@@ -383,14 +383,14 @@ static unsigned int calculate_data_blocks(struct amdtp_stream *s,
return data_blocks;
}
-static unsigned int calculate_syt_offset(struct amdtp_stream *s)
+static unsigned int calculate_syt_offset(unsigned int *last_syt_offset,
+ unsigned int *syt_offset_state, enum cip_sfc sfc)
{
- unsigned int syt_offset, phase, index;
+ unsigned int syt_offset;
- if (s->ctx_data.rx.last_syt_offset < TICKS_PER_CYCLE) {
- if (!cip_sfc_is_base_44100(s->sfc))
- syt_offset = s->ctx_data.rx.last_syt_offset +
- s->ctx_data.rx.syt_offset_state;
+ if (*last_syt_offset < TICKS_PER_CYCLE) {
+ if (!cip_sfc_is_base_44100(sfc))
+ syt_offset = *last_syt_offset + *syt_offset_state;
else {
/*
* The time, in ticks, of the n'th SYT_INTERVAL sample is:
@@ -402,18 +402,19 @@ static unsigned int calculate_syt_offset(struct amdtp_stream *s)
* 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
* This code generates _exactly_ the same sequence.
*/
- phase = s->ctx_data.rx.syt_offset_state;
- index = phase % 13;
- syt_offset = s->ctx_data.rx.last_syt_offset;
+ unsigned int phase = *syt_offset_state;
+ unsigned int index = phase % 13;
+
+ syt_offset = *last_syt_offset;
syt_offset += 1386 + ((index && !(index & 3)) ||
phase == 146);
if (++phase >= 147)
phase = 0;
- s->ctx_data.rx.syt_offset_state = phase;
+ *syt_offset_state = phase;
}
} else
- syt_offset = s->ctx_data.rx.last_syt_offset - TICKS_PER_CYCLE;
- s->ctx_data.rx.last_syt_offset = syt_offset;
+ syt_offset = *last_syt_offset - TICKS_PER_CYCLE;
+ *last_syt_offset = syt_offset;
if (syt_offset >= TICKS_PER_CYCLE)
syt_offset = CIP_SYT_NO_INFO;
@@ -759,7 +760,9 @@ static void generate_ideal_pkt_descs(struct amdtp_stream *s,
unsigned int syt_offset;
desc->cycle = compute_it_cycle(*ctx_header, s->queue_size);
- syt_offset = calculate_syt_offset(s);
+ syt_offset = calculate_syt_offset(
+ &s->ctx_data.rx.last_syt_offset,
+ &s->ctx_data.rx.syt_offset_state, s->sfc);
if (syt_offset != CIP_SYT_NO_INFO) {
desc->syt = compute_syt(syt_offset, desc->cycle,
s->ctx_data.rx.transfer_delay);
When calculating syt offset, some states are stored in AMDTP stream structure. This is inconvenient when reuse the calculation from non-stream structure. This commit applies refactoring to helper function for the calculation so that the function doesn't touch AMDTP stream structure. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> --- sound/firewire/amdtp-stream.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-)