[3.16.y-ckt stable] Patch "IB/mlx5: Fix RC transport send queue overhead computation" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    IB/mlx5: Fix RC transport send queue overhead computation

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt25.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 83b3bba00681de9eaaecc4926187bfbb2af2d581 Mon Sep 17 00:00:00 2001
From: Leon Romanovsky <leon at leon.nu>
Date: Thu, 11 Feb 2016 21:09:57 +0200
Subject: IB/mlx5: Fix RC transport send queue overhead computation

commit 75c1657e1d50730dc0130a67977f7831a4e241f4 upstream.

Fix the RC QPs send queue overhead computation to take into account
two additional segments in the WQE which are needed for registration
operations.

The ATOMIC and UMR segments can't coexist together, so chose maximum out
of them.

The commit 9e65dc371b5c ("IB/mlx5: Fix RC transport send queue overhead
computation") was intended to update RC transport as commit messages
states, but added the code to UC transport.

Fixes: 9e65dc371b5c ("IB/mlx5: Fix RC transport send queue overhead computation")
Signed-off-by: Kamal Heib <kamalh at mellanox.com>
Signed-off-by: Leon Romanovsky <leonro at mellanox.com>
Reviewed-by: Sagi Grimberg <sagig at mellanox.com>
Signed-off-by: Doug Ledford <dledford at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/infiniband/hw/mlx5/qp.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index bbbcf389272c..44f4f3976f7c 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -207,8 +207,10 @@ static int sq_overhead(enum ib_qp_type qp_type)
 		/* fall through */
 	case IB_QPT_RC:
 		size += sizeof(struct mlx5_wqe_ctrl_seg) +
-			sizeof(struct mlx5_wqe_atomic_seg) +
-			sizeof(struct mlx5_wqe_raddr_seg);
+			max(sizeof(struct mlx5_wqe_atomic_seg) +
+			    sizeof(struct mlx5_wqe_raddr_seg),
+			    sizeof(struct mlx5_wqe_umr_ctrl_seg) +
+			    sizeof(struct mlx5_mkey_seg));
 		break;

 	case IB_QPT_XRC_TGT:
@@ -216,9 +218,9 @@ static int sq_overhead(enum ib_qp_type qp_type)

 	case IB_QPT_UC:
 		size += sizeof(struct mlx5_wqe_ctrl_seg) +
-			sizeof(struct mlx5_wqe_raddr_seg) +
-			sizeof(struct mlx5_wqe_umr_ctrl_seg) +
-			sizeof(struct mlx5_mkey_seg);
+			max(sizeof(struct mlx5_wqe_raddr_seg),
+			    sizeof(struct mlx5_wqe_umr_ctrl_seg) +
+			    sizeof(struct mlx5_mkey_seg));
 		break;

 	case IB_QPT_UD: