From: Sinan Kaya <okaya@codeaurora.org>
Date: Sun, 25 Mar 2018 14:39:15 +0000 (-0400)
Subject: net: qla3xxx: Eliminate duplicate barriers on weakly-ordered archs
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=3c95c567322e1dfaa7e0348171181aaf63aa6049;p=openwrt%2Fstaging%2Fblogic.git

net: qla3xxx: Eliminate duplicate barriers on weakly-ordered archs

Code includes wmb() followed by writel(). writel() already has a
barrier on some architectures like arm64.

This ends up CPU observing two barriers back to back before executing
the register write.

Since code already has an explicit barrier call, changing code to

wmb()
writel_relaxed()
mmiowb()

for multi-arch support.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/qlogic/qla3xxx.c b/drivers/net/ethernet/qlogic/qla3xxx.c
index 9e5264d8773b..b48f76182049 100644
--- a/drivers/net/ethernet/qlogic/qla3xxx.c
+++ b/drivers/net/ethernet/qlogic/qla3xxx.c
@@ -1858,8 +1858,9 @@ static void ql_update_small_bufq_prod_index(struct ql3_adapter *qdev)
 			qdev->small_buf_release_cnt -= 8;
 		}
 		wmb();
-		writel(qdev->small_buf_q_producer_index,
-			&port_regs->CommonRegs.rxSmallQProducerIndex);
+		writel_relaxed(qdev->small_buf_q_producer_index,
+			       &port_regs->CommonRegs.rxSmallQProducerIndex);
+		mmiowb();
 	}
 }