ALSA: firewire: fireworks: 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 <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

sound/firewire/fireworks/fireworks.c

···
 {
 	struct snd_efw *efw = card->private_data;
 
-	mutex_lock(&devices_mutex);
-	clear_bit(efw->card_index, devices_used);
-	mutex_unlock(&devices_mutex);
+	scoped_guard(mutex, &devices_mutex) {
+		clear_bit(efw->card_index, devices_used);
+	}
 
 	snd_efw_stream_destroy_duplex(efw);
 	snd_efw_transaction_remove_instance(efw);
···
 	int err;
 
 	// check registered cards.
-	mutex_lock(&devices_mutex);
-	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index) {
-		if (!test_bit(card_index, devices_used) && enable[card_index])
-			break;
-	}
-	if (card_index >= SNDRV_CARDS) {
-		mutex_unlock(&devices_mutex);
-		return -ENOENT;
-	}
+	scoped_guard(mutex, &devices_mutex) {
+		for (card_index = 0; card_index < SNDRV_CARDS; ++card_index) {
+			if (!test_bit(card_index, devices_used) && enable[card_index])
+				break;
+		}
+		if (card_index >= SNDRV_CARDS)
+			return -ENOENT;
 
-	err = snd_card_new(&unit->device, index[card_index], id[card_index], THIS_MODULE,
-			   sizeof(*efw), &card);
-	if (err < 0) {
-		mutex_unlock(&devices_mutex);
-		return err;
+		err = snd_card_new(&unit->device, index[card_index], id[card_index], THIS_MODULE,
+				   sizeof(*efw), &card);
+		if (err < 0)
+			return err;
+		card->private_free = efw_card_free;
+		set_bit(card_index, devices_used);
 	}
-	card->private_free = efw_card_free;
-	set_bit(card_index, devices_used);
-	mutex_unlock(&devices_mutex);
 
 	efw = card->private_data;
 	efw->unit = fw_unit_get(unit);
···
 
 	snd_efw_transaction_bus_reset(efw->unit);
 
-	mutex_lock(&efw->mutex);
+	guard(mutex)(&efw->mutex);
 	snd_efw_stream_update_duplex(efw);
-	mutex_unlock(&efw->mutex);
 }
 
 static void efw_remove(struct fw_unit *unit)

sound/firewire/fireworks/fireworks_midi.c

···
 
 	err = snd_efw_stream_lock_try(efw);
 	if (err < 0)
-		goto end;
+		return err;
 
-	mutex_lock(&efw->mutex);
-	err = snd_efw_stream_reserve_duplex(efw, 0, 0, 0);
-	if (err >= 0) {
-		++efw->substreams_counter;
-		err = snd_efw_stream_start_duplex(efw);
-		if (err < 0)
-			--efw->substreams_counter;
+	scoped_guard(mutex, &efw->mutex) {
+		err = snd_efw_stream_reserve_duplex(efw, 0, 0, 0);
+		if (err >= 0) {
+			++efw->substreams_counter;
+			err = snd_efw_stream_start_duplex(efw);
+			if (err < 0)
+				--efw->substreams_counter;
+		}
 	}
-	mutex_unlock(&efw->mutex);
 	if (err < 0)
 		snd_efw_stream_lock_release(efw);
-end:
 	return err;
 }
 
···
 {
 	struct snd_efw *efw = substream->rmidi->private_data;
 
-	mutex_lock(&efw->mutex);
-	--efw->substreams_counter;
-	snd_efw_stream_stop_duplex(efw);
-	mutex_unlock(&efw->mutex);
+	scoped_guard(mutex, &efw->mutex) {
+		--efw->substreams_counter;
+		snd_efw_stream_stop_duplex(efw);
+	}
 
 	snd_efw_stream_lock_release(efw);
 	return 0;

sound/firewire/fireworks/fireworks_pcm.c

···
 	if (err < 0)
 		goto err_locked;
 
-	mutex_lock(&efw->mutex);
+	scoped_guard(mutex, &efw->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_source != SND_EFW_CLOCK_SOURCE_INTERNAL) ||
+		    (efw->substreams_counter > 0 && d->events_per_period > 0)) {
+			unsigned int frames_per_period = d->events_per_period;
+			unsigned int frames_per_buffer = d->events_per_buffer;
+			unsigned int sampling_rate;
 
-	// 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_source != SND_EFW_CLOCK_SOURCE_INTERNAL) ||
-	    (efw->substreams_counter > 0 && d->events_per_period > 0)) {
-		unsigned int frames_per_period = d->events_per_period;
-		unsigned int frames_per_buffer = d->events_per_buffer;
-		unsigned int sampling_rate;
-
-		err = snd_efw_command_get_sampling_rate(efw, &sampling_rate);
-		if (err < 0) {
-			mutex_unlock(&efw->mutex);
-			goto err_locked;
-		}
-		substream->runtime->hw.rate_min = sampling_rate;
-		substream->runtime->hw.rate_max = sampling_rate;
-
-		if (frames_per_period > 0) {
-			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(&efw->mutex);
+			err = snd_efw_command_get_sampling_rate(efw, &sampling_rate);
+			if (err < 0)
 				goto err_locked;
-			}
+			substream->runtime->hw.rate_min = sampling_rate;
+			substream->runtime->hw.rate_max = sampling_rate;
 
-			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(&efw->mutex);
-				goto err_locked;
+			if (frames_per_period > 0) {
+				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(&efw->mutex);
 
 	snd_pcm_set_sync(substream);
 
···
 		unsigned int frames_per_period = params_period_size(hw_params);
 		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
-		mutex_lock(&efw->mutex);
+		guard(mutex)(&efw->mutex);
 		err = snd_efw_stream_reserve_duplex(efw, rate,
 					frames_per_period, frames_per_buffer);
 		if (err >= 0)
 			++efw->substreams_counter;
-		mutex_unlock(&efw->mutex);
 	}
 
 	return err;
···
 {
 	struct snd_efw *efw = substream->private_data;
 
-	mutex_lock(&efw->mutex);
+	guard(mutex)(&efw->mutex);
 
 	if (substream->runtime->state != SNDRV_PCM_STATE_OPEN)
 		--efw->substreams_counter;
 
 	snd_efw_stream_stop_duplex(efw);
-
-	mutex_unlock(&efw->mutex);
 
 	return 0;
 }