From f937b43d48f1080e39de723d15680b2ad5d7e6fd Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Tue, 20 Oct 2015 23:46:59 +0900 Subject: [PATCH 69/69] ALSA: firewire-tascam: clear extra MIDI bytes in an asynchronous transaction When MIDI buffer stores two or more MIDI messages, TASCAM driver transfers asynchronous transactions including one MIDI message and extra bytes from second MIDI message. This commit fixes this bug by clearing needless bytes in the buffer. The consumed bytes are already calculated correctly, thus the sequence of transactions is already correct. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- sound/firewire/tascam/tascam-transaction.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/sound/firewire/tascam/tascam-transaction.c b/sound/firewire/tascam/tascam-transaction.c index 99098aa2391e..904ce0329fa1 100644 --- a/sound/firewire/tascam/tascam-transaction.c +++ b/sound/firewire/tascam/tascam-transaction.c @@ -93,8 +93,10 @@ static int fill_message(struct snd_rawmidi_substream *substream, u8 *buf) *label = (port << 4) | 0x04; /* We need to fill whole 3 bytes. Go to next change. */ } else { - consume = 0; + return 0; } + + len = consume; } else { /* The beginning of exclusives. */ if (msg[0] == 0xf0) { @@ -115,24 +117,30 @@ static int fill_message(struct snd_rawmidi_substream *substream, u8 *buf) /* On running-status. */ if ((msg[0] & 0x80) != 0x80) { + /* Enough MIDI bytes were not retrieved. */ + if (consume < len - 1) + return 0; + consume = len - 1; + msg[2] = msg[1]; msg[1] = msg[0]; msg[0] = tscm->running_status[port]; - consume--; } else { + /* Enough MIDI bytes were not retrieved. */ + if (consume < len) + return 0; + consume = len; + tscm->running_status[port] = msg[0]; } - - /* Confirm length. */ - if (consume < len) - return 0; - if (consume > len) - consume = len; } *label = (port << 4) | (msg[0] >> 4); } + if (len > 0 && len < 3) + memset(msg + len, 0, 3 - len); + return consume; } -- 2.4.10