1 files changed, 6 insertions, 2 deletions

diff --git a/sound/firewire/amdtp-am824.c b/sound/firewire/amdtp-am824.c
index fd5d6b8ac557..99c567ded7a3 100644
--- a/sound/firewire/amdtp-am824.c
+++ b/sound/firewire/amdtp-am824.c
@@ -315,12 +315,16 @@ static void read_midi_messages(struct amdtp_stream *s,
                                __be32 *buffer, unsigned int frames)
 {
         struct amdtp_am824 *p = s->protocol;
-        unsigned int f, port;
         int len;
         u8 *b;
+        int f;
 
         for (f = 0; f < frames; f++) {
-                port = (8 - s->ctx_data.tx.first_dbc + s->data_block_counter + f) % 8;
+                unsigned int port = f;
+
+                if (!(s->flags & CIP_UNALIGHED_DBC))
+                        port += s->data_block_counter;
+                port %= 8;
                 b = (u8 *)&buffer[p->midi_position];
 
                 len = b[0] - 0x80;