Bluetooth: Controller: Introduce BT_CTLR_PERIPHERAL_ISO_RESERVE_MAX

Introduce BT_CTLR_PERIPHERAL_ISO_RESERVE_MAX Kconfig option
so that disabling this option will use minimum time
reservation and exercise the peripheral ISO connection event
continuation using is_abort_cb mechanism.

Signed-off-by: Vinayak Kariappa Chettimada <[email protected]>

Author: cvinayak

samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf

@@ -73,6 +73,7 @@ CONFIG_BT_CTLR_SCAN_AUX_SET=1
 CONFIG_BT_CTLR_ADV_RESERVE_MAX=n
 CONFIG_BT_CTLR_CENTRAL_RESERVE_MAX=n
 CONFIG_BT_CTLR_PERIPHERAL_RESERVE_MAX=n
+CONFIG_BT_CTLR_PERIPHERAL_ISO_RESERVE_MAX=n
 CONFIG_BT_CTLR_EVENT_OVERHEAD_RESERVE_MAX=y
 CONFIG_BT_CTLR_SLOT_RESERVATION_UPDATE=n
 CONFIG_BT_CTLR_SCAN_UNRESERVED=y

subsys/bluetooth/controller/Kconfig.ll_sw_split

@@ -767,6 +767,17 @@ config BT_CTLR_PERIPHERAL_RESERVE_MAX
 	  the is_abort_cb mechanism to decide on continuation of the connection
 	  event.
 
+config BT_CTLR_PERIPHERAL_ISO_RESERVE_MAX
+	bool "Use maximum data PDU size time reservation for Peripheral"
+	depends on BT_CTLR_PERIPHERAL_ISO
+	default y
+	help
+	  Use the maximum Peripheral CIG event time reservation.
+
+	  If maximum Peripheral CIG event time reservation is not enabled, then
+	  only time required to transmit or receive the burst number of CIS PDUs
+	  is reserved.
+
 config BT_CTLR_EVENT_OVERHEAD_RESERVE_MAX
 	bool "Reserve maximum event overhead in time reservations"
 	default y

subsys/bluetooth/controller/ll_sw/ull_conn_iso.c

@@ -1032,7 +1032,11 @@ void ull_conn_iso_start(struct ll_conn *conn, uint16_t cis_handle,
 
 		/* FIXME: Time reservation for interleaved packing */
 		/* Below is time reservation for sequential packing */
-		slot_us = cis->lll.sub_interval * cis->lll.nse;
+		if (IS_ENABLED(CONFIG_BT_CTLR_PERIPHERAL_ISO_RESERVE_MAX)) {
+			slot_us = cis->lll.sub_interval * cis->lll.nse;
+		} else {
+			slot_us = cis->lll.sub_interval * MAX(cis->lll.tx.bn, cis->lll.rx.bn);
+		}
 
 		if (IS_ENABLED(CONFIG_BT_CTLR_EVENT_OVERHEAD_RESERVE_MAX)) {
 			slot_us += EVENT_OVERHEAD_START_US + EVENT_OVERHEAD_END_US;