This is an automated email from the ASF dual-hosted git repository.
andk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-nimble.git
commit 64d5000f7257c774e17235c1f96d85eda28c0971
Author: Andrzej Kaczmarek <andrzej.kaczma...@codecoup.pl>
AuthorDate: Mon Sep 23 15:03:21 2024 +0200
nimble/ll: Fix periodic advertising event timing
This modifies padv event start time calculations to use single event
start time as anchor and calculate subsequent event start times as an
offset from that event.
This virtually removes drift due to rounding errors and avoids relative
drift of padv vs. BIG events.
---
nimble/controller/src/ble_ll_adv.c | 80 +++++++++++++++++++++-----------------
1 file changed, 45 insertions(+), 35 deletions(-)
diff --git a/nimble/controller/src/ble_ll_adv.c
b/nimble/controller/src/ble_ll_adv.c
index f194ec21c..d8eaaaf3a 100644
--- a/nimble/controller/src/ble_ll_adv.c
+++ b/nimble/controller/src/ble_ll_adv.c
@@ -170,10 +170,16 @@ struct ble_ll_adv_sm
uint8_t periodic_num_used_chans;
uint8_t periodic_chanmap[BLE_LL_CHAN_MAP_LEN];
uint16_t periodic_adv_itvl;
- uint32_t periodic_adv_itvl_ticks;
- uint8_t periodic_adv_itvl_rem_us;
- uint8_t periodic_adv_event_start_time_remainder;
- uint32_t periodic_adv_event_start_time;
+
+ uint32_t padv_itvl_us;
+
+ uint16_t padv_anchor_offset;
+ uint32_t padv_anchor;
+ uint8_t padv_anchor_rem_us;
+
+ uint32_t padv_event_start;
+ uint8_t padv_event_start_rem_us;
+
struct ble_ll_adv_sync periodic_sync[2];
struct ble_npl_event adv_periodic_txdone_ev;
#if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_PERIODIC_ADV_SYNC_TRANSFER)
@@ -639,20 +645,20 @@ ble_ll_adv_put_syncinfo(struct ble_ll_adv_sm *advsm,
conn_cnt = connsm->event_cntr;
/* get anchor for conn event that is before
periodic_adv_event_start_time */
- while (LL_TMR_GT(anchor_ticks, advsm->periodic_adv_event_start_time)) {
+ while (LL_TMR_GT(anchor_ticks, advsm->padv_event_start)) {
ble_ll_conn_get_anchor(connsm, --conn_cnt, &anchor_ticks,
&anchor_rem_us);
}
- offset = ble_ll_tmr_t2u(advsm->periodic_adv_event_start_time -
anchor_ticks);
+ offset = ble_ll_tmr_t2u(advsm->padv_event_start - anchor_ticks);
offset -= anchor_rem_us;
- offset += advsm->periodic_adv_event_start_time_remainder;
+ offset += advsm->padv_event_start_rem_us;
/* connEventCount */
put_le16(conn_event_cnt, conn_cnt);
#endif
} else {
- anchor_ticks = advsm->periodic_adv_event_start_time;
- anchor_rem_us = advsm->periodic_adv_event_start_time_remainder;
+ anchor_ticks = advsm->padv_event_start;
+ anchor_rem_us = advsm->padv_event_start_rem_us;
itvl_us = advsm->periodic_adv_itvl * BLE_LL_ADV_PERIODIC_ITVL;
/* Get periodic event that is past AUX start time (so that we always
@@ -2420,7 +2426,7 @@ ble_ll_adv_periodic_schedule_first(struct ble_ll_adv_sm
*advsm,
* Preincrement event counter as we later send this in PDU so make sure
* same values are used
*/
- chan = ble_ll_utils_dci_csa2(++advsm->periodic_event_cntr,
+ chan = ble_ll_utils_dci_csa2(advsm->periodic_event_cntr,
advsm->periodic_channel_id,
advsm->periodic_num_used_chans,
advsm->periodic_chanmap);
@@ -2432,14 +2438,20 @@ ble_ll_adv_periodic_schedule_first(struct ble_ll_adv_sm
*advsm,
sch = &sync->sch;
- ble_ll_tmr_add_u(&advsm->periodic_adv_event_start_time,
- &advsm->periodic_adv_event_start_time_remainder,
- advsm->periodic_adv_itvl_rem_us);
+ advsm->padv_event_start = advsm->padv_anchor;
+ advsm->padv_event_start_rem_us = advsm->padv_anchor_rem_us;
+ ble_ll_tmr_add(&advsm->padv_event_start, &advsm->padv_event_start_rem_us,
+ advsm->padv_itvl_us * advsm->padv_anchor_offset);
