[PATCH AUTOSEL for 4.9 078/219] ALSA: firewire-lib: add a quirk of packet without valid EOH in CIP format

Sasha Levin
2018-03-03T22:33:11Z

From: Takashi Sakamoto <o-takashi@sakamocchi.jp>

[ Upstream commit 2128f78f75a36a34dfef0e127273c2f820c5c904 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
sound/firewire/amdtp-stream.c | 5 +++--
sound/firewire/amdtp-stream.h | 3 +++
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 9741757436be..d0ad61f563e2 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -471,8 +471,9 @@ 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 f7c054bc9d92..8136bd20c8b1 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,
};

/**
--
2.14.1