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 <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/tascam/tascam-transaction.c b/sound/firewire/tascam/tascam-transaction.c
index 99098aa..904ce03 100644
--- a/sound/firewire/tascam/tascam-transaction.c
+++ b/sound/firewire/tascam/tascam-transaction.c
@@ -93,8 +93,10 @@
*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 @@
/* 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;
}