ALSA: firewire-lib: code refactoring for cache position in sequence replay

When sequence replay is enabled for media clock recovery, current
implementation refers to cache of sequence descriptors in tx packets, then
fulfil sequence descriptors for rx packets. The initialization for rx
packets is done before starting packet streaming, while it can be postponed
till the cache has enough entries for the replay.

This commit refactors for the purpose as well as minor code change for
renaming of structure member.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230107023214.29132-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 08fd61a06e2e3aa42c3ad715a182938e10862257..5ecb449ff6fa05049248643feef37df3805b07ba 100644 (file)
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -546,16 +546,16 @@ static void pool_replayed_seq(struct amdtp_stream *s, struct seq_desc *descs, un
        struct amdtp_stream *target = s->ctx_data.rx.replay_target;
        const struct seq_desc *cache = target->ctx_data.tx.cache.descs;
        const unsigned int cache_size = target->ctx_data.tx.cache.size;
-       unsigned int cache_head = s->ctx_data.rx.cache_head;
+       unsigned int cache_pos = s->ctx_data.rx.cache_pos;
        int i;
 
        for (i = 0; i < count; ++i) {
-               descs[pos] = cache[cache_head];
-               cache_head = (cache_head + 1) % cache_size;
+               descs[pos] = cache[cache_pos];
+               cache_pos = (cache_pos + 1) % cache_size;
                pos = (pos + 1) % size;
        }
 
-       s->ctx_data.rx.cache_head = cache_head;
+       s->ctx_data.rx.cache_pos = cache_pos;
 }
 
 static void pool_seq_descs(struct amdtp_stream *s, struct seq_desc *descs, unsigned int size,
@@ -573,8 +573,8 @@ static void pool_seq_descs(struct amdtp_stream *s, struct seq_desc *descs, unsig
                } else {
                        struct amdtp_stream *tx = s->ctx_data.rx.replay_target;
                        const unsigned int cache_size = tx->ctx_data.tx.cache.size;
-                       const unsigned int cache_head = s->ctx_data.rx.cache_head;
-                       unsigned int cached_cycles = calculate_cached_cycle_count(tx, cache_head);
+                       const unsigned int cache_pos = s->ctx_data.rx.cache_pos;
+                       unsigned int cached_cycles = calculate_cached_cycle_count(tx, cache_pos);
 
                        if (cached_cycles > count && cached_cycles > cache_size / 2)
                                pool_seq_descs = pool_replayed_seq;
@@ -1181,6 +1181,9 @@ static void process_rx_packets_intermediately(struct fw_iso_context *context, u3
                s->ready_processing = true;
                wake_up(&s->ready_wait);
 
+               if (d->replay.enable)
+                       s->ctx_data.rx.cache_pos = 0;
+
                process_rx_packets(context, tstamp, header_length, ctx_header, private_data);
                if (amdtp_streaming_error(s))
                        return;
@@ -1909,7 +1912,6 @@ static int make_association(struct amdtp_domain *d)
                        }
 
                        rx->ctx_data.rx.replay_target = tx;
-                       rx->ctx_data.rx.cache_head = 0;
 
                        ++dst_index;
                }

diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index 094a140baa191fdc0914abaed26b5a6441f8b22b..f021c1f491372713800d9d9efcddbd02ddd1629f 100644 (file)
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -167,7 +167,7 @@ struct amdtp_stream {
                        unsigned int last_syt_offset;
 
                        struct amdtp_stream *replay_target;
-                       unsigned int cache_head;
+                       unsigned int cache_pos;
                } rx;
        } ctx_data;