[PATCH] ALSA: seq: Restore created port information after insertion

From: Cássio Gabriel

Date: Tue Jun 02 2026 - 06:56:19 EST


Commit 2ee646353cd5 ("ALSA: seq: Register kernel port with full
information") split sequencer port creation from list insertion so a
port can be filled before it becomes visible.

However, snd_seq_ioctl_create_port() still copies port->addr back to the
ioctl argument before snd_seq_insert_port() assigns the final port
number. A successful SNDRV_SEQ_IOCTL_CREATE_PORT without
SNDRV_SEQ_PORT_FLG_GIVEN_PORT can therefore report port -1 to userspace.

Move the ioctl address copy after successful insertion, and keep the
default "port-%d" name assignment from overwriting a caller-provided port
name. This restores the observable behavior from before the split while
keeping the port populated before publication.

Fixes: 2ee646353cd5 ("ALSA: seq: Register kernel port with full information")
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>
---
sound/core/seq/seq_clientmgr.c | 3 +--
sound/core/seq/seq_ports.c | 3 ++-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 19d6fea012f6..81ef461a9118 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1306,14 +1306,13 @@ static int snd_seq_ioctl_create_port(struct snd_seq_client *client, void *arg)
}
}

- info->addr = port->addr;
-
snd_seq_set_port_info(port, info);
err = snd_seq_insert_port(client, port_idx, port);
if (err < 0) {
kfree(port);
return err;
}
+ info->addr = port->addr;
if (info->capability & SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT)
client->ump_endpoint_port = port->addr.port;
snd_seq_system_client_ev_port_start(port->addr.client, port->addr.port);
diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c
index 17daacd4476a..6612e92d801f 100644
--- a/sound/core/seq/seq_ports.c
+++ b/sound/core/seq/seq_ports.c
@@ -170,7 +170,8 @@ int snd_seq_insert_port(struct snd_seq_client *client, int port,
list_add_tail(&new_port->list, insert_before);
client->num_ports++;
new_port->addr.port = num; /* store the port number in the port */
- sprintf(new_port->name, "port-%d", num);
+ if (!new_port->name[0])
+ sprintf(new_port->name, "port-%d", num);

return num;
}

---
base-commit: 96d4780e9ff5168195e891c474a85bb0d510fe9f
change-id: 20260601-alsa-seq-create-port-info-fix-81457ed3c864

Best regards,
--
Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>