firewire-motu: fix wrong reference count for stream functionality at …

…error path of rawmidi interface In IEC 61883-6, several types of sampling data can be multiplexed into payload of common isochronous packet (CIP). For typical audio and music units, PCM samples and MIDI messages are multiplexed into one packet streaming. ALSA firewire-motu driver allows applications of rawmidi interface to start packet streaming for transmission of MIDI messages. However at error path, the reference count of stream functionality is not operated correctly. This can brings a bug that packet streaming is not stopped when all referrers release the count. This commit fixes the bug. Fixes: 8edc56e ("ALSA: firewire-motu: reserve/release isochronous resources in pcm.hw_params/hw_free callbacks") Signed-off-by: Takashi Sakamoto <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
josf · Jul 7, 2019 · ba18ca2 · ba18ca2
1 parent 64582c5
commit ba18ca2
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/sound/firewire/motu/motu-midi.c b/sound/firewire/motu/motu-midi.c
@@ -22,6 +22,8 @@ static int midi_open(struct snd_rawmidi_substream *substream)
 	if (err >= 0) {
 		++motu->substreams_counter;
 		err = snd_motu_stream_start_duplex(motu);
+		if (err < 0)
+			--motu->substreams_counter;
 	}
 
 	mutex_unlock(&motu->mutex);