On Tue, 11 Apr 2017 13:33:18 +0200, Takashi Sakamoto wrote:
During packet streaming, maximum length of payload for isochronous packet is invariable, therefore no need to recalculate. Current ALSA IEC 61883-1/6 engine calls a function to calculate it 8,000 or more times per second for incoming packet processing.
This commit adds a member to have maximum length of payload into 'struct amdtp_stream', to reduces the function calls. At first callback from isochronous context, the length is calculated and stored for later processing.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp
Applied, thanks.
Takashi
sound/firewire/amdtp-stream.c | 9 +++++---- sound/firewire/amdtp-stream.h | 1 + 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index f6af8e6..9e6f54f 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -412,8 +412,7 @@ static inline int queue_out_packet(struct amdtp_stream *s,
static inline int queue_in_packet(struct amdtp_stream *s) {
- return queue_packet(s, IN_PACKET_HEADER_SIZE,
amdtp_stream_get_max_payload(s));
- return queue_packet(s, IN_PACKET_HEADER_SIZE, s->max_payload_length);
}
static int handle_out_packet(struct amdtp_stream *s, @@ -713,12 +712,12 @@ static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, cycle = decrement_cycle_count(cycle, packets);
/* For buffer-over-run prevention. */
- max_payload_length = amdtp_stream_get_max_payload(s);
max_payload_length = s->max_payload_length;
for (i = 0; i < packets; i++) { cycle = increment_cycle_count(cycle, 1);
/* The number of quadlets in this packet */
/* The number of bytes in this packet */@@ -751,6 +750,8 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context, u32 cycle; unsigned int packets;
- s->max_payload_length = amdtp_stream_get_max_payload(s);
- /*
- For in-stream, first packet has come.
- For out-stream, prepared to transmit first packet
diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h index 2bd4de4..7e88317 100644 --- a/sound/firewire/amdtp-stream.h +++ b/sound/firewire/amdtp-stream.h @@ -110,6 +110,7 @@ struct amdtp_stream { int (*handle_packet)(struct amdtp_stream *s, unsigned int payload_quadlets, unsigned int cycle, unsigned int index);
unsigned int max_payload_length;
/* For CIP headers. */ unsigned int source_node_id_field;
-- 2.9.3