diff options
| -rw-r--r-- | sound/firewire/amdtp-stream.c | 51 |
1 files changed, 28 insertions, 23 deletions
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index 5ebdac2086c0..f43943fd962d 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -694,13 +694,12 @@ static int handle_in_packet_without_header(struct amdtp_stream *s, return 0; } -/* - * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On - * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent - * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second. - */ -static inline u32 compute_cycle_count(u32 tstamp) +// In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On +// the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent +// it. Thus, via Linux firewire subsystem, we can get the 3 bits for second. +static inline u32 compute_cycle_count(__be32 ctx_header_tstamp) { + u32 tstamp = be32_to_cpu(ctx_header_tstamp) & HEADER_TSTAMP_MASK; return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff); } @@ -712,6 +711,16 @@ static inline u32 increment_cycle_count(u32 cycle, unsigned int addend) return cycle; } +// Align to actual cycle count for the packet which is going to be scheduled. +// This module queued the same number of isochronous cycle as QUEUE_LENGTH to +// skip isochronous cycle, therefore it's OK to just increment the cycle by +// QUEUE_LENGTH for scheduled cycle. +static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp) +{ + u32 cycle = compute_cycle_count(ctx_header_tstamp); + return increment_cycle_count(cycle, QUEUE_LENGTH); +} + static inline void cancel_stream(struct amdtp_stream *s) { s->packet_index = -1; @@ -725,23 +734,23 @@ static void out_stream_callback(struct fw_iso_context *context, u32 tstamp, void *private_data) { struct amdtp_stream *s = private_data; - unsigned int i, packets = header_length / 4; - u32 cycle; + const __be32 *ctx_header = header; + unsigned int i, packets = header_length / sizeof(*ctx_header); if (s->packet_index < 0) return; - cycle = compute_cycle_count(tstamp); + for (i = 0; i < packets; ++i) { + u32 cycle; - /* Align to actual cycle count for the last packet. */ - cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); + cycle = compute_it_cycle(*ctx_header); - for (i = 0; i < packets; ++i) { - cycle = increment_cycle_count(cycle, 1); if (s->handle_packet(s, 0, cycle, i) < 0) { cancel_stream(s); return; } + + ++ctx_header; } fw_iso_context_queue_flush(s->context); @@ -767,10 +776,9 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, for (i = 0; i < packets; i++) { u32 iso_header = be32_to_cpu(ctx_header[0]); - unsigned int cycle; + u32 cycle; - tstamp = be32_to_cpu(ctx_header[1]) & HEADER_TSTAMP_MASK; - cycle = compute_cycle_count(tstamp); + cycle = compute_cycle_count(ctx_header[1]); /* The number of bytes in this packet */ payload_length = iso_header >> ISO_DATA_LENGTH_SHIFT; @@ -802,9 +810,8 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context, void *header, void *private_data) { struct amdtp_stream *s = private_data; - __be32 *ctx_header = header; + const __be32 *ctx_header = header; u32 cycle; - unsigned int packets; /* * For in-stream, first packet has come. @@ -814,8 +821,7 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context, wake_up(&s->callback_wait); if (s->direction == AMDTP_IN_STREAM) { - tstamp = be32_to_cpu(ctx_header[1]) & HEADER_TSTAMP_MASK; - cycle = compute_cycle_count(tstamp); + cycle = compute_cycle_count(ctx_header[1]); context->callback.sc = in_stream_callback; if (s->flags & CIP_NO_HEADER) @@ -823,9 +829,8 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context, else s->handle_packet = handle_in_packet; } else { - packets = header_length / 4; - cycle = compute_cycle_count(tstamp); - cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); + cycle = compute_it_cycle(*ctx_header); + context->callback.sc = out_stream_callback; if (s->flags & CIP_NO_HEADER) s->handle_packet = handle_out_packet_without_header; |