nimble/ll: Fix restarting RX on wfr while scanning

With this patch we move restarting RX on wfr while scanning to interrupt
context instead of LL context.
It is because we want to restart RX as fast as possible while scanning.
Also previous ble_phy_restart_rx call in LL context during
interrupts enabled was incorrect.

Author: rymanluk

nimble/controller/src/ble_ll_scan.c

@@ -1392,7 +1392,6 @@ ble_ll_scan_interrupted_event_cb(struct ble_npl_event *ev)
     }
 
     ble_ll_scan_chk_resume();
-    ble_phy_restart_rx();
 }
 
 /**
@@ -2512,9 +2511,45 @@ void
 ble_ll_scan_wfr_timer_exp(void)
 {
     struct ble_ll_scan_sm *scansm;
+    uint8_t chan;
+    int phy;
+    int rc;
+#if (BLE_LL_BT5_PHY_SUPPORTED == 1)
+    uint8_t phy_mode;
+#endif
 
     scansm = &g_ble_ll_scan_sm;
-    ble_ll_scan_interrupted(scansm);
+    if (scansm->cur_aux_data) {
+        /* We actually care about interrupted scan only for EXT ADV because only
+         * then we might consider to send truncated event to the host.
+         */
+        ble_ll_scan_interrupted(scansm);
+
+        /* Need to disable phy since we are going to move to BLE_LL_STATE_STANDBY
+         * or we will need to change channel to primary one
+         */
+        ble_phy_disable();
+
+        if (ble_ll_scan_window_chk(scansm, os_cputime_get32()) == 1) {
+            /* Outside the window scan */
+            ble_ll_state_set(BLE_LL_STATE_STANDBY);
+            return;
+        }
+
+        ble_ll_get_chan_to_scan(scansm, &chan, &phy);
+#if (BLE_LL_BT5_PHY_SUPPORTED == 1)
+        phy_mode = ble_ll_phy_to_phy_mode(phy, BLE_HCI_LE_PHY_CODED_ANY);
+        ble_phy_mode_set(phy_mode, phy_mode);
+#endif
+        rc = ble_phy_setchan(chan, BLE_ACCESS_ADDR_ADV, BLE_LL_CRCINIT_ADV);
+        BLE_LL_ASSERT(rc == 0);
+    }
+
+    if (scansm->scan_rsp_pending) {
+        ble_ll_scan_req_backoff(scansm, 0);
+    }
+
+    ble_phy_restart_rx();
 }
 
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)