mlx5: shd: Gracefully avoid shared devlink creation when no usable SN is found

On some HW, not even fall-back "SERIALNO" is found in VPD data. Unify
the behavior with the case there are no VPD data at all and avoid
creation of shared devlink instance.

Fixes: 2a8c8a03f306 ("net/mlx5: Add a shared devlink instance for PFs on same chip")
Reported-by: Adam Young <admiyo@amperemail.onmicrosoft.com>
Closes: https://lore.kernel.org/all/bab5b6bc-aa42-4af1-80d1-e56bcef06bc2@amperemail.onmicrosoft.com/
Reported-by: Ben Copeland <ben.copeland@linaro.org>
Closes: https://lore.kernel.org/all/20260324151014.860376-1-ben.copeland@linaro.org/
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Tested-by: Ben Copeland <ben.copeland@linaro.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260325152801.236343-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
index bc33f95302df6e1218cfe3f37ee19c3efcdf1e45..b925364765ac27911b2ef42e36aaf28ff5323eb0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
@@ -33,7 +33,7 @@ int mlx5_shd_init(struct mlx5_core_dev *dev)
                start = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
                                                     PCI_VPD_RO_KEYWORD_SERIALNO, &kw_len);
                if (start < 0)
-                       return -ENOENT;
+                       return 0; /* No usable serial number found, ignore. */
        }
        sn = kstrndup(vpd_data + start, kw_len, GFP_KERNEL);
        if (!sn)