From 5111dd3e422d08435164fc6d405d849ff6421eec Mon Sep 17 00:00:00 2001
From: Larry Finger <Larry.Finger@lwfinger.net>
Date: Mon, 23 May 2011 20:37:31 -0500
Subject: [PATCH] rtlwifi: rtl8192se: Use write barrier when assigning
 ownership

As noted by Mike McCormack <mikem@ring3k.org> for rtl8192ce, make sure
all updates to a descriptor are flushed to memory before assigning ownship
to hardware.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 drivers/net/wireless/rtlwifi/rtl8192se/trx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/rtlwifi/rtl8192se/trx.c b/drivers/net/wireless/rtlwifi/rtl8192se/trx.c
index 14a8b7866c0d..d509cf6a1e4d 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192se/trx.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192se/trx.c
@@ -873,6 +873,7 @@ void rtl92se_tx_fill_cmddesc(struct ieee80211_hw *hw, u8 *pdesc,
 		SET_TX_DESC_TX_BUFFER_SIZE(pdesc, (u16)(skb->len));
 		SET_TX_DESC_TX_BUFFER_ADDRESS(pdesc, cpu_to_le32(mapping));
 
+		wmb();
 		SET_TX_DESC_OWN(pdesc, 1);
 	} else { /* H2C Command Desc format (Host TXCMD) */
 		/* 92SE must set as 1 for firmware download HW DMA error */
@@ -891,6 +892,7 @@ void rtl92se_tx_fill_cmddesc(struct ieee80211_hw *hw, u8 *pdesc,
 		SET_TX_DESC_TX_BUFFER_SIZE(pdesc, (u16)(skb->len));
 		SET_TX_DESC_TX_BUFFER_ADDRESS(pdesc, cpu_to_le32(mapping));
 
+		wmb();
 		SET_TX_DESC_OWN(pdesc, 1);
 
 	}
@@ -901,6 +903,7 @@ void rtl92se_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:
@@ -914,6 +917,7 @@ void rtl92se_set_desc(u8 *pdesc, bool istx, u8 desc_name, u8 *val)
 	} else {
 		switch (desc_name) {
 		case HW_DESC_RXOWN:
+			wmb();
 			SET_RX_STATUS_DESC_OWN(pdesc, 1);
 			break;
 		case HW_DESC_RXBUFF_ADDR:
-- 
2.34.1