Commit 6aa2e4e8 authored by Jack Morgenstein's avatar Jack Morgenstein Committed by Roland Dreier
Browse files

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: default avatarJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 94361cf7

drivers/infiniband/hw/mthca/mthca_qp.c

+6 −11
Original line number Diff line number Diff line
@@ -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;

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