Re: [PATCH net-next v4] ppp: enable TX scatter-gather

On 2/3/26 4:08 PM, Qingfang Deng wrote:

On Tue, Feb 3, 2026 at 6:55 PM Paolo Abeni [off-list ref] wrote:

quoted

I'm sorry for missing this point before, but AFAICS channels with
chan->direct_xmit == 0 do not support GSO packets at all, and here such
packets will be transmitted after linearization (but still as GSO).

I think that while transmitting over !chan->direct_xmit you additionally
need to check for GSO packet. If ppp features are recomputed depending
on the channels configuration, you could chose to drop such packets.
Otherwise you will need to segment them before transmission, and that
looks error prone in case of multilink.

I don't think that's true. Using the current features set (NETIF_F_SG
| NETIF_F_FRAGLIST), the network core will only enable the generic
software GSO (NETIF_F_GSO), and a GSO skb will be segmented in
validate_xmit_skb before being passed to the PPP driver.

Right you are! I thought TSO was enabled here at some point but it's not
the case. No need to resubmit, let me resurrect this patch in PW.

Thanks,

Paolo