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ALSA: firewire-lib: fix to process MIDI conformant data channel for AM824 format 

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: e335425b65 ("ALSA: firewire-lib: split helper function to check incoming CIP header")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
alistair/sunxi64-5.4-dsi
Takashi Sakamoto 2019-06-28 14:53:31 +09:00 committed by Takashi Iwai
parent 76864868db
commit 973b059ca9
1 changed files with 14 additions and 12 deletions
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26
sound/firewire/amdtp-stream.c
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@ -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, &params) < 0)