| Message ID | 9b88a0238679d24aa5d68a4c473483943a8ea2b6.1715427163.git.pav@iki.fi |
|---|---|
| State | New |
| Headers | show |
| Series | [BlueZ] client: fix ISO send data rate | expand |
Hi Pauli, On Sat, May 11, 2024 at 7:34 AM Pauli Virtanen <pav@iki.fi> wrote: > > We are sending data to controller at wrong average rate not equal to > 1 packet / SDU interval, if Transport_Latency is not an integer multiple > of SDU_Interval. The calculation currently may also give zero, so no > data gets sent. > > We are sending data in bursts of num ~= Transport_Latency/SDU_Interval > packets, in hopes that possibly larger timer interval makes things more > efficient. > > Fix the data rate by sending num packets every num*SDU_Interval, so that > the average data rate is correct. > > Also fix use of itimerspect.it_value with TFD_TIMER_ABSTIME. The value > set previously is going to always be in the past in CLOCK_MONOTONIC so > just set it to 1, and leave sending the initial packets to the main > loop. > --- > > Notes: > This assumes kernel shall set qos.interval to SDU_Interval and not > ISO_Interval. > > client/player.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/client/player.c b/client/player.c > index 7f67425aa..8d17022de 100644 > --- a/client/player.c > +++ b/client/player.c > @@ -5066,22 +5066,30 @@ static int transport_send(struct transport *transport, int fd, > if (timer_fd < 0) > return -errno; > > + /* Send data in bursts of > + * num = ROUND_CLOSEST(Transport_Latency (ms) / SDU_Interval (us)) > + * with average data rate = 1 packet / SDU_Interval > + */ > + transport->num = ROUND_CLOSEST(qos->latency * 1000, qos->interval); > + if (!transport->num) > + transport->num = 1; > + > memset(&ts, 0, sizeof(ts)); > - ts.it_value.tv_nsec = qos->latency * 1000000; > - ts.it_interval.tv_nsec = qos->latency * 1000000; > + ts.it_value.tv_nsec = 1; > + ts.it_interval.tv_nsec = transport->num * qos->interval * 1000; > > - if (timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &ts, NULL) < 0) > + if (timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &ts, NULL) < 0) { > + close(timer_fd); > return -errno; > + } > > transport->fd = fd; > - /* num of packets = ROUND_CLOSEST(latency (ms) / interval (us)) */ > - transport->num = ROUND_CLOSEST(qos->latency * 1000, qos->interval); > transport->timer_io = io_new(timer_fd); > > io_set_read_handler(transport->timer_io, transport_timer_read, > transport, NULL); > > - return transport_send_seq(transport, fd, 1); The above was actually done on purpose so we are always one interval ahead to keep controller buffer full as much as possible. > + return 0; > } > > static void cmd_send_transport(int argc, char *argv[]) > -- > 2.45.0 > >
diff --git a/client/player.c b/client/player.c index 7f67425aa..8d17022de 100644 --- a/client/player.c +++ b/client/player.c @@ -5066,22 +5066,30 @@ static int transport_send(struct transport *transport, int fd, if (timer_fd < 0) return -errno; + /* Send data in bursts of + * num = ROUND_CLOSEST(Transport_Latency (ms) / SDU_Interval (us)) + * with average data rate = 1 packet / SDU_Interval + */ + transport->num = ROUND_CLOSEST(qos->latency * 1000, qos->interval); + if (!transport->num) + transport->num = 1; + memset(&ts, 0, sizeof(ts)); - ts.it_value.tv_nsec = qos->latency * 1000000; - ts.it_interval.tv_nsec = qos->latency * 1000000; + ts.it_value.tv_nsec = 1; + ts.it_interval.tv_nsec = transport->num * qos->interval * 1000; - if (timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &ts, NULL) < 0) + if (timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &ts, NULL) < 0) { + close(timer_fd); return -errno; + } transport->fd = fd; - /* num of packets = ROUND_CLOSEST(latency (ms) / interval (us)) */ - transport->num = ROUND_CLOSEST(qos->latency * 1000, qos->interval); transport->timer_io = io_new(timer_fd); io_set_read_handler(transport->timer_io, transport_timer_read, transport, NULL); - return transport_send_seq(transport, fd, 1); + return 0; } static void cmd_send_transport(int argc, char *argv[])
We are sending data to controller at wrong average rate not equal to 1 packet / SDU interval, if Transport_Latency is not an integer multiple of SDU_Interval. The calculation currently may also give zero, so no data gets sent. We are sending data in bursts of num ~= Transport_Latency/SDU_Interval packets, in hopes that possibly larger timer interval makes things more efficient. Fix the data rate by sending num packets every num*SDU_Interval, so that the average data rate is correct. Also fix use of itimerspect.it_value with TFD_TIMER_ABSTIME. The value set previously is going to always be in the past in CLOCK_MONOTONIC so just set it to 1, and leave sending the initial packets to the main loop. --- Notes: This assumes kernel shall set qos.interval to SDU_Interval and not ISO_Interval. client/player.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)