From 34c7bb4705a0a2d344b0c82eaf3d3bfa2bc9da45 Mon Sep 17 00:00:00 2001 From: Sudarsana Reddy Kalluru Date: Tue, 28 Jun 2016 07:46:03 -0400 Subject: [PATCH] qed: Protect the doorbell BAR with the write barriers. SPQ doorbell is currently protected with the compilation barrier. Under the stress scenarios, we may get into a state where (due to the weak ordering) several ramrod doorbells were written to the BAR with an out-of-order producer values. Need to change the barrier type to a write barrier to make sure that the write buffer is flushed after each doorbell. Signed-off-by: Sudarsana Reddy Kalluru Signed-off-by: David S. Miller --- drivers/net/ethernet/qlogic/qed/qed_spq.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/qlogic/qed/qed_spq.c b/drivers/net/ethernet/qlogic/qed/qed_spq.c index 67d9893774d8..b122f6013b6c 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_spq.c +++ b/drivers/net/ethernet/qlogic/qed/qed_spq.c @@ -213,19 +213,15 @@ static int qed_spq_hw_post(struct qed_hwfn *p_hwfn, SET_FIELD(db.params, CORE_DB_DATA_AGG_VAL_SEL, DQ_XCM_CORE_SPQ_PROD_CMD); db.agg_flags = DQ_XCM_CORE_DQ_CF_CMD; - - /* validate producer is up to-date */ - rmb(); - db.spq_prod = cpu_to_le16(qed_chain_get_prod_idx(p_chain)); - /* do not reorder */ - barrier(); + /* make sure the SPQE is updated before the doorbell */ + wmb(); DOORBELL(p_hwfn, qed_db_addr(p_spq->cid, DQ_DEMS_LEGACY), *(u32 *)&db); /* make sure doorbell is rang */ - mmiowb(); + wmb(); DP_VERBOSE(p_hwfn, QED_MSG_SPQ, "Doorbelled [0x%08x, CID 0x%08x] with Flags: %02x agg_params: %02x, prod: %04x\n", -- 2.20.1