From 6aa2e4e8063114bd7cea8616dd5848d3c64b4c36 Mon Sep 17 00:00:00 2001 From: Jack Morgenstein Date: Fri, 9 Dec 2005 16:38:04 -0800 Subject: [PATCH] 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 Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mthca/mthca_qp.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c index c5c3d0edbbf..84056a8b794 100644 --- a/drivers/infiniband/hw/mthca/mthca_qp.c +++ b/drivers/infiniband/hw/mthca/mthca_qp.c @@ -728,9 +728,9 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask) } 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 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask) } 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 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask) 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; -- 2.41.0