From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.9 10/18] qed: Fix reading wrong value in loop condition Date: Thu, 29 Nov 2018 01:03:22 -0500 Message-ID: <20181129060331.160224-10-sashal@kernel.org> References: <20181129060331.160224-1-sashal@kernel.org> Cc: Denis Bolotin , Michal Kalderon , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20181129060331.160224-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Denis Bolotin [ Upstream commit ed4eac20dcffdad47709422e0cb925981b056668 ] The value of "sb_index" is written by the hardware. Reading its value and writing it to "index" must finish before checking the loop condition. Signed-off-by: Denis Bolotin Signed-off-by: Michal Kalderon Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/qlogic/qed/qed_int.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/qlogic/qed/qed_int.c b/drivers/net/ethernet/qlogic/qed/qed_int.c index 2adedc6fb6cf..fd19372db2f8 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_int.c +++ b/drivers/net/ethernet/qlogic/qed/qed_int.c @@ -2135,6 +2135,8 @@ static int qed_int_attentions(struct qed_hwfn *p_hwfn) */ do { index = p_sb_attn->sb_index; + /* finish reading index before the loop condition */ + dma_rmb(); attn_bits = le32_to_cpu(p_sb_attn->atten_bits); attn_acks = le32_to_cpu(p_sb_attn->atten_ack); } while (index != p_sb_attn->sb_index); -- 2.17.1