[PATCH rdma-next] RDMA/mlx5: Send cong param changes to the resolved port mdev

[Leon Romanovsky]

From: Leon Romanovsky <leonro@xxxxxxxxxx>

mlx5_ib_set_cc_params() resolves the port-specific mlx5_core_dev via
mlx5_ib_get_native_port_mdev() but issued MLX5_CMD_OP_MODIFY_CONG_PARAMS
through dev->mdev. On an affiliated secondary RoCE port those pointers
refer to different devices, so a write to the secondary port's cc_params
debugfs file either altered the master port or failed with a master-side
command error, while the read path already used the resolved mdev and
returned the unchanged secondary value.

Issue the command to the resolved mdev, the same device whose capabilities
were checked when its debugfs directory was created. It is already
referenced by the get/put pair, so its lifetime is safe.

Fixes: 31578defe4eb ("RDMA/mlx5: Update mlx5_ib to use new cmd interface")
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 drivers/infiniband/hw/mlx5/cong.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx5/cong.c b/drivers/infiniband/hw/mlx5/cong.c
index d0edf83a2f20..d1b625a52fa6 100644
--- a/drivers/infiniband/hw/mlx5/cong.c
+++ b/drivers/infiniband/hw/mlx5/cong.c
@@ -361,7 +361,7 @@ static int mlx5_ib_set_cc_params(struct mlx5_ib_dev *dev, u32 port_num,
 	MLX5_SET(field_select_r_roce_rp, field, field_select_r_roce_rp,
 		 attr_mask);
 
-	err = mlx5_cmd_exec_in(dev->mdev, modify_cong_params, in);
+	err = mlx5_cmd_exec_in(mdev, modify_cong_params, in);
 	kvfree(in);
 alloc_err:
 	mlx5_ib_put_native_port_mdev(dev, port_num + 1);

---
base-commit: 9b66c9af7172ffcf727214fa0ebe9a5e1ed6eb16
change-id: 20260726-mlx5-ib-set-cc-params-applies-conges-a64520996573

Best regards,
--  
Leon Romanovsky <leonro@xxxxxxxxxx>