ALSA: ump: Use guard() for locking

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

Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-2-tiwai@suse.de

sound/core/ump.c

@@ -985,13 +985,11 @@ static int snd_ump_legacy_open(struct snd_rawmidi_substream *substream)
 	struct snd_ump_endpoint *ump = substream->rmidi->private_data;
 	int dir = substream->stream;
 	int group = ump->legacy_mapping[substream->number];
-	int err = 0;
+	int err;
 
-	mutex_lock(&ump->open_mutex);
-	if (ump->legacy_substreams[dir][group]) {
-		err = -EBUSY;
-		goto unlock;
-	}
+	guard(mutex)(&ump->open_mutex);
+	if (ump->legacy_substreams[dir][group])
+		return -EBUSY;
 	if (dir == SNDRV_RAWMIDI_STREAM_OUTPUT) {
 		if (!ump->legacy_out_opens) {
 			err = snd_rawmidi_kernel_open(&ump->core, 0,
@@ -999,17 +997,14 @@ static int snd_ump_legacy_open(struct snd_rawmidi_substream *substream)
 						      SNDRV_RAWMIDI_LFLG_APPEND,
 						      &ump->legacy_out_rfile);
 			if (err < 0)
-				goto unlock;
+				return err;
 		}
 		ump->legacy_out_opens++;
 		snd_ump_convert_reset(&ump->out_cvts[group]);
 	}
-	spin_lock_irq(&ump->legacy_locks[dir]);
+	guard(spinlock_irq)(&ump->legacy_locks[dir]);
 	ump->legacy_substreams[dir][group] = substream;
-	spin_unlock_irq(&ump->legacy_locks[dir]);
- unlock:
-	mutex_unlock(&ump->open_mutex);
-	return err;
+	return 0;
 }
 
 static int snd_ump_legacy_close(struct snd_rawmidi_substream *substream)
@@ -1018,15 +1013,13 @@ static int snd_ump_legacy_close(struct snd_rawmidi_substream *substream)
 	int dir = substream->stream;
 	int group = ump->legacy_mapping[substream->number];
 
-	mutex_lock(&ump->open_mutex);
-	spin_lock_irq(&ump->legacy_locks[dir]);
-	ump->legacy_substreams[dir][group] = NULL;
-	spin_unlock_irq(&ump->legacy_locks[dir]);
+	guard(mutex)(&ump->open_mutex);
+	scoped_guard(spinlock_irq, &ump->legacy_locks[dir])
+		ump->legacy_substreams[dir][group] = NULL;
 	if (dir == SNDRV_RAWMIDI_STREAM_OUTPUT) {
 		if (!--ump->legacy_out_opens)
 			snd_rawmidi_kernel_release(&ump->legacy_out_rfile);
 	}
-	mutex_unlock(&ump->open_mutex);
 	return 0;
 }
 
@@ -1078,12 +1071,11 @@ static int process_legacy_output(struct snd_ump_endpoint *ump,
 	const int dir = SNDRV_RAWMIDI_STREAM_OUTPUT;
 	unsigned char c;
 	int group, size = 0;
-	unsigned long flags;
 
 	if (!ump->out_cvts || !ump->legacy_out_opens)
 		return 0;
 
-	spin_lock_irqsave(&ump->legacy_locks[dir], flags);
+	guard(spinlock_irqsave)(&ump->legacy_locks[dir]);
 	for (group = 0; group < SNDRV_UMP_MAX_GROUPS; group++) {
 		substream = ump->legacy_substreams[dir][group];
 		if (!substream)
@@ -1099,7 +1091,6 @@ static int process_legacy_output(struct snd_ump_endpoint *ump,
 			break;
 		}
 	}
-	spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
 	return size;
 }
 
@@ -1109,18 +1100,16 @@ static void process_legacy_input(struct snd_ump_endpoint *ump, const u32 *src,
 	struct snd_rawmidi_substream *substream;
 	unsigned char buf[16];
 	unsigned char group;
-	unsigned long flags;
 	const int dir = SNDRV_RAWMIDI_STREAM_INPUT;
 	int size;
 
 	size = snd_ump_convert_from_ump(src, buf, &group);
 	if (size <= 0)
 		return;
-	spin_lock_irqsave(&ump->legacy_locks[dir], flags);
+	guard(spinlock_irqsave)(&ump->legacy_locks[dir]);
 	substream = ump->legacy_substreams[dir][group];
 	if (substream)
 		snd_rawmidi_receive(substream, buf, size);
-	spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
 }
 
 /* Fill ump->legacy_mapping[] for groups to be used for legacy rawmidi */