From: Denis Bolotin <dbolotin@marvell.com>
Date: Thu, 3 Jan 2019 10:02:40 +0000 (+0200)
Subject: qed: Fix qed_ll2_post_rx_buffer_notify_fw() by adding a write memory barrier
X-Git-Tag: v4.19.26~117
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=08eb17ec3c1b3f0b51b2fa18fcd6cd8e04aa572e;p=users%2Fdwmw2%2Flinux.git

qed: Fix qed_ll2_post_rx_buffer_notify_fw() by adding a write memory barrier

[ Upstream commit 46721c3d9e273aea880e9ff835b0e1271e1cd2fb ]

Make sure chain element is updated before ringing the doorbell.

Signed-off-by: Denis Bolotin <dbolotin@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/net/ethernet/qlogic/qed/qed_ll2.c b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
index 2fa1c050a14b4..92cd8abeb41d7 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
@@ -1592,6 +1592,10 @@ static void qed_ll2_post_rx_buffer_notify_fw(struct qed_hwfn *p_hwfn,
 	cq_prod = qed_chain_get_prod_idx(&p_rx->rcq_chain);
 	rx_prod.bd_prod = cpu_to_le16(bd_prod);
 	rx_prod.cqe_prod = cpu_to_le16(cq_prod);
+
+	/* Make sure chain element is updated before ringing the doorbell */
+	dma_wmb();
+
 	DIRECT_REG_WR(p_rx->set_prod_addr, *((u32 *)&rx_prod));
 }