linux-kernel - [PATCH 30/36] ALSA: seq: Allow suppressing UMP conversions

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Message-Id: <20230519093114.28813-31-tiwai@suse.de>
Date:   Fri, 19 May 2023 11:31:08 +0200
From:   Takashi Iwai <tiwai@...e.de>
To:     alsa-devel@...a-project.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH 30/36] ALSA: seq: Allow suppressing UMP conversions

A sequencer client like seq_dummy rather doesn't want to convert UMP
events but receives / sends as is.  Add a new event filter flag to
suppress the automatic UMP conversion and applies accordingly.

Signed-off-by: Takashi Iwai <tiwai@...e.de>
---
 include/uapi/sound/asequencer.h |  1 +
 sound/core/seq/seq_clientmgr.c  | 18 ++++++++++--------
 sound/core/seq/seq_dummy.c      |  8 ++++++++
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h
index 2470eaa5edc5..c4632bd9d3a0 100644
--- a/include/uapi/sound/asequencer.h
+++ b/include/uapi/sound/asequencer.h
@@ -347,6 +347,7 @@ typedef int __bitwise snd_seq_client_type_t;
 #define SNDRV_SEQ_FILTER_BROADCAST	(1U<<0)	/* accept broadcast messages */
 #define SNDRV_SEQ_FILTER_MULTICAST	(1U<<1)	/* accept multicast messages */
 #define SNDRV_SEQ_FILTER_BOUNCE		(1U<<2)	/* accept bounce event in error */
+#define SNDRV_SEQ_FILTER_NO_CONVERT	(1U<<30) /* don't convert UMP events */
 #define SNDRV_SEQ_FILTER_USE_EVENT	(1U<<31)	/* use event filter */
 
 struct snd_seq_client_info {
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 07b090f76b5f..3b1adcb1ccdd 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -671,14 +671,16 @@ static int snd_seq_deliver_single_event(struct snd_seq_client *client,
 					  dest_port->time_real);
 
 #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
-	if (snd_seq_ev_is_ump(event)) {
-		result = snd_seq_deliver_from_ump(client, dest, dest_port,
-						  event, atomic, hop);
-		goto __skip;
-	} else if (snd_seq_client_is_ump(dest)) {
-		result = snd_seq_deliver_to_ump(client, dest, dest_port,
-						event, atomic, hop);
-		goto __skip;
+	if (!(dest->filter & SNDRV_SEQ_FILTER_NO_CONVERT)) {
+		if (snd_seq_ev_is_ump(event)) {
+			result = snd_seq_deliver_from_ump(client, dest, dest_port,
+							  event, atomic, hop);
+			goto __skip;
+		} else if (snd_seq_client_is_ump(dest)) {
+			result = snd_seq_deliver_to_ump(client, dest, dest_port,
+							event, atomic, hop);
+			goto __skip;
+		}
 	}
 #endif /* CONFIG_SND_SEQ_UMP */
 
diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
index 2e8844ee32ed..9308194b2d9a 100644
--- a/sound/core/seq/seq_dummy.c
+++ b/sound/core/seq/seq_dummy.c
@@ -152,6 +152,7 @@ static int __init
 register_client(void)
 {
 	struct snd_seq_dummy_port *rec1, *rec2;
+	struct snd_seq_client *client;
 	int i;
 
 	if (ports < 1) {
@@ -165,6 +166,13 @@ register_client(void)
 	if (my_client < 0)
 		return my_client;
 
+	/* don't convert events but just pass-through */
+	client = snd_seq_kernel_client_get(my_client);
+	if (!client)
+		return -EINVAL;
+	client->filter = SNDRV_SEQ_FILTER_NO_CONVERT;
+	snd_seq_kernel_client_put(client);
+
 	/* create ports */
 	for (i = 0; i < ports; i++) {
 		rec1 = create_port(i, 0);
-- 
2.35.3