ALSA: seq: Drop UMP events when no UMP-conversion is set

[ Upstream commit e77aa4b2ea ]

When a destination client is a user client in the legacy MIDI mode and
it sets the no-UMP-conversion flag, currently the all UMP events are
still passed as-is.  But this may confuse the user-space, because the
event packet size is different from the legacy mode.

Since we cannot handle UMP events in user clients unless it's running
in the UMP client mode, we should filter out those events instead of
accepting blindly.  This patch addresses it by slightly adjusting the
conditions for UMP event handling at the event delivery time.

Fixes: 329ffe11a0 ("ALSA: seq: Allow suppressing UMP conversions")
Link: https://lore.kernel.org/b77a2cd6-7b59-4eb0-a8db-22d507d3af5f@gmail.com
Link: https://patch.msgid.link/20250217170034.21930-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Takashi Iwai
2025-02-17 18:00:30 +01:00
committed by Greg Kroah-Hartman
parent de4b679aa3
commit 48e348ff3e
+9 -3
View File
@@ -682,12 +682,18 @@ static int snd_seq_deliver_single_event(struct snd_seq_client *client,
dest_port->time_real);
#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
if (!(dest->filter & SNDRV_SEQ_FILTER_NO_CONVERT)) {
if (snd_seq_ev_is_ump(event)) {
if (snd_seq_ev_is_ump(event)) {
if (!(dest->filter & SNDRV_SEQ_FILTER_NO_CONVERT)) {
result = snd_seq_deliver_from_ump(client, dest, dest_port,
event, atomic, hop);
goto __skip;
} else if (snd_seq_client_is_ump(dest)) {
} else if (dest->type == USER_CLIENT &&
!snd_seq_client_is_ump(dest)) {
result = 0; // drop the event
goto __skip;
}
} else if (snd_seq_client_is_ump(dest)) {
if (!(dest->filter & SNDRV_SEQ_FILTER_NO_CONVERT)) {
result = snd_seq_deliver_to_ump(client, dest, dest_port,
event, atomic, hop);
goto __skip;