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IB/mthca: Fix posting lists of 256 receive requests to SRQ for Tavor

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If we post a list of length exactly a multiple of 256, nreq in
doorbell gets set to 256 which is wrong: it should be encoded by 0.
This is because we only zero it out on the next WR, which may not be
there.  The solution is to ring the doorbell after posting a WQE, not
before posting the next one.

This is the same bug that we just fixed for QPs with non-shared RQ.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Michael S. Tsirkin 2006-05-24 18:27:07 +03:00 committed by Roland Dreier
parent da8bacf6d5
commit ab28b171ea
1 changed files with 21 additions and 20 deletions
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41
drivers/infiniband/hw/mthca/mthca_srq.c
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@ -490,26 +490,7 @@ int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
first_ind = srq->first_free;
for (nreq = 0; wr; ++nreq, wr = wr->next) {
if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
nreq = 0;
doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
doorbell[1] = cpu_to_be32(srq->srqn << 8);
/*
* Make sure that descriptors are written
* before doorbell is rung.
*/
wmb();
mthca_write64(doorbell,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
first_ind = srq->first_free;
}
for (nreq = 0; wr; wr = wr->next) {
ind = srq->first_free;
if (ind < 0) {
@ -569,6 +550,26 @@ int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
srq->wrid[ind] = wr->wr_id;
srq->first_free = next_ind;
++nreq;
if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
nreq = 0;
doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
doorbell[1] = cpu_to_be32(srq->srqn << 8);
/*
* Make sure that descriptors are written
* before doorbell is rung.
*/
wmb();
mthca_write64(doorbell,
dev->kar + MTHCA_RECEIVE_DOORBELL,
MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
first_ind = srq->first_free;
}
}
if (likely(nreq)) {