From: Eli Cohen <eli@mellanox.com>
Date: Thu, 9 Feb 2017 17:31:47 +0000 (+0200)
Subject: IB/mlx5: Fix blue flame buffer size calculation
X-Git-Tag: v4.14-rc1~1433^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d8030b0de03ec6bdf3665e1d915fa0f02e5ec89d;p=platform%2Fkernel%2Flinux-rpi.git

IB/mlx5: Fix blue flame buffer size calculation

A blue flame register is comprised of two buffers of equal size.

Fixes: 5fe9dec0d0454 ("IB/mlx5: Use blue flame register allocator in mlx5_ib")
Signed-off-by: Eli Cohen <eli@mellanox.com>
Reviewed-by: Noa Osherovich <noaos@mellanox.com>
Reviewed-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
---

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index fbfff12..69a1604a 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -905,7 +905,10 @@ static int create_kernel_qp(struct mlx5_ib_dev *dev,
 	else
 		qp->bf.bfreg = &dev->bfreg;
 
-	qp->bf.buf_size = 1 << MLX5_CAP_GEN(dev->mdev, log_bf_reg_size);
+	/* We need to divide by two since each register is comprised of
+	 * two buffers of identical size, namely odd and even
+	 */
+	qp->bf.buf_size = (1 << MLX5_CAP_GEN(dev->mdev, log_bf_reg_size)) / 2;
 	uar_index = qp->bf.bfreg->index;
 
 	err = calc_sq_size(dev, init_attr, qp);