ALSA: firewire: digi00x: 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/digi00x/digi00x-midi.c

···
 	if (err < 0)
 		return err;
 
-	mutex_lock(&dg00x->mutex);
-	err = snd_dg00x_stream_reserve_duplex(dg00x, 0, 0, 0);
-	if (err >= 0) {
-		++dg00x->substreams_counter;
-		err = snd_dg00x_stream_start_duplex(dg00x);
-		if (err < 0)
-			--dg00x->substreams_counter;
+	scoped_guard(mutex, &dg00x->mutex) {
+		err = snd_dg00x_stream_reserve_duplex(dg00x, 0, 0, 0);
+		if (err >= 0) {
+			++dg00x->substreams_counter;
+			err = snd_dg00x_stream_start_duplex(dg00x);
+			if (err < 0)
+				--dg00x->substreams_counter;
+		}
 	}
-	mutex_unlock(&dg00x->mutex);
 	if (err < 0)
 		snd_dg00x_stream_lock_release(dg00x);
 
···
 {
 	struct snd_dg00x *dg00x = substream->rmidi->private_data;
 
-	mutex_lock(&dg00x->mutex);
-	--dg00x->substreams_counter;
-	snd_dg00x_stream_stop_duplex(dg00x);
-	mutex_unlock(&dg00x->mutex);
+	scoped_guard(mutex, &dg00x->mutex) {
+		--dg00x->substreams_counter;
+		snd_dg00x_stream_stop_duplex(dg00x);
+	}
 
 	snd_dg00x_stream_lock_release(dg00x);
 	return 0;

sound/firewire/digi00x/digi00x-pcm.c

···
 		}
 	}
 
-	mutex_lock(&dg00x->mutex);
+	scoped_guard(mutex, &dg00x->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_DG00X_CLOCK_INTERNAL) ||
+		    (dg00x->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 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 != SND_DG00X_CLOCK_INTERNAL) ||
-	    (dg00x->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 rate;
-
-		err = snd_dg00x_stream_get_external_rate(dg00x, &rate);
-		if (err < 0) {
-			mutex_unlock(&dg00x->mutex);
-			goto err_locked;
-		}
-		substream->runtime->hw.rate_min = rate;
-		substream->runtime->hw.rate_max = 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(&dg00x->mutex);
+			err = snd_dg00x_stream_get_external_rate(dg00x, &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_BUFFER_SIZE,
-					frames_per_buffer, frames_per_buffer);
-			if (err < 0) {
-				mutex_unlock(&dg00x->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(&dg00x->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(&dg00x->mutex);
+		guard(mutex)(&dg00x->mutex);
 		err = snd_dg00x_stream_reserve_duplex(dg00x, rate,
 					frames_per_period, frames_per_buffer);
 		if (err >= 0)
 			++dg00x->substreams_counter;
-		mutex_unlock(&dg00x->mutex);
 	}
 
 	return err;
···
 {
 	struct snd_dg00x *dg00x = substream->private_data;
 
-	mutex_lock(&dg00x->mutex);
+	guard(mutex)(&dg00x->mutex);
 
 	if (substream->runtime->state != SNDRV_PCM_STATE_OPEN)
 		--dg00x->substreams_counter;
 
 	snd_dg00x_stream_stop_duplex(dg00x);
-
-	mutex_unlock(&dg00x->mutex);
 
 	return 0;
 }
···
 	struct snd_dg00x *dg00x = substream->private_data;
 	int err;
 
-	mutex_lock(&dg00x->mutex);
+	guard(mutex)(&dg00x->mutex);
 
 	err = snd_dg00x_stream_start_duplex(dg00x);
 	if (err >= 0)
 		amdtp_stream_pcm_prepare(&dg00x->tx_stream);
-
-	mutex_unlock(&dg00x->mutex);
 
 	return err;
 }
···
 	struct snd_dg00x *dg00x = substream->private_data;
 	int err;
 
-	mutex_lock(&dg00x->mutex);
+	guard(mutex)(&dg00x->mutex);
 
 	err = snd_dg00x_stream_start_duplex(dg00x);
 	if (err >= 0) {
 		amdtp_stream_pcm_prepare(&dg00x->rx_stream);
 		amdtp_dot_reset(&dg00x->rx_stream);
 	}
-
-	mutex_unlock(&dg00x->mutex);
 
 	return err;
 }

sound/firewire/digi00x/digi00x.c

···
 
 	snd_dg00x_transaction_reregister(dg00x);
 
-	mutex_lock(&dg00x->mutex);
+	guard(mutex)(&dg00x->mutex);
 	snd_dg00x_stream_update_duplex(dg00x);
-	mutex_unlock(&dg00x->mutex);
 }
 
 static void snd_dg00x_remove(struct fw_unit *unit)