From: Michael S. Tsirkin Date: Thu, 18 May 2006 15:32:54 +0000 (+0300) Subject: IB/mthca: Fix posting lists of 256 receive requests for Tavor X-Git-Tag: v2.6.17-rc5~90^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=23f3bc0f2c1e26215b671499c07047c325d54d9c;p=linux-2.6 IB/mthca: Fix posting lists of 256 receive requests for Tavor If we post a list of length 256 exactly, 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. Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c index 19765f6f8d..07c13be07a 100644 --- a/drivers/infiniband/hw/mthca/mthca_qp.c +++ b/drivers/infiniband/hw/mthca/mthca_qp.c @@ -1727,23 +1727,7 @@ int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr, ind = qp->rq.next_ind; - 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((qp->rq.next_ind << qp->rq.wqe_shift) | size0); - doorbell[1] = cpu_to_be32(qp->qpn << 8); - - wmb(); - - mthca_write64(doorbell, - dev->kar + MTHCA_RECEIVE_DOORBELL, - MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock)); - - qp->rq.head += MTHCA_TAVOR_MAX_WQES_PER_RECV_DB; - size0 = 0; - } - + for (nreq = 0; wr; wr = wr->next) { if (mthca_wq_overflow(&qp->rq, nreq, qp->ibqp.recv_cq)) { mthca_err(dev, "RQ %06x full (%u head, %u tail," " %d max, %d nreq)\n", qp->qpn, @@ -1797,6 +1781,23 @@ int mthca_tavor_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr, ++ind; if (unlikely(ind >= qp->rq.max)) ind -= qp->rq.max; + + ++nreq; + if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) { + nreq = 0; + + doorbell[0] = cpu_to_be32((qp->rq.next_ind << qp->rq.wqe_shift) | size0); + doorbell[1] = cpu_to_be32(qp->qpn << 8); + + wmb(); + + mthca_write64(doorbell, + dev->kar + MTHCA_RECEIVE_DOORBELL, + MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock)); + + qp->rq.head += MTHCA_TAVOR_MAX_WQES_PER_RECV_DB; + size0 = 0; + } } out: