Commit 34c7bb47 authored by Sudarsana Reddy Kalluru's avatar Sudarsana Reddy Kalluru Committed by David S. Miller

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: default avatarSudarsana Reddy Kalluru <sudarsana.kalluru@qlogic.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b560f03d
......@@ -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",
......
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