net/mlx5: Avoid "No data available" when FW version queries fail

Avoid printing the misleading "kernel answers: No data available" devlink
output when querying firmware or pending firmware version fails
(e.g. MLX5 fw state errors / flash failures).

FW can fail on loading the pending flash image and get its version due
to various reasons, examples:

mlxfw: Firmware flash failed: key not applicable, err (7)
mlx5_fw_image_pending: can't read pending fw version while fw state is 1

and the resulting:
$ devlink dev info
kernel answers: No data available

Instead, just report 0 or 0xfff.. versions in case of failure to indicate
a problem, and let other information be shown.

after the fix:
$ devlink dev info
pci/0000:00:06.0:
  driver mlx5_core
  serial_number xxx...
  board.serial_number MT2225300179
  versions:
      fixed:
        fw.psid MT_0000000436
      running:
        fw.version 22.41.0188
        fw 22.41.0188
      stored:
        fw.version 255.255.65535
        fw 255.255.65535

Fixes: 9c86b07e30 ("net/mlx5: Added fw version query command")
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260330194015.53585-3-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -107,9 +107,7 @@ mlx5_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 	if (err)
 		return err;
 
-	err = mlx5_fw_version_query(dev, &running_fw, &stored_fw);
-	if (err)
-		return err;
+	mlx5_fw_version_query(dev, &running_fw, &stored_fw);
 
 	snprintf(version_str, sizeof(version_str), "%d.%d.%04d",
 		 mlx5_fw_ver_major(running_fw), mlx5_fw_ver_minor(running_fw),

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

@@ -822,48 +822,63 @@ mlx5_fw_image_pending(struct mlx5_core_dev *dev,
 	return 0;
 }
 
-int mlx5_fw_version_query(struct mlx5_core_dev *dev,
-			  u32 *running_ver, u32 *pending_ver)
+void mlx5_fw_version_query(struct mlx5_core_dev *dev,
+			   u32 *running_ver, u32 *pending_ver)
 {
 	u32 reg_mcqi_version[MLX5_ST_SZ_DW(mcqi_version)] = {};
 	bool pending_version_exists;
 	int component_index;
 	int err;
 
+	*running_ver = 0;
+	*pending_ver = 0;
+
 	if (!MLX5_CAP_GEN(dev, mcam_reg) || !MLX5_CAP_MCAM_REG(dev, mcqi) ||
 	    !MLX5_CAP_MCAM_REG(dev, mcqs)) {
 		mlx5_core_warn(dev, "fw query isn't supported by the FW\n");
-		return -EOPNOTSUPP;
+		return;
 	}
 
 	component_index = mlx5_get_boot_img_component_index(dev);
-	if (component_index < 0)
-		return component_index;
+	if (component_index < 0) {
+		mlx5_core_warn(dev, "fw query failed to find boot img component index, err %d\n",
+			       component_index);
+		return;
+	}
 
+	*running_ver = U32_MAX; /* indicate failure */
 	err = mlx5_reg_mcqi_version_query(dev, component_index,
 					  MCQI_FW_RUNNING_VERSION,
 					  reg_mcqi_version);
-	if (err)
-		return err;
-
-	*running_ver = MLX5_GET(mcqi_version, reg_mcqi_version, version);
+	if (!err)
+		*running_ver = MLX5_GET(mcqi_version, reg_mcqi_version,
+					version);
+	else
+		mlx5_core_warn(dev, "failed to query running version, err %d\n",
+			       err);
 
+	*pending_ver = U32_MAX; /* indicate failure */
 	err = mlx5_fw_image_pending(dev, component_index, &pending_version_exists);
-	if (err)
-		return err;
+	if (err) {
+		mlx5_core_warn(dev, "failed to query pending image, err %d\n",
+			       err);
+		return;
+	}
 
 	if (!pending_version_exists) {
 		*pending_ver = 0;
-		return 0;
+		return;
 	}
 
 	err = mlx5_reg_mcqi_version_query(dev, component_index,
 					  MCQI_FW_STORED_VERSION,
 					  reg_mcqi_version);
-	if (err)
-		return err;
+	if (!err)
+		*pending_ver = MLX5_GET(mcqi_version, reg_mcqi_version,
+					version);
+	else
+		mlx5_core_warn(dev, "failed to query pending version, err %d\n",
+			       err);
 
-	*pending_ver = MLX5_GET(mcqi_version, reg_mcqi_version, version);
-
-	return 0;
+	return;
 }

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

@@ -393,8 +393,8 @@ int mlx5_port_max_linkspeed(struct mlx5_core_dev *mdev, u32 *speed);
 
 int mlx5_firmware_flash(struct mlx5_core_dev *dev, const struct firmware *fw,
 			struct netlink_ext_ack *extack);
-int mlx5_fw_version_query(struct mlx5_core_dev *dev,
-			  u32 *running_ver, u32 *stored_ver);
+void mlx5_fw_version_query(struct mlx5_core_dev *dev, u32 *running_ver,
+			   u32 *stored_ver);
 
 #ifdef CONFIG_MLX5_CORE_EN
 int mlx5e_init(void);