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.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-32-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h
index 2470eaa..c4632bd 100644 (file)
--- 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 07b090f..3b1adcb 100644 (file)
--- 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 2e8844e..9308194 100644 (file)
--- 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);