Bluetooth: Controller: Fix Sync Failed to be Established on no memory

Update implementation to generate Periodic Sync Failed to be
Established when Sync Established message could not be
generate due to lack of free node rx buffers and when there
is sync lost before sync established message could be
generated.

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

Author: cvinayak

subsys/bluetooth/controller/ll_sw/ull_sync.c

@@ -86,9 +86,6 @@ static void *sync_free;
 static struct k_sem sem_ticker_cb;
 #endif /* CONFIG_BT_CTLR_DF_SCAN_CTE_RX */
 
-static memq_link_t link_lll_prepare;
-static struct mayfly mfy_lll_prepare = { 0, 0, &link_lll_prepare, NULL, lll_sync_prepare };
-
 uint8_t ll_sync_create(uint8_t options, uint8_t sid, uint8_t adv_addr_type,
 			    uint8_t *adv_addr, uint16_t skip,
 			    uint16_t sync_timeout, uint8_t sync_cte_type)
@@ -720,7 +717,7 @@ void ull_sync_setup(struct ll_scan_set *scan, struct ll_scan_aux_set *aux,
 	}
 	ticks_slot_offset += HAL_TICKER_US_TO_TICKS(EVENT_OVERHEAD_START_US);
 
-	mfy_lll_prepare.fp = lll_sync_create_prepare;
+	sync->lll_sync_prepare = lll_sync_create_prepare;
 
 	ret = ticker_start(TICKER_INSTANCE_ID_CTLR, TICKER_USER_ID_ULL_HIGH,
 			   (TICKER_ID_SCAN_SYNC_BASE + sync_handle),
@@ -758,12 +755,14 @@ void ull_sync_setup_complete(struct ll_scan_set *scan)
 void ull_sync_established_report(memq_link_t *link, struct node_rx_hdr *rx)
 {
 	struct node_rx_pdu *rx_establ;
-	struct ll_sync_set *ull_sync;
+	struct ll_sync_set *sync;
 	struct node_rx_ftr *ftr;
 	struct node_rx_sync *se;
 	struct lll_sync *lll;
 
 	ftr = &rx->rx_ftr;
+	lll = ftr->param;
+	sync = HDR_LLL2ULL(lll);
 
 #if defined(CONFIG_BT_CTLR_SYNC_PERIODIC_CTE_TYPE_FILTERING)
 	enum sync_status sync_status;
@@ -773,8 +772,6 @@ void ull_sync_established_report(memq_link_t *link, struct node_rx_hdr *rx)
 #else
 	struct pdu_cte_info *rx_cte_info;
 
-	lll = ftr->param;
-
 	rx_cte_info = pdu_cte_info_get((struct pdu_adv *)((struct node_rx_pdu *)rx)->pdu);
 	if (rx_cte_info != NULL) {
 		sync_status = lll_sync_cte_is_allowed(lll->cte_type, lll->filter_policy,
@@ -794,15 +791,10 @@ void ull_sync_established_report(memq_link_t *link, struct node_rx_hdr *rx)
 	if (1) {
 #endif /* !CONFIG_BT_CTLR_SYNC_PERIODIC_CTE_TYPE_FILTERING */
 
-		/* Set the sync handle corresponding to the LLL context passed in the node rx
-		 * footer field.
-		 */
-		lll = ftr->param;
-		ull_sync = HDR_LLL2ULL(lll);
-
 		/* Prepare and dispatch sync notification */
-		rx_establ = (void *)ull_sync->node_rx_sync_estab;
+		rx_establ = (void *)sync->node_rx_sync_estab;
 		rx_establ->hdr.type = NODE_RX_TYPE_SYNC;
+		rx_establ->hdr.handle = ull_sync_handle_get(sync);
 		se = (void *)rx_establ->pdu;
 
 #if defined(CONFIG_BT_CTLR_SYNC_PERIODIC_CTE_TYPE_FILTERING)
@@ -812,7 +804,7 @@ void ull_sync_established_report(memq_link_t *link, struct node_rx_hdr *rx)
 
 #if !defined(CONFIG_BT_CTLR_CTEINLINE_SUPPORT)
 		/* Notify done event handler to terminate sync scan if required. */
-		ull_sync->is_term = (sync_status == SYNC_STAT_TERM);
+		sync->is_term = (sync_status == SYNC_STAT_TERM);
 #endif /* !CONFIG_BT_CTLR_CTEINLINE_SUPPORT */
 #else
 		se->status = BT_HCI_ERR_SUCCESS;
@@ -836,8 +828,9 @@ void ull_sync_established_report(memq_link_t *link, struct node_rx_hdr *rx)
 
 	if (1) {
 #endif /* !CONFIG_BT_CTLR_SYNC_PERIODIC_CTE_TYPE_FILTERING */
+
 		/* Switch sync event prepare function to one reposnsible for regular PDUs receive */
-		mfy_lll_prepare.fp = lll_sync_prepare;
+		sync->lll_sync_prepare = lll_sync_prepare;
 
 		/* Change node type to appropriately handle periodic
 		 * advertising PDU report.
@@ -1128,6 +1121,9 @@ static void ticker_cb(uint32_t ticks_at_expire, uint32_t ticks_drift,
 		      uint32_t remainder, uint16_t lazy, uint8_t force,
 		      void *param)
 {
+	static memq_link_t link_lll_prepare;
+	static struct mayfly mfy_lll_prepare = {
+		0, 0, &link_lll_prepare, NULL, NULL};
 	static struct lll_prepare_param p;
 	struct ll_sync_set *sync = param;
 	struct lll_sync *lll;
@@ -1152,9 +1148,11 @@ static void ticker_cb(uint32_t ticks_at_expire, uint32_t ticks_drift,
 	p.force = force;
 	p.param = lll;
 	mfy_lll_prepare.param = &p;
+	mfy_lll_prepare.fp = sync->lll_sync_prepare;
 
 	/* Kick LLL prepare */
-	ret = mayfly_enqueue(TICKER_USER_ID_ULL_HIGH, TICKER_USER_ID_LLL, 0, &mfy_lll_prepare);
+	ret = mayfly_enqueue(TICKER_USER_ID_ULL_HIGH, TICKER_USER_ID_LLL, 0,
+			     &mfy_lll_prepare);
 	LL_ASSERT(!ret);
 
 	DEBUG_RADIO_PREPARE_O(1);
@@ -1235,9 +1233,17 @@ static void ticker_stop_sync_lost_op_cb(uint32_t status, void *param)
 
 static void sync_lost(void *param)
 {
-	struct ll_sync_set *sync = param;
+	struct ll_sync_set *sync;
 	struct node_rx_pdu *rx;
 
+	/* sync established was not generated yet, no free node rx */
+	sync = param;
+	if (sync->lll_sync_prepare != lll_sync_prepare) {
+		sync_expire(param);
+
+		return;
+	}
+
 	/* Generate Periodic advertising sync lost */
 	rx = (void *)&sync->node_rx_lost;
 	rx->hdr.handle = ull_sync_handle_get(sync);

subsys/bluetooth/controller/ll_sw/ull_sync_types.h

@@ -21,6 +21,8 @@ struct ll_sync_set {
 	uint16_t volatile timeout_reload; /* Non-zero when sync established */
 	uint16_t timeout_expire;
 
+	void (*lll_sync_prepare)(void *param);
+
 #if defined(CONFIG_BT_CTLR_CHECK_SAME_PEER_SYNC) || \
 	defined(CONFIG_BT_CTLR_SYNC_PERIODIC_ADI_SUPPORT)
 	uint8_t peer_id_addr[BDADDR_SIZE];