Bluetooth: Controller: Fix max PDU len radio config for BIS Ctrl PDUs

Fix missing radio configuration that limits the maximum PDU
len on reception to consider that Control PDU can be larger
than the max PDU size in the BIS parameters.
Use dedicated PDU buffer for transmission and reception of
BIG Control PDUs so that it is independent of maximum ISO
PDU length which can be less than BIG Control PDU length.

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

Author: cvinayak

subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/radio/radio.c

@@ -667,6 +667,18 @@ void *radio_pkt_decrypt_get(void)
 #error "Undefined HAL_RADIO_PDU_LEN_MAX."
 #endif
 
+#if defined(CONFIG_BT_CTLR_ADV_ISO) || defined(CONFIG_BT_CTLR_SYNC_ISO)
+/* Dedicated Rx PDU Buffer for Control PDU independent of node_rx with BIS Data
+ * PDU buffer
+ */
+static uint8_t pkt_big_ctrl[sizeof(struct pdu_big_ctrl)];
+
+void *radio_pkt_big_ctrl_get(void)
+{
+	return pkt_big_ctrl;
+}
+#endif /* CONFIG_BT_CTLR_ADV_ISO || CONFIG_BT_CTLR_SYNC_ISO */
+
 #if !defined(CONFIG_BT_CTLR_TIFS_HW)
 static uint8_t sw_tifs_toggle;
 /**

subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/radio/radio.h

@@ -94,6 +94,7 @@ uint32_t radio_crc_is_valid(void);
 void *radio_pkt_empty_get(void);
 void *radio_pkt_scratch_get(void);
 void *radio_pkt_decrypt_get(void);
+void *radio_pkt_big_ctrl_get(void);
 
 void radio_switch_complete_and_rx(uint8_t phy_rx);
 void radio_switch_complete_and_tx(uint8_t phy_rx, uint8_t flags_rx, uint8_t phy_tx,

subsys/bluetooth/controller/ll_sw/nordic/lll/lll_adv_iso.c

@@ -505,7 +505,7 @@ static void isr_tx_common(void *param,
 		 */
 		struct pdu_big_ctrl_term_ind *term;
 
-		pdu = radio_pkt_scratch_get();
+		pdu = radio_pkt_big_ctrl_get();
 		pdu->ll_id = PDU_BIS_LLID_CTRL;
 		pdu->cssn = lll->cssn;
 		pdu->cstf = 0U;
@@ -529,7 +529,7 @@ static void isr_tx_common(void *param,
 		 */
 		struct pdu_big_ctrl_chan_map_ind *chm;
 
-		pdu = radio_pkt_scratch_get();
+		pdu = radio_pkt_big_ctrl_get();
 		pdu->ll_id = PDU_BIS_LLID_CTRL;
 		pdu->cssn = lll->cssn;
 		pdu->cstf = 0U;
@@ -696,6 +696,21 @@ static void isr_tx_common(void *param,
 
 	/* Control subevent, then complete subevent and close radio use */
 	if (!bis) {
+		uint8_t pkt_flags;
+
+		pkt_flags = RADIO_PKT_CONF_FLAGS(RADIO_PKT_CONF_PDU_TYPE_BIS,
+						 lll->phy,
+						 RADIO_PKT_CONF_CTE_DISABLED);
+		if (lll->enc) {
+			radio_pkt_configure(RADIO_PKT_CONF_LENGTH_8BIT,
+					    (sizeof(struct pdu_big_ctrl) + PDU_MIC_SIZE),
+					    pkt_flags);
+		} else {
+			radio_pkt_configure(RADIO_PKT_CONF_LENGTH_8BIT,
+					    sizeof(struct pdu_big_ctrl),
+					    pkt_flags);
+		}
+
 		radio_switch_complete_and_disable();
 
 		radio_isr_set(isr_done_term, lll);

subsys/bluetooth/controller/ll_sw/nordic/lll/lll_sync_iso.c

@@ -563,22 +563,12 @@ static void isr_rx(void *param)
 		    lll->ctrl) {
 			lll->cssn_curr = lll->cssn_next;
 
-			/* By design, there shall alway be one free node rx
-			 * available for setting up radio for new PDU reception.
-			 * Control procedure handling does not consume any
-			 * node rx, hence checking for one free node rx is
-			 * sufficient.
-			 */
-			node_rx = ull_iso_pdu_rx_alloc_peek(1U);
-			LL_ASSERT(node_rx);
-
-			pdu = (void *)node_rx->pdu;
-			if (pdu->ll_id != PDU_BIS_LLID_CTRL) {
-				goto isr_rx_done;
+			/* Check the dedicated Control PDU buffer */
+			pdu = radio_pkt_big_ctrl_get();
+			if (pdu->ll_id == PDU_BIS_LLID_CTRL) {
+				isr_rx_ctrl_recv(lll, pdu);
 			}
 
-			isr_rx_ctrl_recv(lll, pdu);
-
 			goto isr_rx_done;
 		} else {
 			/* Check if there are 2 free rx buffers, one will be
@@ -794,6 +784,8 @@ static void isr_rx(void *param)
 
 	/* Control subevent */
 	if (!lll->ctrl && (lll->cssn_next != lll->cssn_curr)) {
+		uint8_t pkt_flags;
+
 		/* Receive the control PDU and close the BIG event
 		 *  there after.
 		 */
@@ -802,6 +794,22 @@ static void isr_rx(void *param)
 		/* control subevent to use bis = 0 and se_n = 1 */
 		bis = 0U;
 
+		/* Configure Radio to receive Control PDU that can have greater
+		 * PDU length than max_pdu length.
+		 */
+		pkt_flags = RADIO_PKT_CONF_FLAGS(RADIO_PKT_CONF_PDU_TYPE_BIS,
+						 lll->phy,
+						 RADIO_PKT_CONF_CTE_DISABLED);
+		if (lll->enc) {
+			radio_pkt_configure(RADIO_PKT_CONF_LENGTH_8BIT,
+					    (sizeof(struct pdu_big_ctrl) + PDU_MIC_SIZE),
+					    pkt_flags);
+		} else {
+			radio_pkt_configure(RADIO_PKT_CONF_LENGTH_8BIT,
+					    sizeof(struct pdu_big_ctrl),
+					    pkt_flags);
+		}
+
 		goto isr_rx_next_subevent;
 	}
 
@@ -997,31 +1005,52 @@ static void isr_rx(void *param)
 
 	lll_chan_set(data_chan_use);
 
-	/* By design, there shall alway be one free node rx available for
-	 * setting up radio for new PDU reception.
-	 */
-	node_rx = ull_iso_pdu_rx_alloc_peek(1U);
-	LL_ASSERT(node_rx);
-
 	/* Encryption */
 	if (lll->enc) {
 		uint64_t payload_count;
+		struct pdu_bis *pdu;
 
 		payload_count = lll->payload_count - lll->bn;
 		if (bis) {
 			payload_count += (lll->bn_curr - 1U) +
 					 (lll->ptc_curr * lll->pto);
+
+			/* By design, there shall alway be one free node rx
+			 * available for setting up radio for new PDU reception.
+			 */
+			node_rx = ull_iso_pdu_rx_alloc_peek(1U);
+			LL_ASSERT(node_rx);
+
+			pdu = (void *)node_rx->pdu;
+		} else {
+			/* Use the dedicated Control PDU buffer */
+			pdu = radio_pkt_big_ctrl_get();
 		}
 
 		lll->ccm_rx.counter = payload_count;
 
 		(void)memcpy(lll->ccm_rx.iv, lll->giv, 4U);
 		mem_xor_32(lll->ccm_rx.iv, lll->ccm_rx.iv, access_addr);
 
-		radio_pkt_rx_set(radio_ccm_rx_pkt_set(&lll->ccm_rx, lll->phy,
-						      node_rx->pdu));
+		radio_pkt_rx_set(radio_ccm_rx_pkt_set(&lll->ccm_rx, lll->phy, pdu));
+
 	} else {
-		radio_pkt_rx_set(node_rx->pdu);
+		struct pdu_bis *pdu;
+
+		if (bis) {
+			/* By design, there shall alway be one free node rx
+			 * available for setting up radio for new PDU reception.
+			 */
+			node_rx = ull_iso_pdu_rx_alloc_peek(1U);
+			LL_ASSERT(node_rx);
+
+			pdu = (void *)node_rx->pdu;
+		} else {
+			/* Use the dedicated Control PDU buffer */
+			pdu = radio_pkt_big_ctrl_get();
+		}
+
+		radio_pkt_rx_set(pdu);
 	}
 
 	radio_switch_complete_and_disable();