+
+ if (advsm->padv_anchor_offset == UINT16_MAX) {
+ advsm->padv_anchor_offset = 0;
+ advsm->padv_anchor = advsm->padv_event_start;
+ advsm->padv_anchor_rem_us = advsm->padv_event_start_rem_us;
+ }
- sch->start_time = advsm->periodic_adv_event_start_time;
- sch->remainder = advsm->periodic_adv_event_start_time_remainder;
- sch->end_time = sch->start_time + ble_ll_tmr_u2t_up(max_usecs);
- sch->start_time -= g_ble_ll_sched_offset_ticks;
+ sch->start_time = advsm->padv_event_start - g_ble_ll_sched_offset_ticks;
+ sch->remainder = advsm->padv_event_start_rem_us;
+ sch->end_time = advsm->padv_event_start + ble_ll_tmr_u2t_up(max_usecs);
rc = ble_ll_sched_periodic_adv(sch, first_pdu);
if (rc) {
@@ -2451,10 +2463,14 @@ ble_ll_adv_periodic_schedule_first(struct ble_ll_adv_sm
*advsm,
sync->start_time = sch->start_time + g_ble_ll_sched_offset_ticks;
assert(first_pdu ||
- (sync->start_time == advsm->periodic_adv_event_start_time));
+ (sync->start_time == advsm->padv_event_start));
- /* The event start time is when we start transmission of the SYNC PDU */
- advsm->periodic_adv_event_start_time = sync->start_time;
+ if (first_pdu) {
+ /* Need to update anchor on 1st PDU since it's start time can be
changed
+ * while scheduling */
+ advsm->padv_anchor = sync->start_time;
+ advsm->padv_event_start = sync->start_time;
+ }
}
static void
@@ -2535,8 +2551,8 @@ ble_ll_adv_periodic_schedule_next(struct ble_ll_adv_sm
*advsm)
* is scheduled past advertising interval.
*/
if (sync->auxptr_zero ||
- (LL_TMR_GT(sch->end_time, advsm->periodic_adv_event_start_time +
- advsm->periodic_adv_itvl_ticks))) {
+ (LL_TMR_GT(sch->end_time, advsm->padv_event_start +
+ advsm->periodic_adv_itvl))) {
STATS_INC(ble_ll_stats, periodic_chain_drop_event);
ble_ll_sched_rmv_elem(&sync->sch);
}
@@ -2560,7 +2576,9 @@ ble_ll_adv_sync_schedule(struct ble_ll_adv_sm *advsm,
bool first_pdu)
static void
ble_ll_adv_reschedule_periodic_event(struct ble_ll_adv_sm *advsm)
{
- advsm->periodic_adv_event_start_time += advsm->periodic_adv_itvl_ticks;
+ advsm->periodic_event_cntr++;
+ advsm->padv_anchor_offset++;
+
ble_ll_adv_sync_schedule(advsm, false);
}
@@ -2634,8 +2652,6 @@ ble_ll_adv_periodic_event_done(struct ble_npl_event *ev)
static void
ble_ll_adv_sm_start_periodic(struct ble_ll_adv_sm *advsm)
{
- uint32_t usecs;
-
/*
* The Advertising DID is not required to change when a SyncInfo field is
* added to or removed from an advertising set. However, if it does not
@@ -2660,16 +2676,9 @@ ble_ll_adv_sm_start_periodic(struct ble_ll_adv_sm *advsm)
(advsm->periodic_access_addr & 0x0000ffff);
advsm->periodic_crcinit = ble_ll_rand() & 0xffffff;
- usecs = (uint32_t)advsm->periodic_adv_itvl * BLE_LL_ADV_PERIODIC_ITVL;
- advsm->periodic_adv_itvl_ticks = ble_ll_tmr_u2t_r(usecs,
-
&advsm->periodic_adv_itvl_rem_us);
-
- /* There is no point in starting periodic advertising until next
advertising
- * event since SyncInfo is needed for synchronization
- */
- advsm->periodic_adv_event_start_time_remainder = 0;
- advsm->periodic_adv_event_start_time = advsm->adv_pdu_start_time +
- ble_ll_tmr_u2t(advsm->adv_itvl_usecs + 5000);
+ advsm->padv_anchor_offset = 1;
+ advsm->padv_anchor = ble_ll_tmr_get();
+ advsm->padv_anchor_rem_us = 0;
ble_ll_adv_sync_schedule(advsm, true);
}
@@ -3977,6 +3986,7 @@ ble_ll_adv_periodic_set_param(const uint8_t *cmdbuf,
uint8_t len)
}
advsm->periodic_adv_itvl = adv_itvl_max;
+ advsm->padv_itvl_us = adv_itvl_max * BLE_LL_ADV_PERIODIC_ITVL;
advsm->periodic_adv_props = props;
ble_ll_adv_flags_set(advsm, BLE_LL_ADV_SM_FLAG_PERIODIC_CONFIGURED);
