ALSA: fireworks/firewire-lib: Add a quirk for empty packet with TAG0

Fireworks has a quirk to transmit empty packets with TAG0. This commit
adds handling this quirk for full duplex stream synchronization.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

3 files changed, 10 insertions, 3 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index 5b8846123474..dce4c6dd3f6d 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -815,7 +815,7 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
         };
         unsigned int header_size;
         enum dma_data_direction dir;
-        int type, err;
+        int type, tag, err;
 
         mutex_lock(&s->mutex);
 
@@ -869,9 +869,12 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
         } while (s->packet_index > 0);
 
         /* NOTE: TAG1 matches CIP. This just affects in stream. */
+        tag = FW_ISO_CONTEXT_MATCH_TAG1;
+        if (s->flags & CIP_EMPTY_WITH_TAG0)
+                tag |= FW_ISO_CONTEXT_MATCH_TAG0;
+
         s->callbacked = false;
-        err = fw_iso_context_start(s->context, -1, 0,
-                                   FW_ISO_CONTEXT_MATCH_TAG1);
+        err = fw_iso_context_start(s->context, -1, 0, tag);
         if (err < 0)
                 goto err_context;
 
diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h
index 3de34639b1c7..96b96ec812b2 100644
--- a/sound/firewire/amdtp.h
+++ b/sound/firewire/amdtp.h
@@ -18,11 +18,13 @@
  *      the overall sample rate comes out right.
  * @CIP_SYNC_TO_DEVICE: In sync to device mode, time stamp in out packets is
  *      generated by in packets. Defaultly this driver generates timestamp.
+ * @CIP_EMPTY_WITH_TAG0: Only for in-stream. Empty in-packets have TAG0.
  */
 enum cip_flags {
         CIP_NONBLOCKING         = 0x00,
         CIP_BLOCKING            = 0x01,
         CIP_SYNC_TO_DEVICE      = 0x02,
+        CIP_EMPTY_WITH_TAG0     = 0x04,
 };
 
 /**
diff --git a/sound/firewire/fireworks/fireworks_stream.c b/sound/firewire/fireworks/fireworks_stream.c
index ec62aa65cfae..360e871bf838 100644
--- a/sound/firewire/fireworks/fireworks_stream.c
+++ b/sound/firewire/fireworks/fireworks_stream.c
@@ -194,6 +194,8 @@ int snd_efw_stream_init_duplex(struct snd_efw *efw)
         err = init_stream(efw, &efw->tx_stream);
         if (err < 0)
                 goto end;
+        /* Fireworks transmits NODATA packets with TAG0. */
+        efw->tx_stream.flags |= CIP_EMPTY_WITH_TAG0;
 
         err = init_stream(efw, &efw->rx_stream);
         if (err < 0) {