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| author |   Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2020-05-08 13:36:31 +0900 |
|---|---|---|
| committer |   Takashi Iwai <tiwai@suse.de> | 2020-05-08 09:45:46 +0200 |
| commit | 816d84826e89399858a1f086d78f5a4dd615a9ae (patch) | |
| tree | 5d29a9e4720e14c6f9cc18a6c622d3ea14b75cc5 /sound/firewire | |
| parent | ALSA: firewire-lib: code refactoring for syt computation (diff) | |
| download | linux-dev-816d84826e89399858a1f086d78f5a4dd615a9ae.tar.xz linux-dev-816d84826e89399858a1f086d78f5a4dd615a9ae.zip | |
ALSA: firewire-lib: code refactoring for syt offset calculation
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>
Link: https://lore.kernel.org/r/20200508043635.349339-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire')
| -rw-r--r-- | sound/firewire/amdtp-stream.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index 1605ea4301ce..9041510cb6aa 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -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); |