# Re: \[PATCH net-next RFC\] net: x25: Queue received packets in the drivers instead of per-CPU queues

- From: Martin Schiller \<ms@dev.tdt.de\>
- Date: 2021-03-09 13:24:44 
- List: linux-doc
- Page: https://ratatoskr.run/linux-doc/2021/03/6293714
- Thread: https://ratatoskr.run/netdev/2021/03/6289114/t.md

```text
On 2021-03-05 06:43, Xie He wrote:
> X.25 Layer 3 (the Packet Layer) expects layer 2 to provide a reliable
> datalink service such that no packets are reordered or dropped. And
> X.25 Layer 2 (the LAPB layer) is indeed designed to provide such service.
>
> However, this reliability is not preserved when a driver calls "netif_rx"
> to deliver the received packets to layer 3, because "netif_rx" will put
> the packets into per-CPU queues before they are delivered to layer 3.
> If there are multiple CPUs, the order of the packets may not be preserved.
> The per-CPU queues may also drop packets if there are too many.
>
> Therefore, we should not call "netif_rx" to let it queue the packets.
> Instead, we should use our own queue that won't reorder or drop packets.
>
> This patch changes all X.25 drivers to use their own queues instead of
> calling "netif_rx". The patch also documents this requirement in the
> "x25-iface" documentation.

I've tested the hdlc_x25 driver.
Looks good to me.

Acked-by: Martin Schiller <ms@dev.tdt.de>
```