diff --git a/core/rtw_ap.c b/core/rtw_ap.c
index 1527834..0250880 100644
--- a/core/rtw_ap.c
+++ b/core/rtw_ap.c
@@ -3567,6 +3567,25 @@ void start_ap_mode(_adapter *padapter)
 
 }
 
+void rtw_ap_bcmc_sta_flush(_adapter *padapter)
+{
+#ifdef CONFIG_CONCURRENT_MODE
+	int cam_id = -1;
+	u8 *addr = adapter_mac_addr(padapter);
+
+	cam_id = rtw_iface_bcmc_id_get(padapter);
+	if (cam_id != INVALID_SEC_MAC_CAM_ID) {
+		RTW_PRINT("clear group key for "ADPT_FMT" addr:"MAC_FMT", camid:%d\n",
+			ADPT_ARG(padapter), MAC_ARG(addr), cam_id);
+		clear_cam_entry(padapter, cam_id);
+		rtw_camid_free(padapter, cam_id);
+		rtw_iface_bcmc_id_set(padapter, INVALID_SEC_MAC_CAM_ID);	/*init default value*/
+	}
+#else
+	invalidate_cam_all(padapter);
+#endif
+}
+
 void stop_ap_mode(_adapter *padapter)
 {
 	_irqL irqL;
@@ -3599,6 +3618,7 @@ void stop_ap_mode(_adapter *padapter)
 #endif
 
 	rtw_sta_flush(padapter, _TRUE);
+	rtw_ap_bcmc_sta_flush(padapter);
 
 	/* free_assoc_sta_resources	 */
 	rtw_free_all_stainfo(padapter);
diff --git a/os_dep/linux/ioctl_cfg80211.c b/os_dep/linux/ioctl_cfg80211.c
index b9b05d4..9af4eff 100644
--- a/os_dep/linux/ioctl_cfg80211.c
+++ b/os_dep/linux/ioctl_cfg80211.c
@@ -3731,7 +3731,7 @@ static int rtw_cfg80211_add_monitor_if(_adapter *padapter, char *name, struct ne
 	mon_ndev->name[IFNAMSIZ - 1] = 0;
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12 ,0))
 	mon_ndev->needs_free_netdev = true;
-#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0))
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 9))
 	mon_ndev->priv_destructor = rtw_ndev_destructor;
 #else
 	mon_ndev->destructor = rtw_ndev_destructor;
diff --git a/os_dep/linux/usb_intf.c b/os_dep/linux/usb_intf.c
index 0fc63b6..a35d045 100644
--- a/os_dep/linux/usb_intf.c
+++ b/os_dep/linux/usb_intf.c
@@ -665,26 +665,7 @@ static int usb_reprobe_switch_usb_mode(PADAPTER Adapter)
 	if (registry_par->switch_usb_mode == 0)
 		goto exit;
 
-#if defined(CONFIG_RTL8812A) || defined(CONFIG_RTL8821A) || defined(CONFIG_RTL8814A)
-        if (IS_HIGH_SPEED_USB(Adapter)) {
-          if ((rtw_read8(Adapter, 0x74) & (BIT(2)|BIT(3))) != BIT(3)) {
-            rtw_write8(Adapter, 0x74, 0x8);
-            rtw_write8(Adapter, 0x70, 0x2);
-            rtw_write8(Adapter, 0x3e, 0x1);
-            rtw_write8(Adapter, 0x3d, 0x3);
-            /* usb disconnect */
-            rtw_write8(Adapter, 0x5, 0x80);
-            ret = _TRUE;
-          }
-
-        } else if (IS_SUPER_SPEED_USB(Adapter)) {
-          rtw_write8(Adapter, 0x70, rtw_read8(Adapter, 0x70) & (~BIT(1)));
-          rtw_write8(Adapter, 0x3e, rtw_read8(Adapter, 0x3e) & (~BIT(0)));
-        }
-#else
 	rtw_hal_set_hwreg(Adapter, HW_VAR_USB_MODE, &ret);
-#endif
-
 exit:
 	return ret;
 }