Patch "ALSA: ump: Use guard() for locking" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ALSA: ump: Use guard() for locking

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     alsa-ump-use-guard-for-locking.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 891e572af18fce844430490b2c019dd6f6d30022
Author: Takashi Iwai <tiwai@xxxxxxx>
Date:   Tue Feb 27 09:52:43 2024 +0100

    ALSA: ump: Use guard() for locking
    
    [ Upstream commit 631896f7eaaf8cf8c639b065d3c9fbaa66da5d32 ]
    
    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@xxxxxxx>
    Link: https://lore.kernel.org/r/20240227085306.9764-2-tiwai@xxxxxxx
    Stable-dep-of: 3978d53df723 ("ALSA: ump: Don't open legacy substream for an inactive group")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/sound/core/ump.c b/sound/core/ump.c
index 83856b2f88b8..ada2625ce78f 100644
--- a/sound/core/ump.c
+++ b/sound/core/ump.c
@@ -1076,13 +1076,11 @@ 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,
@@ -1090,17 +1088,14 @@ 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)
@@ -1109,15 +1104,13 @@ 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;
 }
 
@@ -1169,12 +1162,11 @@ 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)
@@ -1190,7 +1182,6 @@ static int process_legacy_output(struct snd_ump_endpoint *ump,
 			break;
 		}
 	}
-	spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
 	return size;
 }
 
@@ -1200,18 +1191,16 @@ 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 */