ALSA: firewire-lib: add a quirk of packet without valid EOH in CIP format

In IEC 61883-1, when two quadlets CIP header is used, the most significant
bit in second CIP header stands. However, packets from units with MOTU
protocol version 3 have a quirk without this flag. Current packet streaming
layer handles this as protocol error.

This commit adds a new enumeration constant for this quirk, to handle MOTU
protocol version 3.

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

2 files changed, 6 insertions, 2 deletions

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index f9d12f454483..112ad039ed25 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -480,8 +480,9 @@ static int handle_in_packet(struct amdtp_stream *s,
          * This module supports 'Two-quadlet CIP header with SYT field'.
          * For convenience, also check FMT field is AM824 or not.
          */
-        if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
-            ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) {
+        if ((((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
+             ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) &&
+            (!(s->flags & CIP_HEADER_WITHOUT_EOH))) {
                 dev_info_ratelimited(&s->unit->device,
                                 "Invalid CIP header for AMDTP: %08X:%08X\n",
                                 cip_header[0], cip_header[1]);
diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index d2a316309704..a31dfd849821 100644
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -29,6 +29,8 @@
  * @CIP_JUMBO_PAYLOAD: Only for in-stream. The number of data blocks in an
  *      packet is larger than IEC 61883-6 defines. Current implementation
  *      allows 5 times as large as IEC 61883-6 defines.
+ * @CIP_HEADER_WITHOUT_EOH: Only for in-stream. CIP Header doesn't include
+ *      valid EOH.
  */
 enum cip_flags {
         CIP_NONBLOCKING         = 0x00,
@@ -39,6 +41,7 @@ enum cip_flags {
         CIP_SKIP_DBC_ZERO_CHECK = 0x10,
         CIP_EMPTY_HAS_WRONG_DBC = 0x20,
         CIP_JUMBO_PAYLOAD       = 0x40,
+        CIP_HEADER_WITHOUT_EOH  = 0x80,
 };
 
 /**