rtlwifi: Use write barrier when assigning ownership

Make sure all updates to a descriptor are flushed to memory
before assigning ownship to hardware.
Signed-off-by: Mike McCormack <mikem@ring3k.org>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtlwifi/rtl8192ce/trx.c

@@ -930,6 +930,7 @@ void rtl92ce_set_desc(u8 *pdesc, bool istx, u8 desc_name, u8 *val)
 	if (istx == true) {
 		switch (desc_name) {
 		case HW_DESC_OWN:
+			wmb();
 			SET_TX_DESC_OWN(pdesc, 1);
 			break;
 		case HW_DESC_TX_NEXTDESC_ADDR:
@@ -943,6 +944,7 @@ void rtl92ce_set_desc(u8 *pdesc, bool istx, u8 desc_name, u8 *val)
 	} else {
 		switch (desc_name) {
 		case HW_DESC_RXOWN:
+			wmb();
 			SET_RX_DESC_OWN(pdesc, 1);
 			break;
 		case HW_DESC_RXBUFF_ADDR: