nimble/ll: Recalculate effective TX/RX time after PHY update

If LE Coded is supported, effective TX/RX time may change after PHY
update due to following restriction:

  * connEffectiveMaxTxTimeCoded - the greater of 2704 and
    connEffectiveMaxTxTimeAvailable.
  * connEffectiveMaxTxTime - equal to connEffectiveMaxTxTimeUncoded
    while the connection is on an LE Uncoded PHY and equal to
    connEffectiveMaxTxTimeCoded while the connection is on the LE Coded
    PHY.

This means after PHY change we should recalculate effective TX/RX time
and update host if necessary.

Reference: Core 5.1, Vol B, Part B, 4.5.10.

nimble/controller/src/ble_ll_conn.c

@@ -1772,38 +1772,33 @@ ble_ll_conn_sm_new(struct ble_ll_conn_sm *connsm)
     SLIST_INSERT_HEAD(&g_ble_ll_conn_active_list, connsm, act_sle);
 }
 
-/**
- * Called when a remotes data length parameters change.
- *
- * Context: Link Layer task
- *
- * @param connsm
- * @param req
- */
 void
-ble_ll_conn_datalen_update(struct ble_ll_conn_sm *connsm,
-                           struct ble_ll_len_req *req)
+ble_ll_conn_update_eff_data_len(struct ble_ll_conn_sm *connsm)
 {
     int send_event;
     uint16_t eff_time;
     uint16_t eff_bytes;
 
-    /* Update parameters */
-    connsm->rem_max_rx_time = req->max_rx_time;
-    connsm->rem_max_tx_time = req->max_tx_time;
-    connsm->rem_max_rx_octets = req->max_rx_bytes;
-    connsm->rem_max_tx_octets = req->max_tx_bytes;
-
     /* Assume no event sent */
     send_event = 0;
 
     /* See if effective times have changed */
     eff_time = min(connsm->rem_max_tx_time, connsm->max_rx_time);
+#if MYNEWT_VAL(BLE_LL_CFG_FEAT_LE_CODED_PHY)
+    if (connsm->phy_data.cur_rx_phy == BLE_PHY_CODED) {
+        eff_time = max(eff_time, BLE_LL_CONN_SUPP_TIME_MIN_CODED);
+    }
+#endif
     if (eff_time != connsm->eff_max_rx_time) {
         connsm->eff_max_rx_time = eff_time;
         send_event = 1;
     }
     eff_time = min(connsm->rem_max_rx_time, connsm->max_tx_time);
+#if MYNEWT_VAL(BLE_LL_CFG_FEAT_LE_CODED_PHY)
+    if (connsm->phy_data.cur_tx_phy == BLE_PHY_CODED) {
+        eff_time = max(eff_time, BLE_LL_CONN_SUPP_TIME_MIN_CODED);
+    }
+#endif
     if (eff_time != connsm->eff_max_tx_time) {
         connsm->eff_max_tx_time = eff_time;
         send_event = 1;
@@ -2149,6 +2144,9 @@ ble_ll_conn_next_event(struct ble_ll_conn_sm *connsm)
         ble_ll_ctrl_phy_update_proc_complete(connsm);
 
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LE_CODED_PHY)
+        /* Recalculate effective connection parameters */
+        ble_ll_conn_update_eff_data_len(connsm);
+
         /*
          * If PHY in either direction was changed to coded, we assume that peer
          * does support LE Coded PHY even if features were not exchanged yet.

nimble/controller/src/ble_ll_conn_priv.h

@@ -134,8 +134,7 @@ void ble_ll_conn_ext_set_params(struct ble_ll_conn_sm *connsm,
 #endif
 
 struct ble_ll_conn_sm *ble_ll_conn_find_active_conn(uint16_t handle);
-void ble_ll_conn_datalen_update(struct ble_ll_conn_sm *connsm,
-                                struct ble_ll_len_req *req);
+void ble_ll_conn_update_eff_data_len(struct ble_ll_conn_sm *connsm);
 
 /* Advertising interface */
 int ble_ll_conn_slave_start(uint8_t *rxbuf, uint8_t pat,

nimble/controller/src/ble_ll_ctrl.c

@@ -210,8 +210,14 @@ ble_ll_ctrl_len_proc(struct ble_ll_conn_sm *connsm, uint8_t *dptr)
         (ctrl_req.max_tx_time < BLE_LL_CONN_SUPP_TIME_MIN)) {
         rc = 1;
     } else {
-        /* Update the connection with the new parameters */
-        ble_ll_conn_datalen_update(connsm, &ctrl_req);
+        /* Update parameters */
+        connsm->rem_max_rx_time = ctrl_req.max_rx_time;
+        connsm->rem_max_tx_time = ctrl_req.max_tx_time;
+        connsm->rem_max_rx_octets = ctrl_req.max_rx_bytes;
+        connsm->rem_max_tx_octets = ctrl_req.max_tx_bytes;
+
+        /* Recalculate effective connection parameters */
+        ble_ll_conn_update_eff_data_len(connsm);
         rc = 0;
     }