This is a note to let you know that I've just added the patch titled
ALSA: ump: Don't create unused substreams for static blocks
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-ump-don-t-create-unused-substreams-for-static-b.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 32d737240fa38a1c2eb7c07c59be2e9d933e2311
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Thu Aug 24 09:51:07 2023 +0200
ALSA: ump: Don't create unused substreams for static blocks
[ Upstream commit b2bcbd031d34d1ba1f491b9152474cf9f6d4d51b ]
When the UMP Endpoint is declared as "static", that is, no dynamic
reassignment of UMP Groups, it makes little sense to expose always all
16 groups with 16 substreams. Many of those substreams are disabled
groups, hence they are useless, but applications don't know it and try
to open / access all those substreams unnecessarily.
This patch limits the number of UMP legacy rawmidi substreams only to
the active groups. The behavior is changed only for the static
endpoint (i.e. devices without UMP v1.1 feature implemented or with
the static block flag is set).
Fixes: 0b5288f5fe63 ("ALSA: ump: Add legacy raw MIDI support")
Link: https://lore.kernel.org/r/20230824075108.29958-4-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/sound/ump.h b/include/sound/ump.h
index 44d2c2fd021d2..91238dabe3075 100644
--- a/include/sound/ump.h
+++ b/include/sound/ump.h
@@ -45,6 +45,7 @@ struct snd_ump_endpoint {
spinlock_t legacy_locks[2];
struct snd_rawmidi *legacy_rmidi;
struct snd_rawmidi_substream *legacy_substreams[2][SNDRV_UMP_MAX_GROUPS];
+ unsigned char legacy_mapping[SNDRV_UMP_MAX_GROUPS];
/* for legacy output; need to open the actual substream unlike input */
int legacy_out_opens;
diff --git a/sound/core/ump.c b/sound/core/ump.c
index beb439f25b09e..9d6e3e748f7e7 100644
--- a/sound/core/ump.c
+++ b/sound/core/ump.c
@@ -984,7 +984,7 @@ static int snd_ump_legacy_open(struct snd_rawmidi_substream *substream)
{
struct snd_ump_endpoint *ump = substream->rmidi->private_data;
int dir = substream->stream;
- int group = substream->number;
+ int group = ump->legacy_mapping[substream->number];
int err;
mutex_lock(&ump->open_mutex);
@@ -1016,7 +1016,7 @@ static int snd_ump_legacy_close(struct snd_rawmidi_substream *substream)
{
struct snd_ump_endpoint *ump = substream->rmidi->private_data;
int dir = substream->stream;
- int group = substream->number;
+ int group = ump->legacy_mapping[substream->number];
mutex_lock(&ump->open_mutex);
spin_lock_irq(&ump->legacy_locks[dir]);
@@ -1123,6 +1123,34 @@ static void process_legacy_input(struct snd_ump_endpoint *ump, const u32 *src,
spin_unlock_irqrestore(&ump->legacy_locks[dir], flags);
}
+/* Fill ump->legacy_mapping[] for groups to be used for legacy rawmidi */
+static int fill_legacy_mapping(struct snd_ump_endpoint *ump)
+{
+ struct snd_ump_block *fb;
+ unsigned int group_maps = 0;
+ int i, num;
+
+ if (ump->info.flags & SNDRV_UMP_EP_INFO_STATIC_BLOCKS) {
+ list_for_each_entry(fb, &ump->block_list, list) {
+ for (i = 0; i < fb->info.num_groups; i++)
+ group_maps |= 1U << (fb->info.first_group + i);
+ }
+ if (!group_maps)
+ ump_info(ump, "No UMP Group is found in FB\n");
+ }
+
+ /* use all groups for non-static case */
+ if (!group_maps)
+ group_maps = (1U << SNDRV_UMP_MAX_GROUPS) - 1;
+
+ num = 0;
+ for (i = 0; i < SNDRV_UMP_MAX_GROUPS; i++)
+ if (group_maps & (1U << i))
+ ump->legacy_mapping[num++] = i;
+
+ return num;
+}
+
static void fill_substream_names(struct snd_ump_endpoint *ump,
struct snd_rawmidi *rmidi, int dir)
{
@@ -1130,7 +1158,7 @@ static void fill_substream_names(struct snd_ump_endpoint *ump,
list_for_each_entry(s, &rmidi->streams[dir].substreams, list)
snprintf(s->name, sizeof(s->name), "Group %d (%s)",
- s->number + 1, ump->info.name);
+ ump->legacy_mapping[s->number] + 1, ump->info.name);
}
int snd_ump_attach_legacy_rawmidi(struct snd_ump_endpoint *ump,
@@ -1138,16 +1166,19 @@ int snd_ump_attach_legacy_rawmidi(struct snd_ump_endpoint *ump,
{
struct snd_rawmidi *rmidi;
bool input, output;
- int err;
+ int err, num;
- ump->out_cvts = kcalloc(16, sizeof(*ump->out_cvts), GFP_KERNEL);
+ ump->out_cvts = kcalloc(SNDRV_UMP_MAX_GROUPS,
+ sizeof(*ump->out_cvts), GFP_KERNEL);
if (!ump->out_cvts)
return -ENOMEM;
+ num = fill_legacy_mapping(ump);
+
input = ump->core.info_flags & SNDRV_RAWMIDI_INFO_INPUT;
output = ump->core.info_flags & SNDRV_RAWMIDI_INFO_OUTPUT;
err = snd_rawmidi_new(ump->core.card, id, device,
- output ? 16 : 0, input ? 16 : 0,
+ output ? num : 0, input ? num : 0,
&rmidi);
if (err < 0) {
kfree(ump->out_cvts);
