IB/mlx4: Correct max_srq_wr returned from mlx4_ib_query_device()
We need to keep a spare entry in the SRQ so that there always is a
next WQE available when posting receives (so that we can tell the
difference between a full queue and an empty queue). So subtract 1
from the value HW gives us before reporting the limit on SRQ entries
to consumers.
Found by Mellanox QA.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 1095c82..c591616 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -120,7 +120,7 @@
props->max_qp_init_rd_atom = dev->dev->caps.max_qp_init_rdma;
props->max_res_rd_atom = props->max_qp_rd_atom * props->max_qp;
props->max_srq = dev->dev->caps.num_srqs - dev->dev->caps.reserved_srqs;
- props->max_srq_wr = dev->dev->caps.max_srq_wqes;
+ props->max_srq_wr = dev->dev->caps.max_srq_wqes - 1;
props->max_srq_sge = dev->dev->caps.max_srq_sge;
props->local_ca_ack_delay = dev->dev->caps.local_ca_ack_delay;
props->atomic_cap = dev->dev->caps.flags & MLX4_DEV_CAP_FLAG_ATOMIC ?