This is a note to let you know that I've just added the patch titled
ALSA: seq: Avoid delivery of events for disabled UMP groups
to the 6.5-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-seq-avoid-delivery-of-events-for-disabled-ump-g.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1eef3f912a660dcecd245ece2cdc5c8bff10f611
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Tue Sep 12 10:51:44 2023 +0200
ALSA: seq: Avoid delivery of events for disabled UMP groups
[ Upstream commit 22eefaeab03fe968ab7786fb3d5c5abd203a8bab ]
ALSA sequencer core still delivers events to the disabled UMP Group,
leaving this handling to the device. But it's rather risky and it's
easy to imagine that such an unexpected event may screw up the device
firmware.
This patch avoids the superfluous event deliveries by setting the
group_filter of the UMP client as default, and evaluate the
group_filter properly at delivery from non-UMP clients.
The grouop_filter is updated upon the dynamic UMP Function Block
updates, so that it follows the change of the disabled UMP Groups,
too.
Fixes: d2b706077792 ("ALSA: seq: Add UMP group filter")
Link: https://lore.kernel.org/r/20230912085144.32534-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/core/seq/seq_ump_client.c b/sound/core/seq/seq_ump_client.c
index f26a1812dfa73..a60e3f069a80f 100644
--- a/sound/core/seq/seq_ump_client.c
+++ b/sound/core/seq/seq_ump_client.c
@@ -416,6 +416,25 @@ static void setup_client_midi_version(struct seq_ump_client *client)
snd_seq_kernel_client_put(cptr);
}
+/* set up client's group_filter bitmap */
+static void setup_client_group_filter(struct seq_ump_client *client)
+{
+ struct snd_seq_client *cptr;
+ unsigned int filter;
+ int p;
+
+ cptr = snd_seq_kernel_client_get(client->seq_client);
+ if (!cptr)
+ return;
+ filter = ~(1U << 0); /* always allow groupless messages */
+ for (p = 0; p < SNDRV_UMP_MAX_GROUPS; p++) {
+ if (client->groups[p].active)
+ filter &= ~(1U << (p + 1));
+ }
+ cptr->group_filter = filter;
+ snd_seq_kernel_client_put(cptr);
+}
+
/* UMP group change notification */
static void handle_group_notify(struct work_struct *work)
{
@@ -424,6 +443,7 @@ static void handle_group_notify(struct work_struct *work)
update_group_attrs(client);
update_port_infos(client);
+ setup_client_group_filter(client);
}
/* UMP FB change notification */
@@ -492,6 +512,8 @@ static int snd_seq_ump_probe(struct device *_dev)
goto error;
}
+ setup_client_group_filter(client);
+
err = create_ump_endpoint_port(client);
if (err < 0)
goto error;
diff --git a/sound/core/seq/seq_ump_convert.c b/sound/core/seq/seq_ump_convert.c
index 7cc84e137999c..b141024830ecc 100644
--- a/sound/core/seq/seq_ump_convert.c
+++ b/sound/core/seq/seq_ump_convert.c
@@ -1197,6 +1197,8 @@ int snd_seq_deliver_to_ump(struct snd_seq_client *source,
struct snd_seq_event *event,
int atomic, int hop)
{
+ if (dest->group_filter & (1U << dest_port->ump_group))
+ return 0; /* group filtered - skip the event */
if (event->type == SNDRV_SEQ_EVENT_SYSEX)
return cvt_sysex_to_ump(dest, dest_port, event, atomic, hop);
else if (snd_seq_client_is_midi2(dest))
