ALSA: firewire-lib: use packet descriptor for IT context

This commit uses packet descriptor to parse headers of IT context and
generate timing information for ideal sequence.

Signed-off-by: Takashi Sakamoto <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 2bea15151d4a85f300e50f18d28dc9c4352650e2..463c7a340a45afd92596b1d1f51d880bb67c81bf 100644 (file)
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -676,6 +676,38 @@ static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp)
        return increment_cycle_count(cycle, QUEUE_LENGTH);
 }
 
+static void generate_ideal_pkt_descs(struct amdtp_stream *s,
+                                    struct pkt_desc *descs,
+                                    const __be32 *ctx_header,
+                                    unsigned int packets)
+{
+       unsigned int dbc = s->data_block_counter;
+       int i;
+
+       for (i = 0; i < packets; ++i) {
+               struct pkt_desc *desc = descs + i;
+               unsigned int index = (s->packet_index + i) % QUEUE_LENGTH;
+
+               desc->cycle = compute_cycle_count(*ctx_header);
+               desc->syt = calculate_syt(s, desc->cycle);
+               desc->data_blocks = calculate_data_blocks(s, desc->syt);
+
+               if (s->flags & CIP_DBC_IS_END_EVENT)
+                       dbc = (dbc + desc->data_blocks) & 0xff;
+
+               desc->data_block_counter = dbc;
+
+               if (!(s->flags & CIP_DBC_IS_END_EVENT))
+                       dbc = (dbc + desc->data_blocks) & 0xff;
+
+               desc->ctx_payload = s->buffer.packets[index].buffer;
+
+               ++ctx_header;
+       }
+
+       s->data_block_counter = dbc;
+}
+
 static inline void cancel_stream(struct amdtp_stream *s)
 {
        s->packet_index = -1;
@@ -696,39 +728,29 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
        if (s->packet_index < 0)
                return;
 
+       generate_ideal_pkt_descs(s, s->pkt_descs, ctx_header, packets);
+
        for (i = 0; i < packets; ++i) {
-               u32 cycle;
-               unsigned int syt;
-               unsigned int data_blocks;
-               unsigned int dbc;
-               __be32 *buffer;
+               const struct pkt_desc *desc = s->pkt_descs + i;
                unsigned int pcm_frames;
+               unsigned int syt;
                struct {
                        struct fw_iso_packet params;
                        __be32 header[IT_PKT_HEADER_SIZE_CIP / sizeof(__be32)];
                } template = { {0}, {0} };
                struct snd_pcm_substream *pcm;
 
-               cycle = compute_it_cycle(*ctx_header);
-               syt = calculate_syt(s, cycle);
-               data_blocks = calculate_data_blocks(s, syt);
-               buffer = s->buffer.packets[s->packet_index].buffer;
-               dbc = s->data_block_counter;
-               pcm_frames = s->process_data_blocks(s, buffer, data_blocks, dbc);
+               pcm_frames = s->process_data_blocks(s, desc->ctx_payload,
+                               desc->data_blocks, desc->data_block_counter);
 
-               if (s->flags & CIP_DBC_IS_END_EVENT)
-                       dbc = (dbc + data_blocks) & 0xff;
-
-               if (s->ctx_data.rx.syt_override >= 0)
+               if (s->ctx_data.rx.syt_override < 0)
+                       syt = desc->syt;
+               else
                        syt = s->ctx_data.rx.syt_override;
 
-               build_it_pkt_header(s, cycle, &template.params, data_blocks,
-                                   dbc, syt, i);
-
-               if (!(s->flags & CIP_DBC_IS_END_EVENT))
-                       dbc = (dbc + data_blocks) & 0xff;
-
-               s->data_block_counter = dbc;
+               build_it_pkt_header(s, desc->cycle, &template.params,
+                                   desc->data_blocks, desc->data_block_counter,
+                                   syt, i);
 
                if (queue_out_packet(s, &template.params) < 0) {
                        cancel_stream(s);
@@ -738,8 +760,6 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
                pcm = READ_ONCE(s->pcm);
                if (pcm && pcm_frames > 0)
                        update_pcm_pointers(s, pcm, pcm_frames);
-
-               ++ctx_header;
        }
 
        fw_iso_context_queue_flush(s->context);