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| author | Kalderon, Michal <Michal.Kalderon@cavium.com> | 2018-03-21 14:51:50 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-03-21 14:38:41 -0600 |
| commit | c3594f22302cca5e924e47ec1cc8edd265708f41 (patch) | |
| tree | 6dd9d2cd76fb2008e2fda83b3937d68ac823cc1f /drivers/infiniband/hw | |
| parent | 5f3e3b85cc0a5eae1c46d72e47d3de7bf208d9e2 (diff) | |
| download | linux-c3594f22302cca5e924e47ec1cc8edd265708f41.tar.gz linux-c3594f22302cca5e924e47ec1cc8edd265708f41.tar.bz2 linux-c3594f22302cca5e924e47ec1cc8edd265708f41.zip | |
RDMA/qedr: fix QP's ack timeout configuration
QPs that were configured with ack timeout value lower than 1
msec will not implement re-transmission timeout.
This means that if a packet / ACK were dropped, the QP
will not retransmit this packet.
This can lead to an application hang.
Fixes: cecbcddf6 ("qedr: Add support for QP verbs")
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw')
| -rw-r--r-- | drivers/infiniband/hw/qedr/verbs.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c index 875b17272d65..716fae063122 100644 --- a/drivers/infiniband/hw/qedr/verbs.c +++ b/drivers/infiniband/hw/qedr/verbs.c @@ -2086,18 +2086,23 @@ int qedr_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, SET_FIELD(qp_params.modify_flags, QED_ROCE_MODIFY_QP_VALID_ACK_TIMEOUT, 1); - qp_params.ack_timeout = attr->timeout; - if (attr->timeout) { - u32 temp; - - temp = 4096 * (1UL << attr->timeout) / 1000 / 1000; - /* FW requires [msec] */ - qp_params.ack_timeout = temp; - } else { - /* Infinite */ + /* The received timeout value is an exponent used like this: + * "12.7.34 LOCAL ACK TIMEOUT + * Value representing the transport (ACK) timeout for use by + * the remote, expressed as: 4.096 * 2^timeout [usec]" + * The FW expects timeout in msec so we need to divide the usec + * result by 1000. We'll approximate 1000~2^10, and 4.096 ~ 2^2, + * so we get: 2^2 * 2^timeout / 2^10 = 2^(timeout - 8). + * The value of zero means infinite so we use a 'max_t' to make + * sure that sub 1 msec values will be configured as 1 msec. + */ + if (attr->timeout) + qp_params.ack_timeout = + 1 << max_t(int, attr->timeout - 8, 0); + else qp_params.ack_timeout = 0; - } } + if (attr_mask & IB_QP_RETRY_CNT) { SET_FIELD(qp_params.modify_flags, QED_ROCE_MODIFY_QP_VALID_RETRY_CNT, 1); |