[PATCH net] net/mlx5: Not returning mlx5_link_info table when speed is unknown

[PATCH net] net/mlx5: Not returning mlx5_link_info table when speed is unknown

[Li Tian]

Because mlx5e_link_mode is sparse e.g. Azure mlx5 reports PTYS 19.
Do not return it when speed unless retrieved successfully.

Fixes: 65a5d35571849 ("net/mlx5: Refactor link speed handling with mlx5_link_info struct")
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Li Tian <litian@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/port.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
index 2d7adf7444ba..a69c83da2542 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
@@ -1170,7 +1170,11 @@ const struct mlx5_link_info *mlx5_port_ptys2info(struct mlx5_core_dev *mdev,
 	mlx5e_port_get_link_mode_info_arr(mdev, &table, &max_size,
 					  force_legacy);
 	i = find_first_bit(&temp, max_size);
-	if (i < max_size)
+	/*
+	 * mlx5e_link_mode is sparse. Check speed
+	 * is non-zero as indication of a hole.
+	 */
+	if (i < max_size && table[i].speed)
 		return &table[i];
 
 	return NULL;
-- 
2.50.0

Re: [PATCH net] net/mlx5: Not returning mlx5_link_info table when speed is unknown

[Vitaly Kuznetsov]

Li Tian <litian@redhat.com> writes:

> Because mlx5e_link_mode is sparse e.g. Azure mlx5 reports PTYS 19.
> Do not return it when speed unless retrieved successfully.
>
> Fixes: 65a5d35571849 ("net/mlx5: Refactor link speed handling with mlx5_link_info struct")
> Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Li Tian <litian@redhat.com>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/port.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
> index 2d7adf7444ba..a69c83da2542 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
> @@ -1170,7 +1170,11 @@ const struct mlx5_link_info *mlx5_port_ptys2info(struct mlx5_core_dev *mdev,
>  	mlx5e_port_get_link_mode_info_arr(mdev, &table, &max_size,
>  					  force_legacy);
>  	i = find_first_bit(&temp, max_size);
> -	if (i < max_size)
> +	/*
> +	 * mlx5e_link_mode is sparse. Check speed

The array is either 'mlx5e_link_mode' or 'mlx5e_ext_link_info' but both
have holes in them.

> +	 * is non-zero as indication of a hole.
> +	 */
> +	if (i < max_size && table[i].speed)
>  		return &table[i];
>  
>  	return NULL;

-- 
Vitaly

Re: [PATCH net] net/mlx5: Not returning mlx5_link_info table when speed is unknown

[Tariq Toukan]

On 08/09/2025 12:58, Vitaly Kuznetsov wrote:
> Li Tian <litian@redhat.com> writes:
> 
>> Because mlx5e_link_mode is sparse e.g. Azure mlx5 reports PTYS 19.
>> Do not return it when speed unless retrieved successfully.
>>
>> Fixes: 65a5d35571849 ("net/mlx5: Refactor link speed handling with mlx5_link_info struct")

++

Adding author and reviewer of offending patch.

>> Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>> Signed-off-by: Li Tian <litian@redhat.com>
>> ---
>>   drivers/net/ethernet/mellanox/mlx5/core/port.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
>> index 2d7adf7444ba..a69c83da2542 100644
>> --- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
>> @@ -1170,7 +1170,11 @@ const struct mlx5_link_info *mlx5_port_ptys2info(struct mlx5_core_dev *mdev,
>>   	mlx5e_port_get_link_mode_info_arr(mdev, &table, &max_size,
>>   					  force_legacy);
>>   	i = find_first_bit(&temp, max_size);
>> -	if (i < max_size)

Keep an empty line before comment.

>> +	/*

Can have the comment text starting from the first line.
>> +	 * mlx5e_link_mode is sparse. Check speed
> 
> The array is either 'mlx5e_link_mode' or 'mlx5e_ext_link_info' but both
> have holes in them.
> 

You mean 'mlx5e_link_info' and 'mlx5e_ext_link_info'.
I wouldn't say they are sparse. They have holes indeed.


>> +	 * is non-zero as indication of a hole.
>> +	 */
>> +	if (i < max_size && table[i].speed)
>>   		return &table[i];
>>   
>>   	return NULL;
>