[PATCH AUTOSEL 6.1 20/52] ALSA: firewire-lib: handle quirk to calculate payload quadlets as data block counter

From: Sasha Levin
Date: Fri Mar 29 2024 - 10:22:48 EST


From: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>

[ Upstream commit 4a486439d2ca85752c46711f373b6ddc107bb35d ]

Miglia Harmony Audio (OXFW970) has a quirk to put the number of
accumulated quadlets in CIP payload into the dbc field of CIP header.

This commit handles the quirk in the packet processing layer.

Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240218074128.95210-4-o-takashi@xxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/firewire/amdtp-stream.c | 12 ++++++++----
sound/firewire/amdtp-stream.h | 4 ++++
2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index f8b644cb9157a..8753125683692 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -771,10 +771,14 @@ static int check_cip_header(struct amdtp_stream *s, const __be32 *buf,
} else {
unsigned int dbc_interval;

- if (*data_blocks > 0 && s->ctx_data.tx.dbc_interval > 0)
- dbc_interval = s->ctx_data.tx.dbc_interval;
- else
- dbc_interval = *data_blocks;
+ if (!(s->flags & CIP_DBC_IS_PAYLOAD_QUADLETS)) {
+ if (*data_blocks > 0 && s->ctx_data.tx.dbc_interval > 0)
+ dbc_interval = s->ctx_data.tx.dbc_interval;
+ else
+ dbc_interval = *data_blocks;
+ } else {
+ dbc_interval = payload_length / sizeof(__be32);
+ }

lost = dbc != ((*data_block_counter + dbc_interval) & 0xff);
}
diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index 1f957c946c956..cf9ab347277f2 100644
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -37,6 +37,9 @@
* the value of current SYT_INTERVAL; e.g. initial value is not zero.
* @CIP_UNAWARE_SYT: For outgoing packet, the value in SYT field of CIP is 0xffff.
* For incoming packet, the value in SYT field of CIP is not handled.
+ * @CIP_DBC_IS_PAYLOAD_QUADLETS: Available for incoming packet, and only effective with
+ * CIP_DBC_IS_END_EVENT flag. The value of dbc field is the number of accumulated quadlets
+ * in CIP payload, instead of the number of accumulated data blocks.
*/
enum cip_flags {
CIP_NONBLOCKING = 0x00,
@@ -51,6 +54,7 @@ enum cip_flags {
CIP_NO_HEADER = 0x100,
CIP_UNALIGHED_DBC = 0x200,
CIP_UNAWARE_SYT = 0x400,
+ CIP_DBC_IS_PAYLOAD_QUADLETS = 0x800,
};

/**
--
2.43.0