From: Sinan Kaya <okaya@codeaurora.org>
Date: Sun, 25 Mar 2018 10:39:17 -0400
Subject: bnx2x: Replace doorbell barrier() with wmb()
Patch-mainline: v4.17-rc1
Git-commit: edd874235ac20a04483f15b27251203e9508dec5
References: bsc#1086323 FATE#324899

barrier() doesn't guarantee memory writes to be observed by the hardware on
all architectures. barrier() only tells compiler not to move this code
with respect to other read/writes.

If memory write needs to be observed by the HW, wmb() is the right choice.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c     |    3 ++-
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -4152,7 +4152,8 @@ netdev_tx_t bnx2x_start_xmit(struct sk_b
 	wmb();
 
 	txdata->tx_db.data.prod += nbd;
-	barrier();
+	/* make sure descriptor update is observed by HW */
+	wmb();
 
 	DOORBELL(bp, txdata->cid, txdata->tx_db.raw);
 
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
@@ -2591,7 +2591,8 @@ static int bnx2x_run_loopback(struct bnx
 	wmb();
 
 	txdata->tx_db.data.prod += 2;
-	barrier();
+	/* make sure descriptor update is observed by the HW */
+	wmb();
 	DOORBELL(bp, txdata->cid, txdata->tx_db.raw);
 
 	mmiowb();