diff mbox series

[AUTOSEL,4.4,07/13] qed: Fix reading wrong value in loop condition

Message ID 20181129060444.160434-7-sashal@kernel.org
State Not Applicable, archived
Delegated to: David Miller
Headers show
Series None | expand

Commit Message

Sasha Levin Nov. 29, 2018, 6:04 a.m. UTC 
From: Denis Bolotin <denis.bolotin@cavium.com>

[ 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 <denis.bolotin@cavium.com>
Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/qlogic/qed/qed_int.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/qlogic/qed/qed_int.c b/drivers/net/ethernet/qlogic/qed/qed_int.c
index 9cc9d62c1fec..8b15a018d625 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_int.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_int.c
@@ -177,6 +177,8 @@  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);