Re: [PATCH net 3/3] net: stmmac: check if interface is running before TC block setup

[Jakub Kicinski <kuba@kernel.org>]

On Tue, 9 Sep 2025 20:47:01 +0200 Sebastian Basierski wrote:
> >> Before this patch driver couldn't be unloaded with tc filter applied.
> >>
> >> Running those commands is enough to reproduce the issue:
> >>     tc qdisc add dev enp0s29f2 ingress
> >>     tc filter add dev enp0s29f2 ingress protocol all prio 1 u32
> >>     rmmod dwmac_intel
> >>
> >> in effect module would not unload.  
> > Makes sense. Could you also confirm that the offload doesn't in fact
> > work if set up when device is down? I think block setup is when qdisc
> > is installed?
> >
> > ip link set dev $x down
> > tc qdisc add dev enp0s29f2 ingress
> > ip link set dev $x up
> > tc filter add dev enp0s29f2 ingress protocol all prio 1 u32 ...
> >
> > If it doesn't work we can feel safe we're not breaking anyone's
> > scripts, however questionable.  
> Sorry for late response.
> I just checked what you asked for.
>    x="enp129s29f0"
>    ip link set dev $x down
>    tc qdisc add dev $x ingress
>    ip link set dev $x up
>    tc filter add dev $x ingress protocol ip flower ip_proto 1 action drop
> Looks like with and without patch ICMP packets are dropped.

Aren't you testing non-offloaded filter?
Test with skip_sw, if it works it means that some order of commands may
have indeed worked.