net/mlx5: Fix query ISSI flow

In old FWs query ISSI command is not supported and for some of those FWs
it might fail with status other than "MLX5_CMD_STAT_BAD_OP_ERR".

In such case instead of failing the driver load, we will treat any FW
status other than 0 for Query ISSI FW command as ISSI not supported and
assume ISSI=0 (most basic driver/FW interface).

In case of driver syndrom (query ISSI failure by driver) we will fail
driver load.

Fixes: f62b8bb8 ('net/mlx5: Extend mlx5_core to support ConnectX-4
Ethernet functionality')
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -268,11 +268,6 @@ static void dump_buf(void *buf, int size, int data_only, int offset)
 		pr_debug("\n");
 }
 
-enum {
-	MLX5_DRIVER_STATUS_ABORTED = 0xfe,
-	MLX5_DRIVER_SYND = 0xbadd00de,
-};
-
 static int mlx5_internal_err_ret_value(struct mlx5_core_dev *dev, u16 op,
 				       u32 *synd, u8 *status)
 {

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

@@ -732,13 +732,15 @@ static int mlx5_core_set_issi(struct mlx5_core_dev *dev)
 		u8 status;
 
 		mlx5_cmd_mbox_status(query_out, &status, &syndrome);
-		if (status == MLX5_CMD_STAT_BAD_OP_ERR) {
-			pr_debug("Only ISSI 0 is supported\n");
-			return 0;
+		if (!status || syndrome == MLX5_DRIVER_SYND) {
+			mlx5_core_err(dev, "Failed to query ISSI err(%d) status(%d) synd(%d)\n",
+				      err, status, syndrome);
+			return err;
 		}
 
-		pr_err("failed to query ISSI err(%d)\n", err);
-		return err;
+		mlx5_core_warn(dev, "Query ISSI is not supported by FW, ISSI is 0\n");
+		dev->issi = 0;
+		return 0;
 	}
 
 	sup_issi = MLX5_GET(query_issi_out, query_out, supported_issi_dw0);
@@ -752,7 +754,8 @@ static int mlx5_core_set_issi(struct mlx5_core_dev *dev)
 		err = mlx5_cmd_exec(dev, set_in, sizeof(set_in),
 				    set_out, sizeof(set_out));
 		if (err) {
-			pr_err("failed to set ISSI=1 err(%d)\n", err);
+			mlx5_core_err(dev, "Failed to set ISSI to 1 err(%d)\n",
+				      err);
 			return err;
 		}
 

drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h

@@ -75,6 +75,11 @@ enum {
 	MLX5_CMD_TIME, /* print command execution time */
 };
 
+enum {
+	MLX5_DRIVER_STATUS_ABORTED = 0xfe,
+	MLX5_DRIVER_SYND = 0xbadd00de,
+};
+
 int mlx5_query_hca_caps(struct mlx5_core_dev *dev);
 int mlx5_query_board_id(struct mlx5_core_dev *dev);
 int mlx5_cmd_init_hca(struct mlx5_core_dev *dev);