4.9-stable review patch. If anyone has any objections, please let me know.
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[ 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 --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);