staging: rtl8723au: Add warning about this driver being deprecated

This driver is deprecated and superseded by rtl8xxxu. It will be
removed in a future kernel release.

Add a warning to Kconfig and at device init time to notify users and
allow them time to switch over.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/Kconfig

 config R8723AU
-	tristate "Realtek RTL8723AU Wireless LAN NIC driver"
+	tristate "Realtek RTL8723AU Wireless LAN NIC driver (deprecated)"
 	depends on USB && WLAN && RFKILL
 	select WIRELESS_EXT
 	select WEXT_PRIV
@@ -7,7 +7,10 @@ config R8723AU
 	default n
 	---help---
 	This option adds the Realtek RTL8723AU USB device such as found in
-	the Lenovo Yogi 13 tablet. If built as a module, it will be called r8723au.
+	the Lenovo Yoga 13 tablet. If built as a module, it will be called r8723au.
+
+	Note: This driver is deprecated and scheduled to be removed in a
+	future kernel release. Please use rtl8xxxu instead.
 
 if R8723AU
 

drivers/staging/rtl8723au/os_dep/usb_intf.c

@@ -532,6 +532,7 @@ static int rtw_drv_init(struct usb_interface *pusb_intf,
 {
 	struct rtw_adapter *if1 = NULL;
 	struct dvobj_priv *dvobj;
+	struct usb_device *udev;
 	int status = _FAIL;
 
 	RT_TRACE(_module_hci_intfs_c_, _drv_err_, "+rtw_drv_init\n");
@@ -544,6 +545,10 @@ static int rtw_drv_init(struct usb_interface *pusb_intf,
 		goto exit;
 	}
 
+	udev = dvobj->pusbdev;
+	dev_warn(&udev->dev, "WARNING: The rtl8723au driver is deprecated!");
+	dev_warn(&udev->dev, "Please use the rtl8xxxu driver for this device!");
+
 	if1 = rtw_usb_if1_init(dvobj, pusb_intf, pdid);
 	if (!if1) {
 		DBG_8723A("rtw_init_primary_adapter Failed!\n");