[PATCH 3/3] net/mlx5: fix missing adjustment MPRQ stride devargs

[Ferruh Yigit]

On 11/23/2021 6:38 PM, michaelba at nvidia.com wrote:
> From: Michael Baum<michaelba at nvidia.com>
> 
> In Multy-Packet RQ creation, the user can choose the number of strides

Multi-Packet ?

> and their size in bytes. The user updates it using specific devargs for
> both of these parameters.
> The above two parameters determine the size of the WQE which is actually
> their product of multiplication.
> 
> If the user selects values that are not in the supported range, the PMD
> changes them to default values. However, apart from the range
> limitations for each parameter individually there is also a minimum
> value on their multiplication. When the user selects values that their
> multiplication are lower than minimum value, no adjustment is made and
> the creation of the WQE fails.
> > This patch adds an adjustment in these cases as well. When the user
> selects values whose multiplication is lower than the minimum, they are
> replaced with the default values.
> 
> Fixes: ecb160456aed ("net/mlx5: add device parameter for MPRQ stride size")
> Cc:stable at dpdk.org
> 

Again, not sure if we can backport this patch, this looks a behavior change more
than a fix.

Previously if the user provided values ends up being invalid, PMD seems
returning error.
With this patch, instead of returning error PMD prefers to use default
values and doesn't return error.

I am not sure if it is correct thing to ignore (adjust) user provided values,
but that can be up to the PMD as long as the behavior is documented.

But I think it is wrong to backport the behavior change.

> Signed-off-by: Michael Baum<michaelba at nvidia.com>
> Acked-by: Matan Azrad<matan at nvidia.com>
> ---