From: Takashi Iwai <tiwai@suse.de>
Date: Fri, 29 Aug 2025 15:00:13 +0000 (+0200)
Subject: ALSA: aloop: Use guard() for spin locks
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1ef2cb6b29c2c9c26b490ab5a1e8161923fb7798;p=users%2Fhch%2Fmisc.git

ALSA: aloop: Use guard() for spin locks

Clean up the code using guard() for spin locks.

Merely code refactoring, and no behavior change.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250829150026.6379-3-tiwai@suse.de
---

diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 79e7f03e51e9..64ef03b2d579 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -414,39 +414,39 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 		dpcm->last_jiffies = jiffies;
 		dpcm->pcm_rate_shift = 0;
 		dpcm->last_drift = 0;
-		spin_lock(&cable->lock);	
-		cable->running |= stream;
-		cable->pause &= ~stream;
-		err = cable->ops->start(dpcm);
-		spin_unlock(&cable->lock);
+		scoped_guard(spinlock, &cable->lock) {
+			cable->running |= stream;
+			cable->pause &= ~stream;
+			err = cable->ops->start(dpcm);
+		}
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			loopback_active_notify(dpcm);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
-		spin_lock(&cable->lock);	
-		cable->running &= ~stream;
-		cable->pause &= ~stream;
-		err = cable->ops->stop(dpcm);
-		spin_unlock(&cable->lock);
+		scoped_guard(spinlock, &cable->lock) {
+			cable->running &= ~stream;
+			cable->pause &= ~stream;
+			err = cable->ops->stop(dpcm);
+		}
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			loopback_active_notify(dpcm);
 		break;
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
-		spin_lock(&cable->lock);	
-		cable->pause |= stream;
-		err = cable->ops->stop(dpcm);
-		spin_unlock(&cable->lock);
+		scoped_guard(spinlock, &cable->lock) {
+			cable->pause |= stream;
+			err = cable->ops->stop(dpcm);
+		}
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			loopback_active_notify(dpcm);
 		break;
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 	case SNDRV_PCM_TRIGGER_RESUME:
-		spin_lock(&cable->lock);
-		dpcm->last_jiffies = jiffies;
-		cable->pause &= ~stream;
-		err = cable->ops->start(dpcm);
-		spin_unlock(&cable->lock);
+		scoped_guard(spinlock, &cable->lock) {
+			dpcm->last_jiffies = jiffies;
+			cable->pause &= ~stream;
+			err = cable->ops->start(dpcm);
+		}
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			loopback_active_notify(dpcm);
 		break;
@@ -700,21 +700,22 @@ static unsigned int loopback_jiffies_timer_pos_update
 static void loopback_jiffies_timer_function(struct timer_list *t)
 {
 	struct loopback_pcm *dpcm = timer_container_of(dpcm, t, timer);
-	unsigned long flags;
-
-	spin_lock_irqsave(&dpcm->cable->lock, flags);
-	if (loopback_jiffies_timer_pos_update(dpcm->cable) &
-			(1 << dpcm->substream->stream)) {
-		loopback_jiffies_timer_start(dpcm);
-		if (dpcm->period_update_pending) {
-			dpcm->period_update_pending = 0;
-			spin_unlock_irqrestore(&dpcm->cable->lock, flags);
-			/* need to unlock before calling below */
-			snd_pcm_period_elapsed(dpcm->substream);
-			return;
+	bool period_elapsed = false;
+
+	scoped_guard(spinlock_irqsave, &dpcm->cable->lock) {
+		if (loopback_jiffies_timer_pos_update(dpcm->cable) &
+		    (1 << dpcm->substream->stream)) {
+			loopback_jiffies_timer_start(dpcm);
+			if (dpcm->period_update_pending) {
+				dpcm->period_update_pending = 0;
+				period_elapsed = true;
+				break;
+			}
 		}
 	}
-	spin_unlock_irqrestore(&dpcm->cable->lock, flags);
+
+	if (period_elapsed)
+		snd_pcm_period_elapsed(dpcm->substream);
 }
 
 /* call in cable->lock */
@@ -759,68 +760,68 @@ static void loopback_snd_timer_period_elapsed(struct loopback_cable *cable,
 	struct snd_pcm_substream *substream_play, *substream_capt;
 	struct snd_pcm_runtime *valid_runtime;
 	unsigned int running, elapsed_bytes;
-	unsigned long flags;
+	bool xrun = false;
 
-	spin_lock_irqsave(&cable->lock, flags);
-	running = cable->running ^ cable->pause;
-	/* no need to do anything if no stream is running */
-	if (!running) {
-		spin_unlock_irqrestore(&cable->lock, flags);
-		return;
-	}
+	scoped_guard(spinlock_irqsave, &cable->lock) {
+		running = cable->running ^ cable->pause;
+		/* no need to do anything if no stream is running */
+		if (!running)
+			return;
 
