From 22eefaeab03fe968ab7786fb3d5c5abd203a8bab Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 12 Sep 2023 10:51:44 +0200 Subject: [PATCH] ALSA: seq: Avoid delivery of events for disabled UMP groups 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@suse.de Signed-off-by: Takashi Iwai --- sound/core/seq/seq_ump_client.c | 22 ++++++++++++++++++++++ sound/core/seq/seq_ump_convert.c | 2 ++ 2 files changed, 24 insertions(+) diff --git a/sound/core/seq/seq_ump_client.c b/sound/core/seq/seq_ump_client.c index f26a181..a60e3f0 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 7cc84e1..b141024 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)) -- 2.7.4