ALSA: fireworks/firewire-lib: Add a quirk to reset data block counter at bus reset

Fireworks has a quirk to reset data block counter at bus reset.

This commit adds a flag of CIP_SKIP_DBC_ZERO_CHECK. This flag has an effect
to skip checking dbc continuity when dbc is zero.

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

3 files changed, 8 insertions, 1 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index 4a7cc1f77d88..5e13b3f15516 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -662,7 +662,9 @@ static void handle_in_packet(struct amdtp_stream *s,
 
         /* Check data block counter continuity */
         data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
-        if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
+        if ((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && data_block_counter == 0) {
+                lost = false;
+        } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
                 lost = data_block_counter != s->data_block_counter;
         } else {
                 if ((data_blocks > 0) && (s->tx_dbc_interval > 0))
diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h
index 05f1b8b30e2b..42c75c916684 100644
--- a/sound/firewire/amdtp.h
+++ b/sound/firewire/amdtp.h
@@ -23,6 +23,8 @@
  *      corresponds to the end of event in the packet. Out of IEC 61883.
  * @CIP_WRONG_DBS: Only for in-stream. The value of dbs is wrong in in-packets.
  *      The value of data_block_quadlets is used instead of reported value.
+ * @SKIP_DBC_ZERO_CHECK: Only for in-stream.  Packets with zero in dbc is
+ *      skipped for detecting discontinuity.
  */
 enum cip_flags {
         CIP_NONBLOCKING         = 0x00,
@@ -31,6 +33,7 @@ enum cip_flags {
         CIP_EMPTY_WITH_TAG0     = 0x04,
         CIP_DBC_IS_END_EVENT    = 0x08,
         CIP_WRONG_DBS           = 0x10,
+        CIP_SKIP_DBC_ZERO_CHECK = 0x20,
 };
 
 /**
diff --git a/sound/firewire/fireworks/fireworks_stream.c b/sound/firewire/fireworks/fireworks_stream.c
index c75c2ef2ae31..3a3f203177b1 100644
--- a/sound/firewire/fireworks/fireworks_stream.c
+++ b/sound/firewire/fireworks/fireworks_stream.c
@@ -198,6 +198,8 @@ int snd_efw_stream_init_duplex(struct snd_efw *efw)
         efw->tx_stream.flags |= CIP_EMPTY_WITH_TAG0;
         /* Fireworks has its own meaning for dbc. */
         efw->tx_stream.flags |= CIP_DBC_IS_END_EVENT;
+        /* Fireworks reset dbc at bus reset. */
+        efw->tx_stream.flags |= CIP_SKIP_DBC_ZERO_CHECK;
         /* AudioFire9 always reports wrong dbs. */
         if (efw->is_af9)
                 efw->tx_stream.flags |= CIP_WRONG_DBS;