-	dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
-	dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE];
+		dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
+		dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 
-	if (event == SNDRV_TIMER_EVENT_MSTOP) {
-		if (!dpcm_play ||
-		    dpcm_play->substream->runtime->state !=
-				SNDRV_PCM_STATE_DRAINING) {
-			spin_unlock_irqrestore(&cable->lock, flags);
-			return;
+		if (event == SNDRV_TIMER_EVENT_MSTOP) {
+			if (!dpcm_play ||
+			    dpcm_play->substream->runtime->state !=
+			    SNDRV_PCM_STATE_DRAINING)
+				return;
 		}
-	}
 
-	substream_play = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
+		substream_play = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 			dpcm_play->substream : NULL;
-	substream_capt = (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) ?
+		substream_capt = (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) ?
 			dpcm_capt->substream : NULL;
-	valid_runtime = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
-				dpcm_play->substream->runtime :
-				dpcm_capt->substream->runtime;
-
-	/* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */
-	if (event == SNDRV_TIMER_EVENT_TICK) {
-		/* The hardware rules guarantee that playback and capture period
-		 * are the same. Therefore only one device has to be checked
-		 * here.
-		 */
-		if (loopback_snd_timer_check_resolution(valid_runtime,
-							resolution) < 0) {
-			spin_unlock_irqrestore(&cable->lock, flags);
-			if (substream_play)
-				snd_pcm_stop_xrun(substream_play);
-			if (substream_capt)
-				snd_pcm_stop_xrun(substream_capt);
-			return;
+		valid_runtime = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
+			dpcm_play->substream->runtime :
+			dpcm_capt->substream->runtime;
+
+		/* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */
+		if (event == SNDRV_TIMER_EVENT_TICK) {
+			/* The hardware rules guarantee that playback and capture period
+			 * are the same. Therefore only one device has to be checked
+			 * here.
+			 */
+			if (loopback_snd_timer_check_resolution(valid_runtime,
+								resolution) < 0) {
+				xrun = true;
+				break;
+			}
+		}
+
+		elapsed_bytes = frames_to_bytes(valid_runtime,
+						valid_runtime->period_size);
+		/* The same timer interrupt is used for playback and capture device */
+		if ((running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) &&
+		    (running & (1 << SNDRV_PCM_STREAM_CAPTURE))) {
+			copy_play_buf(dpcm_play, dpcm_capt, elapsed_bytes);
+			bytepos_finish(dpcm_play, elapsed_bytes);
+			bytepos_finish(dpcm_capt, elapsed_bytes);
+		} else if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
+			bytepos_finish(dpcm_play, elapsed_bytes);
+		} else if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
+			clear_capture_buf(dpcm_capt, elapsed_bytes);
+			bytepos_finish(dpcm_capt, elapsed_bytes);
 		}
 	}
 
-	elapsed_bytes = frames_to_bytes(valid_runtime,
-					valid_runtime->period_size);
-	/* The same timer interrupt is used for playback and capture device */
-	if ((running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) &&
-	    (running & (1 << SNDRV_PCM_STREAM_CAPTURE))) {
-		copy_play_buf(dpcm_play, dpcm_capt, elapsed_bytes);
-		bytepos_finish(dpcm_play, elapsed_bytes);
-		bytepos_finish(dpcm_capt, elapsed_bytes);
-	} else if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
-		bytepos_finish(dpcm_play, elapsed_bytes);
-	} else if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
-		clear_capture_buf(dpcm_capt, elapsed_bytes);
-		bytepos_finish(dpcm_capt, elapsed_bytes);
+	if (xrun) {
+		if (substream_play)
+			snd_pcm_stop_xrun(substream_play);
+		if (substream_capt)
+			snd_pcm_stop_xrun(substream_capt);
+		return;
 	}
-	spin_unlock_irqrestore(&cable->lock, flags);
 
 	if (substream_play)
 		snd_pcm_period_elapsed(substream_play);
@@ -909,11 +910,10 @@ static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 	struct loopback_pcm *dpcm = runtime->private_data;
 	snd_pcm_uframes_t pos;
 
-	spin_lock(&dpcm->cable->lock);
+	guard(spinlock)(&dpcm->cable->lock);
 	if (dpcm->cable->ops->pos_update)
 		dpcm->cable->ops->pos_update(dpcm->cable);
 	pos = dpcm->buf_pos;
-	spin_unlock(&dpcm->cable->lock);
 	return bytes_to_frames(runtime, pos);
 }
 
@@ -1045,9 +1045,8 @@ static void free_cable(struct snd_pcm_substream *substream)
 		return;
 	if (cable->streams[!substream->stream]) {
 		/* other stream is still alive */
-		spin_lock_irq(&cable->lock);
+		guard(spinlock_irq)(&cable->lock);
 		cable->streams[substream->stream] = NULL;
-		spin_unlock_irq(&cable->lock);
 	} else {
 		struct loopback_pcm *dpcm = substream->runtime->private_data;
 
@@ -1313,9 +1312,9 @@ static int loopback_open(struct snd_pcm_substream *substream)
 	else
 		runtime->hw = cable->hw;
 
-	spin_lock_irq(&cable->lock);
-	cable->streams[substream->stream] = dpcm;
-	spin_unlock_irq(&cable->lock);
+	scoped_guard(spinlock_irq, &cable->lock) {
+		cable->streams[substream->stream] = dpcm;
+	}
 
  unlock:
 	if (err < 0) {