ALSA: firewire-lib: use no-info SYT for packets without SYT sample

[pandora-kernel.git] / sound / firewire / amdtp.c

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index 09f70ee..046007d 100644 (file)
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -228,11 +228,15 @@ static unsigned int calculate_syt(struct amdtp_out_stream *s,
                syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
        s->last_syt_offset = syt_offset;
 
-       syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
-       syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
-       syt += syt_offset % TICKS_PER_CYCLE;
+       if (syt_offset < TICKS_PER_CYCLE) {
+               syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
+               syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
+               syt += syt_offset % TICKS_PER_CYCLE;
 
-       return syt & 0xffff;
+               return syt & 0xffff;
+       } else {
+               return 0xffff; /* no info */
+       }
 }
 
 static void amdtp_write_s32(struct amdtp_out_stream *s,