Re: [PATCH net] net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled

[Jakub Kicinski]

On Wed,  4 Nov 2020 12:21:41 +0200 Tariq Toukan wrote:
> With NETIF_F_HW_TLS_TX packets are encrypted in HW. This cannot be
> logically done when HW_CSUM offload is off.

Right. Do you expect drivers to nack clearing NETIF_F_HW_TLS_TX when
there are active connections, then?  I don't think NFP does.  We either
gotta return -EBUSY when there are offloaded connections, or at least
clearly document the expected behavior.

> Fixes: 2342a8512a1e ("net: Add TLS TX offload features")
> Signed-off-by: Tariq Toukan <tar...@nvidia.com>
> Reviewed-by: Boris Pismenny <bor...@nvidia.com>

> diff --git a/net/core/dev.c b/net/core/dev.c
> index 82dc6b48e45f..5f72ea17d3f7 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -9588,6 +9588,11 @@ static netdev_features_t netdev_fix_features(struct 
> net_device *dev,
>               }
>       }
>  
> +     if ((features & NETIF_F_HW_TLS_TX) && !(features & NETIF_F_HW_CSUM)) {
> +             netdev_dbg(dev, "Dropping TLS TX HW offload feature since no 
> CSUM feature.\n");
> +             features &= ~NETIF_F_HW_TLS_TX;
> +     }