ALSA: firewire-lib: fix initial value of data block count for IR cont…

…ext without CIP_DBC_IS_END_EVENT For IR context, ALSA IEC 61883-1/6 engine uses initial value of data block counter as UINT_MAX, to detect first isochronous packet in the middle of packet streaming. At present, when CIP_DBC_IS_END_EVENT is not used (i.e. for drivers except for ALSA fireworks driver), the initial value is used as is for tracepoints event. However, the engine can detect the value of dbc field in the payload of first isochronous packet and the value should be assigned to the event. This commit fixes the bug. Fixes: 7686486 ("ALSA: firewire-lib: cache next data_block_counter after probing tracepoints event for IR context") Signed-off-by: Takashi Sakamoto <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
jb55 · Jul 8, 2019 · 4ece7f6 · 4ece7f6
1 parent 7fbf909
commit 4ece7f6
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
@@ -654,8 +654,10 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 			*dbc = 0;
 	}
 
-	if (err >= 0 && s->flags & CIP_DBC_IS_END_EVENT)
-		s->data_block_counter = *dbc;
+	if (err < 0)
+		return err;
+
+	s->data_block_counter = *dbc;
 
 	trace_amdtp_packet(s, cycle, cip_header, *payload_length, *data_blocks,
 			   index);