In IEC 61883-6, 8 MIDI data streams are multiplexed into single MIDI conformant data channel. The index of stream is calculated by modulo 8 of the value of data block counter. Therefore data block processing layer requires valid value of data block counter.
In recent changes of ALSA IEC 61883-1/6 engine, the value of data block counter is changed before calling data block processing layer. This brings miss detection of MIDI messages in non-blocking transmission method is used.
This commit fixes the bug by changing chached data block counter after calling data block processing layer.
Fixes: e335425b6596 ("ALSA: firewire-lib: split helper function to check incoming CIP header") Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/amdtp-stream.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index b341bd86605e..91b890241840 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -614,11 +614,10 @@ static int check_cip_header(struct amdtp_stream *s, const __be32 *buf, static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle, const __be32 *ctx_header, unsigned int *payload_length, - unsigned int *data_blocks, + unsigned int *data_blocks, unsigned int *dbc, unsigned int *syt, unsigned int index) { const __be32 *cip_header; - unsigned int dbc; int err;
*payload_length = be32_to_cpu(ctx_header[0]) >> ISO_DATA_LENGTH_SHIFT; @@ -633,32 +632,28 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle, if (!(s->flags & CIP_NO_HEADER)) { cip_header = ctx_header + 2; err = check_cip_header(s, cip_header, *payload_length, - data_blocks, &dbc, syt); + data_blocks, dbc, syt); if (err < 0) { if (err != -EAGAIN) return err;
*data_blocks = 0; - dbc = s->data_block_counter; } } else { cip_header = NULL; err = 0; *data_blocks = *payload_length / sizeof(__be32) / s->data_block_quadlets; - dbc = s->data_block_counter; + *dbc = s->data_block_counter; *syt = 0; }
if (err >= 0 && s->flags & CIP_DBC_IS_END_EVENT) - s->data_block_counter = dbc; + s->data_block_counter = *dbc;
trace_amdtp_packet(s, cycle, cip_header, *payload_length, *data_blocks, index);
- if (err >= 0 && !(s->flags & CIP_DBC_IS_END_EVENT)) - s->data_block_counter = (dbc + *data_blocks) & 0xff; - return err; }
@@ -761,7 +756,8 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, for (i = 0; i < packets; i++) { u32 cycle; unsigned int payload_length; - unsigned int data_block; + unsigned int data_blocks; + unsigned int dbc; unsigned int syt; __be32 *buffer; unsigned int pcm_frames = 0; @@ -771,13 +767,19 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
cycle = compute_cycle_count(ctx_header[1]); err = parse_ir_ctx_header(s, cycle, ctx_header, &payload_length, - &data_block, &syt, i); + &data_blocks, &dbc, &syt, i); if (err < 0 && err != -EAGAIN) break; + if (err >= 0) { buffer = s->buffer.packets[s->packet_index].buffer; pcm_frames = s->process_data_blocks(s, buffer, - data_block, &syt); + data_blocks, &syt); + + if (!(s->flags & CIP_DBC_IS_END_EVENT)) { + s->data_block_counter = + (dbc + data_blocks) & 0xff; + } }
if (queue_in_packet(s, ¶ms) < 0)