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 2fa1c05..92cd8ab 100644 (file)
--- 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));
 }