Re: [PATCH net-next 3/4] mlx4: Do not mask failure accessing page A2h (0x51)

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 9/12/24 08:41, Krzysztof Olędzki wrote:
> Due to HW/FW limitation, page A2h (I2C 0x51) may not be available.
> Do not mask the problem so the userspace can properly handle it.
> 
> When returning the error to the userspace, use -EIO instead of
> "err" because it holds MAD_STATUS.
> 
> Fixes: f5826c8c9d57 ("net/mlx4_en: Fix wrong return value on ioctl EEPROM query failure")
> Fixes: 32a173c7f9e9 ("net/mlx4_core: Introduce mlx4_get_module_info for cable module info reading")
> Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
> ---
>   drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 2 +-
>   drivers/net/ethernet/mellanox/mlx4/port.c       | 9 +--------
>   2 files changed, 2 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
> index 4c985d62af12..677917168bd5 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
> @@ -2094,7 +2094,7 @@ static int mlx4_en_get_module_eeprom(struct net_device *dev,
>   			en_err(priv,
>   			       "mlx4_get_module_info i(%d) offset(%d) bytes_to_read(%d) - FAILED (0x%x)\n",
>   			       i, offset, ee->len - i, ret);
> -			return ret;
> +			return -EIO;

here you are masking also all other explicit error paths of
mlx4_get_module_info(), what is not good in general, I would instead
mask below (see next comment)

>   		}
>   
>   		i += ret;
> diff --git a/drivers/net/ethernet/mellanox/mlx4/port.c b/drivers/net/ethernet/mellanox/mlx4/port.c
> index 1ebd459d1d21..8c2a384404f9 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/port.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/port.c
> @@ -2198,14 +2198,7 @@ int mlx4_get_module_info(struct mlx4_dev *dev, u8 port,
>   			  MLX4_ATTR_CABLE_INFO, port, i2c_addr, offset, size,
>   			  ret, cable_info_mad_err_str(ret));
>   
> -		if (i2c_addr == I2C_ADDR_HIGH &&
> -		    MAD_STATUS_2_CABLE_ERR(ret) == CABLE_INF_I2C_ADDR)
> -			/* Some SFP cables do not support i2c slave
> -			 * address 0x51 (high page), abort silently.
> -			 */
> -			ret = 0;
> -		else
> -			ret = -ret;
> +		ret = -ret;

this is the only place that mlx4_get_module_info() returns non standard
error code so, I believe, it's here where we want to overwrite with -EIO

then you could limit to just a single Fixes: tag (the second one)