From: Takashi Iwai tiwai@suse.de
[ Upstream commit 0759e77a6d9bd34a874da73721ce4a7dc6665023 ]
The MIDI substream name string is constructed from the combination of the card shortname (which is taken from USB iProduct) and the USB iJack. The problem is that some devices put the product name to the iJack field, too. For example, aplaymidi -l output on the Lanchkey MK 49 are like:
% aplaymidi -l Port Client name Port name 44:0 Launchkey MK4 49 Launchkey MK4 49 Launchkey MK4 44:1 Launchkey MK4 49 Launchkey MK4 49 Launchkey MK4
where the actual iJack name can't be seen because it's truncated due to the doubly words.
For resolving those situations, this patch compares the iJack string with the card shortname, and drops if both start with the same words. Then the result becomes like:
% aplaymidi -l Port Client name Port name 40:0 Launchkey MK4 49 Launchkey MK4 49 MIDI In 40:1 Launchkey MK4 49 Launchkey MK4 49 DAW In
A caveat is that there are some pre-defined names for certain devices in the driver code, and this workaround shouldn't be applied to them. Similarly, when the iJack isn't specified, we should skip this check, too. The patch added those checks in addition to the string comparison.
Suggested-by: Paul Davis paul@linuxaudiosystems.com Tested-by: Paul Davis paul@linuxaudiosystems.com Link: https://lore.kernel.org/CAFa_cKmEDQWcJatbYWi6A58Zg4Ma9_6Nr3k5LhqwyxC-P_kXtw@... Link: https://patch.msgid.link/20250429183626.20773-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/midi.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/sound/usb/midi.c b/sound/usb/midi.c index 826ac870f2469..a792ada18863a 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1885,10 +1885,18 @@ static void snd_usbmidi_init_substream(struct snd_usb_midi *umidi, }
port_info = find_port_info(umidi, number); - name_format = port_info ? port_info->name : - (jack_name != default_jack_name ? "%s %s" : "%s %s %d"); - snprintf(substream->name, sizeof(substream->name), - name_format, umidi->card->shortname, jack_name, number + 1); + if (port_info || jack_name == default_jack_name || + strncmp(umidi->card->shortname, jack_name, strlen(umidi->card->shortname)) != 0) { + name_format = port_info ? port_info->name : + (jack_name != default_jack_name ? "%s %s" : "%s %s %d"); + snprintf(substream->name, sizeof(substream->name), + name_format, umidi->card->shortname, jack_name, number + 1); + } else { + /* The manufacturer included the iProduct name in the jack + * name, do not use both + */ + strscpy(substream->name, jack_name); + }
*rsubstream = substream; }