From: Takashi Iwai <tiwai@suse.de>
Date: Thu, 28 Aug 2025 13:27:11 +0000 (+0200)
Subject: ALSA: firewire: tascam: Use guard() for mutex locks
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=61a5f22fb15129a90d3be6a32ce8131cb84db002;p=users%2Fhch%2Fmisc.git

ALSA: firewire: tascam: Use guard() for mutex locks

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

Only code refactoring, and no behavior change.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250828132802.9032-8-tiwai@suse.de
---

diff --git a/sound/firewire/tascam/tascam-pcm.c b/sound/firewire/tascam/tascam-pcm.c
index a73003ac11e6..d885fef0c8ca 100644
--- a/sound/firewire/tascam/tascam-pcm.c
+++ b/sound/firewire/tascam/tascam-pcm.c
@@ -59,43 +59,35 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	if (err < 0)
 		goto err_locked;
 
-	mutex_lock(&tscm->mutex);
-
-	// When source of clock is not internal or any stream is reserved for
-	// transmission of PCM frames, the available sampling rate is limited
-	// at current one.
-	if (clock != SND_TSCM_CLOCK_INTERNAL || tscm->substreams_counter > 0) {
-		unsigned int frames_per_period = d->events_per_period;
-		unsigned int frames_per_buffer = d->events_per_buffer;
-		unsigned int rate;
-
-		err = snd_tscm_stream_get_rate(tscm, &rate);
-		if (err < 0) {
-			mutex_unlock(&tscm->mutex);
-			goto err_locked;
-		}
-		substream->runtime->hw.rate_min = rate;
-		substream->runtime->hw.rate_max = rate;
-
-		err = snd_pcm_hw_constraint_minmax(substream->runtime,
-					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
-					frames_per_period, frames_per_period);
-		if (err < 0) {
-			mutex_unlock(&tscm->mutex);
-			goto err_locked;
-		}
-
-		err = snd_pcm_hw_constraint_minmax(substream->runtime,
-					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
-					frames_per_buffer, frames_per_buffer);
-		if (err < 0) {
-			mutex_unlock(&tscm->mutex);
-			goto err_locked;
+	scoped_guard(mutex, &tscm->mutex) {
+		// When source of clock is not internal or any stream is reserved for
+		// transmission of PCM frames, the available sampling rate is limited
+		// at current one.
+		if (clock != SND_TSCM_CLOCK_INTERNAL || tscm->substreams_counter > 0) {
+			unsigned int frames_per_period = d->events_per_period;
+			unsigned int frames_per_buffer = d->events_per_buffer;
+			unsigned int rate;
+
+			err = snd_tscm_stream_get_rate(tscm, &rate);
+			if (err < 0)
+				goto err_locked;
+			substream->runtime->hw.rate_min = rate;
+			substream->runtime->hw.rate_max = rate;
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+							   SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+							   frames_per_period, frames_per_period);
+			if (err < 0)
+				goto err_locked;
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+							   SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+							   frames_per_buffer, frames_per_buffer);
+			if (err < 0)
+				goto err_locked;
 		}
 	}
 
-	mutex_unlock(&tscm->mutex);
-
 	snd_pcm_set_sync(substream);
 
 	return 0;
@@ -124,12 +116,11 @@ static int pcm_hw_params(struct snd_pcm_substream *substream,
 		unsigned int frames_per_period = params_period_size(hw_params);
 		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
-		mutex_lock(&tscm->mutex);
+		guard(mutex)(&tscm->mutex);
 		err = snd_tscm_stream_reserve_duplex(tscm, rate,
 					frames_per_period, frames_per_buffer);
 		if (err >= 0)
 			++tscm->substreams_counter;
-		mutex_unlock(&tscm->mutex);
 	}
 
 	return err;
@@ -139,15 +130,13 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_tscm *tscm = substream->private_data;
 
-	mutex_lock(&tscm->mutex);
+	guard(mutex)(&tscm->mutex);
 
 	if (substream->runtime->state != SNDRV_PCM_STATE_OPEN)
 		--tscm->substreams_counter;
 
 	snd_tscm_stream_stop_duplex(tscm);
 
-	mutex_unlock(&tscm->mutex);
-
 	return 0;
 }
 
@@ -157,14 +146,12 @@ static int pcm_capture_prepare(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;
 
-	mutex_lock(&tscm->mutex);
+	guard(mutex)(&tscm->mutex);
 
 	err = snd_tscm_stream_start_duplex(tscm, runtime->rate);
 	if (err >= 0)
 		amdtp_stream_pcm_prepare(&tscm->tx_stream);
 
-	mutex_unlock(&tscm->mutex);
-
 	return err;
 }
 
@@ -174,14 +161,12 @@ static int pcm_playback_prepare(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;
 
-	mutex_lock(&tscm->mutex);
+	guard(mutex)(&tscm->mutex);
 
 	err = snd_tscm_stream_start_duplex(tscm, runtime->rate);
 	if (err >= 0)
 		amdtp_stream_pcm_prepare(&tscm->rx_stream);
 
-	mutex_unlock(&tscm->mutex);
-
 	return err;
 }
 
diff --git a/sound/firewire/tascam/tascam.c b/sound/firewire/tascam/tascam.c
index 4f68bb4c58bc..f4092df8650c 100644
--- a/sound/firewire/tascam/tascam.c
+++ b/sound/firewire/tascam/tascam.c
@@ -158,9 +158,8 @@ static void snd_tscm_update(struct fw_unit *unit)
 
 	snd_tscm_transaction_reregister(tscm);
 
-	mutex_lock(&tscm->mutex);
+	guard(mutex)(&tscm->mutex);
 	snd_tscm_stream_update_duplex(tscm);
-	mutex_unlock(&tscm->mutex);
 }
 
 static void snd_tscm_remove(struct fw_unit *unit)