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ALSA: usb-audio: Parse UMP Endpoint and Function Blocks at first

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Try to parse the UMP Endpoint and UMP Function Blocks for building the
topology at first.  Only when those are missing (e.g. on an older USB
MIDI 2.0 spec or a unidirectional endpoint), the driver still creates
blocks based on USB group terminal block information as fallback.

Link: https://lore.kernel.org/r/20230612081054.17200-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2023-06-12 10:10:47 +02:00
parent 37e0e14128
commit 54852e8f40
1 changed files with 33 additions and 1 deletions
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34
sound/usb/midi2.c
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@ -80,6 +80,7 @@ struct snd_usb_midi2_ump {
struct snd_usb_midi2_endpoint *eps[2]; /* USB MIDI endpoints */
int index; /* rawmidi device index */
unsigned char usb_block_id; /* USB GTB id used for finding a pair */
bool ump_parsed; /* Parsed UMP 1.1 EP/FB info*/
struct list_head list; /* list to umidi->rawmidi_list */
};
@ -786,6 +787,31 @@ static int find_matching_ep_partner(struct snd_usb_midi2_interface *umidi,
return 0;
}
/* Call UMP helper to parse UMP endpoints;
* this needs to be called after starting the input streams for bi-directional
* communications
*/
static int parse_ump_endpoints(struct snd_usb_midi2_interface *umidi)
{
struct snd_usb_midi2_ump *rmidi;
int err;
list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
if (!rmidi->ump ||
!(rmidi->ump->core.info_flags & SNDRV_RAWMIDI_INFO_DUPLEX))
continue;
err = snd_ump_parse_endpoint(rmidi->ump);
if (!err) {
rmidi->ump_parsed = true;
} else {
if (err == -ENOMEM)
return err;
/* fall back to GTB later */
}
}
return 0;
}
/* create a UMP block from a GTB entry */
static int create_gtb_block(struct snd_usb_midi2_ump *rmidi, int dir, int blk)
{
@ -856,7 +882,7 @@ static int create_blocks_from_gtb(struct snd_usb_midi2_interface *umidi)
if (!rmidi->ump)
continue;
/* Blocks have been already created? */
if (rmidi->ump->info.num_blocks)
if (rmidi->ump_parsed || rmidi->ump->info.num_blocks)
continue;
/* loop over GTBs */
for (dir = 0; dir < 2; dir++) {
@ -1110,6 +1136,12 @@ int snd_usb_midi_v2_create(struct snd_usb_audio *chip,
goto error;
}
err = parse_ump_endpoints(umidi);
if (err < 0) {
usb_audio_err(chip, "Failed to parse UMP endpoint\n");
goto error;
}
err = create_blocks_from_gtb(umidi);
if (err < 0) {
usb_audio_err(chip, "Failed to create GTB blocks\n");