[PATCH 4.11 17/84] net/mlx5: Enable 4K UAR only when page size is bigger than 4K

[Greg Kroah-Hartman]

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Majd Dibbiny <majd@xxxxxxxxxxxx>


[ Upstream commit 91828bd89940e8145f91751a015bc11bc486aad0 ]

When the page size isn't bigger than 4K, there is no added value of enabling 4K
UAR feature in the Firmware.

Modified the condition of enabling the 4K UAR accordingly.

Fixes: f502d834950a ("net/mlx5: Activate support for 4K UARs")
Signed-off-by: Majd Dibbiny <majd@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/main.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -537,8 +537,10 @@ static int handle_hca_cap(struct mlx5_co
 	/* disable cmdif checksum */
 	MLX5_SET(cmd_hca_cap, set_hca_cap, cmdif_checksum, 0);
 
-	/* If the HCA supports 4K UARs use it */
-	if (MLX5_CAP_GEN_MAX(dev, uar_4k))
+	/* Enable 4K UAR only when HCA supports it and page size is bigger
+	 * than 4K.
+	 */
+	if (MLX5_CAP_GEN_MAX(dev, uar_4k) && PAGE_SIZE > 4096)
 		MLX5_SET(cmd_hca_cap, set_hca_cap, uar_4k, 1);
 
 	MLX5_SET(cmd_hca_cap, set_hca_cap, log_uar_page_sz, PAGE_SHIFT - 12);