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bluetooth: controller: Vendor specific ticker resolution margin

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With sub-microsecond resolution in ticker, it is not necessary to add a
precision margin to the conn_offset. A macro is created to allow setting
the margin to something other than the hard coded 2 * EVENT_JITTER_US.

Signed-off-by: Morten Priess <mtpr@oticon.com>
This commit is contained in:
Morten Priess 2019-10-26 16:54:24 +02:00 • committed by Alberto Escolar
commit 89ab68f242
3 changed files with 10 additions and 4 deletions
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2
subsys/bluetooth/controller/ll_sw/nordic/lll/lll_scan.c
View file

@ -703,7 +703,7 @@ static inline u32_t isr_rx_pdu(struct lll_scan *lll, u8_t devmatch_ok,
evt = HDR_LLL2EVT(lll);
if (pdu_end_us > (HAL_TICKER_TICKS_TO_US(evt->ticks_slot) -
502 - EVENT_OVERHEAD_START_US -
(EVENT_JITTER_US << 1))) {
EVENT_TICKER_RES_MARGIN_US)) {
return -ETIME;
}

6
subsys/bluetooth/controller/ll_sw/nordic/lll/lll_vendor.h
View file

@ -14,6 +14,12 @@
*/
#define EVENT_OVERHEAD_END_US 40
#define EVENT_JITTER_US 16
/* Ticker resolution margin
* Needed due to the lack of fine timing resolution in ticker_start
* and ticker_update. Set to 32 us, which is ~1 tick with 32768 Hz
* clock.
*/
#define EVENT_TICKER_RES_MARGIN_US 32
#define EVENT_RX_JITTER_US(phy) 16 /* Radio Rx timing uncertainty */
#define EVENT_RX_TO_US(phy) ((((((phy)&0x03) + 4)<<3)/BIT((((phy)&0x3)>>1))) + \

6
subsys/bluetooth/controller/ll_sw/ull_slave.c
View file

@ -232,7 +232,7 @@ void ull_slave_setup(memq_link_t *link, struct node_rx_hdr *rx,
conn_offset_us = ftr->us_radio_end;
conn_offset_us += ((u64_t)win_offset + 1) * 1250U;
conn_offset_us -= EVENT_OVERHEAD_START_US;
conn_offset_us -= EVENT_JITTER_US << 1;
conn_offset_us -= EVENT_TICKER_RES_MARGIN_US;
conn_offset_us -= EVENT_JITTER_US;
conn_offset_us -= ftr->us_radio_rdy;
@ -317,7 +317,7 @@ void ull_slave_done(struct node_rx_event_done *done, u32_t *ticks_drift_plus,
done->extra.slave.preamble_to_addr_us;
start_to_address_expected_us = EVENT_JITTER_US +
(EVENT_JITTER_US << 1) +
EVENT_TICKER_RES_MARGIN_US +
window_widening_event_us +
preamble_to_addr_us;
@ -332,7 +332,7 @@ void ull_slave_done(struct node_rx_event_done *done, u32_t *ticks_drift_plus,
HAL_TICKER_US_TO_TICKS(start_to_address_actual_us);
*ticks_drift_minus =
HAL_TICKER_US_TO_TICKS(EVENT_JITTER_US +
(EVENT_JITTER_US << 1) +
EVENT_TICKER_RES_MARGIN_US +
preamble_to_addr_us);
}
}