ALSA: bebob: loosen up severity of checking continuity for BeBoB v3 quirk

PrismSound Orpheus, Behringer UFX1604 and FCA610 work with BeBoB v3, and
they're confirmed to transmit discontinuous packets in the beginning of
streaming.

payload    CIP headers
  8        0x00070000 0x9002FFFF
  8        0x00070000 0x9002FFFF
  8        0x00070000 0x9002FFFF
  8        0x00070008 0x9002FFFF <-
  8        0x00070008 0x9002FFFF
  8        0x00070008 0x9002FFFF
  8        0x00070008 0x9002FFFF
  8        0x00070008 0x9002FFFF
  8        0x00070008 0x9002FFFF
232        0x00070000 0x9002E798 <-
232        0x00070008 0x9002FB99
232        0x00070010 0x90021398
  8        0x00070018 0x9002FFFF
(This sample was got with Behringer FCA610 and FFADO library.)

This commit sets CIP_EMPTY_HAS_WRONG_DBC and CIP_SKIP_DBC_ZERO_CHECK to
ignore these discontinuities.

Tested-by: Kim Tore Jensen <kim@incendio.no>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/bebob/bebob_stream.c b/sound/firewire/bebob/bebob_stream.c
index 9c810f9ec8d6e81d0be732aa239a0a68851ed0e1..d0df6c17f7f7c485b934743cfe7bb3ca4001417e 100644 (file)
--- a/sound/firewire/bebob/bebob_stream.c
+++ b/sound/firewire/bebob/bebob_stream.c
@@ -540,6 +540,17 @@ int snd_bebob_stream_init_duplex(struct snd_bebob *bebob)
        /* See comments in next function */
        init_completion(&bebob->bus_reset);
        bebob->tx_stream.flags |= CIP_SKIP_INIT_DBC_CHECK;
+
+       /*
+        * BeBoB v3 transfers packets with these qurks:
+        *  - In the beginning of streaming, the value of dbc is incremented
+        *    even if no data blocks are transferred.
+        *  - The value of dbc is reset suddenly.
+        */
+       if (bebob->version > 2)
+               bebob->tx_stream.flags |= CIP_EMPTY_HAS_WRONG_DBC |
+                                         CIP_SKIP_DBC_ZERO_CHECK;
+
        /*
         * At high sampling rate, M-Audio special firmware transmits empty
         * packet with the value of dbc incremented by 8 but the others are