IB/mthca: correct log2 calculation
Fix thinko in rd_atomic calculation: ffs(x) - 1 does not find the next
power of 2 -- it should be fls(x - 1).
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c
index c5c3d0e..84056a8 100644
--- a/drivers/infiniband/hw/mthca/mthca_qp.c
+++ b/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -728,9 +728,9 @@
}
if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC) {
- qp_context->params1 |= cpu_to_be32(min(attr->max_rd_atomic ?
- ffs(attr->max_rd_atomic) - 1 : 0,
- 7) << 21);
+ if (attr->max_rd_atomic)
+ qp_context->params1 |=
+ cpu_to_be32(fls(attr->max_rd_atomic - 1) << 21);
qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_SRA_MAX);
}
@@ -769,8 +769,6 @@
}
if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC) {
- u8 rra_max;
-
if (qp->resp_depth && !attr->max_dest_rd_atomic) {
/*
* Lowering our responder resources to zero.
@@ -798,13 +796,10 @@
MTHCA_QP_OPTPAR_RAE);
}
- for (rra_max = 0;
- 1 << rra_max < attr->max_dest_rd_atomic &&
- rra_max < dev->qp_table.rdb_shift;
- ++rra_max)
- ; /* nothing */
+ if (attr->max_dest_rd_atomic)
+ qp_context->params2 |=
+ cpu_to_be32(fls(attr->max_dest_rd_atomic - 1) << 21);
- qp_context->params2 |= cpu_to_be32(rra_max << 21);
qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_RRA_MAX);
qp->resp_depth = attr->max_dest_rd_atomic;