net/mlx5: Enable 4K UAR only when page size is bigger than 4K

[ Upstream commit 91828bd8 ]

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: f502d834 ("net/mlx5: Activate support for 4K UARs")
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/ethernet/mellanox/mlx5/core/main.c

@@ -537,8 +537,10 @@ static int handle_hca_cap(struct mlx5_core_dev *dev)
 	/* 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);