlock_irq(&tu->qlock);
 
 	return mask;
 }
diff --git a/sound/core/timer_compat.c b/sound/core/timer_compat.c
index ee973b7b804499..4ae9eaeb5afb1a 100644
--- a/sound/core/timer_compat.c
+++ b/sound/core/timer_compat.c
@@ -115,10 +115,7 @@ static long snd_timer_user_ioctl_compat(struct file *file, unsigned int cmd,
 					unsigned long arg)
 {
 	struct snd_timer_user *tu = file->private_data;
-	long ret;
 
-	mutex_lock(&tu->ioctl_lock);
-	ret = __snd_timer_user_ioctl_compat(file, cmd, arg);
-	mutex_unlock(&tu->ioctl_lock);
-	return ret;
+	guard(mutex)(&tu->ioctl_lock);
+	return __snd_timer_user_ioctl_compat(file, cmd, arg);
 }